fix coding style

For indexed PNGs, we only need to allocate a palette large enough to accommodate the number of indexed colours in the image. For images that don't use all 256 colours, this slightly reduces the memory usage for these images.

.github/workflows/ci.yml

@@ -3,39 +3,43 @@ name: Continuous Integration
 on:
   push:
   pull_request:
-    branches: [ bleed ]
+    branches: [ bleed, 'prep-*' ]
+
+permissions:
+  contents: read  #  to fetch code (actions/checkout)
 
 jobs:
   linux:
     name: Linux (.NET 6.0)
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '6.0.x'
 
       - name: Check Code
         run: |
           make check
+          make tests
 
       - name: Check Mods
         run: |
           sudo apt-get install lua5.1
           make check-scripts
-          make test
+          make TREAT_WARNINGS_AS_ERRORS=true test
 
   linux-mono:
     name: Linux (mono)
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Check Code
         run: |
@@ -45,7 +49,7 @@ jobs:
       - name: Check Mods
         run: |
           # check-scripts does not depend on .net/mono, so is not needed here
-          make RUNTIME=mono test
+          make RUNTIME=mono TREAT_WARNINGS_AS_ERRORS=true test
 
   windows:
     name: Windows (.NET 6.0)
@@ -53,10 +57,10 @@ jobs:
 
     steps:
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '6.0.x'
 
@@ -66,12 +70,12 @@ jobs:
           # Work around runtime failures on the GH Actions runner
           dotnet nuget add source https://api.nuget.org/v3/index.json -n nuget.org
           .\make.ps1 check
-          dotnet build OpenRA.Test\OpenRA.Test.csproj -c Debug --nologo -p:TargetPlatform=win-x64
-          dotnet test bin\OpenRA.Test.dll --test-adapter-path:.
+          .\make.ps1 tests
 
       - name: Check Mods
         run: |
-          chocolatey install lua --version 5.1.5.52
+          choco install lua --version 5.1.5.52
           $ENV:Path = $ENV:Path + ";C:\Program Files (x86)\Lua\5.1\"
+          $ENV:TREAT_WARNINGS_AS_ERRORS = "true"
           .\make.ps1 check-scripts
           .\make.ps1 test

.github/workflows/documentation.yml

@@ -1,6 +1,9 @@
 name: Deploy Documentation
 
 on:
+  push:
+    branches: [ bleed ]
+    tags: [ 'release-*', 'playtest-*' ]
   workflow_dispatch:
     inputs:
       tag:
@@ -8,19 +11,53 @@ on:
         required: true
         default: 'release-xxxxxxxx'
 
+permissions:
+  contents: read  #  to fetch code (actions/checkout)
+
 jobs:
+  prepare:
+    name: Prepare version strings
+    if: github.repository == 'openra/openra'
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Prepare environment variables
+        run: |
+          if [ "${{ github.event_name }}" = "push" ]; then
+            if [ "${{ github.ref_type }}" = "tag" ]; then
+              VERSION_TYPE=`echo "${GITHUB_REF#refs/tags/}" | cut -d"-" -f1`
+              echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
+              echo "VERSION_TYPE=$VERSION_TYPE" >> $GITHUB_ENV
+            else
+              echo "GIT_TAG=bleed" >> $GITHUB_ENV
+              echo "VERSION_TYPE=bleed" >> $GITHUB_ENV
+            fi
+          else
+            VERSION_TYPE=`echo "${{ github.event.inputs.tag }}" | cut -d"-" -f1`
+            echo "GIT_TAG=${{ github.event.inputs.tag }}" >> $GITHUB_ENV
+            echo "VERSION_TYPE=$VERSION_TYPE" >> $GITHUB_ENV
+          fi
+    outputs:
+      git_tag: ${{ env.GIT_TAG }}
+      version_type: ${{ env.VERSION_TYPE }}
+
   wiki:
     name: Update Wiki
-    if: github.repository == 'openra/openra'
-    runs-on: ubuntu-20.04
+    needs: prepare
+    if: github.repository == 'openra/openra' && needs.prepare.outputs.version_type != 'bleed'
+    runs-on: ubuntu-22.04
     steps:
+      - name: Debug output
+        run: |
+          echo ${{ needs.prepare.outputs.git_tag }}
+          echo ${{ needs.prepare.outputs.version_type }}
+
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.tag }}
+          ref: ${{ needs.prepare.outputs.git_tag }}
 
       - name: Install .NET 6
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '6.0.x'
 
@@ -29,49 +66,53 @@ jobs:
           make all
 
       - name: Clone Wiki
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           repository: openra/openra.wiki
           token: ${{ secrets.DOCS_TOKEN }}
           path: wiki
 
       - name: Update Wiki (Playtest)
-        if: startsWith(github.event.inputs.tag, 'playtest-')
-        env:
-          GIT_TAG: ${{ github.event.inputs.tag }}
+        if: startsWith(needs.prepare.outputs.git_tag, 'playtest-')
         run: |
-          ./utility.sh all --settings-docs "${GIT_TAG}" > "wiki/Settings (playtest).md"
+          ./utility.sh all --settings-docs "${{ needs.prepare.outputs.git_tag }}" > "wiki/Settings (playtest).md"
 
       - name: Update Wiki (Release)
-        if: startsWith(github.event.inputs.tag, 'release-')
-        env:
-          GIT_TAG: ${{ github.event.inputs.tag }}
+        if: startsWith(needs.prepare.outputs.git_tag, 'release-')
         run: |
-          ./utility.sh all --settings-docs "${GIT_TAG}" > "wiki/Settings.md"
+          ./utility.sh all --settings-docs "${{ needs.prepare.outputs.git_tag }}" > "wiki/Settings.md"
 
       - name: Push Wiki
-        env:
-          GIT_TAG: ${{ github.event.inputs.tag }}
         run: |
           cd wiki
           git config --local user.email "actions@github.com"
           git config --local user.name "GitHub Actions"
-          git add --all
-          git commit -m "Update auto-generated documentation for ${GIT_TAG}"
-          git push origin master
+          git status
+          git diff-index --quiet HEAD || \
+          (
+            git add --all && \
+            git commit -m "Update auto-generated documentation for ${{ needs.prepare.outputs.git_tag }}" && \
+            git push origin master
+          )
 
   docs:
     name: Update docs.openra.net
+    needs: prepare
     if: github.repository == 'openra/openra'
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
+      - name: Debug output
+        run: |
+          echo ${{ needs.prepare.outputs.git_tag }}
+          echo ${{ needs.prepare.outputs.version_type }}
+
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.tag }}
+          ref: ${{ needs.prepare.outputs.git_tag }}
 
       - name: Install .NET 6
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '6.0.x'
 
@@ -79,51 +120,31 @@ jobs:
         run: |
           make all
 
+      # version_type is release/playtest/bleed - the name of the target branch.
       - name: Clone docs.openra.net
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           repository: openra/docs
           token: ${{ secrets.DOCS_TOKEN }}
           path: docs
+          ref: ${{ needs.prepare.outputs.version_type }}
 
-      - name: Update docs.openra.net (Playtest)
-        if: startsWith(github.event.inputs.tag, 'playtest-')
-        env:
-          GIT_TAG: ${{ github.event.inputs.tag }}
+      - name: Generate docs files
         run: |
-          git checkout playtest
-          ./utility.sh all --docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/traits.md"
-          ./utility.sh all --weapon-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/weapons.md"
-          ./utility.sh all --sprite-sequence-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/sprite-sequences.md"
-          ./utility.sh all --lua-docs "${GIT_TAG}" > "docs/api/lua.md"
+          ./utility.sh all --docs "${{ needs.prepare.outputs.git_tag }}" | python3 ./packaging/format-docs.py > "docs/api/traits.md"
+          ./utility.sh all --weapon-docs "${{ needs.prepare.outputs.git_tag }}" | python3 ./packaging/format-docs.py > "docs/api/weapons.md"
+          ./utility.sh all --sprite-sequence-docs "${{ needs.prepare.outputs.git_tag }}" | python3 ./packaging/format-docs.py > "docs/api/sprite-sequences.md"
+          ./utility.sh all --lua-docs "${{ needs.prepare.outputs.git_tag }}" > "docs/api/lua.md"
 
-      - name: Update docs.openra.net (Release)
-        if: startsWith(github.event.inputs.tag, 'release-')
-        env:
-          GIT_TAG: ${{ github.event.inputs.tag }}
-        run: |
-          git checkout release
-          ./utility.sh all --docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/traits.md"
-          ./utility.sh all --weapon-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/weapons.md"
-          ./utility.sh all --sprite-sequence-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/sprite-sequences.md"
-          ./utility.sh all --lua-docs "${GIT_TAG}" > "docs/api/lua.md"
-
-      - name: Commit docs.openra.net
-        env:
-          GIT_TAG: ${{ github.event.inputs.tag }}
+      - name: Update docs.openra.net
         run: |
           cd docs
           git config --local user.email "actions@github.com"
           git config --local user.name "GitHub Actions"
-          git add *.md
-          git commit -m "Update auto-generated documentation for ${GIT_TAG}"
-
-      - name: Push docs.openra.net (Release)
-        if: startsWith(github.event.inputs.tag, 'release-')
-        run: |
-          git push origin release
-
-      - name: Push docs.openra.net (Playtest)
-        if: startsWith(github.event.inputs.tag, 'playtest-')
-        run: |
-          git push origin playtest
+          git status
+          git diff-index --quiet HEAD || \
+          (
+            git add api/*.md && \
+            git commit -m "Update auto-generated documentation for ${{ needs.prepare.outputs.git_tag }}" && \
+            git push origin ${{ needs.prepare.outputs.version_type }}
+          )

.github/workflows/itch.yml

@@ -8,10 +8,11 @@ on:
         required: true
         default: 'release-xxxxxxxx'
 
+permissions: {}
 jobs:
   itch:
     name: Deploy to itch.io
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     if: github.repository == 'openra/openra'
     steps:
       - name: Download Packages

.github/workflows/packaging.yml

@@ -7,13 +7,16 @@ on:
     - 'playtest-*'
     - 'devtest-*'
 
+permissions:
+  contents: write  #  for release creation (svenstaro/upload-release-action)
+
 jobs:
   source:
     name: Source Tarball
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Prepare Environment
         run: echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> ${GITHUB_ENV}
@@ -34,13 +37,13 @@ jobs:
 
   linux:
     name: Linux AppImages
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '6.0.x'
 
@@ -50,6 +53,7 @@ jobs:
       - name: Package AppImages
         run: |
           mkdir -p build/linux
+          sudo apt install libfuse2
           ./packaging/linux/buildpackage.sh "${GIT_TAG}" "${PWD}/build/linux"
 
       - name: Upload Packages
@@ -62,21 +66,21 @@ jobs:
           file: build/linux/*
 
   macos:
-    name: macOS Disk Images
+    name: macOS Disk Image
     runs-on: macos-11
     steps:
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '6.0.x'
 
       - name: Prepare Environment
         run: echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> ${GITHUB_ENV}
 
-      - name: Package Disk Images
+      - name: Package Disk Image
         env:
           MACOS_DEVELOPER_IDENTITY: ${{ secrets.MACOS_DEVELOPER_IDENTITY }}
           MACOS_DEVELOPER_CERTIFICATE_BASE64: ${{ secrets.MACOS_DEVELOPER_CERTIFICATE_BASE64 }}
@@ -87,7 +91,7 @@ jobs:
           mkdir -p build/macos
           ./packaging/macos/buildpackage.sh "${GIT_TAG}" "${PWD}/build/macos"
 
-      - name: Upload Packages
+      - name: Upload Package
         uses: svenstaro/upload-release-action@v2
         with:
           repo_token: ${{ secrets.GITHUB_TOKEN }}
@@ -98,13 +102,13 @@ jobs:
 
   windows:
     name: Windows Installers
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - name: Clone Repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '6.0.x'
 

AUTHORS

@@ -74,6 +74,7 @@ Also thanks to:
     * Glenn Martin Jensen (Baxxster)
     * Gordon Martin (Happy0)
     * Guido Lipke (LipkeGu)
+    * Guillermo Cuenca (Wylli)
     * Hervé Matysiak (Herve-M)
     * Huw Pascoe
     * Ian T. Jacobsen (Smilex)
@@ -119,6 +120,7 @@ Also thanks to:
     * Mike Gagné (AngryBirdz)
     * Muh
     * Mustafa Alperen Seki (MustaphaTR)
+    * Nathan Nichols (cracksmoka420)
     * Neil Shivkar (havok13888)
     * Nikolay Fomin (netnazgul)
     * Nooze
@@ -148,6 +150,7 @@ Also thanks to:
     * Teemu Nieminen (Temeez)
     * Thomas Christlieb (ThomasChr)
     * Tim Mylemans (gecko)
+    * Tinix
     * Tirili
     * Tomas Einarsson (Mesacer)
     * Tom van Leth (tovl)

Directory.Build.props

@@ -5,15 +5,16 @@
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Optimize>true</Optimize>
-    <LangVersion>7.3</LangVersion>
+    <LangVersion>9</LangVersion>
     <DebugSymbols>true</DebugSymbols>
     <EngineRootPath Condition="'$(EngineRootPath)' == ''">..</EngineRootPath>
     <OutputPath>$(EngineRootPath)/bin</OutputPath>
     <PlatformTarget>AnyCPU</PlatformTarget>
     <ExternalConsole>false</ExternalConsole>
     <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
-    <CodeAnalysisRuleSet>$(EngineRootPath)/OpenRA.ruleset</CodeAnalysisRuleSet>
     <Nullable>disable</Nullable>
+    <Product>OpenRA</Product>
+    <Copyright>Copyright (c) The OpenRA Developers and Contributors</Copyright>
   </PropertyGroup>
 
   <PropertyGroup>
@@ -30,6 +31,12 @@
   <PropertyGroup Condition="'$(Configuration)' == 'Debug'">
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <Optimize>false</Optimize>
+    <!-- Enable only for Debug builds to improve compile-time performance for Release builds -->
+    <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
+    <!-- Enabling GenerateDocumentationFile is required for IDE0005 (Remove unnecessary import)
+      rule to run in command line builds. https://github.com/dotnet/roslyn/issues/41640
+      Enable only for Debug builds to improve compile-time performance for Release builds -->
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
   </PropertyGroup>
 
   <ItemGroup>
@@ -44,9 +51,10 @@
     </ItemGroup>
   </Target>
 
-  <!-- StyleCop -->
+  <!-- StyleCop/Roslynator -->
   <ItemGroup>
-    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.2" PrivateAssets="All" />
-    <PackageReference Include="StyleCop.Analyzers" Version="1.1.118" PrivateAssets="All" />
+    <PackageReference Include="StyleCop.Analyzers" Version="1.2.0-beta.435" PrivateAssets="All" />
+    <!-- Roslynator analyzers fail to run under Mono (AD0001) -->
+    <PackageReference Include="Roslynator.Analyzers" Version="4.2.0" PrivateAssets="All" Condition="'$(MSBuildRuntimeType)'!='Mono'" />
   </ItemGroup>
 </Project>

INSTALL.md

@@ -17,7 +17,7 @@ Run the game with `launch-game.cmd`. It can be handed arguments that specify the
 Linux
 =====
 
-.NET 6 or Mono (version 6.4 or later) is required to compile OpenRA. We recommend using .NET 6 when possible, as Mono is poorly packaged by most Linux distributions (e.g. missing the required `msbuild` toolchain), and has been deprecated as a standalone project.
+.NET 6 or Mono (version 6.12 or later) is required to compile OpenRA. We recommend using .NET 6 when possible, as Mono is poorly packaged by most Linux distributions (e.g. missing the required `msbuild` toolchain), and has been deprecated as a standalone project.
 
 The [.NET 6 download page](https://dotnet.microsoft.com/download/dotnet/6.0) provides repositories for various package managers and binary releases for several architectures. If you prefer to use Mono, we suggest adding the [upstream repository](https://www.mono-project.com/download/stable/#download-lin) for your distro to obtain the latest version and the `msbuild` toolchain.
 
@@ -78,6 +78,6 @@ Type `sudo make install` for system-wide installation. Run `sudo make install-li
 macOS
 =====
 
-[.NET 6](https://dotnet.microsoft.com/download/dotnet/6.0) or [Mono](https://www.mono-project.com/download/stable/#download-mac) (version 6.4 or later) is required to compile OpenRA. We recommend using .NET 6 unless you are running a very old version of macOS (10.9 through 10.14).
+[.NET 6](https://dotnet.microsoft.com/download/dotnet/6.0) or [Mono](https://www.mono-project.com/download/stable/#download-mac) (version 6.12 or later) is required to compile OpenRA. We recommend using .NET 6 unless you are running a very old version of macOS (10.9 through 10.14).
 
 To compile OpenRA, run `make` from the command line (or `make RUNTIME=mono` if using Mono). Run with `./launch-game.sh`.

Makefile

@@ -3,7 +3,7 @@
 # to compile, run:
 #   make
 #
-# to compile using Mono (version 6.4 or greater) instead of .NET 6, run:
+# to compile using Mono (version 6.12 or greater) instead of .NET 6, run:
 #   make RUNTIME=mono
 #
 # to compile using system libraries for native dependencies, run:
@@ -58,6 +58,8 @@ RM_RF = $(RM) -rf
 
 RUNTIME ?= net6
 CONFIGURATION ?= Release
+DOTNET_RID = $(shell ${DOTNET} --info | grep RID: | cut -w -f3)
+ARCH_X64 = $(shell echo ${DOTNET_RID} | grep x64)
 
 # Only for use in target version:
 VERSION := $(shell git name-rev --name-only --tags --no-undefined HEAD 2>/dev/null || (c=$$(git rev-parse --short HEAD 2>/dev/null) && echo git-$$c))
@@ -67,22 +69,30 @@ ifndef TARGETPLATFORM
 UNAME_S := $(shell uname -s)
 UNAME_M := $(shell uname -m)
 ifeq ($(UNAME_S),Darwin)
+ifeq ($(ARCH_X64),)
+TARGETPLATFORM = osx-arm64
+else
 TARGETPLATFORM = osx-x64
+endif
 else
 ifeq ($(UNAME_M),x86_64)
 TARGETPLATFORM = linux-x64
 else
+ifeq ($(UNAME_M),aarch64)
+TARGETPLATFORM = linux-arm64
+else
 TARGETPLATFORM = unix-generic
 endif
 endif
 endif
+endif
 
 ##################### DEVELOPMENT BUILDS AND TESTS #####################
 #
 all:
 	@echo "Compiling in ${CONFIGURATION} mode..."
 ifeq ($(RUNTIME), mono)
-	@command -v $(firstword $(MSBUILD)) >/dev/null || (echo "OpenRA requires the '$(MSBUILD)' tool provided by Mono >= 6.4."; exit 1)
+	@command -v $(firstword $(MSBUILD)) >/dev/null || (echo "OpenRA requires the '$(MSBUILD)' tool provided by Mono >= 6.12."; exit 1)
 	@$(MSBUILD) -t:Build -restore -p:Configuration=${CONFIGURATION} -p:TargetPlatform=$(TARGETPLATFORM)
 else
 	@$(DOTNET) build -c ${CONFIGURATION} -nologo -p:TargetPlatform=$(TARGETPLATFORM)
@@ -102,11 +112,10 @@ check:
 	@echo
 	@echo "Compiling in Debug mode..."
 ifeq ($(RUNTIME), mono)
-# Enabling EnforceCodeStyleInBuild and GenerateDocumentationFile as a workaround for some code style rules (in particular IDE0005) being bugged and not reporting warnings/errors otherwise.
-	@$(MSBUILD) -t:build -restore -p:Configuration=Debug -warnaserror -p:TargetPlatform=$(TARGETPLATFORM) -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
+	@$(MSBUILD) -t:clean\;build -restore -p:Configuration=Debug -warnaserror -p:TargetPlatform=$(TARGETPLATFORM)
 else
-# Enabling EnforceCodeStyleInBuild and GenerateDocumentationFile as a workaround for some code style rules (in particular IDE0005) being bugged and not reporting warnings/errors otherwise.
-	@$(DOTNET) build -c Debug -nologo -warnaserror -p:TargetPlatform=$(TARGETPLATFORM) -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
+	@$(DOTNET) clean -c Debug --nologo --verbosity minimal
+	@$(DOTNET) build -c Debug -nologo -warnaserror -p:TargetPlatform=$(TARGETPLATFORM)
 endif
 ifeq ($(TARGETPLATFORM), unix-generic)
 	@./configure-system-libraries.sh
@@ -121,7 +130,7 @@ endif
 check-scripts:
 	@echo
 	@echo "Checking for Lua syntax errors..."
-	@find lua/ mods/*/{maps,scripts}/ -iname "*.lua" -print0 | xargs -0n1 luac -p
+	@find mods/*/maps/ mods/*/scripts/ -iname "*.lua" -print0 | xargs -0n1 luac -p
 
 test: all
 	@echo
@@ -137,6 +146,11 @@ test: all
 	@echo "Testing Red Alert mod MiniYAML..."
 	@./utility.sh ra --check-yaml
 
+tests:
+	@dotnet build OpenRA.Test/OpenRA.Test.csproj -c Debug --nologo -p:TargetPlatform=$(TARGETPLATFORM)
+	@echo
+	@dotnet test bin/OpenRA.Test.dll --test-adapter-path:.
+
 ############# LOCAL INSTALLATION AND DOWNSTREAM PACKAGING ##############
 #
 version: VERSION mods/ra/mod.yaml mods/cnc/mod.yaml mods/d2k/mod.yaml mods/ts/mod.yaml mods/modcontent/mod.yaml mods/all/mod.yaml
@@ -164,14 +178,14 @@ help:
 	@echo 'to compile, run:'
 	@echo '  make'
 	@echo
-	@echo 'to compile using Mono (version 6.4 or greater) instead of .NET 6, run:'
+	@echo 'to compile using Mono (version 6.12 or greater) instead of .NET 6, run:'
 	@echo '  make RUNTIME=mono'
 	@echo
 	@echo 'to compile using system libraries for native dependencies, run:'
 	@echo '  make [RUNTIME=net6] TARGETPLATFORM=unix-generic'
 	@echo
 	@echo 'to check the official mods for erroneous yaml files, run:'
-	@echo '  make [RUNTIME=net6] test'
+	@echo '  make [RUNTIME=net6] [TREAT_WARNINGS_AS_ERRORS=false] test'
 	@echo
 	@echo 'to check the engine and official mod dlls for code style violations, run:'
 	@echo '  make [RUNTIME=net6] check'

OpenRA.Game/Activities/Activity.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -86,7 +86,7 @@ namespace OpenRA.Activities
 		bool firstRunCompleted;
 		bool lastRun;
 
-		public Activity()
+		protected Activity()
 		{
 			IsInterruptible = true;
 			ChildHasPriority = true;
@@ -146,18 +146,22 @@ namespace OpenRA.Activities
 		}
 
 		/// <summary>
+		/// <para>
 		/// Called every tick to run activity logic. Returns false if the activity should
 		/// remain active, or true if it is complete. Cancelled activities must ensure they
 		/// return the actor to a consistent state before returning true.
-		///
+		/// </para>
+		/// <para>
 		/// Child activities can be queued using QueueChild, and these will be ticked
 		/// instead of the parent while they are active. Activities that need to run logic
 		/// in parallel with child activities should set ChildHasPriority to false and
 		/// manually call TickChildren.
-		///
+		/// </para>
+		/// <para>
 		/// Queuing one or more child activities and returning true is valid, and causes
 		/// the activity to be completed immediately (without ticking again) once the
 		/// children have completed.
+		/// </para>
 		/// </summary>
 		public virtual bool Tick(Actor self)
 		{
@@ -222,10 +226,11 @@ namespace OpenRA.Activities
 		}
 
 		/// <summary>
-		/// Prints the activity tree, starting from the top or optionally from a given origin.
-		///
+		/// <para>Prints the activity tree, starting from the top or optionally from a given origin.</para>
+		/// <para>
 		/// Call this method from any place that's called during a tick, such as the Tick() method itself or
 		/// the Before(First|Last)Run() methods. The origin activity will be marked in the output.
+		/// </para>
 		/// </summary>
 		/// <param name="self">The actor performing this activity.</param>
 		/// <param name="origin">Activity from which to start traversing, and which to mark. If null, mark the calling activity, and start traversal from the top.</param>

OpenRA.Game/Activities/CallFunc.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Actor.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -35,6 +35,9 @@ namespace OpenRA
 
 	public sealed class Actor : IScriptBindable, IScriptNotifyBind, ILuaTableBinding, ILuaEqualityBinding, ILuaToStringBinding, IEquatable<Actor>, IDisposable
 	{
+		/// <summary>Value used to represent an invalid token.</summary>
+		public const int InvalidConditionToken = -1;
+
 		internal readonly struct SyncHash
 		{
 			public readonly ISync Trait;
@@ -68,7 +71,12 @@ namespace OpenRA
 		public IEffectiveOwner EffectiveOwner { get; }
 		public IOccupySpace OccupiesSpace { get; }
 		public ITargetable[] Targetables { get; }
-		public IEnumerable<ITargetablePositions> EnabledTargetablePositions { get; private set; }
+		public IEnumerable<ITargetablePositions> EnabledTargetablePositions { get; }
+		readonly ICrushable[] crushables;
+		public ICrushable[] Crushables
+		{
+			get => crushables ?? throw new InvalidOperationException($"Crushables for {Info.Name} are not initialized.");
+		}
 
 		public bool IsIdle => CurrentActivity == null;
 		public bool IsDead => Disposed || (health != null && health.IsDead);
@@ -78,27 +86,24 @@ namespace OpenRA
 
 		public WRot Orientation => facing?.Orientation ?? WRot.None;
 
-		/// <summary>Value used to represent an invalid token.</summary>
-		public static readonly int InvalidConditionToken = -1;
-
-		class ConditionState
+		sealed class ConditionState
 		{
 			/// <summary>Delegates that have registered to be notified when this condition changes.</summary>
-			public readonly List<VariableObserverNotifier> Notifiers = new List<VariableObserverNotifier>();
+			public readonly List<VariableObserverNotifier> Notifiers = new();
 
 			/// <summary>Unique integers identifying granted instances of the condition.</summary>
-			public readonly HashSet<int> Tokens = new HashSet<int>();
+			public readonly HashSet<int> Tokens = new();
 		}
 
-		readonly Dictionary<string, ConditionState> conditionStates = new Dictionary<string, ConditionState>();
+		readonly Dictionary<string, ConditionState> conditionStates = new();
 
 		/// <summary>Each granted condition receives a unique token that is used when revoking.</summary>
-		readonly Dictionary<int, string> conditionTokens = new Dictionary<int, string>();
+		readonly Dictionary<int, string> conditionTokens = new();
 
 		int nextConditionToken = 1;
 
 		/// <summary>Cache of condition -> enabled state for quick evaluation of token counter conditions.</summary>
-		readonly Dictionary<string, int> conditionCache = new Dictionary<string, int>();
+		readonly Dictionary<string, int> conditionCache = new();
 
 		/// <summary>Read-only version of conditionCache that is passed to IConditionConsumers.</summary>
 		readonly IReadOnlyDictionary<string, int> readOnlyConditionCache;
@@ -155,6 +160,7 @@ namespace OpenRA
 				var targetablesList = new List<ITargetable>();
 				var targetablePositionsList = new List<ITargetablePositions>();
 				var syncHashesList = new List<SyncHash>();
+				var crushablesList = new List<ICrushable>();
 
 				foreach (var traitInfo in Info.TraitsInConstructOrder())
 				{
@@ -181,6 +187,7 @@ namespace OpenRA
 					{ if (trait is ITargetable t) targetablesList.Add(t); }
 					{ if (trait is ITargetablePositions t) targetablePositionsList.Add(t); }
 					{ if (trait is ISync t) syncHashesList.Add(new SyncHash(t)); }
+					{ if (trait is ICrushable t) crushablesList.Add(t); }
 				}
 
 				resolveOrders = resolveOrdersList.ToArray();
@@ -195,6 +202,7 @@ namespace OpenRA
 				EnabledTargetablePositions = targetablePositions.Where(Exts.IsTraitEnabled);
 				enabledTargetableWorldPositions = EnabledTargetablePositions.SelectMany(tp => tp.TargetablePositions(this));
 				SyncHashes = syncHashesList.ToArray();
+				crushables = crushablesList.ToArray();
 			}
 		}
 
@@ -587,7 +595,7 @@ namespace OpenRA
 			return InvalidConditionToken;
 		}
 
-		/// <summary>Returns whether the specified token is valid for RevokeCondition</summary>
+		/// <summary>Returns whether the specified token is valid for RevokeCondition.</summary>
 		public bool TokenValid(int token)
 		{
 			return conditionTokens.ContainsKey(token);
@@ -600,8 +608,7 @@ namespace OpenRA
 		Lazy<ScriptActorInterface> luaInterface;
 		public void OnScriptBind(ScriptContext context)
 		{
-			if (luaInterface == null)
-				luaInterface = Exts.Lazy(() => new ScriptActorInterface(context, this));
+			luaInterface ??= Exts.Lazy(() => new ScriptActorInterface(context, this));
 		}
 
 		public LuaValue this[LuaRuntime runtime, LuaValue keyValue]

OpenRA.Game/CPos.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -41,7 +41,7 @@ namespace OpenRA
 			Bits = (x & 0xFFF) << 20 | (y & 0xFFF) << 8 | layer;
 		}
 
-		public static readonly CPos Zero = new CPos(0, 0, 0);
+		public static readonly CPos Zero = new(0, 0, 0);
 
 		public static explicit operator CPos(int2 a) { return new CPos(a.X, a.Y); }
 
@@ -56,7 +56,7 @@ namespace OpenRA
 		public override int GetHashCode() { return Bits.GetHashCode(); }
 
 		public bool Equals(CPos other) { return Bits == other.Bits; }
-		public override bool Equals(object obj) { return obj is CPos && Equals((CPos)obj); }
+		public override bool Equals(object obj) { return obj is CPos cell && Equals(cell); }
 
 		public override string ToString()
 		{

OpenRA.Game/CVec.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -22,7 +22,7 @@ namespace OpenRA
 		public readonly int X, Y;
 
 		public CVec(int x, int y) { X = x; Y = y; }
-		public static readonly CVec Zero = new CVec(0, 0);
+		public static readonly CVec Zero = new(0, 0);
 
 		public static CVec operator +(CVec a, CVec b) { return new CVec(a.X + b.X, a.Y + b.Y); }
 		public static CVec operator -(CVec a, CVec b) { return new CVec(a.X - b.X, a.Y - b.Y); }
@@ -55,20 +55,20 @@ namespace OpenRA
 		public override int GetHashCode() { return X.GetHashCode() ^ Y.GetHashCode(); }
 
 		public bool Equals(CVec other) { return other == this; }
-		public override bool Equals(object obj) { return obj is CVec && Equals((CVec)obj); }
+		public override bool Equals(object obj) { return obj is CVec vec && Equals(vec); }
 
 		public override string ToString() { return X + "," + Y; }
 
 		public static readonly CVec[] Directions =
 		{
-			new CVec(-1, -1),
-			new CVec(-1,  0),
-			new CVec(-1,  1),
-			new CVec(0, -1),
-			new CVec(0,  1),
-			new CVec(1, -1),
-			new CVec(1,  0),
-			new CVec(1,  1),
+			new(-1, -1),
+			new(-1,  0),
+			new(-1,  1),
+			new(0, -1),
+			new(0,  1),
+			new(1, -1),
+			new(1,  0),
+			new(1,  1),
 		};
 
 		#region Scripting interface

OpenRA.Game/CryptoUtil.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -22,6 +22,9 @@ namespace OpenRA
 		// Fixed byte pattern for the OID header
 		static readonly byte[] OIDHeader = { 0x30, 0xD, 0x6, 0x9, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0xD, 0x1, 0x1, 0x1, 0x5, 0x0 };
 
+		static readonly char[] HexUpperAlphabet = "0123456789ABCDEF".ToArray();
+		static readonly char[] HexLowerAlphabet = "0123456789abcdef".ToArray();
+
 		public static string PublicKeyFingerprint(RSAParameters parameters)
 		{
 			// Public key fingerprint is defined as the SHA1 of the modulus + exponent bytes
@@ -53,33 +56,33 @@ namespace OpenRA
 				using (var s = new MemoryStream(data))
 				{
 					// SEQUENCE
-					s.ReadByte();
+					s.ReadUInt8();
 					ReadTLVLength(s);
 
 					// SEQUENCE -> fixed header junk
-					s.ReadByte();
+					s.ReadUInt8();
 					var headerLength = ReadTLVLength(s);
 					s.Position += headerLength;
 
 					// SEQUENCE -> BIT_STRING
-					s.ReadByte();
+					s.ReadUInt8();
 					ReadTLVLength(s);
-					s.ReadByte();
+					s.ReadUInt8();
 
 					// SEQUENCE -> BIT_STRING -> SEQUENCE
-					s.ReadByte();
+					s.ReadUInt8();
 					ReadTLVLength(s);
 
 					// SEQUENCE -> BIT_STRING -> SEQUENCE -> INTEGER (modulus)
-					s.ReadByte();
+					s.ReadUInt8();
 					var modulusLength = ReadTLVLength(s);
-					s.ReadByte();
+					s.ReadUInt8();
 					var modulus = s.ReadBytes(modulusLength - 1);
 
 					// SEQUENCE -> BIT_STRING -> SEQUENCE -> INTEGER (exponent)
-					s.ReadByte();
+					s.ReadUInt8();
 					var exponentLength = ReadTLVLength(s);
-					s.ReadByte();
+					s.ReadUInt8();
 					var exponent = s.ReadBytes(exponentLength - 1);
 
 					return new RSAParameters
@@ -158,13 +161,13 @@ namespace OpenRA
 
 		static int ReadTLVLength(Stream s)
 		{
-			var length = s.ReadByte();
+			var length = s.ReadUInt8();
 			if (length < 0x80)
 				return length;
 
-			var data = new byte[4];
-			s.ReadBytes(data, 0, Math.Min(length & 0x7F, 4));
-			return BitConverter.ToInt32(data.ToArray(), 0);
+			Span<byte> data = stackalloc byte[4];
+			s.ReadBytes(data[..Math.Min(length & 0x7F, 4)]);
+			return BitConverter.ToInt32(data);
 		}
 
 		static int TripletFullLength(int dataLength)
@@ -187,8 +190,10 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to decrypt string with exception: {0}", e);
-				Console.WriteLine("String decryption failed: {0}", e);
+				Log.Write("debug", "Failed to decrypt string with exception:");
+				Log.Write("debug", e);
+				Console.WriteLine("String decryption failed:");
+				Console.WriteLine(e);
 				return null;
 			}
 		}
@@ -211,8 +216,10 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to sign string with exception: {0}", e);
-				Console.WriteLine("String signing failed: {0}", e);
+				Log.Write("debug", "Failed to sign string with exception");
+				Log.Write("debug", e);
+				Console.WriteLine("String signing failed:");
+				Console.WriteLine(e);
 				return null;
 			}
 		}
@@ -235,27 +242,54 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to verify signature with exception: {0}", e);
-				Console.WriteLine("Signature validation failed: {0}", e);
+				Log.Write("debug", "Failed to verify signature with exception:");
+				Log.Write("debug", e);
+				Console.WriteLine("Signature validation failed:");
+				Console.WriteLine(e);
 				return false;
 			}
 		}
 
 		public static string SHA1Hash(Stream data)
 		{
-			using (var csp = SHA1.Create())
-				return new string(csp.ComputeHash(data).SelectMany(a => a.ToString("x2")).ToArray());
+			using var csp = SHA1.Create();
+			return ToHex(csp.ComputeHash(data), true);
 		}
 
 		public static string SHA1Hash(byte[] data)
 		{
-			using (var csp = SHA1.Create())
-				return new string(csp.ComputeHash(data).SelectMany(a => a.ToString("x2")).ToArray());
+			using var csp = SHA1.Create();
+			return ToHex(csp.ComputeHash(data), true);
 		}
 
 		public static string SHA1Hash(string data)
 		{
 			return SHA1Hash(Encoding.UTF8.GetBytes(data));
 		}
+
+		public static string ToHex(ReadOnlySpan<byte> source, bool lowerCase = false)
+		{
+			if (source.Length == 0)
+				return string.Empty;
+
+			// excessively avoid stack overflow if source is too large (considering that we're allocating a new string)
+			var buffer = source.Length <= 256 ? stackalloc char[source.Length * 2] : new char[source.Length * 2];
+			return ToHexInternal(source, buffer, lowerCase);
+		}
+
+		static string ToHexInternal(ReadOnlySpan<byte> source, Span<char> buffer, bool lowerCase)
+		{
+			var sourceIndex = 0;
+			var alphabet = lowerCase ? HexLowerAlphabet : HexUpperAlphabet;
+
+			for (var i = 0; i < buffer.Length; i += 2)
+			{
+				var b = source[sourceIndex++];
+				buffer[i] = alphabet[b >> 4];
+				buffer[i + 1] = alphabet[b & 0xF];
+			}
+
+			return new string(buffer);
+		}
 	}
 }

OpenRA.Game/DefaultPlayer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Effects/AsyncAction.cs

@@ -1,39 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System;
-using System.Collections.Generic;
-using OpenRA.Graphics;
-
-namespace OpenRA.Effects
-{
-	public class AsyncAction : IEffect
-	{
-		readonly Action a;
-		readonly IAsyncResult ar;
-
-		public AsyncAction(IAsyncResult ar, Action a)
-		{
-			this.a = a;
-			this.ar = ar;
-		}
-
-		public void Tick(World world)
-		{
-			if (ar.IsCompleted)
-			{
-				world.AddFrameEndTask(w => { w.Remove(this); a(); });
-			}
-		}
-
-		public IEnumerable<IRenderable> Render(WorldRenderer r) { yield break; }
-	}
-}

OpenRA.Game/Effects/DelayedAction.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Effects/DelayedImpact.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Effects/IEffect.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/ExternalMods.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -41,7 +41,7 @@ namespace OpenRA
 
 	public class ExternalMods : IReadOnlyDictionary<string, ExternalMod>
 	{
-		readonly Dictionary<string, ExternalMod> mods = new Dictionary<string, ExternalMod>();
+		readonly Dictionary<string, ExternalMod> mods = new();
 		readonly SheetBuilder sheetBuilder;
 
 		Sheet CreateSheet()
@@ -66,6 +66,7 @@ namespace OpenRA
 			// Several types of support directory types are available, depending on
 			// how the player has installed and launched the game.
 			// Read registration metadata from all of them
+			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
 			foreach (var source in GetSupportDirs(ModRegistration.User | ModRegistration.System))
 			{
 				var metadataPath = Path.Combine(source, "ModMetadata");
@@ -76,13 +77,13 @@ namespace OpenRA
 				{
 					try
 					{
-						var yaml = MiniYaml.FromStream(File.OpenRead(path), path).First().Value;
+						var yaml = MiniYaml.FromFile(path, stringPool: stringPool).First().Value;
 						LoadMod(yaml, path);
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", "Failed to parse mod metadata file '{0}'", path);
-						Log.Write("debug", e.ToString());
+						Log.Write("debug", $"Failed to parse mod metadata file '{path}'");
+						Log.Write("debug", e);
 					}
 				}
 			}
@@ -94,17 +95,17 @@ namespace OpenRA
 
 			if (sheetBuilder != null)
 			{
-				var iconNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon");
+				var iconNode = yaml.NodeWithKeyOrDefault("Icon");
 				if (iconNode != null && !string.IsNullOrEmpty(iconNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(iconNode.Value.Value)))
 						mod.Icon = sheetBuilder.Add(new Png(stream));
 
-				var icon2xNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon2x");
+				var icon2xNode = yaml.NodeWithKeyOrDefault("Icon2x");
 				if (icon2xNode != null && !string.IsNullOrEmpty(icon2xNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(icon2xNode.Value.Value)))
 						mod.Icon2x = sheetBuilder.Add(new Png(stream), 1f / 2);
 
-				var icon3xNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon3x");
+				var icon3xNode = yaml.NodeWithKeyOrDefault("Icon3x");
 				if (icon3xNode != null && !string.IsNullOrEmpty(icon3xNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(icon3xNode.Value.Value)))
 						mod.Icon3x = sheetBuilder.Add(new Png(stream), 1f / 3);
@@ -122,7 +123,7 @@ namespace OpenRA
 				return;
 
 			var key = ExternalMod.MakeKey(mod);
-			var yaml = new MiniYamlNode("Registration", new MiniYaml("", new List<MiniYamlNode>()
+			var yaml = new MiniYamlNode("Registration", new MiniYaml("", new[]
 			{
 				new MiniYamlNode("Id", mod.Id),
 				new MiniYamlNode("Version", mod.Metadata.Version),
@@ -131,17 +132,21 @@ namespace OpenRA
 				new MiniYamlNode("LaunchArgs", new[] { "Game.Mod=" + mod.Id }.Concat(launchArgs).JoinWith(", "))
 			}));
 
+			var iconNodes = new List<MiniYamlNode>();
+
 			using (var stream = mod.Package.GetStream("icon.png"))
 				if (stream != null)
-					yaml.Value.Nodes.Add(new MiniYamlNode("Icon", Convert.ToBase64String(stream.ReadAllBytes())));
+					iconNodes.Add(new MiniYamlNode("Icon", Convert.ToBase64String(stream.ReadAllBytes())));
 
 			using (var stream = mod.Package.GetStream("icon-2x.png"))
 				if (stream != null)
-					yaml.Value.Nodes.Add(new MiniYamlNode("Icon2x", Convert.ToBase64String(stream.ReadAllBytes())));
+					iconNodes.Add(new MiniYamlNode("Icon2x", Convert.ToBase64String(stream.ReadAllBytes())));
 
 			using (var stream = mod.Package.GetStream("icon-3x.png"))
 				if (stream != null)
-					yaml.Value.Nodes.Add(new MiniYamlNode("Icon3x", Convert.ToBase64String(stream.ReadAllBytes())));
+					iconNodes.Add(new MiniYamlNode("Icon3x", Convert.ToBase64String(stream.ReadAllBytes())));
+
+			yaml = yaml.WithValue(yaml.Value.WithNodesAppended(iconNodes));
 
 			var sources = new HashSet<string>();
 			if (registration.HasFlag(ModRegistration.System))
@@ -174,17 +179,19 @@ namespace OpenRA
 				catch (Exception e)
 				{
 					Log.Write("debug", "Failed to register current mod metadata");
-					Log.Write("debug", e.ToString());
+					Log.Write("debug", e);
 				}
 			}
 		}
 
 		/// <summary>
 		/// Removes invalid mod registrations:
-		/// * LaunchPath no longer exists
-		/// * LaunchPath and mod id matches the active mod, but the version is different
-		/// * Filename doesn't match internal key
-		/// * Fails to parse as a mod registration
+		/// <list type="bullet">
+		/// <item>LaunchPath no longer exists.</item>
+		/// <item>LaunchPath and mod id matches the active mod, but the version is different.</item>
+		/// <item>Filename doesn't match internal key.</item>
+		/// <item>Fails to parse as a mod registration.</item>
+		/// </list>
 		/// </summary>
 		internal void ClearInvalidRegistrations(ModRegistration registration)
 		{
@@ -199,7 +206,7 @@ namespace OpenRA
 					string modKey = null;
 					try
 					{
-						var yaml = MiniYaml.FromStream(File.OpenRead(path), path).First().Value;
+						var yaml = MiniYaml.FromFile(path).First().Value;
 						var m = FieldLoader.Load<ExternalMod>(yaml);
 						modKey = ExternalMod.MakeKey(m);
 
@@ -211,8 +218,8 @@ namespace OpenRA
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", "Failed to parse mod metadata file '{0}'", path);
-						Log.Write("debug", e.ToString());
+						Log.Write("debug", $"Failed to parse mod metadata file '{path}'");
+						Log.Write("debug", e);
 					}
 
 					// Remove from the ingame mod switcher
@@ -223,12 +230,12 @@ namespace OpenRA
 					try
 					{
 						File.Delete(path);
-						Log.Write("debug", "Removed invalid mod metadata file '{0}'", path);
+						Log.Write("debug", $"Removed invalid mod metadata file '{path}'");
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", "Failed to remove mod metadata file '{0}'", path);
-						Log.Write("debug", e.ToString());
+						Log.Write("debug", $"Failed to remove mod metadata file '{path}'");
+						Log.Write("debug", e);
 					}
 				}
 			}
@@ -249,13 +256,13 @@ namespace OpenRA
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", "Failed to remove mod metadata file '{0}'", path);
-					Log.Write("debug", e.ToString());
+					Log.Write("debug", $"Failed to remove mod metadata file '{path}'");
+					Log.Write("debug", e);
 				}
 			}
 		}
 
-		IEnumerable<string> GetSupportDirs(ModRegistration registration)
+		static IEnumerable<string> GetSupportDirs(ModRegistration registration)
 		{
 			var sources = new HashSet<string>(4);
 			if (registration.HasFlag(ModRegistration.System))

OpenRA.Game/Exts.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -22,20 +22,14 @@ namespace OpenRA
 {
 	public static class Exts
 	{
-		public static bool IsUppercase(this string str)
+		public static string FormatInvariant(this string format, params object[] args)
 		{
-			return string.Compare(str.ToUpperInvariant(), str, false) == 0;
+			return string.Format(CultureInfo.InvariantCulture, format, args);
 		}
 
-		public static string F(this string fmt, params object[] args)
+		public static string FormatCurrent(this string format, params object[] args)
 		{
-			return string.Format(fmt, args);
-		}
-
-		public static T WithDefault<T>(T def, Func<T> f)
-		{
-			try { return f(); }
-			catch { return def; }
+			return string.Format(CultureInfo.CurrentCulture, format, args);
 		}
 
 		public static Lazy<T> Lazy<T>(Func<T> p) { return new Lazy<T>(p); }
@@ -45,21 +39,16 @@ namespace OpenRA
 			return a.GetTypes().Select(t => t.Namespace).Distinct().Where(n => n != null);
 		}
 
-		public static bool HasAttribute<T>(this MemberInfo mi)
+		public static bool HasAttribute<TAttribute>(this MemberInfo mi)
+			where TAttribute : Attribute
 		{
-			return Attribute.IsDefined(mi, typeof(T));
+			return Attribute.IsDefined(mi, typeof(TAttribute));
 		}
 
-		public static T[] GetCustomAttributes<T>(this MemberInfo mi, bool inherit)
-			where T : class
+		public static TAttribute[] GetCustomAttributes<TAttribute>(this MemberInfo mi, bool inherit)
+			where TAttribute : Attribute
 		{
-			return (T[])mi.GetCustomAttributes(typeof(T), inherit);
-		}
-
-		public static T[] GetCustomAttributes<T>(this ParameterInfo mi)
-			where T : class
-		{
-			return (T[])mi.GetCustomAttributes(typeof(T), true);
+			return (TAttribute[])mi.GetCustomAttributes(typeof(TAttribute), inherit);
 		}
 
 		public static T Clamp<T>(this T val, T min, T max) where T : IComparable<T>
@@ -119,23 +108,57 @@ namespace OpenRA
 
 		public static V GetOrAdd<K, V>(this Dictionary<K, V> d, K k, V v)
 		{
+#if NET5_0_OR_GREATER
+			// SAFETY: Dictionary cannot be modified whilst the ref is alive.
+			ref var value = ref System.Runtime.InteropServices.CollectionsMarshal.GetValueRefOrAddDefault(d, k, out var exists);
+			if (!exists)
+				value = v;
+			return value;
+#else
 			if (!d.TryGetValue(k, out var ret))
 				d.Add(k, ret = v);
 			return ret;
+#endif
 		}
 
 		public static V GetOrAdd<K, V>(this Dictionary<K, V> d, K k, Func<K, V> createFn)
 		{
+			// Cannot use CollectionsMarshal.GetValueRefOrAddDefault here,
+			// the creation function could mutate the dictionary which would invalidate the ref.
 			if (!d.TryGetValue(k, out var ret))
 				d.Add(k, ret = createFn(k));
 			return ret;
 		}
 
+		public static T GetOrAdd<T>(this HashSet<T> set, T value)
+		{
+			if (!set.TryGetValue(value, out var ret))
+				set.Add(ret = value);
+			return ret;
+		}
+
+		public static T GetOrAdd<T>(this HashSet<T> set, T value, Func<T, T> createFn)
+		{
+			if (!set.TryGetValue(value, out var ret))
+				set.Add(ret = createFn(value));
+			return ret;
+		}
+
 		public static int IndexOf<T>(this T[] array, T value)
 		{
 			return Array.IndexOf(array, value);
 		}
 
+		public static T FirstOrDefault<T>(this T[] array, Predicate<T> match)
+		{
+			return Array.Find(array, match);
+		}
+
+		public static T FirstOrDefault<T>(this List<T> list, Predicate<T> match)
+		{
+			return list.Find(match);
+		}
+
 		public static T Random<T>(this IEnumerable<T> ts, MersenneTwister r)
 		{
 			return Random(ts, r, true);
@@ -148,8 +171,8 @@ namespace OpenRA
 
 		static T Random<T>(IEnumerable<T> ts, MersenneTwister r, bool throws)
 		{
-			var xs = ts as ICollection<T>;
-			xs = xs ?? ts.ToList();
+			var xs = ts as IReadOnlyCollection<T>;
+			xs ??= ts.ToList();
 			if (xs.Count == 0)
 			{
 				if (throws)
@@ -303,9 +326,9 @@ namespace OpenRA
 
 			// Adjust for other rounding modes
 			if (round == ISqrtRoundMode.Nearest && remainder > root)
-				root += 1;
+				root++;
 			else if (round == ISqrtRoundMode.Ceiling && root * root < number)
-				root += 1;
+				root++;
 
 			return root;
 		}
@@ -344,9 +367,9 @@ namespace OpenRA
 
 			// Adjust for other rounding modes
 			if (round == ISqrtRoundMode.Nearest && remainder > root)
-				root += 1;
+				root++;
 			else if (round == ISqrtRoundMode.Ceiling && root * root < number)
-				root += 1;
+				root++;
 
 			return root;
 		}
@@ -356,6 +379,11 @@ namespace OpenRA
 			return number * 46341 / 32768;
 		}
 
+		public static int MultiplyBySqrtTwoOverTwo(int number)
+		{
+			return (int)(number * 23170L / 32768L);
+		}
+
 		public static int IntegerDivisionRoundingAwayFromZero(int dividend, int divisor)
 		{
 			var quotient = Math.DivRem(dividend, divisor, out var remainder);
@@ -396,8 +424,8 @@ namespace OpenRA
 			string debugName, Func<TKey, string> logKey = null, Func<TElement, string> logValue = null)
 		{
 			// Fall back on ToString() if null functions are provided:
-			logKey = logKey ?? (s => s.ToString());
-			logValue = logValue ?? (s => s.ToString());
+			logKey ??= s => s.ToString();
+			logValue ??= s => s.ToString();
 
 			// Try to build a dictionary and log all duplicates found (if any):
 			var dupKeys = new Dictionary<TKey, List<string>>();
@@ -493,17 +521,22 @@ namespace OpenRA
 			return result;
 		}
 
-		public static int ParseIntegerInvariant(string s)
-		{
-			return int.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
-		}
-
-		public static byte ParseByte(string s)
+		public static byte ParseByteInvariant(string s)
 		{
 			return byte.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
 		}
 
-		public static bool TryParseIntegerInvariant(string s, out int i)
+		public static short ParseInt16Invariant(string s)
+		{
+			return short.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
+		}
+
+		public static int ParseInt32Invariant(string s)
+		{
+			return int.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
+		}
+
+		public static bool TryParseInt32Invariant(string s, out int i)
 		{
 			return int.TryParse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out i);
 		}
@@ -513,9 +546,29 @@ namespace OpenRA
 			return long.TryParse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out i);
 		}
 
+		public static string ToStringInvariant(this byte i)
+		{
+			return i.ToString(NumberFormatInfo.InvariantInfo);
+		}
+
+		public static string ToStringInvariant(this byte i, string format)
+		{
+			return i.ToString(format, NumberFormatInfo.InvariantInfo);
+		}
+
+		public static string ToStringInvariant(this int i)
+		{
+			return i.ToString(NumberFormatInfo.InvariantInfo);
+		}
+
+		public static string ToStringInvariant(this int i, string format)
+		{
+			return i.ToString(format, NumberFormatInfo.InvariantInfo);
+		}
+
 		public static bool IsTraitEnabled<T>(this T trait)
 		{
-			return !(trait is IDisabledTrait disabledTrait) || !disabledTrait.IsTraitDisabled;
+			return trait is not IDisabledTrait disabledTrait || !disabledTrait.IsTraitDisabled;
 		}
 
 		public static T FirstEnabledTraitOrDefault<T>(this IEnumerable<T> ts)
@@ -576,7 +629,7 @@ namespace OpenRA
 			Current = default;
 		}
 
-		public LineSplitEnumerator GetEnumerator() => this;
+		public readonly LineSplitEnumerator GetEnumerator() => this;
 
 		public bool MoveNext()
 		{
@@ -595,8 +648,8 @@ namespace OpenRA
 				return true;
 			}
 
-			Current = span.Slice(0, index);
-			str = span.Slice(index + 1);
+			Current = span[..index];
+			str = span[(index + 1)..];
 			return true;
 		}
 

OpenRA.Game/FieldLoader.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -56,24 +56,20 @@ namespace OpenRA
 		}
 
 		public static Func<string, Type, string, object> InvalidValueAction = (s, t, f) =>
-		{
 			throw new YamlException($"FieldLoader: Cannot parse `{s}` into `{f}.{t}` ");
-		};
 
 		public static Action<string, Type> UnknownFieldAction = (s, f) =>
-		{
 			throw new NotImplementedException($"FieldLoader: Missing field `{s}` on `{f.Name}`");
-		};
 
 		static readonly ConcurrentCache<Type, FieldLoadInfo[]> TypeLoadInfo =
-			new ConcurrentCache<Type, FieldLoadInfo[]>(BuildTypeLoadInfo);
+			new(BuildTypeLoadInfo);
 		static readonly ConcurrentCache<string, BooleanExpression> BooleanExpressionCache =
-			new ConcurrentCache<string, BooleanExpression>(expression => new BooleanExpression(expression));
+			new(expression => new BooleanExpression(expression));
 		static readonly ConcurrentCache<string, IntegerExpression> IntegerExpressionCache =
-			new ConcurrentCache<string, IntegerExpression>(expression => new IntegerExpression(expression));
+			new(expression => new IntegerExpression(expression));
 
 		static readonly Dictionary<Type, Func<string, Type, string, MemberInfo, object>> TypeParsers =
-			new Dictionary<Type, Func<string, Type, string, MemberInfo, object>>()
+			new()
 			{
 				{ typeof(int), ParseInt },
 				{ typeof(ushort), ParseUShort },
@@ -91,6 +87,7 @@ namespace OpenRA
 				{ typeof(WAngle), ParseWAngle },
 				{ typeof(WRot), ParseWRot },
 				{ typeof(CPos), ParseCPos },
+				{ typeof(CPos[]), ParseCPosArray },
 				{ typeof(CVec), ParseCVec },
 				{ typeof(CVec[]), ParseCVecArray },
 				{ typeof(BooleanExpression), ParseBooleanExpression },
@@ -107,7 +104,7 @@ namespace OpenRA
 			};
 
 		static readonly Dictionary<Type, Func<string, Type, string, MiniYaml, MemberInfo, object>> GenericTypeParsers =
-			new Dictionary<Type, Func<string, Type, string, MiniYaml, MemberInfo, object>>()
+			new()
 			{
 				{ typeof(HashSet<>), ParseHashSetOrList },
 				{ typeof(List<>), ParseHashSetOrList },
@@ -116,10 +113,19 @@ namespace OpenRA
 				{ typeof(Nullable<>), ParseNullable },
 			};
 
+		static readonly object BoxedTrue = true;
+		static readonly object BoxedFalse = false;
+		static readonly object[] BoxedInts = Exts.MakeArray(33, i => (object)i);
+
 		static object ParseInt(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
-			if (Exts.TryParseIntegerInvariant(value, out var res))
+			if (Exts.TryParseInt32Invariant(value, out var res))
+			{
+				if (res >= 0 && res < BoxedInts.Length)
+					return BoxedInts[res];
 				return res;
+			}
+
 			return InvalidValueAction(value, fieldType, fieldName);
 		}
 
@@ -159,7 +165,7 @@ namespace OpenRA
 		static object ParseColor(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
 			if (value != null && Color.TryParse(value, out var color))
-					return color;
+				return color;
 
 			return InvalidValueAction(value, fieldType, fieldName);
 		}
@@ -190,11 +196,11 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma);
-				if (parts.Length == 3)
-				{
-					if (WDist.TryParse(parts[0], out var rx) && WDist.TryParse(parts[1], out var ry) && WDist.TryParse(parts[2], out var rz))
-						return new WVec(rx, ry, rz);
-				}
+				if (parts.Length == 3
+					&& WDist.TryParse(parts[0], out var rx)
+					&& WDist.TryParse(parts[1], out var ry)
+					&& WDist.TryParse(parts[2], out var rz))
+					return new WVec(rx, ry, rz);
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -214,8 +220,8 @@ namespace OpenRA
 				for (var i = 0; i < vecs.Length; ++i)
 				{
 					if (WDist.TryParse(parts[3 * i], out var rx)
-							&& WDist.TryParse(parts[3 * i + 1], out var ry)
-							&& WDist.TryParse(parts[3 * i + 2], out var rz))
+						&& WDist.TryParse(parts[3 * i + 1], out var ry)
+						&& WDist.TryParse(parts[3 * i + 2], out var rz))
 						vecs[i] = new WVec(rx, ry, rz);
 				}
 
@@ -230,13 +236,11 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma);
-				if (parts.Length == 3)
-				{
-					if (WDist.TryParse(parts[0], out var rx)
-						&& WDist.TryParse(parts[1], out var ry)
-						&& WDist.TryParse(parts[2], out var rz))
-						return new WPos(rx, ry, rz);
-				}
+				if (parts.Length == 3
+					&& WDist.TryParse(parts[0], out var rx)
+					&& WDist.TryParse(parts[1], out var ry)
+					&& WDist.TryParse(parts[2], out var rz))
+					return new WPos(rx, ry, rz);
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -244,7 +248,7 @@ namespace OpenRA
 
 		static object ParseWAngle(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
-			if (Exts.TryParseIntegerInvariant(value, out var res))
+			if (Exts.TryParseInt32Invariant(value, out var res))
 				return new WAngle(res);
 			return InvalidValueAction(value, fieldType, fieldName);
 		}
@@ -254,13 +258,11 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma);
-				if (parts.Length == 3)
-				{
-					if (Exts.TryParseIntegerInvariant(parts[0], out var rr)
-							&& Exts.TryParseIntegerInvariant(parts[1], out var rp)
-							&& Exts.TryParseIntegerInvariant(parts[2], out var ry))
-						return new WRot(new WAngle(rr), new WAngle(rp), new WAngle(ry));
-				}
+				if (parts.Length == 3
+					&& Exts.TryParseInt32Invariant(parts[0], out var rr)
+					&& Exts.TryParseInt32Invariant(parts[1], out var rp)
+					&& Exts.TryParseInt32Invariant(parts[2], out var ry))
+					return new WRot(new WAngle(rr), new WAngle(rp), new WAngle(ry));
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -273,10 +275,33 @@ namespace OpenRA
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
 				if (parts.Length == 3)
 					return new CPos(
-						Exts.ParseIntegerInvariant(parts[0]),
-						Exts.ParseIntegerInvariant(parts[1]),
-						Exts.ParseByte(parts[2]));
-				return new CPos(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+						Exts.ParseInt32Invariant(parts[0]),
+						Exts.ParseInt32Invariant(parts[1]),
+						Exts.ParseByteInvariant(parts[2]));
+				return new CPos(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseCPosArray(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma);
+
+				if (parts.Length % 2 != 0)
+					return InvalidValueAction(value, fieldType, fieldName);
+
+				var vecs = new CPos[parts.Length / 2];
+				for (var i = 0; i < vecs.Length; i++)
+				{
+					if (int.TryParse(parts[2 * i], out var rx)
+							&& int.TryParse(parts[2 * i + 1], out var ry))
+						vecs[i] = new CPos(rx, ry);
+				}
+
+				return vecs;
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -287,7 +312,7 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
-				return new CVec(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+				return new CVec(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -365,7 +390,7 @@ namespace OpenRA
 		static object ParseBool(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
 			if (bool.TryParse(value.ToLowerInvariant(), out var result))
-				return result;
+				return result ? BoxedTrue : BoxedFalse;
 
 			return InvalidValueAction(value, fieldType, fieldName);
 		}
@@ -380,7 +405,7 @@ namespace OpenRA
 
 				var ints = new int2[parts.Length / 2];
 				for (var i = 0; i < ints.Length; i++)
-					ints[i] = new int2(Exts.ParseIntegerInvariant(parts[2 * i]), Exts.ParseIntegerInvariant(parts[2 * i + 1]));
+					ints[i] = new int2(Exts.ParseInt32Invariant(parts[2 * i]), Exts.ParseInt32Invariant(parts[2 * i + 1]));
 
 				return ints;
 			}
@@ -393,7 +418,7 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
-				return new Size(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+				return new Size(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -407,7 +432,7 @@ namespace OpenRA
 				if (parts.Length != 2)
 					return InvalidValueAction(value, fieldType, fieldName);
 
-				return new int2(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+				return new int2(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -455,10 +480,10 @@ namespace OpenRA
 			{
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
 				return new Rectangle(
-					Exts.ParseIntegerInvariant(parts[0]),
-					Exts.ParseIntegerInvariant(parts[1]),
-					Exts.ParseIntegerInvariant(parts[2]),
-					Exts.ParseIntegerInvariant(parts[3]));
+					Exts.ParseInt32Invariant(parts[0]),
+					Exts.ParseInt32Invariant(parts[1]),
+					Exts.ParseInt32Invariant(parts[2]),
+					Exts.ParseInt32Invariant(parts[3]));
 			}
 
 			return InvalidValueAction(value, fieldType, fieldName);
@@ -473,11 +498,11 @@ namespace OpenRA
 
 		static object ParseHashSetOrList(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
 		{
-			var set = Activator.CreateInstance(fieldType);
 			if (value == null)
-				return set;
+				return Activator.CreateInstance(fieldType);
 
 			var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+			var set = Activator.CreateInstance(fieldType, parts.Length);
 			var arguments = fieldType.GetGenericArguments();
 			var addMethod = fieldType.GetMethod(nameof(List<object>.Add), arguments);
 			var addArgs = new object[1];
@@ -492,7 +517,10 @@ namespace OpenRA
 
 		static object ParseDictionary(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
 		{
-			var dict = Activator.CreateInstance(fieldType);
+			if (yaml == null)
+				return Activator.CreateInstance(fieldType);
+
+			var dict = Activator.CreateInstance(fieldType, yaml.Nodes.Length);
 			var arguments = fieldType.GetGenericArguments();
 			var addMethod = fieldType.GetMethod(nameof(Dictionary<object, object>.Add), arguments);
 			var addArgs = new object[2];
@@ -523,7 +551,7 @@ namespace OpenRA
 			if (string.IsNullOrEmpty(value))
 				return null;
 
-			var innerType = fieldType.GetGenericArguments().First();
+			var innerType = fieldType.GetGenericArguments()[0];
 			var innerValue = GetValue("Nullable<T>", innerType, value, field);
 			return fieldType.GetConstructor(new[] { innerType }).Invoke(new[] { innerValue });
 		}
@@ -531,7 +559,7 @@ namespace OpenRA
 		public static void Load(object self, MiniYaml my)
 		{
 			var loadInfo = TypeLoadInfo[self.GetType()];
-			var missing = new List<string>();
+			List<string> missing = null;
 
 			Dictionary<string, MiniYaml> md = null;
 
@@ -539,14 +567,14 @@ namespace OpenRA
 			{
 				object val;
 
-				if (md == null)
-					md = my.ToDictionary();
+				md ??= my.ToDictionary();
 				if (fli.Loader != null)
 				{
 					if (!fli.Attribute.Required || md.ContainsKey(fli.YamlName))
 						val = fli.Loader(my);
 					else
 					{
+						missing ??= new List<string>();
 						missing.Add(fli.YamlName);
 						continue;
 					}
@@ -556,7 +584,11 @@ namespace OpenRA
 					if (!TryGetValueFromYaml(fli.YamlName, fli.Field, md, out val))
 					{
 						if (fli.Attribute.Required)
+						{
+							missing ??= new List<string>();
 							missing.Add(fli.YamlName);
+						}
+
 						continue;
 					}
 				}
@@ -564,7 +596,7 @@ namespace OpenRA
 				fli.Field.SetValue(self, val);
 			}
 
-			if (missing.Count > 0)
+			if (missing != null)
 				throw new MissingFieldsException(missing.ToArray());
 		}
 
@@ -625,12 +657,17 @@ namespace OpenRA
 
 		public static object GetValue(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
-			return GetValue(fieldName, fieldType, new MiniYaml(value), field);
+			return GetValue(fieldName, fieldType, value, null, field);
 		}
 
 		public static object GetValue(string fieldName, Type fieldType, MiniYaml yaml, MemberInfo field)
 		{
-			var value = yaml.Value?.Trim();
+			return GetValue(fieldName, fieldType, yaml.Value, yaml, field);
+		}
+
+		static object GetValue(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
+		{
+			value = value?.Trim();
 			if (fieldType.IsGenericType)
 			{
 				if (GenericTypeParsers.TryGetValue(fieldType.GetGenericTypeDefinition(), out var parseFuncGeneric))
@@ -754,7 +791,7 @@ namespace OpenRA
 		[AttributeUsage(AttributeTargets.Field)]
 		public class SerializeAttribute : Attribute
 		{
-			public static readonly SerializeAttribute Default = new SerializeAttribute(true);
+			public static readonly SerializeAttribute Default = new(true);
 
 			public bool IsDefault => this == Default;
 

OpenRA.Game/FieldSaver.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -15,6 +15,7 @@ using System.ComponentModel;
 using System.Globalization;
 using System.Linq;
 using System.Reflection;
+using System.Text;
 using OpenRA.Primitives;
 
 namespace OpenRA
@@ -58,7 +59,7 @@ namespace OpenRA
 
 			return new MiniYaml(
 				null,
-				fields.Select(info => new MiniYamlNode(info.YamlName, FormatValue(o, info.Field))).ToList());
+				fields.Select(info => new MiniYamlNode(info.YamlName, FormatValue(o, info.Field))));
 		}
 
 		public static MiniYamlNode SaveField(object o, string field)
@@ -84,7 +85,7 @@ namespace OpenRA
 			// This is only for documentation generation
 			if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Dictionary<,>))
 			{
-				var result = "";
+				var result = new StringBuilder();
 				var dict = (System.Collections.IDictionary)v;
 				foreach (var kvp in dict)
 				{
@@ -94,10 +95,10 @@ namespace OpenRA
 					var formattedKey = FormatValue(key);
 					var formattedValue = FormatValue(value);
 
-					result += $"{formattedKey}: {formattedValue}{Environment.NewLine}";
+					result.Append($"{formattedKey}: {formattedValue}{Environment.NewLine}");
 				}
 
-				return result;
+				return result.ToString();
 			}
 
 			if (v is DateTime d)

OpenRA.Game/FileFormats/Png.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -16,6 +16,7 @@ using System.Linq;
 using System.Net;
 using System.Text;
 using ICSharpCode.SharpZipLib.Checksum;
+using ICSharpCode.SharpZipLib.Zip.Compression;
 using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
 using OpenRA.Graphics;
 using OpenRA.Primitives;
@@ -31,7 +32,7 @@ namespace OpenRA.FileFormats
 		public Color[] Palette { get; }
 		public byte[] Data { get; }
 		public SpriteFrameType Type { get; }
-		public Dictionary<string, string> EmbeddedData = new Dictionary<string, string>();
+		public Dictionary<string, string> EmbeddedData = new();
 
 		public int PixelStride => Type == SpriteFrameType.Indexed8 ? 1 : Type == SpriteFrameType.Rgb24 ? 3 : 4;
 
@@ -45,12 +46,13 @@ namespace OpenRA.FileFormats
 			var data = new List<byte>();
 			Type = SpriteFrameType.Rgba32;
 
+			byte bitDepth = 8;
 			while (true)
 			{
 				var length = IPAddress.NetworkToHostOrder(s.ReadInt32());
-				var type = Encoding.UTF8.GetString(s.ReadBytes(4));
+				var type = s.ReadASCII(4);
 				var content = s.ReadBytes(length);
-				/*var crc = */s.ReadInt32();
+				s.ReadInt32(); // crc
 
 				if (!headerParsed && type != "IHDR")
 					throw new InvalidDataException("Invalid PNG file - header does not appear first.");
@@ -66,8 +68,8 @@ namespace OpenRA.FileFormats
 							Width = IPAddress.NetworkToHostOrder(ms.ReadInt32());
 							Height = IPAddress.NetworkToHostOrder(ms.ReadInt32());
 
-							var bitDepth = ms.ReadUInt8();
-							var colorType = (PngColorType)ms.ReadByte();
+							bitDepth = ms.ReadUInt8();
+							var colorType = (PngColorType)ms.ReadUInt8();
 							if (IsPaletted(bitDepth, colorType))
 								Type = SpriteFrameType.Indexed8;
 							else if (colorType == PngColorType.Color)
@@ -75,9 +77,9 @@ namespace OpenRA.FileFormats
 
 							Data = new byte[Width * Height * PixelStride];
 
-							var compression = ms.ReadByte();
-							/*var filter = */ms.ReadByte();
-							var interlace = ms.ReadByte();
+							var compression = ms.ReadUInt8();
+							ms.ReadUInt8(); // filter
+							var interlace = ms.ReadUInt8();
 
 							if (compression != 0)
 								throw new InvalidDataException("Compression method not supported");
@@ -92,10 +94,10 @@ namespace OpenRA.FileFormats
 
 						case "PLTE":
 						{
-							Palette = new Color[256];
-							for (var i = 0; i < length / 3; i++)
+							Palette = new Color[length / 3];
+							for (var i = 0; i < Palette.Length; i++)
 							{
-								var r = ms.ReadByte(); var g = ms.ReadByte(); var b = ms.ReadByte();
+								var r = ms.ReadUInt8(); var g = ms.ReadUInt8(); var b = ms.ReadUInt8();
 								Palette[i] = Color.FromArgb(r, g, b);
 							}
 
@@ -108,7 +110,7 @@ namespace OpenRA.FileFormats
 								throw new InvalidDataException("Non-Palette indexed PNG are not supported.");
 
 							for (var i = 0; i < length; i++)
-								Palette[i] = Color.FromArgb(ms.ReadByte(), Palette[i]);
+								Palette[i] = Color.FromArgb(ms.ReadUInt8(), Palette[i]);
 
 							break;
 						}
@@ -136,22 +138,77 @@ namespace OpenRA.FileFormats
 								{
 									var pxStride = PixelStride;
 									var rowStride = Width * pxStride;
+									var pixelsPerByte = 8 / bitDepth;
+									var sourceRowStride = Exts.IntegerDivisionRoundingAwayFromZero(rowStride, pixelsPerByte);
 
-									var prevLine = new byte[rowStride];
+									Span<byte> prevLine = new byte[rowStride];
 									for (var y = 0; y < Height; y++)
 									{
-										var filter = (PngFilter)ds.ReadByte();
-										var line = ds.ReadBytes(rowStride);
+										var filter = (PngFilter)ds.ReadUInt8();
+										ds.ReadBytes(Data, y * rowStride, sourceRowStride);
+										var line = Data.AsSpan(y * rowStride, rowStride);
 
-										for (var i = 0; i < rowStride; i++)
-											line[i] = i < pxStride
-												? UnapplyFilter(filter, line[i], 0, prevLine[i], 0)
-												: UnapplyFilter(filter, line[i], line[i - pxStride], prevLine[i], prevLine[i - pxStride]);
+										// If the source has a bit depth of 1, 2 or 4 it packs multiple pixels per byte.
+										// Unpack to bit depth of 8, yielding 1 pixel per byte.
+										// This makes life easier for consumers of palleted data.
+										if (bitDepth < 8)
+										{
+											var mask = 0xFF >> (8 - bitDepth);
+											for (var i = sourceRowStride - 1; i >= 0; i--)
+											{
+												var packed = line[i];
+												for (var j = 0; j < pixelsPerByte; j++)
+												{
+													var dest = i * pixelsPerByte + j;
+													if (dest < line.Length) // Guard against last byte being only partially packed
+														line[dest] = (byte)(packed >> (8 - (j + 1) * bitDepth) & mask);
+												}
+											}
+										}
 
-										Array.Copy(line, 0, Data, y * rowStride, rowStride);
+										switch (filter)
+										{
+											case PngFilter.None:
+												break;
+											case PngFilter.Sub:
+												for (var i = pxStride; i < rowStride; i++)
+													line[i] += line[i - pxStride];
+												break;
+											case PngFilter.Up:
+												for (var i = 0; i < rowStride; i++)
+													line[i] += prevLine[i];
+												break;
+											case PngFilter.Average:
+												for (var i = 0; i < pxStride; i++)
+													line[i] += Average(0, prevLine[i]);
+												for (var i = pxStride; i < rowStride; i++)
+													line[i] += Average(line[i - pxStride], prevLine[i]);
+												break;
+											case PngFilter.Paeth:
+												for (var i = 0; i < pxStride; i++)
+													line[i] += Paeth(0, prevLine[i], 0);
+												for (var i = pxStride; i < rowStride; i++)
+													line[i] += Paeth(line[i - pxStride], prevLine[i], prevLine[i - pxStride]);
+												break;
+											default:
+												throw new InvalidOperationException("Unsupported Filter");
+										}
 
 										prevLine = line;
 									}
+
+									static byte Average(byte a, byte b) => (byte)((a + b) / 2);
+
+									static byte Paeth(byte a, byte b, byte c)
+									{
+										var p = a + b - c;
+										var pa = Math.Abs(p - a);
+										var pb = Math.Abs(p - b);
+										var pc = Math.Abs(p - c);
+
+										return (pa <= pb && pa <= pc) ? a :
+											(pb <= pc) ? b : c;
+									}
 								}
 							}
 
@@ -228,38 +285,13 @@ namespace OpenRA.FileFormats
 			return isPng;
 		}
 
-		static byte UnapplyFilter(PngFilter f, byte x, byte a, byte b, byte c)
-		{
-			switch (f)
-			{
-				case PngFilter.None: return x;
-				case PngFilter.Sub: return (byte)(x + a);
-				case PngFilter.Up: return (byte)(x + b);
-				case PngFilter.Average: return (byte)(x + (a + b) / 2);
-				case PngFilter.Paeth: return (byte)(x + Paeth(a, b, c));
-				default:
-					throw new InvalidOperationException("Unsupported Filter");
-			}
-		}
-
-		static byte Paeth(byte a, byte b, byte c)
-		{
-			var p = a + b - c;
-			var pa = Math.Abs(p - a);
-			var pb = Math.Abs(p - b);
-			var pc = Math.Abs(p - c);
-
-			return (pa <= pb && pa <= pc) ? a :
-				(pb <= pc) ? b : c;
-		}
-
 		[Flags]
-		enum PngColorType { Indexed = 1, Color = 2, Alpha = 4 }
-		enum PngFilter { None, Sub, Up, Average, Paeth }
+		enum PngColorType : byte { Indexed = 1, Color = 2, Alpha = 4 }
+		enum PngFilter : byte { None, Sub, Up, Average, Paeth }
 
 		static bool IsPaletted(byte bitDepth, PngColorType colorType)
 		{
-			if (bitDepth == 8 && colorType == (PngColorType.Indexed | PngColorType.Color))
+			if (bitDepth <= 8 && colorType == (PngColorType.Indexed | PngColorType.Color))
 				return true;
 
 			if (bitDepth == 8 && colorType == (PngColorType.Color | PngColorType.Alpha))
@@ -271,16 +303,16 @@ namespace OpenRA.FileFormats
 			throw new InvalidDataException("Unknown pixel format");
 		}
 
-		void WritePngChunk(Stream output, string type, Stream input)
+		static void WritePngChunk(Stream output, string type, Stream input)
 		{
 			input.Position = 0;
 
 			var typeBytes = Encoding.ASCII.GetBytes(type);
 			output.Write(IPAddress.HostToNetworkOrder((int)input.Length));
-			output.WriteArray(typeBytes);
+			output.Write(typeBytes);
 
 			var data = input.ReadAllBytes();
-			output.WriteArray(data);
+			output.Write(data);
 
 			var crc32 = new Crc32();
 			crc32.Update(typeBytes);
@@ -292,7 +324,7 @@ namespace OpenRA.FileFormats
 		{
 			using (var output = new MemoryStream())
 			{
-				output.WriteArray(Signature);
+				output.Write(Signature);
 				using (var header = new MemoryStream())
 				{
 					header.Write(IPAddress.HostToNetworkOrder(Width));
@@ -340,13 +372,14 @@ namespace OpenRA.FileFormats
 
 				using (var data = new MemoryStream())
 				{
-					using (var compressed = new DeflaterOutputStream(data))
+					using (var compressed = new DeflaterOutputStream(data, new Deflater(Deflater.BEST_COMPRESSION)))
 					{
 						var rowStride = Width * PixelStride;
 						for (var y = 0; y < Height; y++)
 						{
-							// Write uncompressed scanlines for simplicity
-							compressed.WriteByte(0);
+							// Assuming no filtering for simplicity
+							const byte FilterType = 0;
+							compressed.WriteByte(FilterType);
 							compressed.Write(Data, y * rowStride, rowStride);
 						}
 
@@ -361,7 +394,7 @@ namespace OpenRA.FileFormats
 				{
 					using (var text = new MemoryStream())
 					{
-						text.WriteArray(Encoding.ASCII.GetBytes(kv.Key + (char)0 + kv.Value));
+						text.Write(Encoding.ASCII.GetBytes(kv.Key + (char)0 + kv.Value));
 						WritePngChunk(output, "tEXt", text);
 					}
 				}

OpenRA.Game/FileFormats/ReplayMetadata.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -47,8 +47,8 @@ namespace OpenRA.FileFormats
 				throw new NotSupportedException($"Metadata version {version} is not supported");
 
 			// Read game info (max 100K limit as a safeguard against corrupted files)
-			var data = fs.ReadString(Encoding.UTF8, 1024 * 100);
-			GameInfo = GameInformation.Deserialize(data);
+			var data = fs.ReadLengthPrefixedString(Encoding.UTF8, 1024 * 100);
+			GameInfo = GameInformation.Deserialize(data, path);
 		}
 
 		public void Write(BinaryWriter writer)
@@ -62,7 +62,7 @@ namespace OpenRA.FileFormats
 			{
 				// Write lobby info data
 				writer.Flush();
-				dataLength += writer.BaseStream.WriteString(Encoding.UTF8, GameInfo.Serialize());
+				dataLength += writer.BaseStream.WriteLengthPrefixedString(Encoding.UTF8, GameInfo.Serialize());
 			}
 
 			// Write total length & end marker

OpenRA.Game/FileSystem/FileSystem.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -29,16 +29,16 @@ namespace OpenRA.FileSystem
 	public class FileSystem : IReadOnlyFileSystem
 	{
 		public IEnumerable<IReadOnlyPackage> MountedPackages => mountedPackages.Keys;
-		readonly Dictionary<IReadOnlyPackage, int> mountedPackages = new Dictionary<IReadOnlyPackage, int>();
-		readonly Dictionary<string, IReadOnlyPackage> explicitMounts = new Dictionary<string, IReadOnlyPackage>();
+		readonly Dictionary<IReadOnlyPackage, int> mountedPackages = new();
+		readonly Dictionary<string, IReadOnlyPackage> explicitMounts = new();
 		readonly string modID;
 
 		// Mod packages that should not be disposed
-		readonly List<IReadOnlyPackage> modPackages = new List<IReadOnlyPackage>();
+		readonly List<IReadOnlyPackage> modPackages = new();
 		readonly IReadOnlyDictionary<string, Manifest> installedMods;
 		readonly IPackageLoader[] packageLoaders;
 
-		Cache<string, List<IReadOnlyPackage>> fileIndex = new Cache<string, List<IReadOnlyPackage>>(_ => new List<IReadOnlyPackage>());
+		Cache<string, List<IReadOnlyPackage>> fileIndex = new(_ => new List<IReadOnlyPackage>());
 
 		public FileSystem(string modID, IReadOnlyDictionary<string, Manifest> installedMods, IPackageLoader[] packageLoaders)
 		{
@@ -83,16 +83,16 @@ namespace OpenRA.FileSystem
 
 		public void Mount(string name, string explicitName = null)
 		{
-			var optional = name.StartsWith("~", StringComparison.Ordinal);
+			var optional = name.StartsWith('~');
 			if (optional)
-				name = name.Substring(1);
+				name = name[1..];
 
 			try
 			{
 				IReadOnlyPackage package;
-				if (name.StartsWith("$", StringComparison.Ordinal))
+				if (name.StartsWith('$'))
 				{
-					name = name.Substring(1);
+					name = name[1..];
 
 					if (!installedMods.TryGetValue(name, out var mod))
 						throw new InvalidOperationException($"Could not load mod '{name}'. Available mods: {installedMods.Keys.JoinWith(", ")}");
@@ -109,10 +109,8 @@ namespace OpenRA.FileSystem
 
 				Mount(package, explicitName);
 			}
-			catch
+			catch when (optional)
 			{
-				if (!optional)
-					throw;
 			}
 		}
 
@@ -161,9 +159,7 @@ namespace OpenRA.FileSystem
 					explicitMounts.Remove(key);
 
 				// Mod packages aren't owned by us, so we shouldn't dispose them
-				if (modPackages.Contains(package))
-					modPackages.Remove(package);
-				else
+				if (!modPackages.Remove(package))
 					package.Dispose();
 			}
 			else
@@ -190,6 +186,12 @@ namespace OpenRA.FileSystem
 			UnmountAll();
 			foreach (var kv in manifest.Packages)
 				Mount(kv.Key, kv.Value);
+
+			mountedPackages.TrimExcess();
+			explicitMounts.TrimExcess();
+			modPackages.TrimExcess();
+			foreach (var packages in fileIndex.Values)
+				packages.TrimExcess();
 		}
 
 		Stream GetFromCache(string filename)
@@ -211,9 +213,9 @@ namespace OpenRA.FileSystem
 		public bool TryGetPackageContaining(string path, out IReadOnlyPackage package, out string filename)
 		{
 			var explicitSplit = path.IndexOf('|');
-			if (explicitSplit > 0 && explicitMounts.TryGetValue(path.Substring(0, explicitSplit), out package))
+			if (explicitSplit > 0 && explicitMounts.TryGetValue(path[..explicitSplit], out package))
 			{
-				filename = path.Substring(explicitSplit + 1);
+				filename = path[(explicitSplit + 1)..];
 				return true;
 			}
 
@@ -226,14 +228,11 @@ namespace OpenRA.FileSystem
 		public bool TryOpen(string filename, out Stream s)
 		{
 			var explicitSplit = filename.IndexOf('|');
-			if (explicitSplit > 0)
+			if (explicitSplit > 0 && explicitMounts.TryGetValue(filename[..explicitSplit], out var explicitPackage))
 			{
-				if (explicitMounts.TryGetValue(filename.Substring(0, explicitSplit), out var explicitPackage))
-				{
-					s = explicitPackage.GetStream(filename.Substring(explicitSplit + 1));
-					if (s != null)
-						return true;
-				}
+				s = explicitPackage.GetStream(filename[(explicitSplit + 1)..]);
+				if (s != null)
+					return true;
 			}
 
 			s = GetFromCache(filename);
@@ -262,16 +261,16 @@ namespace OpenRA.FileSystem
 		public bool Exists(string filename)
 		{
 			var explicitSplit = filename.IndexOf('|');
-			if (explicitSplit > 0)
-				if (explicitMounts.TryGetValue(filename.Substring(0, explicitSplit), out var explicitPackage))
-					if (explicitPackage.Contains(filename.Substring(explicitSplit + 1)))
-						return true;
+			if (explicitSplit > 0 &&
+				explicitMounts.TryGetValue(filename[..explicitSplit], out var explicitPackage) &&
+				explicitPackage.Contains(filename[(explicitSplit + 1)..]))
+				return true;
 
 			return fileIndex.ContainsKey(filename);
 		}
 
 		/// <summary>
-		/// Returns true if the given filename references an external mod via an explicit mount
+		/// Returns true if the given filename references an external mod via an explicit mount.
 		/// </summary>
 		public bool IsExternalModFile(string filename)
 		{
@@ -279,7 +278,7 @@ namespace OpenRA.FileSystem
 			if (explicitSplit < 0)
 				return false;
 
-			if (!explicitMounts.TryGetValue(filename.Substring(0, explicitSplit), out var explicitPackage))
+			if (!explicitMounts.TryGetValue(filename[..explicitSplit], out var explicitPackage))
 				return false;
 
 			if (installedMods[modID].Package == explicitPackage)
@@ -295,21 +294,21 @@ namespace OpenRA.FileSystem
 		public static string ResolveAssemblyPath(string path, Manifest manifest, InstalledMods installedMods)
 		{
 			var explicitSplit = path.IndexOf('|');
-			if (explicitSplit > 0 && !path.StartsWith("^"))
+			if (explicitSplit > 0 && !path.StartsWith('^'))
 			{
-				var parent = path.Substring(0, explicitSplit);
-				var filename = path.Substring(explicitSplit + 1);
+				var parent = path[..explicitSplit];
+				var filename = path[(explicitSplit + 1)..];
 
 				var parentPath = manifest.Packages.FirstOrDefault(kv => kv.Value == parent).Key;
 				if (parentPath == null)
 					return null;
 
-				if (parentPath.StartsWith("$", StringComparison.Ordinal))
+				if (parentPath.StartsWith('$'))
 				{
-					if (!installedMods.TryGetValue(parentPath.Substring(1), out var mod))
+					if (!installedMods.TryGetValue(parentPath[1..], out var mod))
 						return null;
 
-					if (!(mod.Package is Folder))
+					if (mod.Package is not Folder)
 						return null;
 
 					path = Path.Combine(mod.Package.Name, filename);
@@ -322,6 +321,28 @@ namespace OpenRA.FileSystem
 			return File.Exists(resolvedPath) ? resolvedPath : null;
 		}
 
+		public static string ResolveCaseInsensitivePath(string path)
+		{
+			var resolved = Path.GetPathRoot(path);
+
+			if (resolved == null)
+				return null;
+
+			foreach (var name in path[resolved.Length..].Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar))
+			{
+				// Filter out paths of the form /foo/bar/./baz
+				if (name == ".")
+					continue;
+
+				resolved = Directory.GetFileSystemEntries(resolved).FirstOrDefault(e => e.Equals(Path.Combine(resolved, name), StringComparison.InvariantCultureIgnoreCase));
+
+				if (resolved == null)
+					return null;
+			}
+
+			return resolved;
+		}
+
 		public string GetPrefix(IReadOnlyPackage package)
 		{
 			return explicitMounts.ContainsValue(package) ? explicitMounts.First(f => f.Value == package).Key : null;

OpenRA.Game/FileSystem/Folder.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -18,24 +18,22 @@ namespace OpenRA.FileSystem
 {
 	public sealed class Folder : IReadWritePackage
 	{
-		readonly string path;
+		public string Name { get; }
 
 		public Folder(string path)
 		{
-			this.path = path;
+			Name = path;
 			if (!Directory.Exists(path))
 				Directory.CreateDirectory(path);
 		}
 
-		public string Name => path;
-
 		public IEnumerable<string> Contents
 		{
 			get
 			{
 				// Order may vary on different file systems and it matters for hashing.
-				return Directory.GetFiles(path, "*", SearchOption.TopDirectoryOnly)
-					.Concat(Directory.GetDirectories(path))
+				return Directory.GetFiles(Name, "*", SearchOption.TopDirectoryOnly)
+					.Concat(Directory.GetDirectories(Name))
 					.Select(Path.GetFileName)
 					.OrderBy(f => f);
 			}
@@ -43,14 +41,18 @@ namespace OpenRA.FileSystem
 
 		public Stream GetStream(string filename)
 		{
-			try { return File.OpenRead(Path.Combine(path, filename)); }
+			var combined = Path.Combine(Name, filename);
+			if (!File.Exists(combined))
+				return null;
+
+			try { return File.OpenRead(combined); }
 			catch { return null; }
 		}
 
 		public bool Contains(string filename)
 		{
-			var combined = Path.Combine(path, filename);
-			return combined.StartsWith(path, StringComparison.Ordinal) && File.Exists(combined);
+			var combined = Path.Combine(Name, filename);
+			return combined.StartsWith(Name, StringComparison.Ordinal) && File.Exists(combined);
 		}
 
 		public IReadOnlyPackage OpenPackage(string filename, FileSystem context)
@@ -82,7 +84,7 @@ namespace OpenRA.FileSystem
 			// in FileSystem.OpenPackage.  Their internal name therefore contains the
 			// full parent path too.  We need to be careful to not add a second path
 			// prefix to these hacked packages.
-			var filePath = filename.StartsWith(path) ? filename : Path.Combine(path, filename);
+			var filePath = filename.StartsWith(Name, StringComparison.Ordinal) ? filename : Path.Combine(Name, filename);
 
 			Directory.CreateDirectory(Path.GetDirectoryName(filePath));
 			using (var s = File.Create(filePath))
@@ -96,7 +98,7 @@ namespace OpenRA.FileSystem
 			// in FileSystem.OpenPackage.  Their internal name therefore contains the
 			// full parent path too.  We need to be careful to not add a second path
 			// prefix to these hacked packages.
-			var filePath = filename.StartsWith(path) ? filename : Path.Combine(path, filename);
+			var filePath = filename.StartsWith(Name, StringComparison.Ordinal) ? filename : Path.Combine(Name, filename);
 			if (Directory.Exists(filePath))
 				Directory.Delete(filePath, true);
 			else if (File.Exists(filePath))

OpenRA.Game/FileSystem/IPackage.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/FileSystem/ZipFile.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -19,9 +19,9 @@ namespace OpenRA.FileSystem
 {
 	public class ZipFileLoader : IPackageLoader
 	{
-		static readonly string[] Extensions = { ".zip", ".oramap" };
+		const uint ZipSignature = 0x04034b50;
 
-		class ReadOnlyZipFile : IReadOnlyPackage
+		public class ReadOnlyZipFile : IReadOnlyPackage
 		{
 			public string Name { get; protected set; }
 			protected ZipFile pkg;
@@ -55,7 +55,8 @@ namespace OpenRA.FileSystem
 				get
 				{
 					foreach (ZipEntry entry in pkg)
-						yield return entry.Name;
+						if (entry.IsFile)
+							yield return entry.Name;
 				}
 			}
 
@@ -67,6 +68,7 @@ namespace OpenRA.FileSystem
 			public void Dispose()
 			{
 				pkg?.Close();
+				GC.SuppressFinalize(this);
 			}
 
 			public IReadOnlyPackage OpenPackage(string filename, FileSystem context)
@@ -92,9 +94,9 @@ namespace OpenRA.FileSystem
 			}
 		}
 
-		sealed class ReadWriteZipFile : ReadOnlyZipFile, IReadWritePackage
+		public sealed class ReadWriteZipFile : ReadOnlyZipFile, IReadWritePackage
 		{
-			readonly MemoryStream pkgStream = new MemoryStream();
+			readonly MemoryStream pkgStream = new();
 
 			public ReadWriteZipFile(string filename, bool create = false)
 			{
@@ -116,10 +118,7 @@ namespace OpenRA.FileSystem
 
 			void Commit()
 			{
-				var pos = pkgStream.Position;
-				pkgStream.Position = 0;
-				File.WriteAllBytes(Name, pkgStream.ReadBytes((int)pkgStream.Length));
-				pkgStream.Position = pos;
+				File.WriteAllBytes(Name, pkgStream.ToArray());
 			}
 
 			public void Update(string filename, byte[] contents)
@@ -141,23 +140,22 @@ namespace OpenRA.FileSystem
 
 		sealed class ZipFolder : IReadOnlyPackage
 		{
-			public string Name => path;
+			public string Name { get; }
 			public ReadOnlyZipFile Parent { get; }
-			readonly string path;
 
 			public ZipFolder(ReadOnlyZipFile parent, string path)
 			{
-				if (path.EndsWith("/", StringComparison.Ordinal))
-					path = path.Substring(0, path.Length - 1);
+				if (path.EndsWith('/'))
+					path = path[..^1];
 
+				Name = path;
 				Parent = parent;
-				this.path = path;
 			}
 
 			public Stream GetStream(string filename)
 			{
 				// Zip files use '/' as a path separator
-				return Parent.GetStream(path + '/' + filename);
+				return Parent.GetStream(Name + '/' + filename);
 			}
 
 			public IEnumerable<string> Contents
@@ -166,9 +164,9 @@ namespace OpenRA.FileSystem
 				{
 					foreach (var entry in Parent.Contents)
 					{
-						if (entry.StartsWith(path, StringComparison.Ordinal) && entry != path)
+						if (entry.StartsWith(Name, StringComparison.Ordinal) && entry != Name)
 						{
-							var filename = entry.Substring(path.Length + 1);
+							var filename = entry[(Name.Length + 1)..];
 							var dirLevels = filename.Split('/').Count(c => !string.IsNullOrEmpty(c));
 							if (dirLevels == 1)
 								yield return filename;
@@ -179,18 +177,18 @@ namespace OpenRA.FileSystem
 
 			public bool Contains(string filename)
 			{
-				return Parent.Contains(path + '/' + filename);
+				return Parent.Contains(Name + '/' + filename);
 			}
 
 			public IReadOnlyPackage OpenPackage(string filename, FileSystem context)
 			{
-				return Parent.OpenPackage(path + '/' + filename, context);
+				return Parent.OpenPackage(Name + '/' + filename, context);
 			}
 
 			public void Dispose() { /* nothing to do */ }
 		}
 
-		class StaticStreamDataSource : IStaticDataSource
+		sealed class StaticStreamDataSource : IStaticDataSource
 		{
 			readonly Stream s;
 			public StaticStreamDataSource(Stream s)
@@ -206,7 +204,10 @@ namespace OpenRA.FileSystem
 
 		public bool TryParsePackage(Stream s, string filename, FileSystem context, out IReadOnlyPackage package)
 		{
-			if (!Extensions.Any(e => filename.EndsWith(e, StringComparison.InvariantCultureIgnoreCase)))
+			var readSignature = s.ReadUInt32();
+			s.Position -= 4;
+
+			if (readSignature != ZipSignature)
 			{
 				package = null;
 				return false;
@@ -218,10 +219,13 @@ namespace OpenRA.FileSystem
 
 		public static bool TryParseReadWritePackage(string filename, out IReadWritePackage package)
 		{
-			if (!Extensions.Any(e => filename.EndsWith(e, StringComparison.InvariantCultureIgnoreCase)))
+			using (var s = File.OpenRead(filename))
 			{
-				package = null;
-				return false;
+				if (s.ReadUInt32() != ZipSignature)
+				{
+					package = null;
+					return false;
+				}
 			}
 
 			package = new ReadWriteZipFile(filename);

OpenRA.Game/Fonts.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Game.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -29,6 +29,9 @@ namespace OpenRA
 {
 	public static class Game
 	{
+		[TranslationReference("filename")]
+		const string SavedScreenshot = "notification-saved-screenshot";
+
 		public const int TimestepJankThreshold = 250; // Don't catch up for delays larger than 250ms
 
 		public static InstalledMods Mods { get; private set; }
@@ -45,7 +48,7 @@ namespace OpenRA
 		internal static OrderManager OrderManager;
 		static Server.Server server;
 
-		public static MersenneTwister CosmeticRandom = new MersenneTwister(); // not synced
+		public static MersenneTwister CosmeticRandom = new(); // not synced
 
 		public static Renderer Renderer;
 		public static Sound Sound;
@@ -62,7 +65,7 @@ namespace OpenRA
 		{
 			var newConnection = new NetworkConnection(endpoint);
 			if (recordReplay)
-				newConnection.StartRecording(() => { return TimestampedFilename(); });
+				newConnection.StartRecording(() => TimestampedFilename());
 
 			var om = new OrderManager(newConnection);
 			JoinInner(om);
@@ -83,8 +86,9 @@ namespace OpenRA
 
 		static void JoinInner(OrderManager om)
 		{
-			// Refresh TextNotificationsManager before the game starts.
+			// Refresh static classes before the game starts.
 			TextNotificationsManager.Clear();
+			UnitOrders.Clear();
 
 			// HACK: The shellmap World and OrderManager are owned by the main menu's WorldRenderer instead of Game.
 			// This allows us to switch Game.OrderManager from the shellmap to the new network connection when joining
@@ -176,6 +180,7 @@ namespace OpenRA
 		}
 
 		public static event Action BeforeGameStart = () => { };
+		public static event Action AfterGameStart = () => { };
 		internal static void StartGame(string mapUID, WorldType type)
 		{
 			// Dispose of the old world before creating a new one.
@@ -184,13 +189,8 @@ namespace OpenRA
 			Cursor.SetCursor(null);
 			BeforeGameStart();
 
-			Map map;
-
-			using (new PerfTimer("PrepareMap"))
-				map = ModData.PrepareMap(mapUID);
-
 			using (new PerfTimer("NewWorld"))
-				OrderManager.World = new World(ModData, map, OrderManager, type);
+				OrderManager.World = new World(mapUID, ModData, OrderManager, type);
 
 			OrderManager.World.GameOver += FinishBenchmark;
 
@@ -224,6 +224,12 @@ namespace OpenRA
 			//   Much better to clean up now then to drop frames during gameplay for GC pauses.
 			GCSettings.LargeObjectHeapCompactionMode = GCLargeObjectHeapCompactionMode.CompactOnce;
 			GC.Collect();
+
+			// PostLoadComplete is designed for anything that should trigger at the very end of loading.
+			// e.g. audio notifications that the game is starting.
+			OrderManager.World.PostLoadComplete(worldRenderer);
+
+			AfterGameStart();
 		}
 
 		public static void RestartGame()
@@ -267,15 +273,14 @@ namespace OpenRA
 		{
 			OrderManager om = null;
 
-			Action lobbyReady = null;
-			lobbyReady = () =>
+			void LobbyReady()
 			{
-				LobbyInfoChanged -= lobbyReady;
+				LobbyInfoChanged -= LobbyReady;
 				foreach (var o in setupOrders)
 					om.IssueOrder(o);
-			};
+			}
 
-			LobbyInfoChanged += lobbyReady;
+			LobbyInfoChanged += LobbyReady;
 
 			om = JoinServer(CreateLocalServer(mapUID), "");
 		}
@@ -318,7 +323,7 @@ namespace OpenRA
 			if (!string.IsNullOrEmpty(supportDirArg))
 				Platform.OverrideSupportDir(supportDirArg);
 
-			Console.WriteLine($"Platform is {Platform.CurrentPlatform}");
+			Console.WriteLine($"Platform is {Platform.CurrentPlatform} ({Platform.CurrentArchitecture})");
 
 			// Load the engine version as early as possible so it can be written to exception logs
 			try
@@ -418,8 +423,8 @@ namespace OpenRA
 
 				// Sanitize input from platform-specific launchers
 				// Process.Start requires paths to not be quoted, even if they contain spaces
-				if (launchPath != null && launchPath.First() == '"' && launchPath.Last() == '"')
-					launchPath = launchPath.Substring(1, launchPath.Length - 2);
+				if (launchPath != null && launchPath[0] == '"' && launchPath.Last() == '"')
+					launchPath = launchPath[1..^1];
 
 				// Metadata registration requires an explicit launch path
 				if (launchPath != null)
@@ -526,10 +531,11 @@ namespace OpenRA
 				.Where(m => m.Status == MapStatus.Available && m.Visibility.HasFlag(MapVisibility.Shellmap))
 				.Select(m => m.Uid);
 
-			if (!shellmaps.Any())
+			var shellmap = shellmaps.RandomOrDefault(CosmeticRandom);
+			if (shellmap == null)
 				throw new InvalidDataException("No valid shellmaps available");
 
-			return shellmaps.Random(CosmeticRandom);
+			return shellmap;
 		}
 
 		public static void SwitchToExternalMod(ExternalMod mod, string[] launchArguments = null, Action onFailed = null)
@@ -566,14 +572,11 @@ namespace OpenRA
 
 		// Note: These delayed actions should only be used by widgets or disposing objects
 		// - things that depend on a particular world should be queuing them on the world actor.
-		static volatile ActionQueue delayedActions = new ActionQueue();
+		static volatile ActionQueue delayedActions = new();
 
 		public static void RunAfterTick(Action a) { delayedActions.Add(a, RunTime); }
 		public static void RunAfterDelay(int delayMilliseconds, Action a) { delayedActions.Add(a, RunTime + delayMilliseconds); }
 
-		[TranslationReference("filename")]
-		static readonly string SavedScreenshot = "saved-screenshot";
-
 		static void TakeScreenshotInner()
 		{
 			using (new PerfTimer("Renderer.SaveScreenshot"))
@@ -587,7 +590,7 @@ namespace OpenRA
 				Log.Write("debug", "Taking screenshot " + path);
 
 				Renderer.SaveScreenshot(path);
-				TextNotificationsManager.Debug(ModData.Translation.GetString(SavedScreenshot, Translation.Arguments("filename", filename)));
+				TextNotificationsManager.Debug(TranslationProvider.GetString(SavedScreenshot, Translation.Arguments("filename", filename)));
 			}
 		}
 
@@ -606,7 +609,10 @@ namespace OpenRA
 
 			if (orderManager.LastTickTime.ShouldAdvance(tick))
 			{
-				using (new PerfSample("tick_time"))
+				if (orderManager.GameStarted && orderManager.LocalFrameNumber == 0)
+					PerfHistory.Reset(); // Remove history that occurred whilst the new game was loading.
+
+				using (var sample = new PerfSample("tick_time"))
 				{
 					orderManager.LastTickTime.AdvanceTickTime(tick);
 
@@ -615,14 +621,15 @@ namespace OpenRA
 					Sync.RunUnsynced(world, orderManager.TickImmediate);
 
 					if (world == null)
+					{
+						if (orderManager.GameStarted)
+							PerfHistory.Reset(); // Remove old history when a new game starts.
 						return;
+					}
 
 					if (orderManager.TryTick())
 					{
-						Sync.RunUnsynced(world, () =>
-						{
-							world.OrderGenerator.Tick(world);
-						});
+						Sync.RunUnsynced(world, () => world.OrderGenerator.Tick(world));
 
 						world.Tick();
 
@@ -672,7 +679,7 @@ namespace OpenRA
 				// Prepare renderables (i.e. render voxels) before calling BeginFrame
 				using (new PerfSample("render_prepare"))
 				{
-					Renderer.WorldModelRenderer.BeginFrame();
+					worldRenderer?.BeginFrame();
 
 					// World rendering is disabled while the loading screen is displayed
 					if (worldRenderer != null && !worldRenderer.World.IsLoadingGameSave)
@@ -682,7 +689,7 @@ namespace OpenRA
 					}
 
 					Ui.PrepareRenderables();
-					Renderer.WorldModelRenderer.EndFrame();
+					worldRenderer?.EndFrame();
 				}
 
 				// worldRenderer is null during the initial install/download screen
@@ -786,7 +793,7 @@ namespace OpenRA
 				var logicWorld = worldRenderer?.World;
 
 				// ReplayTimestep = 0 means the replay is paused: we need to keep logicInterval as UI.Timestep to avoid breakage
-				if (logicWorld != null && !(logicWorld.IsReplay && logicWorld.ReplayTimestep == 0))
+				if (logicWorld != null && (!logicWorld.IsReplay || logicWorld.ReplayTimestep != 0))
 					logicInterval = logicWorld == OrderManager.World ? OrderManager.SuggestedTimestep : logicWorld.Timestep;
 
 				// Ideal time between screen updates
@@ -921,15 +928,15 @@ namespace OpenRA
 		{
 			var endpoints = new List<IPEndPoint>
 			{
-				new IPEndPoint(IPAddress.IPv6Any, settings.ListenPort),
-				new IPEndPoint(IPAddress.Any, settings.ListenPort)
+				new(IPAddress.IPv6Any, settings.ListenPort),
+				new(IPAddress.Any, settings.ListenPort)
 			};
 			server = new Server.Server(endpoints, settings, ModData, ServerType.Multiplayer);
 
 			return server.GetEndpointForLocalConnection();
 		}
 
-		public static ConnectionTarget CreateLocalServer(string map)
+		public static ConnectionTarget CreateLocalServer(string map, bool isSkirmish = false)
 		{
 			var settings = new ServerSettings()
 			{
@@ -943,9 +950,9 @@ namespace OpenRA
 			// This would break the Restart button, which relies on the PlayerIndex always being the same for local servers
 			var endpoints = new List<IPEndPoint>
 			{
-				new IPEndPoint(IPAddress.Loopback, 0)
+				new(IPAddress.Loopback, 0)
 			};
-			server = new Server.Server(endpoints, settings, ModData, ServerType.Local);
+			server = new Server.Server(endpoints, settings, ModData, isSkirmish ? ServerType.Skirmish : ServerType.Local);
 
 			return server.GetEndpointForLocalConnection();
 		}

OpenRA.Game/GameInformation.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -36,7 +36,7 @@ namespace OpenRA
 		public TimeSpan Duration => EndTimeUtc > StartTimeUtc ? EndTimeUtc - StartTimeUtc : TimeSpan.Zero;
 
 		public IList<Player> Players { get; }
-		public HashSet<int> DisabledSpawnPoints = new HashSet<int>();
+		public HashSet<int> DisabledSpawnPoints = new();
 		public MapPreview MapPreview => Game.ModData.MapCache[MapUid];
 		public IEnumerable<Player> HumanPlayers { get { return Players.Where(p => p.IsHuman); } }
 		public bool IsSinglePlayer => HumanPlayers.Count() == 1;
@@ -49,13 +49,13 @@ namespace OpenRA
 			playersByRuntime = new Dictionary<OpenRA.Player, Player>();
 		}
 
-		public static GameInformation Deserialize(string data)
+		public static GameInformation Deserialize(string data, string path)
 		{
 			try
 			{
 				var info = new GameInformation();
 
-				var nodes = MiniYaml.FromString(data);
+				var nodes = MiniYaml.FromString(data, path);
 				foreach (var node in nodes)
 				{
 					var keyParts = node.Key.Split('@');
@@ -85,7 +85,7 @@ namespace OpenRA
 		{
 			var nodes = new List<MiniYamlNode>
 			{
-				new MiniYamlNode("Root", FieldSaver.Save(this))
+				new("Root", FieldSaver.Save(this))
 			};
 
 			for (var i = 0; i < Players.Count; i++)

OpenRA.Game/GameRules/ActorInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -22,7 +22,7 @@ namespace OpenRA
 	/// </summary>
 	public class ActorInfo
 	{
-		public const string AbstractActorPrefix = "^";
+		public const char AbstractActorPrefix = '^';
 		public const char TraitInstanceSeparator = '@';
 
 		/// <summary>
@@ -32,7 +32,7 @@ namespace OpenRA
 		/// You can remove inherited traits by adding a - in front of them as in -TraitName: to inherit everything, but this trait.
 		/// </summary>
 		public readonly string Name;
-		readonly TypeDictionary traits = new TypeDictionary();
+		readonly TypeDictionary traits = new();
 		List<TraitInfo> constructOrderCache = null;
 
 		public ActorInfo(ObjectCreator creator, string name, MiniYaml node)
@@ -115,45 +115,54 @@ namespace OpenRA
 			}).ToList();
 
 			var resolved = source.Where(s => s.Dependencies.Count == 0 && s.OptionalDependencies.Count == 0).ToList();
-			var unresolved = source.Except(resolved);
+			var unresolved = source.ToHashSet();
+			unresolved.ExceptWith(resolved);
 
-			var testResolve = new Func<Type, Type, bool>((a, b) => a == b || a.IsAssignableFrom(b));
+			static bool AreResolvable(Type a, Type b) => a.IsAssignableFrom(b);
 
 			// This query detects which unresolved traits can be immediately resolved as all their direct dependencies are met.
 			var more = unresolved.Where(u =>
 				u.Dependencies.All(d => // To be resolvable, all dependencies must be satisfied according to the following conditions:
-					resolved.Exists(r => testResolve(d, r.Type)) && // There must exist a resolved trait that meets the dependency.
-					!unresolved.Any(u1 => testResolve(d, u1.Type))) && // All matching traits that meet this dependency must be resolved first.
+					resolved.Exists(r => AreResolvable(d, r.Type)) && // There must exist a resolved trait that meets the dependency.
+					!unresolved.Any(u1 => AreResolvable(d, u1.Type))) && // All matching traits that meet this dependency must be resolved first.
 				u.OptionalDependencies.All(d => // To be resolvable, all optional dependencies must be satisfied according to the following condition:
-					!unresolved.Any(u1 => testResolve(d, u1.Type)))); // All matching traits that meet this optional dependencies must be resolved first.
+					!unresolved.Any(u1 => AreResolvable(d, u1.Type)))); // All matching traits that meet this optional dependencies must be resolved first.
 
 			// Continue resolving traits as long as possible.
 			// Each time we resolve some traits, this means dependencies for other traits may then be possible to satisfy in the next pass.
-			while (more.Any())
-				resolved.AddRange(more);
-
-			if (unresolved.Any())
+#pragma warning disable CA1851 // Possible multiple enumerations of 'IEnumerable' collection
+			var readyToResolve = more.ToList();
+			while (readyToResolve.Count != 0)
 			{
-				var exceptionString = "ActorInfo(\"" + Name + "\") failed to initialize because of the following:\r\n";
-				var missing = unresolved.SelectMany(u => u.Dependencies.Where(d => !source.Any(s => testResolve(d, s.Type)))).Distinct();
+				resolved.AddRange(readyToResolve);
+				unresolved.ExceptWith(readyToResolve);
+				readyToResolve.Clear();
+				readyToResolve.AddRange(more);
+			}
+#pragma warning restore CA1851
 
-				exceptionString += "Missing:\r\n";
+			if (unresolved.Count != 0)
+			{
+				var exceptionString = "ActorInfo(\"" + Name + "\") failed to initialize because of the following:\n";
+				var missing = unresolved.SelectMany(u => u.Dependencies.Where(d => !source.Any(s => AreResolvable(d, s.Type)))).Distinct();
+
+				exceptionString += "Missing:\n";
 				foreach (var m in missing)
-					exceptionString += m + " \r\n";
+					exceptionString += m + " \n";
 
-				exceptionString += "Unresolved:\r\n";
+				exceptionString += "Unresolved:\n";
 				foreach (var u in unresolved)
 				{
 					var deps = u.Dependencies.Where(d => !resolved.Exists(r => r.Type == d));
 					var optDeps = u.OptionalDependencies.Where(d => !resolved.Exists(r => r.Type == d));
 					var allDeps = string.Join(", ", deps.Select(o => o.ToString()).Concat(optDeps.Select(o => $"[{o}]")));
-					exceptionString += $"{u.Type}: {{ {allDeps} }}\r\n";
+					exceptionString += $"{u.Type}: {{ {allDeps} }}\n";
 				}
 
 				throw new YamlException(exceptionString);
 			}
 
-			constructOrderCache = resolved.Select(r => r.Trait).ToList();
+			constructOrderCache = resolved.ConvertAll(r => r.Trait);
 			return constructOrderCache;
 		}
 
@@ -178,7 +187,7 @@ namespace OpenRA
 		public bool HasTraitInfo<T>() where T : ITraitInfoInterface { return traits.Contains<T>(); }
 		public T TraitInfo<T>() where T : ITraitInfoInterface { return traits.Get<T>(); }
 		public T TraitInfoOrDefault<T>() where T : ITraitInfoInterface { return traits.GetOrDefault<T>(); }
-		public IEnumerable<T> TraitInfos<T>() where T : ITraitInfoInterface { return traits.WithInterface<T>(); }
+		public IReadOnlyCollection<T> TraitInfos<T>() where T : ITraitInfoInterface { return traits.WithInterface<T>(); }
 
 		public BitSet<TargetableType> GetAllTargetTypes()
 		{

OpenRA.Game/GameRules/MusicInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -28,14 +28,14 @@ namespace OpenRA.GameRules
 			Title = value.Value;
 
 			var nd = value.ToDictionary();
-			if (nd.ContainsKey("Hidden"))
-				bool.TryParse(nd["Hidden"].Value, out Hidden);
+			if (nd.TryGetValue("Hidden", out var yaml))
+				bool.TryParse(yaml.Value, out Hidden);
 
-			if (nd.ContainsKey("VolumeModifier"))
-				VolumeModifier = FieldLoader.GetValue<float>("VolumeModifier", nd["VolumeModifier"].Value);
+			if (nd.TryGetValue("VolumeModifier", out yaml))
+				VolumeModifier = FieldLoader.GetValue<float>("VolumeModifier", yaml.Value);
 
-			var ext = nd.ContainsKey("Extension") ? nd["Extension"].Value : "aud";
-			Filename = (nd.ContainsKey("Filename") ? nd["Filename"].Value : key) + "." + ext;
+			var ext = nd.TryGetValue("Extension", out yaml) ? yaml.Value : "aud";
+			Filename = (nd.TryGetValue("Filename", out yaml) ? yaml.Value : key) + "." + ext;
 		}
 
 		public void Load(IReadOnlyFileSystem fileSystem)

OpenRA.Game/GameRules/Ruleset.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -15,7 +15,6 @@ using System.Linq;
 using System.Threading.Tasks;
 using OpenRA.FileSystem;
 using OpenRA.GameRules;
-using OpenRA.Graphics;
 using OpenRA.Traits;
 
 namespace OpenRA
@@ -28,7 +27,6 @@ namespace OpenRA
 		public readonly IReadOnlyDictionary<string, SoundInfo> Notifications;
 		public readonly IReadOnlyDictionary<string, MusicInfo> Music;
 		public readonly ITerrainInfo TerrainInfo;
-		public readonly SequenceProvider Sequences;
 		public readonly IReadOnlyDictionary<string, MiniYamlNode> ModelSequences;
 
 		public Ruleset(
@@ -38,7 +36,6 @@ namespace OpenRA
 			IReadOnlyDictionary<string, SoundInfo> notifications,
 			IReadOnlyDictionary<string, MusicInfo> music,
 			ITerrainInfo terrainInfo,
-			SequenceProvider sequences,
 			IReadOnlyDictionary<string, MiniYamlNode> modelSequences)
 		{
 			Actors = new ActorInfoDictionary(actors);
@@ -47,7 +44,6 @@ namespace OpenRA
 			Notifications = notifications;
 			Music = music;
 			TerrainInfo = terrainInfo;
-			Sequences = sequences;
 			ModelSequences = modelSequences;
 
 			foreach (var a in Actors.Values)
@@ -124,11 +120,11 @@ namespace OpenRA
 			var fs = modData.DefaultFileSystem;
 
 			Ruleset ruleset = null;
-			Action f = () =>
+			void LoadRuleset()
 			{
 				var actors = MergeOrDefault("Manifest,Rules", fs, m.Rules, null, null,
 					k => new ActorInfo(modData.ObjectCreator, k.Key.ToLowerInvariant(), k.Value),
-					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal));
+					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix));
 
 				var weapons = MergeOrDefault("Manifest,Weapons", fs, m.Weapons, null, null,
 					k => new WeaponInfo(k.Value));
@@ -145,15 +141,15 @@ namespace OpenRA
 				var modelSequences = MergeOrDefault("Manifest,ModelSequences", fs, m.ModelSequences, null, null,
 					k => k);
 
-				// The default ruleset does not include a preferred tileset or sequence set
-				ruleset = new Ruleset(actors, weapons, voices, notifications, music, null, null, modelSequences);
-			};
+				// The default ruleset does not include a preferred tileset
+				ruleset = new Ruleset(actors, weapons, voices, notifications, music, null, modelSequences);
+			}
 
 			if (modData.IsOnMainThread)
 			{
 				modData.HandleLoadingProgress();
 
-				var loader = new Task(f);
+				var loader = new Task(LoadRuleset);
 				loader.Start();
 
 				// Animate the loadscreen while we wait
@@ -161,7 +157,7 @@ namespace OpenRA
 					modData.HandleLoadingProgress();
 			}
 			else
-				f();
+				LoadRuleset();
 
 			return ruleset;
 		}
@@ -170,24 +166,23 @@ namespace OpenRA
 		{
 			var dr = modData.DefaultRules;
 			var terrainInfo = modData.DefaultTerrainInfo[tileSet];
-			var sequences = modData.DefaultSequences[tileSet];
 
-			return new Ruleset(dr.Actors, dr.Weapons, dr.Voices, dr.Notifications, dr.Music, terrainInfo, sequences, dr.ModelSequences);
+			return new Ruleset(dr.Actors, dr.Weapons, dr.Voices, dr.Notifications, dr.Music, terrainInfo, dr.ModelSequences);
 		}
 
 		public static Ruleset Load(ModData modData, IReadOnlyFileSystem fileSystem, string tileSet,
 			MiniYaml mapRules, MiniYaml mapWeapons, MiniYaml mapVoices, MiniYaml mapNotifications,
-			MiniYaml mapMusic, MiniYaml mapSequences, MiniYaml mapModelSequences)
+			MiniYaml mapMusic, MiniYaml mapModelSequences)
 		{
 			var m = modData.Manifest;
 			var dr = modData.DefaultRules;
 
 			Ruleset ruleset = null;
-			Action f = () =>
+			void LoadRuleset()
 			{
 				var actors = MergeOrDefault("Rules", fileSystem, m.Rules, mapRules, dr.Actors,
 					k => new ActorInfo(modData.ObjectCreator, k.Key.ToLowerInvariant(), k.Value),
-					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal));
+					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix));
 
 				var weapons = MergeOrDefault("Weapons", fileSystem, m.Weapons, mapWeapons, dr.Weapons,
 					k => new WeaponInfo(k.Value));
@@ -204,23 +199,19 @@ namespace OpenRA
 				// TODO: Add support for merging custom terrain modifications
 				var terrainInfo = modData.DefaultTerrainInfo[tileSet];
 
-				// TODO: Top-level dictionary should be moved into the Ruleset instead of in its own object
-				var sequences = mapSequences == null ? modData.DefaultSequences[tileSet] :
-					new SequenceProvider(fileSystem, modData, tileSet, mapSequences);
-
 				var modelSequences = dr.ModelSequences;
 				if (mapModelSequences != null)
 					modelSequences = MergeOrDefault("ModelSequences", fileSystem, m.ModelSequences, mapModelSequences, dr.ModelSequences,
 						k => k);
 
-				ruleset = new Ruleset(actors, weapons, voices, notifications, music, terrainInfo, sequences, modelSequences);
-			};
+				ruleset = new Ruleset(actors, weapons, voices, notifications, music, terrainInfo, modelSequences);
+			}
 
 			if (modData.IsOnMainThread)
 			{
 				modData.HandleLoadingProgress();
 
-				var loader = new Task(f);
+				var loader = new Task(LoadRuleset);
 				loader.Start();
 
 				// Animate the loadscreen while we wait
@@ -228,17 +219,17 @@ namespace OpenRA
 					modData.HandleLoadingProgress();
 			}
 			else
-				f();
+				LoadRuleset();
 
 			return ruleset;
 		}
 
 		static bool AnyCustomYaml(MiniYaml yaml)
 		{
-			return yaml != null && (yaml.Value != null || yaml.Nodes.Count > 0);
+			return yaml != null && (yaml.Value != null || yaml.Nodes.Length > 0);
 		}
 
-		static bool AnyFlaggedTraits(ModData modData, List<MiniYamlNode> actors)
+		static bool AnyFlaggedTraits(ModData modData, IEnumerable<MiniYamlNode> actors)
 		{
 			foreach (var actorNode in actors)
 			{
@@ -253,7 +244,7 @@ namespace OpenRA
 					}
 					catch (Exception ex)
 					{
-						Log.Write("debug", "Error in AnyFlaggedTraits\r\n" + ex.ToString());
+						Log.Write("debug", "Error in AnyFlaggedTraits\n" + ex.ToString());
 					}
 				}
 			}
@@ -269,18 +260,18 @@ namespace OpenRA
 				return true;
 
 			// Any trait overrides that aren't explicitly whitelisted are flagged
-			if (mapRules != null)
-			{
-				if (AnyFlaggedTraits(modData, mapRules.Nodes))
-					return true;
+			if (mapRules == null)
+				return false;
 
-				if (mapRules.Value != null)
-				{
-					var mapFiles = FieldLoader.GetValue<string[]>("value", mapRules.Value);
-					foreach (var f in mapFiles)
-						if (AnyFlaggedTraits(modData, MiniYaml.FromStream(fileSystem.Open(f), f)))
-							return true;
-				}
+			if (AnyFlaggedTraits(modData, mapRules.Nodes))
+				return true;
+
+			if (mapRules.Value != null)
+			{
+				var mapFiles = FieldLoader.GetValue<string[]>("value", mapRules.Value);
+				foreach (var f in mapFiles)
+					if (AnyFlaggedTraits(modData, MiniYaml.FromStream(fileSystem.Open(f), f)))
+						return true;
 			}
 
 			return false;

OpenRA.Game/GameRules/SoundInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -17,14 +17,14 @@ namespace OpenRA.GameRules
 {
 	public class SoundInfo
 	{
-		public readonly Dictionary<string, string[]> Variants = new Dictionary<string, string[]>();
-		public readonly Dictionary<string, string[]> Prefixes = new Dictionary<string, string[]>();
-		public readonly Dictionary<string, string[]> Voices = new Dictionary<string, string[]>();
-		public readonly Dictionary<string, string[]> Notifications = new Dictionary<string, string[]>();
+		public readonly Dictionary<string, string[]> Variants = new();
+		public readonly Dictionary<string, string[]> Prefixes = new();
+		public readonly Dictionary<string, string[]> Voices = new();
+		public readonly Dictionary<string, string[]> Notifications = new();
 		public readonly string DefaultVariant = ".aud";
 		public readonly string DefaultPrefix = "";
-		public readonly HashSet<string> DisableVariants = new HashSet<string>();
-		public readonly HashSet<string> DisablePrefixes = new HashSet<string>();
+		public readonly HashSet<string> DisableVariants = new();
+		public readonly HashSet<string> DisablePrefixes = new();
 
 		public readonly Lazy<Dictionary<string, SoundPool>> VoicePools;
 		public readonly Lazy<Dictionary<string, SoundPool>> NotificationsPools;
@@ -40,16 +40,16 @@ namespace OpenRA.GameRules
 		static Dictionary<string, SoundPool> ParseSoundPool(MiniYaml y, string key)
 		{
 			var ret = new Dictionary<string, SoundPool>();
-			var classifiction = y.Nodes.First(x => x.Key == key);
+			var classifiction = y.NodeWithKey(key);
 			foreach (var t in classifiction.Value.Nodes)
 			{
 				var volumeModifier = 1f;
-				var volumeModifierNode = t.Value.Nodes.FirstOrDefault(x => x.Key == nameof(SoundPool.VolumeModifier));
+				var volumeModifierNode = t.Value.NodeWithKeyOrDefault(nameof(SoundPool.VolumeModifier));
 				if (volumeModifierNode != null)
 					volumeModifier = FieldLoader.GetValue<float>(volumeModifierNode.Key, volumeModifierNode.Value.Value);
 
 				var interruptType = SoundPool.DefaultInterruptType;
-				var interruptTypeNode = t.Value.Nodes.FirstOrDefault(x => x.Key == nameof(SoundPool.InterruptType));
+				var interruptTypeNode = t.Value.NodeWithKeyOrDefault(nameof(SoundPool.InterruptType));
 				if (interruptTypeNode != null)
 					interruptType = FieldLoader.GetValue<SoundPool.InterruptType>(interruptTypeNode.Key, interruptTypeNode.Value.Value);
 
@@ -69,7 +69,7 @@ namespace OpenRA.GameRules
 		public readonly float VolumeModifier;
 		public readonly InterruptType Type;
 		readonly string[] clips;
-		readonly List<string> liveclips = new List<string>();
+		readonly List<string> liveclips = new();
 
 		public SoundPool(float volumeModifier, InterruptType interruptType, params string[] clips)
 		{

OpenRA.Game/GameRules/WeaponInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -99,17 +99,20 @@ namespace OpenRA.GameRules
 		[Desc("Number of shots in a single ammo magazine.")]
 		public readonly int Burst = 1;
 
+		[Desc("Can this weapon target the attacker itself?")]
+		public readonly bool CanTargetSelf = false;
+
 		[Desc("What types of targets are affected.")]
-		public readonly BitSet<TargetableType> ValidTargets = new BitSet<TargetableType>("Ground", "Water");
+		public readonly BitSet<TargetableType> ValidTargets = new("Ground", "Water");
 
 		[Desc("What types of targets are unaffected.", "Overrules ValidTargets.")]
 		public readonly BitSet<TargetableType> InvalidTargets;
 
-		static readonly BitSet<TargetableType> TargetTypeAir = new BitSet<TargetableType>("Air");
+		static readonly BitSet<TargetableType> TargetTypeAir = new("Air");
 
 		[Desc("If weapon is not directly targeting an actor and targeted position is above this altitude,",
 			"the weapon will ignore terrain target types and only check TargetTypeAir for validity.")]
-		public readonly WDist AirThreshold = new WDist(128);
+		public readonly WDist AirThreshold = new(128);
 
 		[Desc("Delay in ticks between firing shots from the same ammo magazine. If one entry, it will be used for all bursts.",
 			"If multiple entries, their number needs to match Burst - 1.")]
@@ -125,10 +128,10 @@ namespace OpenRA.GameRules
 		public readonly IProjectileInfo Projectile;
 
 		[FieldLoader.LoadUsing(nameof(LoadWarheads))]
-		public readonly List<IWarhead> Warheads = new List<IWarhead>();
+		public readonly List<IWarhead> Warheads = new();
 
 		/// <summary>
-		/// This constructor is used solely for documentation generation!
+		/// This constructor is used solely for documentation generation.
 		/// </summary>
 		public WeaponInfo() { }
 
@@ -136,13 +139,14 @@ namespace OpenRA.GameRules
 		{
 			// Resolve any weapon-level yaml inheritance or removals
 			// HACK: The "Defaults" sequence syntax prevents us from doing this generally during yaml parsing
-			content.Nodes = MiniYaml.Merge(new[] { content.Nodes });
+			content = content.WithNodes(MiniYaml.Merge(new IReadOnlyCollection<MiniYamlNode>[] { content.Nodes }));
 			FieldLoader.Load(this, content);
 		}
 
 		static object LoadProjectile(MiniYaml yaml)
 		{
-			if (!yaml.ToDictionary().TryGetValue("Projectile", out var proj))
+			var proj = yaml.NodeWithKeyOrDefault("Projectile")?.Value;
+			if (proj == null)
 				return null;
 
 			var ret = Game.CreateObject<IProjectileInfo>(proj.Value + "Info");
@@ -156,7 +160,7 @@ namespace OpenRA.GameRules
 		static object LoadWarheads(MiniYaml yaml)
 		{
 			var retList = new List<IWarhead>();
-			foreach (var node in yaml.Nodes.Where(n => n.Key.StartsWith("Warhead")))
+			foreach (var node in yaml.Nodes.Where(n => n.Key.StartsWith("Warhead", StringComparison.Ordinal)))
 			{
 				var ret = Game.CreateObject<IWarhead>(node.Value.Value + "Warhead");
 				if (ret == null)
@@ -206,29 +210,24 @@ namespace OpenRA.GameRules
 		/// <summary>Checks if the weapon is valid against (can target) the actor.</summary>
 		public bool IsValidAgainst(Actor victim, Actor firedBy)
 		{
-			var targetTypes = victim.GetEnabledTargetTypes();
-
-			if (!IsValidTarget(targetTypes))
+			if (!CanTargetSelf && victim == firedBy)
 				return false;
 
-			// PERF: Avoid LINQ.
-			foreach (var warhead in Warheads)
-				if (warhead.IsValidAgainst(victim, firedBy))
-					return true;
+			var targetTypes = victim.GetEnabledTargetTypes();
 
-			return false;
+			return IsValidTarget(targetTypes);
 		}
 
 		/// <summary>Checks if the weapon is valid against (can target) the frozen actor.</summary>
 		public bool IsValidAgainst(FrozenActor victim, Actor firedBy)
 		{
-			if (!IsValidTarget(victim.TargetTypes))
+			if (!victim.IsValid)
 				return false;
 
-			if (!Warheads.Any(w => w.IsValidAgainst(victim, firedBy)))
+			if (!CanTargetSelf && victim.Actor == firedBy)
 				return false;
 
-			return true;
+			return IsValidTarget(victim.TargetTypes);
 		}
 
 		/// <summary>Applies all the weapon's warheads to the target.</summary>

OpenRA.Game/GameSpeed.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -10,12 +10,12 @@
 #endregion
 
 using System.Collections.Generic;
-using System.Linq;
 
 namespace OpenRA
 {
 	public class GameSpeed
 	{
+		[TranslationReference]
 		[FieldLoader.Require]
 		public readonly string Name;
 
@@ -37,7 +37,7 @@ namespace OpenRA
 		static object LoadSpeeds(MiniYaml y)
 		{
 			var ret = new Dictionary<string, GameSpeed>();
-			var speedsNode = y.Nodes.FirstOrDefault(n => n.Key == "Speeds");
+			var speedsNode = y.NodeWithKeyOrDefault("Speeds");
 			if (speedsNode == null)
 				throw new YamlException("Error parsing GameSpeeds: Missing Speeds node!");
 

OpenRA.Game/Graphics/Animation.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -22,7 +22,7 @@ namespace OpenRA.Graphics
 		public string Name { get; private set; }
 		public bool IsDecoration { get; set; }
 
-		readonly SequenceProvider sequenceProvider;
+		readonly SequenceSet sequences;
 		readonly Func<WAngle> facingFunc;
 		readonly Func<bool> paused;
 
@@ -30,7 +30,7 @@ namespace OpenRA.Graphics
 		bool backwards;
 		bool tickAlways;
 		int timeUntilNextFrame;
-		Action tickFunc = () => { };
+		Action tickFunc;
 
 		public Animation(World world, string name)
 			: this(world, name, () => WAngle.Zero) { }
@@ -43,7 +43,7 @@ namespace OpenRA.Graphics
 
 		public Animation(World world, string name, Func<WAngle> facingFunc, Func<bool> paused)
 		{
-			sequenceProvider = world.Map.Rules.Sequences;
+			sequences = world.Map.Sequences;
 			Name = name.ToLowerInvariant();
 			this.facingFunc = facingFunc;
 			this.paused = paused;
@@ -61,9 +61,9 @@ namespace OpenRA.Graphics
 			var imageRenderable = new SpriteRenderable(image, pos, offset, CurrentSequence.ZOffset + zOffset, palette, CurrentSequence.Scale, alpha, float3.Ones, tintModifiers, IsDecoration,
 				rotation);
 
-			if (CurrentSequence.ShadowStart >= 0)
+			var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
+			if (shadow != null)
 			{
-				var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
 				var shadowRenderable = new SpriteRenderable(shadow, pos, offset, CurrentSequence.ShadowZOffset + zOffset, palette, CurrentSequence.Scale, 1f, float3.Ones, tintModifiers,
 					true, rotation);
 				return new IRenderable[] { shadowRenderable, imageRenderable };
@@ -80,9 +80,9 @@ namespace OpenRA.Graphics
 			var alpha = CurrentSequence.GetAlpha(CurrentFrame);
 			var imageRenderable = new UISpriteRenderable(Image, WPos.Zero + offset, imagePos, CurrentSequence.ZOffset + zOffset, palette, scale, alpha, rotation);
 
-			if (CurrentSequence.ShadowStart >= 0)
+			var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
+			if (shadow != null)
 			{
-				var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
 				var shadowPos = pos - new int2((int)(scale * shadow.Size.X / 2), (int)(scale * shadow.Size.Y / 2));
 				var shadowRenderable = new UISpriteRenderable(shadow, WPos.Zero + offset, shadowPos, CurrentSequence.ShadowZOffset + zOffset, palette, scale, 1f, rotation);
 				return new IRenderable[] { shadowRenderable, imageRenderable };
@@ -164,7 +164,7 @@ namespace OpenRA.Graphics
 				if (frame >= CurrentSequence.Length)
 				{
 					frame = CurrentSequence.Length - 1;
-					tickFunc = () => { };
+					tickFunc = null;
 					after?.Invoke();
 				}
 			};
@@ -212,13 +212,13 @@ namespace OpenRA.Graphics
 		public void Tick(int t)
 		{
 			if (tickAlways)
-				tickFunc();
+				tickFunc?.Invoke();
 			else
 			{
 				timeUntilNextFrame -= t;
 				while (timeUntilNextFrame <= 0)
 				{
-					tickFunc();
+					tickFunc?.Invoke();
 					timeUntilNextFrame += CurrentSequenceTickOrDefault();
 				}
 			}
@@ -236,11 +236,11 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		public bool HasSequence(string seq) { return sequenceProvider.HasSequence(Name, seq); }
+		public bool HasSequence(string seq) { return sequences.HasSequence(Name, seq); }
 
 		public ISpriteSequence GetSequence(string sequenceName)
 		{
-			return sequenceProvider.GetSequence(Name, sequenceName);
+			return sequences.GetSequence(Name, sequenceName);
 		}
 
 		public string GetRandomExistingSequence(string[] sequences, MersenneTwister random)

OpenRA.Game/Graphics/AnimationWithOffset.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/ChromeProvider.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -49,7 +49,7 @@ namespace OpenRA.Graphics
 
 			public readonly int[] PanelRegion = null;
 			public readonly PanelSides PanelSides = PanelSides.All;
-			public readonly Dictionary<string, Rectangle> Regions = new Dictionary<string, Rectangle>();
+			public readonly Dictionary<string, Rectangle> Regions = new();
 		}
 
 		public static IReadOnlyDictionary<string, Collection> Collections => collections;
@@ -77,11 +77,12 @@ namespace OpenRA.Graphics
 			cachedPanelSprites = new Dictionary<string, Sprite[]>();
 			cachedCollectionSheets = new Dictionary<Collection, (Sheet, int)>();
 
+			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
 			var chrome = MiniYaml.Merge(modData.Manifest.Chrome
-				.Select(s => MiniYaml.FromStream(fileSystem.Open(s), s)));
+				.Select(s => MiniYaml.FromStream(fileSystem.Open(s), s, stringPool: stringPool)));
 
 			foreach (var c in chrome)
-				if (!c.Key.StartsWith("^", StringComparison.Ordinal))
+				if (!c.Key.StartsWith('^'))
 					LoadCollection(c.Key, c.Value);
 		}
 
@@ -100,9 +101,7 @@ namespace OpenRA.Graphics
 
 		static void LoadCollection(string name, MiniYaml yaml)
 		{
-			if (Game.ModData.LoadScreen != null)
-				Game.ModData.LoadScreen.Display();
-
+			Game.ModData.LoadScreen?.Display();
 			collections.Add(name, FieldLoader.Load<Collection>(yaml));
 		}
 
@@ -236,7 +235,7 @@ namespace OpenRA.Graphics
 			{
 				// PERF: We don't need to search for images if there are no definitions.
 				// PERF: It's more efficient to send an empty array rather than an array of 9 nulls.
-				if (!collection.Regions.Any())
+				if (collection.Regions.Count == 0)
 					return Array.Empty<Sprite>();
 
 				// Support manual definitions for unusual dialog layouts
@@ -265,13 +264,13 @@ namespace OpenRA.Graphics
 
 			if (!collections.TryGetValue(collectionName, out var collection))
 			{
-				Log.Write("debug", "Could not find collection '{0}'", collectionName);
+				Log.Write("debug", $"Could not find collection '{collectionName}'");
 				return new Size(0, 0);
 			}
 
 			if (collection.PanelRegion == null || collection.PanelRegion.Length != 8)
 			{
-				Log.Write("debug", "Collection '{0}' does not define a valid PanelRegion", collectionName);
+				Log.Write("debug", $"Collection '{collectionName}' does not define a valid PanelRegion");
 				return new Size(0, 0);
 			}
 

OpenRA.Game/Graphics/CursorManager.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -17,7 +17,7 @@ namespace OpenRA.Graphics
 {
 	public sealed class CursorManager
 	{
-		class Cursor
+		sealed class Cursor
 		{
 			public string Name;
 			public int2 PaddedSize;
@@ -28,7 +28,7 @@ namespace OpenRA.Graphics
 			public IHardwareCursor[] Cursors;
 		}
 
-		readonly Dictionary<string, Cursor> cursors = new Dictionary<string, Cursor>();
+		readonly Dictionary<string, Cursor> cursors = new();
 		readonly SheetBuilder sheetBuilder;
 		readonly GraphicSettings graphicSettings;
 
@@ -111,8 +111,7 @@ namespace OpenRA.Graphics
 				var template = kv.Value;
 				for (var i = 0; i < template.Sprites.Length; i++)
 				{
-					if (template.Cursors[i] != null)
-						template.Cursors[i].Dispose();
+					template.Cursors[i]?.Dispose();
 
 					// Calculate the padding to position the frame within sequenceBounds
 					var paddingTL = -(template.Bounds.Location - template.Sprites[i].Offset.XY.ToInt2());

OpenRA.Game/Graphics/CursorProvider.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -24,10 +24,11 @@ namespace OpenRA.Graphics
 		public CursorProvider(ModData modData)
 		{
 			var fileSystem = modData.DefaultFileSystem;
+			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
 			var sequenceYaml = MiniYaml.Merge(modData.Manifest.Cursors.Select(
-				s => MiniYaml.FromStream(fileSystem.Open(s), s)));
+				s => MiniYaml.FromStream(fileSystem.Open(s), s, stringPool: stringPool)));
 
-			var nodesDict = new MiniYaml(null, sequenceYaml).ToDictionary();
+			var cursorsYaml = new MiniYaml(null, sequenceYaml).NodeWithKey("Cursors").Value;
 
 			// Overwrite previous definitions if there are duplicates
 			var pals = new Dictionary<string, IProvidesCursorPaletteInfo>();
@@ -35,14 +36,14 @@ namespace OpenRA.Graphics
 				if (p.Palette != null)
 					pals[p.Palette] = p;
 
-			Palettes = nodesDict["Cursors"].Nodes.Select(n => n.Value.Value)
+			Palettes = cursorsYaml.Nodes.Select(n => n.Value.Value)
 				.Where(p => p != null)
 				.Distinct()
 				.ToDictionary(p => p, p => pals[p].ReadPalette(modData.DefaultFileSystem));
 
 			var frameCache = new FrameCache(fileSystem, modData.SpriteLoaders);
 			var cursors = new Dictionary<string, CursorSequence>();
-			foreach (var s in nodesDict["Cursors"].Nodes)
+			foreach (var s in cursorsYaml.Nodes)
 				foreach (var sequence in s.Value.Nodes)
 					cursors.Add(sequence.Key, new CursorSequence(frameCache, sequence.Key, s.Key, s.Value.Value, sequence.Value));
 

OpenRA.Game/Graphics/CursorSequence.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -27,32 +27,40 @@ namespace OpenRA.Graphics
 		{
 			var d = info.ToDictionary();
 
-			Start = Exts.ParseIntegerInvariant(d["Start"].Value);
+			Start = Exts.ParseInt32Invariant(d["Start"].Value);
 			Palette = palette;
 			Name = name;
 
-			Frames = cache[cursorSrc].Skip(Start).ToArray();
+			var cursorSprites = cache[cursorSrc];
+			Frames = cursorSprites.Skip(Start).ToArray();
 
-			if ((d.ContainsKey("Length") && d["Length"].Value == "*") || (d.ContainsKey("End") && d["End"].Value == "*"))
+			if ((d.TryGetValue("Length", out var yaml) && yaml.Value == "*") ||
+				(d.TryGetValue("End", out yaml) && yaml.Value == "*"))
 				Length = Frames.Length;
-			else if (d.ContainsKey("Length"))
-				Length = Exts.ParseIntegerInvariant(d["Length"].Value);
-			else if (d.ContainsKey("End"))
-				Length = Exts.ParseIntegerInvariant(d["End"].Value) - Start;
+			else if (d.TryGetValue("Length", out yaml))
+				Length = Exts.ParseInt32Invariant(yaml.Value);
+			else if (d.TryGetValue("End", out yaml))
+				Length = Exts.ParseInt32Invariant(yaml.Value) - Start;
 			else
 				Length = 1;
 
 			Frames = Frames.Take(Length).ToArray();
 
-			if (d.ContainsKey("X"))
+			if (Start > cursorSprites.Length)
+				throw new YamlException($"Cursor {name}: {nameof(Start)} is greater than the length of the sprite sequence.");
+
+			if (Length > cursorSprites.Length)
+				throw new YamlException($"Cursor {name}: {nameof(Length)} is greater than the length of the sprite sequence.");
+
+			if (d.TryGetValue("X", out yaml))
 			{
-				Exts.TryParseIntegerInvariant(d["X"].Value, out var x);
+				Exts.TryParseInt32Invariant(yaml.Value, out var x);
 				Hotspot = Hotspot.WithX(x);
 			}
 
-			if (d.ContainsKey("Y"))
+			if (d.TryGetValue("Y", out yaml))
 			{
-				Exts.TryParseIntegerInvariant(d["Y"].Value, out var y);
+				Exts.TryParseInt32Invariant(yaml.Value, out var y);
 				Hotspot = Hotspot.WithY(y);
 			}
 		}

OpenRA.Game/Graphics/HardwarePalette.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -21,9 +21,9 @@ namespace OpenRA.Graphics
 		public ITexture ColorShifts { get; }
 
 		public int Height { get; private set; }
-		readonly Dictionary<string, ImmutablePalette> palettes = new Dictionary<string, ImmutablePalette>();
-		readonly Dictionary<string, MutablePalette> mutablePalettes = new Dictionary<string, MutablePalette>();
-		readonly Dictionary<string, int> indices = new Dictionary<string, int>();
+		readonly Dictionary<string, ImmutablePalette> palettes = new();
+		readonly Dictionary<string, MutablePalette> mutablePalettes = new();
+		readonly Dictionary<string, int> indices = new();
 		byte[] buffer = Array.Empty<byte>();
 		float[] colorShiftBuffer = Array.Empty<float>();
 
@@ -70,7 +70,7 @@ namespace OpenRA.Graphics
 			{
 				Height = Exts.NextPowerOf2(index + 1);
 				Array.Resize(ref buffer, Height * Palette.Size * 4);
-				Array.Resize(ref colorShiftBuffer, Height * 4);
+				Array.Resize(ref colorShiftBuffer, Height * 8);
 			}
 
 			if (allowModifiers)
@@ -79,6 +79,9 @@ namespace OpenRA.Graphics
 				CopyPaletteToBuffer(index, p);
 		}
 
+		[System.Diagnostics.CodeAnalysis.SuppressMessage(
+			"Performance", "CA1854:Prefer the 'IDictionary.TryGetValue(TKey, out TValue)' method",
+			Justification = "False positive - indexer is a set not a get.")]
 		public void ReplacePalette(string name, IPalette p)
 		{
 			if (mutablePalettes.ContainsKey(name))
@@ -90,19 +93,20 @@ namespace OpenRA.Graphics
 			CopyBufferToTexture();
 		}
 
-		public void SetColorShift(string name, float hueOffset, float satOffset, float minHue, float maxHue)
+		public void SetColorShift(string name, float hueOffset, float satOffset, float valueMultiplier, float minHue, float maxHue)
 		{
 			var index = GetPaletteIndex(name);
-			colorShiftBuffer[4 * index + 0] = hueOffset;
-			colorShiftBuffer[4 * index + 1] = satOffset;
-			colorShiftBuffer[4 * index + 2] = minHue;
-			colorShiftBuffer[4 * index + 3] = maxHue;
+			colorShiftBuffer[8 * index + 0] = minHue;
+			colorShiftBuffer[8 * index + 1] = maxHue;
+			colorShiftBuffer[8 * index + 4] = hueOffset;
+			colorShiftBuffer[8 * index + 5] = satOffset;
+			colorShiftBuffer[8 * index + 6] = valueMultiplier;
 		}
 
 		public bool HasColorShift(string name)
 		{
 			var index = GetPaletteIndex(name);
-			return colorShiftBuffer[4 * index + 2] != 0 || colorShiftBuffer[4 * index + 3] != 0;
+			return colorShiftBuffer[8 * index] != 0 || colorShiftBuffer[8 * index + 1] != 0;
 		}
 
 		public void Initialize()
@@ -125,7 +129,7 @@ namespace OpenRA.Graphics
 		void CopyBufferToTexture()
 		{
 			Texture.SetData(buffer, Palette.Size, Height);
-			ColorShifts.SetFloatData(colorShiftBuffer, 1, Height);
+			ColorShifts.SetFloatData(colorShiftBuffer, 2, Height);
 		}
 
 		public void ApplyModifiers(IEnumerable<IPaletteModifier> paletteMods)

OpenRA.Game/Graphics/MarkerTileRenderable.cs

@@ -0,0 +1,56 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Linq;
+using OpenRA.Primitives;
+
+namespace OpenRA.Graphics
+{
+	public class MarkerTileRenderable : IRenderable, IFinalizedRenderable
+	{
+		readonly CPos pos;
+		readonly Color color;
+
+		public MarkerTileRenderable(CPos pos, Color color)
+		{
+			this.pos = pos;
+			this.color = color;
+		}
+
+		public WPos Pos => WPos.Zero;
+		public int ZOffset => 0;
+		public bool IsDecoration => true;
+
+		public IRenderable WithZOffset(int newOffset) { return this; }
+
+		public IRenderable OffsetBy(in WVec vec)
+		{
+			return new MarkerTileRenderable(pos, color);
+		}
+
+		public IRenderable AsDecoration() { return this; }
+
+		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }
+		public void Render(WorldRenderer wr)
+		{
+			var map = wr.World.Map;
+			var r = map.Grid.Ramps[map.Ramp[pos]];
+			var wpos = map.CenterOfCell(pos) - new WVec(0, 0, r.CenterHeightOffset);
+
+			var corners = r.Corners.Select(corner => wr.Viewport.WorldToViewPx(wr.Screen3DPosition(wpos + corner))).ToList();
+
+			Game.Renderer.RgbaColorRenderer.FillRect(corners[0], corners[1], corners[2], corners[3], color);
+		}
+
+		public void RenderDebugGeometry(WorldRenderer wr) { }
+		public Rectangle ScreenBounds(WorldRenderer wr) { return Rectangle.Empty; }
+	}
+}

OpenRA.Game/Graphics/Model.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -10,9 +10,8 @@
 #endregion
 
 using System;
-using System.Collections.Generic;
-using OpenRA.FileSystem;
 using OpenRA.Primitives;
+using OpenRA.Traits;
 
 namespace OpenRA.Graphics
 {
@@ -26,10 +25,18 @@ namespace OpenRA.Graphics
 		float[] Bounds(uint frame);
 		ModelRenderData RenderData(uint section);
 
-		/// <summary>Returns the smallest rectangle that covers all rotations of all frames in a model</summary>
+		/// <summary>Returns the smallest rectangle that covers all rotations of all frames in a model.</summary>
 		Rectangle AggregateBounds { get; }
 	}
 
+	public interface IModelWidget
+	{
+		public string Palette { get; }
+		public float Scale { get; }
+		public void Setup(Func<bool> isVisible, Func<string> getPalette, Func<string> getPlayerPalette,
+			Func<float> getScale, Func<IModel> getVoxel, Func<WRot> getRotation);
+	}
+
 	public readonly struct ModelRenderData
 	{
 		public readonly int Start;
@@ -44,52 +51,13 @@ namespace OpenRA.Graphics
 		}
 	}
 
-	public interface IModelCache : IDisposable
+	public interface IModelCacheInfo : ITraitInfoInterface { }
+
+	public interface IModelCache
 	{
 		IModel GetModel(string model);
 		IModel GetModelSequence(string model, string sequence);
 		bool HasModelSequence(string model, string sequence);
-		IVertexBuffer<Vertex> VertexBuffer { get; }
-	}
-
-	public interface IModelSequenceLoader
-	{
-		Action<string> OnMissingModelError { get; set; }
-		IModelCache CacheModels(IReadOnlyFileSystem fileSystem, ModData modData, IReadOnlyDictionary<string, MiniYamlNode> modelDefinitions);
-	}
-
-	public class PlaceholderModelSequenceLoader : IModelSequenceLoader
-	{
-		public Action<string> OnMissingModelError { get; set; }
-
-		class PlaceholderModelCache : IModelCache
-		{
-			public IVertexBuffer<Vertex> VertexBuffer => throw new NotImplementedException();
-
-			public void Dispose() { }
-
-			public IModel GetModel(string model)
-			{
-				throw new NotImplementedException();
-			}
-
-			public IModel GetModelSequence(string model, string sequence)
-			{
-				throw new NotImplementedException();
-			}
-
-			public bool HasModelSequence(string model, string sequence)
-			{
-				throw new NotImplementedException();
-			}
-		}
-
-		[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "IDE0060:Remove unused parameter", Justification = "Load game API")]
-		public PlaceholderModelSequenceLoader(ModData modData) { }
-
-		public IModelCache CacheModels(IReadOnlyFileSystem fileSystem, ModData modData, IReadOnlyDictionary<string, MiniYamlNode> modelDefinitions)
-		{
-			return new PlaceholderModelCache();
-		}
+		IVertexBuffer<ModelVertex> VertexBuffer { get; }
 	}
 }

OpenRA.Game/Graphics/ModelAnimation.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/ModelVertex.cs

@@ -0,0 +1,53 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Runtime.InteropServices;
+
+namespace OpenRA.Graphics
+{
+	[StructLayout(LayoutKind.Sequential)]
+	public readonly struct ModelVertex
+	{
+		// 3d position
+		public readonly float X, Y, Z;
+
+		// Primary and secondary texture coordinates or RGBA color
+		public readonly float S, T, U, V;
+
+		// Palette and channel flags
+		public readonly float P, C;
+
+		public ModelVertex(in float3 xyz, float s, float t, float u, float v, float p, float c)
+			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, p, c) { }
+
+		public ModelVertex(float x, float y, float z, float s, float t, float u, float v, float p, float c)
+		{
+			X = x; Y = y; Z = z;
+			S = s; T = t;
+			U = u; V = v;
+			P = p; C = c;
+		}
+	}
+
+	public sealed class ModelShaderBindings : ShaderBindings
+	{
+		public ModelShaderBindings()
+			: base("model")
+		{ }
+
+		public override ShaderVertexAttribute[] Attributes { get; } = new[]
+		{
+			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 3, 0),
+			new ShaderVertexAttribute("aVertexTexCoord", ShaderVertexAttributeType.Float, 4, 12),
+			new ShaderVertexAttribute("aVertexTexMetadata", ShaderVertexAttributeType.Float, 2, 28),
+		};
+	}
+}

OpenRA.Game/Graphics/Palette.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -30,7 +30,7 @@ namespace OpenRA.Graphics
 
 		public static Color GetColor(this IPalette palette, int index)
 		{
-			return Color.FromArgb((int)palette[index]);
+			return Color.FromArgb(palette[index]);
 		}
 
 		public static IPalette AsReadOnly(this IPalette palette)
@@ -40,7 +40,7 @@ namespace OpenRA.Graphics
 			return new ReadOnlyPalette(palette);
 		}
 
-		class ReadOnlyPalette : IPalette
+		sealed class ReadOnlyPalette : IPalette
 		{
 			readonly IPalette palette;
 			public ReadOnlyPalette(IPalette palette) { this.palette = palette; }
@@ -103,12 +103,12 @@ namespace OpenRA.Graphics
 			: this(p)
 		{
 			for (var i = 0; i < Palette.Size; i++)
-				colors[i] = (uint)r.GetRemappedColor(this.GetColor(i), i).ToArgb();
+				colors[i] = r.GetRemappedColor(this.GetColor(i), i).ToArgb();
 		}
 
 		public ImmutablePalette(IPalette p)
 		{
-			for (int i = 0; i < Palette.Size; i++)
+			for (var i = 0; i < Palette.Size; i++)
 				colors[i] = p[i];
 		}
 
@@ -142,7 +142,7 @@ namespace OpenRA.Graphics
 
 		public void SetColor(int index, Color color)
 		{
-			colors[index] = (uint)color.ToArgb();
+			colors[index] = color.ToArgb();
 		}
 
 		public void SetFromPalette(IPalette p)
@@ -153,7 +153,7 @@ namespace OpenRA.Graphics
 		public void ApplyRemap(IPaletteRemap r)
 		{
 			for (var i = 0; i < Palette.Size; i++)
-				colors[i] = (uint)r.GetRemappedColor(this.GetColor(i), i).ToArgb();
+				colors[i] = r.GetRemappedColor(this.GetColor(i), i).ToArgb();
 		}
 	}
 }

OpenRA.Game/Graphics/PaletteReference.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -13,19 +13,17 @@ namespace OpenRA.Graphics
 {
 	public sealed class PaletteReference
 	{
-		readonly float index;
 		readonly HardwarePalette hardwarePalette;
 
 		public readonly string Name;
 		public IPalette Palette { get; internal set; }
-		public float TextureIndex => index / hardwarePalette.Height;
-		public float TextureMidIndex => (index + 0.5f) / hardwarePalette.Height;
+		public int TextureIndex { get; }
 
 		public PaletteReference(string name, int index, IPalette palette, HardwarePalette hardwarePalette)
 		{
 			Name = name;
 			Palette = palette;
-			this.index = index;
+			TextureIndex = index;
 			this.hardwarePalette = hardwarePalette;
 		}
 

OpenRA.Game/Graphics/PlatformInterfaces.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -20,13 +20,12 @@ namespace OpenRA
 		Automatic,
 		ANGLE,
 		Modern,
-		Embedded,
-		Legacy
+		Embedded
 	}
 
 	public interface IPlatform
 	{
-		IPlatformWindow CreateWindow(Size size, WindowMode windowMode, float scaleModifier, int batchSize, int videoDisplay, GLProfile profile, bool enableLegacyGL);
+		IPlatformWindow CreateWindow(Size size, WindowMode windowMode, float scaleModifier, int vertexBatchSize, int indexBatchSize, int videoDisplay, GLProfile profile);
 		ISoundEngine CreateSound(string device);
 		IFont CreateFont(byte[] data);
 	}
@@ -83,16 +82,18 @@ namespace OpenRA
 
 	public interface IGraphicsContext : IDisposable
 	{
-		IVertexBuffer<Vertex> CreateVertexBuffer(int size);
-		Vertex[] CreateVertices(int size);
+		IVertexBuffer<T> CreateVertexBuffer<T>(int size) where T : struct;
+		T[] CreateVertices<T>(int size) where T : struct;
+		IIndexBuffer CreateIndexBuffer(uint[] indices);
 		ITexture CreateTexture();
 		IFrameBuffer CreateFrameBuffer(Size s);
 		IFrameBuffer CreateFrameBuffer(Size s, Color clearColor);
-		IShader CreateShader(string name);
+		IShader CreateShader(IShaderBindings shaderBindings);
 		void EnableScissor(int x, int y, int width, int height);
 		void DisableScissor();
 		void Present();
 		void DrawPrimitives(PrimitiveType pt, int firstVertex, int numVertices);
+		void DrawElements(int numIndices, int offset);
 		void Clear();
 		void EnableDepthBuffer();
 		void DisableDepthBuffer();
@@ -102,7 +103,14 @@ namespace OpenRA
 		string GLVersion { get; }
 	}
 
-	public interface IVertexBuffer<T> : IDisposable
+	public interface IRenderer
+	{
+		void BeginFrame();
+		void EndFrame();
+		void SetPalette(HardwarePalette palette);
+	}
+
+	public interface IVertexBuffer<T> : IDisposable where T : struct
 	{
 		void Bind();
 		void SetData(T[] vertices, int length);
@@ -114,6 +122,11 @@ namespace OpenRA
 		void SetData(T[] vertices, int offset, int start, int length);
 	}
 
+	public interface IIndexBuffer : IDisposable
+	{
+		void Bind();
+	}
+
 	public interface IShader
 	{
 		void SetBool(string name, bool value);
@@ -124,6 +137,17 @@ namespace OpenRA
 		void SetTexture(string param, ITexture texture);
 		void SetMatrix(string param, float[] mtx);
 		void PrepareRender();
+		void Bind();
+	}
+
+	public interface IShaderBindings
+	{
+		string VertexShaderName { get; }
+		string VertexShaderCode { get; }
+		string FragmentShaderName { get; }
+		string FragmentShaderCode { get; }
+		int Stride { get; }
+		ShaderVertexAttribute[] Attributes { get; }
 	}
 
 	public enum TextureScaleFilter { Nearest, Linear }
@@ -132,6 +156,7 @@ namespace OpenRA
 	{
 		void SetData(byte[] colors, int width, int height);
 		void SetFloatData(float[] data, int width, int height);
+		void SetDataFromReadBuffer(Rectangle rect);
 		byte[] GetData();
 		Size Size { get; }
 		TextureScaleFilter ScaleFilter { get; set; }

OpenRA.Game/Graphics/PlayerColorRemap.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -20,12 +20,14 @@ namespace OpenRA.Graphics
 		readonly int[] remapIndices;
 		readonly float hue;
 		readonly float saturation;
+		readonly float value;
 
-		public PlayerColorRemap(int[] remapIndices, float hue, float saturation)
+		public PlayerColorRemap(int[] remapIndices, Color color)
 		{
 			this.remapIndices = remapIndices;
-			this.hue = hue;
-			this.saturation = saturation;
+
+			var (r, g, b) = color.ToLinear();
+			(hue, saturation, value) = Color.RgbToHsv(r, g, b);
 		}
 
 		public Color GetRemappedColor(Color original, int index)
@@ -42,7 +44,7 @@ namespace OpenRA.Graphics
 			var value = Math.Max(Math.Max(r, g), b);
 
 			// Construct the new RGB color
-			(r, g, b) = Color.HsvToRgb(hue, saturation, value);
+			(r, g, b) = Color.HsvToRgb(hue, saturation, value * this.value);
 
 			// Convert linear back to SRGB and pre-multiply by the alpha
 			return Color.FromLinear(original.A, r, g, b);

OpenRA.Game/Graphics/RenderPostProcessPassVertex.cs

@@ -0,0 +1,64 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Runtime.InteropServices;
+
+namespace OpenRA.Graphics
+{
+	[StructLayout(LayoutKind.Sequential)]
+	public readonly struct RenderPostProcessPassVertex
+	{
+		public readonly float X, Y;
+
+		public RenderPostProcessPassVertex(float x, float y)
+		{
+			X = x; Y = y;
+		}
+	}
+
+	[StructLayout(LayoutKind.Sequential)]
+	public readonly struct RenderPostProcessPassTexturedVertex
+	{
+		// 3d position
+		public readonly float X, Y;
+		public readonly float S, T;
+
+		public RenderPostProcessPassTexturedVertex(float x, float y, float s, float t)
+		{
+			X = x; Y = y;
+			S = s; T = t;
+		}
+	}
+
+	public sealed class RenderPostProcessPassShaderBindings : ShaderBindings
+	{
+		public RenderPostProcessPassShaderBindings(string name)
+			: base("postprocess", "postprocess_" + name) { }
+
+		public override ShaderVertexAttribute[] Attributes { get; } = new[]
+		{
+			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 2, 0)
+		};
+	}
+
+	public sealed class RenderPostProcessPassTexturedShaderBindings : ShaderBindings
+	{
+		public RenderPostProcessPassTexturedShaderBindings(string name)
+			: base("postprocess_textured", "postprocess_textured_" + name)
+		{ }
+
+		public override ShaderVertexAttribute[] Attributes { get; } = new[]
+		{
+			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 2, 0),
+			new ShaderVertexAttribute("aVertexTexCoord", ShaderVertexAttributeType.Float, 2, 8),
+		};
+	}
+}

OpenRA.Game/Graphics/Renderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/RgbaColorRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -18,10 +18,10 @@ namespace OpenRA.Graphics
 {
 	public class RgbaColorRenderer
 	{
-		static readonly float3 Offset = new float3(0.5f, 0.5f, 0f);
+		static readonly float3 Offset = new(0.5f, 0.5f, 0f);
 
 		readonly SpriteRenderer parent;
-		readonly Vertex[] vertices = new Vertex[6];
+		readonly Vertex[] vertices = new Vertex[4];
 
 		public RgbaColorRenderer(SpriteRenderer parent)
 		{
@@ -45,14 +45,12 @@ namespace OpenRA.Graphics
 			var eb = endColor.B / 255.0f;
 			var ea = endColor.A / 255.0f;
 
-			vertices[0] = new Vertex(start - corner + Offset, sr, sg, sb, sa, 0, 0);
-			vertices[1] = new Vertex(start + corner + Offset, sr, sg, sb, sa, 0, 0);
-			vertices[2] = new Vertex(end + corner + Offset, er, eg, eb, ea, 0, 0);
-			vertices[3] = new Vertex(end + corner + Offset, er, eg, eb, ea, 0, 0);
-			vertices[4] = new Vertex(end - corner + Offset, er, eg, eb, ea, 0, 0);
-			vertices[5] = new Vertex(start - corner + Offset, sr, sg, sb, sa, 0, 0);
+			vertices[0] = new Vertex(start - corner + Offset, sr, sg, sb, sa, 0);
+			vertices[1] = new Vertex(start + corner + Offset, sr, sg, sb, sa, 0);
+			vertices[2] = new Vertex(end + corner + Offset, er, eg, eb, ea, 0);
+			vertices[3] = new Vertex(end - corner + Offset, er, eg, eb, ea, 0);
 
-			parent.DrawRGBAVertices(vertices, blendMode);
+			parent.DrawRGBAQuad(vertices, blendMode);
 		}
 
 		public void DrawLine(in float3 start, in float3 end, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
@@ -66,21 +64,19 @@ namespace OpenRA.Graphics
 			var b = color.B / 255.0f;
 			var a = color.A / 255.0f;
 
-			vertices[0] = new Vertex(start - corner + Offset, r, g, b, a, 0, 0);
-			vertices[1] = new Vertex(start + corner + Offset, r, g, b, a, 0, 0);
-			vertices[2] = new Vertex(end + corner + Offset, r, g, b, a, 0, 0);
-			vertices[3] = new Vertex(end + corner + Offset, r, g, b, a, 0, 0);
-			vertices[4] = new Vertex(end - corner + Offset, r, g, b, a, 0, 0);
-			vertices[5] = new Vertex(start - corner + Offset, r, g, b, a, 0, 0);
-			parent.DrawRGBAVertices(vertices, blendMode);
+			vertices[0] = new Vertex(start - corner + Offset, r, g, b, a, 0);
+			vertices[1] = new Vertex(start + corner + Offset, r, g, b, a, 0);
+			vertices[2] = new Vertex(end + corner + Offset, r, g, b, a, 0);
+			vertices[3] = new Vertex(end - corner + Offset, r, g, b, a, 0);
+			parent.DrawRGBAQuad(vertices, blendMode);
 		}
 
 		/// <summary>
 		/// Calculate the 2D intersection of two lines.
 		/// Will behave badly if the lines are parallel.
-		/// Z position is the average of a and b (ignores actual intersection point if it exists)
+		/// Z position is the average of a and b (ignores actual intersection point if it exists).
 		/// </summary>
-		float3 IntersectionOf(in float3 a, in float3 da, in float3 b, in float3 db)
+		static float3 IntersectionOf(in float3 a, in float3 da, in float3 b, in float3 db)
 		{
 			var crossA = a.X * (a.Y + da.Y) - a.Y * (a.X + da.X);
 			var crossB = b.X * (b.Y + db.Y) - b.Y * (b.X + db.X);
@@ -138,7 +134,7 @@ namespace OpenRA.Graphics
 			// Segment is part of closed loop
 			if (closed)
 			{
-				var prev = points[points.Length - 1];
+				var prev = points[^1];
 				var prevDir = (start - prev) / (start - prev).XY.Length;
 				var prevCorner = width / 2 * new float3(-prevDir.Y, prevDir.X, prevDir.Z);
 				ca = IntersectionOf(start - prevCorner, prevDir, start - corner, dir);
@@ -157,13 +153,11 @@ namespace OpenRA.Graphics
 				var cd = closed || i < limit - 1 ? IntersectionOf(end - corner, dir, end - nextCorner, nextDir) : end - corner;
 
 				// Fill segment
-				vertices[0] = new Vertex(ca + Offset, r, g, b, a, 0, 0);
-				vertices[1] = new Vertex(cb + Offset, r, g, b, a, 0, 0);
-				vertices[2] = new Vertex(cc + Offset, r, g, b, a, 0, 0);
-				vertices[3] = new Vertex(cc + Offset, r, g, b, a, 0, 0);
-				vertices[4] = new Vertex(cd + Offset, r, g, b, a, 0, 0);
-				vertices[5] = new Vertex(ca + Offset, r, g, b, a, 0, 0);
-				parent.DrawRGBAVertices(vertices, blendMode);
+				vertices[0] = new Vertex(ca + Offset, r, g, b, a, 0);
+				vertices[1] = new Vertex(cb + Offset, r, g, b, a, 0);
+				vertices[2] = new Vertex(cc + Offset, r, g, b, a, 0);
+				vertices[3] = new Vertex(cd + Offset, r, g, b, a, 0);
+				parent.DrawRGBAQuad(vertices, blendMode);
 
 				// Advance line segment
 				end = next;
@@ -200,20 +194,6 @@ namespace OpenRA.Graphics
 			DrawPolygon(new[] { tl, tr, br, bl }, width, color, blendMode);
 		}
 
-		public void FillTriangle(in float3 a, in float3 b, in float3 c, Color color, BlendMode blendMode = BlendMode.Alpha)
-		{
-			color = Util.PremultiplyAlpha(color);
-			var cr = color.R / 255.0f;
-			var cg = color.G / 255.0f;
-			var cb = color.B / 255.0f;
-			var ca = color.A / 255.0f;
-
-			vertices[0] = new Vertex(a + Offset, cr, cg, cb, ca, 0, 0);
-			vertices[1] = new Vertex(b + Offset, cr, cg, cb, ca, 0, 0);
-			vertices[2] = new Vertex(c + Offset, cr, cg, cb, ca, 0, 0);
-			parent.DrawRGBAVertices(vertices, blendMode);
-		}
-
 		public void FillRect(in float3 tl, in float3 br, Color color, BlendMode blendMode = BlendMode.Alpha)
 		{
 			var tr = new float3(br.X, tl.Y, tl.Z);
@@ -229,13 +209,11 @@ namespace OpenRA.Graphics
 			var cb = color.B / 255.0f;
 			var ca = color.A / 255.0f;
 
-			vertices[0] = new Vertex(a + Offset, cr, cg, cb, ca, 0, 0);
-			vertices[1] = new Vertex(b + Offset, cr, cg, cb, ca, 0, 0);
-			vertices[2] = new Vertex(c + Offset, cr, cg, cb, ca, 0, 0);
-			vertices[3] = new Vertex(c + Offset, cr, cg, cb, ca, 0, 0);
-			vertices[4] = new Vertex(d + Offset, cr, cg, cb, ca, 0, 0);
-			vertices[5] = new Vertex(a + Offset, cr, cg, cb, ca, 0, 0);
-			parent.DrawRGBAVertices(vertices, blendMode);
+			vertices[0] = new Vertex(a + Offset, cr, cg, cb, ca, 0);
+			vertices[1] = new Vertex(b + Offset, cr, cg, cb, ca, 0);
+			vertices[2] = new Vertex(c + Offset, cr, cg, cb, ca, 0);
+			vertices[3] = new Vertex(d + Offset, cr, cg, cb, ca, 0);
+			parent.DrawRGBAQuad(vertices, blendMode);
 		}
 
 		public void FillRect(in float3 a, in float3 b, in float3 c, in float3 d, Color topLeftColor, Color topRightColor, Color bottomRightColor, Color bottomLeftColor, BlendMode blendMode = BlendMode.Alpha)
@@ -243,11 +221,9 @@ namespace OpenRA.Graphics
 			vertices[0] = VertexWithColor(a + Offset, topLeftColor);
 			vertices[1] = VertexWithColor(b + Offset, topRightColor);
 			vertices[2] = VertexWithColor(c + Offset, bottomRightColor);
-			vertices[3] = VertexWithColor(c + Offset, bottomRightColor);
-			vertices[4] = VertexWithColor(d + Offset, bottomLeftColor);
-			vertices[5] = VertexWithColor(a + Offset, topLeftColor);
+			vertices[3] = VertexWithColor(d + Offset, bottomLeftColor);
 
-			parent.DrawRGBAVertices(vertices, blendMode);
+			parent.DrawRGBAQuad(vertices, blendMode);
 		}
 
 		static Vertex VertexWithColor(in float3 xyz, Color color)
@@ -258,7 +234,7 @@ namespace OpenRA.Graphics
 			var cb = color.B / 255.0f;
 			var ca = color.A / 255.0f;
 
-			return new Vertex(xyz, cr, cg, cb, ca, 0, 0);
+			return new Vertex(xyz, cr, cg, cb, ca, 0);
 		}
 
 		public void FillEllipse(in float3 tl, in float3 br, Color color, BlendMode blendMode = BlendMode.Alpha)

OpenRA.Game/Graphics/RgbaSpriteRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/SequenceProvider.cs

@@ -1,152 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System;
-using System.Collections.Generic;
-using OpenRA.FileSystem;
-using OpenRA.Primitives;
-
-namespace OpenRA.Graphics
-{
-	using Sequences = IReadOnlyDictionary<string, Lazy<IReadOnlyDictionary<string, ISpriteSequence>>>;
-	using UnitSequences = Lazy<IReadOnlyDictionary<string, ISpriteSequence>>;
-
-	public interface ISpriteSequence
-	{
-		string Name { get; }
-		int Start { get; }
-		int Length { get; }
-		int Stride { get; }
-		int Facings { get; }
-		int InterpolatedFacings { get; }
-		int Tick { get; }
-		int ZOffset { get; }
-		int ShadowStart { get; }
-		int ShadowZOffset { get; }
-		int[] Frames { get; }
-		Rectangle Bounds { get; }
-		bool IgnoreWorldTint { get; }
-		float Scale { get; }
-
-		Sprite GetSprite(int frame);
-		Sprite GetSprite(int frame, WAngle facing);
-		(Sprite, WAngle) GetSpriteWithRotation(int frame, WAngle facing);
-		Sprite GetShadow(int frame, WAngle facing);
-		float GetAlpha(int frame);
-	}
-
-	public interface ISpriteSequenceLoader
-	{
-		IReadOnlyDictionary<string, ISpriteSequence> ParseSequences(ModData modData, string tileSet, SpriteCache cache, MiniYamlNode node);
-	}
-
-	public class SequenceProvider : IDisposable
-	{
-		readonly ModData modData;
-		readonly string tileSet;
-		readonly Lazy<Sequences> sequences;
-		readonly Lazy<SpriteCache> spriteCache;
-		public SpriteCache SpriteCache => spriteCache.Value;
-
-		readonly Dictionary<string, UnitSequences> sequenceCache = new Dictionary<string, UnitSequences>();
-
-		public SequenceProvider(IReadOnlyFileSystem fileSystem, ModData modData, string tileSet, MiniYaml additionalSequences)
-		{
-			this.modData = modData;
-			this.tileSet = tileSet;
-			sequences = Exts.Lazy(() =>
-			{
-				using (new Support.PerfTimer("LoadSequences"))
-					return Load(fileSystem, additionalSequences);
-			});
-
-			spriteCache = Exts.Lazy(() => new SpriteCache(fileSystem, modData.SpriteLoaders));
-		}
-
-		public ISpriteSequence GetSequence(string unitName, string sequenceName)
-		{
-			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
-
-			if (!unitSeq.Value.TryGetValue(sequenceName, out var seq))
-				throw new InvalidOperationException($"Unit `{unitName}` does not have a sequence named `{sequenceName}`");
-
-			return seq;
-		}
-
-		public IEnumerable<string> Images => sequences.Value.Keys;
-
-		public bool HasSequence(string unitName)
-		{
-			return sequences.Value.ContainsKey(unitName);
-		}
-
-		public bool HasSequence(string unitName, string sequenceName)
-		{
-			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
-
-			return unitSeq.Value.ContainsKey(sequenceName);
-		}
-
-		public IEnumerable<string> Sequences(string unitName)
-		{
-			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
-
-			return unitSeq.Value.Keys;
-		}
-
-		Sequences Load(IReadOnlyFileSystem fileSystem, MiniYaml additionalSequences)
-		{
-			var nodes = MiniYaml.Load(fileSystem, modData.Manifest.Sequences, additionalSequences);
-			var items = new Dictionary<string, UnitSequences>();
-			foreach (var node in nodes)
-			{
-				// Nodes starting with ^ are inheritable but never loaded directly
-				if (node.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal))
-					continue;
-
-				var key = node.Value.ToLines(node.Key).JoinWith("|");
-
-				if (sequenceCache.TryGetValue(key, out var t))
-					items.Add(node.Key, t);
-				else
-				{
-					t = Exts.Lazy(() => modData.SpriteSequenceLoader.ParseSequences(modData, tileSet, SpriteCache, node));
-					sequenceCache.Add(key, t);
-					items.Add(node.Key, t);
-				}
-			}
-
-			return items;
-		}
-
-		public void Preload()
-		{
-			foreach (var sb in SpriteCache.SheetBuilders.Values)
-				sb.Current.CreateBuffer();
-
-			foreach (var unitSeq in sequences.Value.Values)
-				foreach (var seq in unitSeq.Value.Values) { }
-
-			foreach (var sb in SpriteCache.SheetBuilders.Values)
-				sb.Current.ReleaseBuffer();
-		}
-
-		public void Dispose()
-		{
-			if (spriteCache.IsValueCreated)
-				foreach (var sb in SpriteCache.SheetBuilders.Values)
-					sb.Dispose();
-		}
-	}
-}

OpenRA.Game/Graphics/SequenceSet.cs

@@ -0,0 +1,119 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using OpenRA.FileSystem;
+using OpenRA.Primitives;
+
+namespace OpenRA.Graphics
+{
+	public interface ISpriteSequence
+	{
+		string Name { get; }
+		int Length { get; }
+		int Facings { get; }
+		int Tick { get; }
+		int ZOffset { get; }
+		int ShadowZOffset { get; }
+		Rectangle Bounds { get; }
+		bool IgnoreWorldTint { get; }
+		float Scale { get; }
+		void ResolveSprites(SpriteCache cache);
+		Sprite GetSprite(int frame);
+		Sprite GetSprite(int frame, WAngle facing);
+		(Sprite Sprite, WAngle Rotation) GetSpriteWithRotation(int frame, WAngle facing);
+		Sprite GetShadow(int frame, WAngle facing);
+		float GetAlpha(int frame);
+	}
+
+	public interface ISpriteSequenceLoader
+	{
+		int BgraSheetSize { get; }
+		int IndexedSheetSize { get; }
+		IReadOnlyDictionary<string, ISpriteSequence> ParseSequences(ModData modData, string tileSet, SpriteCache cache, MiniYamlNode node);
+	}
+
+	public sealed class SequenceSet : IDisposable
+	{
+		readonly ModData modData;
+		readonly string tileSet;
+		readonly IReadOnlyDictionary<string, IReadOnlyDictionary<string, ISpriteSequence>> images;
+		public SpriteCache SpriteCache { get; }
+
+		public SequenceSet(IReadOnlyFileSystem fileSystem, ModData modData, string tileSet, MiniYaml additionalSequences)
+		{
+			this.modData = modData;
+			this.tileSet = tileSet;
+			SpriteCache = new SpriteCache(fileSystem, modData.SpriteLoaders, modData.SpriteSequenceLoader.BgraSheetSize, modData.SpriteSequenceLoader.IndexedSheetSize);
+			using (new Support.PerfTimer("LoadSequences"))
+				images = Load(fileSystem, additionalSequences);
+		}
+
+		public ISpriteSequence GetSequence(string image, string sequence)
+		{
+			if (!images.TryGetValue(image, out var sequences))
+				throw new InvalidOperationException($"Image `{image}` does not have any sequences defined.");
+
+			if (!sequences.TryGetValue(sequence, out var seq))
+				throw new InvalidOperationException($"Image `{image}` does not have a sequence named `{sequence}`.");
+
+			return seq;
+		}
+
+		public IEnumerable<string> Images => images.Keys;
+
+		public bool HasSequence(string image, string sequence)
+		{
+			if (!images.TryGetValue(image, out var sequences))
+				throw new InvalidOperationException($"Image `{image}` does not have any sequences defined.");
+
+			return sequences.ContainsKey(sequence);
+		}
+
+		public IEnumerable<string> Sequences(string image)
+		{
+			if (!images.TryGetValue(image, out var sequences))
+				throw new InvalidOperationException($"Image `{image}` does not have any sequences defined.");
+
+			return sequences.Keys;
+		}
+
+		IReadOnlyDictionary<string, IReadOnlyDictionary<string, ISpriteSequence>> Load(IReadOnlyFileSystem fileSystem, MiniYaml additionalSequences)
+		{
+			var nodes = MiniYaml.Load(fileSystem, modData.Manifest.Sequences, additionalSequences);
+			var images = new Dictionary<string, IReadOnlyDictionary<string, ISpriteSequence>>();
+			foreach (var node in nodes)
+			{
+				// Nodes starting with ^ are inheritable but never loaded directly
+				if (node.Key.StartsWith(ActorInfo.AbstractActorPrefix))
+					continue;
+
+				images[node.Key] = modData.SpriteSequenceLoader.ParseSequences(modData, tileSet, SpriteCache, node);
+			}
+
+			return images;
+		}
+
+		public void LoadSprites()
+		{
+			SpriteCache.LoadReservations(modData);
+			foreach (var sequences in images.Values)
+				foreach (var sequence in sequences)
+					sequence.Value.ResolveSprites(SpriteCache);
+		}
+
+		public void Dispose()
+		{
+			SpriteCache.Dispose();
+		}
+	}
+}

OpenRA.Game/Graphics/ShaderBindings.cs

@@ -0,0 +1,70 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.IO;
+using System.Linq;
+
+namespace OpenRA.Graphics
+{
+	public enum ShaderVertexAttributeType
+	{
+		// Assign the underlying OpenGL type values
+		// to simplify enum use in the shader
+		Float = 0x1406, // GL_FLOAT
+		Int = 0x1404, // GL_INT
+		UInt = 0x1405 // GL_UNSIGNED_INT
+	}
+
+	public readonly struct ShaderVertexAttribute
+	{
+		public readonly string Name;
+		public readonly ShaderVertexAttributeType Type;
+		public readonly int Components;
+		public readonly int Offset;
+
+		public ShaderVertexAttribute(string name, ShaderVertexAttributeType type, int components, int offset)
+		{
+			Name = name;
+			Type = type;
+			Components = components;
+			Offset = offset;
+		}
+	}
+
+	public abstract class ShaderBindings : IShaderBindings
+	{
+		public string VertexShaderName { get; }
+		public string VertexShaderCode { get; }
+		public string FragmentShaderName { get; }
+		public string FragmentShaderCode { get; }
+		public int Stride { get; }
+
+		public abstract ShaderVertexAttribute[] Attributes { get; }
+
+		protected ShaderBindings(string name)
+			: this(name, name) { }
+
+		protected ShaderBindings(string vertexName, string fragmentName)
+		{
+			Stride = Attributes.Sum(a => a.Components * 4);
+			VertexShaderName = vertexName;
+			VertexShaderCode = GetShaderCode(VertexShaderName + ".vert");
+			FragmentShaderName = fragmentName;
+			FragmentShaderCode = GetShaderCode(FragmentShaderName + ".frag");
+		}
+
+		public static string GetShaderCode(string filename)
+		{
+			var filepath = Path.Combine(Platform.EngineDir, "glsl", filename);
+			return File.ReadAllText(filepath);
+		}
+	}
+}

OpenRA.Game/Graphics/Sheet.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/SheetBuilder.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -34,15 +34,16 @@ namespace OpenRA.Graphics
 	public sealed class SheetBuilder : IDisposable
 	{
 		public readonly SheetType Type;
-		readonly List<Sheet> sheets = new List<Sheet>();
+		readonly List<Sheet> sheets = new();
 		readonly Func<Sheet> allocateSheet;
 		readonly int margin;
-
-		Sheet current;
-		TextureChannel channel;
 		int rowHeight = 0;
 		int2 p;
 
+		public Sheet Current { get; private set; }
+		public TextureChannel CurrentChannel { get; private set; }
+		public IEnumerable<Sheet> AllSheets => sheets;
+
 		public static Sheet AllocateSheet(SheetType type, int sheetSize)
 		{
 			return new Sheet(type, new Size(sheetSize, sheetSize));
@@ -73,33 +74,33 @@ namespace OpenRA.Graphics
 
 		public SheetBuilder(SheetType t, Func<Sheet> allocateSheet, int margin = 1)
 		{
-			channel = t == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
+			CurrentChannel = t == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
 			Type = t;
-			current = allocateSheet();
-			sheets.Add(current);
+			Current = allocateSheet();
+			sheets.Add(Current);
 			this.allocateSheet = allocateSheet;
 			this.margin = margin;
 		}
 
-		public Sprite Add(ISpriteFrame frame) { return Add(frame.Data, frame.Type, frame.Size, 0, frame.Offset); }
-		public Sprite Add(byte[] src, SpriteFrameType type, Size size) { return Add(src, type, size, 0, float3.Zero); }
-		public Sprite Add(byte[] src, SpriteFrameType type, Size size, float zRamp, in float3 spriteOffset)
+		public Sprite Add(ISpriteFrame frame, bool premultiplied = false) { return Add(frame.Data, frame.Type, frame.Size, 0, frame.Offset, premultiplied); }
+		public Sprite Add(byte[] src, SpriteFrameType type, Size size, bool premultiplied = false) { return Add(src, type, size, 0, float3.Zero, premultiplied); }
+		public Sprite Add(byte[] src, SpriteFrameType type, Size size, float zRamp, in float3 spriteOffset, bool premultiplied = false)
 		{
 			// Don't bother allocating empty sprites
 			if (size.Width == 0 || size.Height == 0)
-				return new Sprite(current, Rectangle.Empty, 0, spriteOffset, channel, BlendMode.Alpha);
+				return new Sprite(Current, Rectangle.Empty, 0, spriteOffset, CurrentChannel, BlendMode.Alpha);
 
 			var rect = Allocate(size, zRamp, spriteOffset);
-			Util.FastCopyIntoChannel(rect, src, type);
-			current.CommitBufferedData();
+			Util.FastCopyIntoChannel(rect, src, type, premultiplied);
+			Current.CommitBufferedData();
 			return rect;
 		}
 
 		public Sprite Add(Png src, float scale = 1f)
 		{
-			var rect = Allocate(new Size(src.Width, src.Height),  scale);
+			var rect = Allocate(new Size(src.Width, src.Height), scale);
 			Util.FastCopyIntoSprite(rect, src);
-			current.CommitBufferedData();
+			Current.CommitBufferedData();
 			return rect;
 		}
 
@@ -115,7 +116,7 @@ namespace OpenRA.Graphics
 		public Sprite Allocate(Size imageSize, float scale = 1f) { return Allocate(imageSize, 0, float3.Zero, scale); }
 		public Sprite Allocate(Size imageSize, float zRamp, in float3 spriteOffset, float scale = 1f)
 		{
-			if (imageSize.Width + p.X + margin > current.Size.Width)
+			if (imageSize.Width + p.X + margin > Current.Size.Width)
 			{
 				p = new int2(0, p.Y + rowHeight + margin);
 				rowHeight = imageSize.Height;
@@ -124,33 +125,29 @@ namespace OpenRA.Graphics
 			if (imageSize.Height > rowHeight)
 				rowHeight = imageSize.Height;
 
-			if (p.Y + imageSize.Height + margin > current.Size.Height)
+			if (p.Y + imageSize.Height + margin > Current.Size.Height)
 			{
-				var next = NextChannel(channel);
+				var next = NextChannel(CurrentChannel);
 				if (next == null)
 				{
-					current.ReleaseBuffer();
-					current = allocateSheet();
-					sheets.Add(current);
-					channel = Type == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
+					Current.ReleaseBuffer();
+					Current = allocateSheet();
+					sheets.Add(Current);
+					CurrentChannel = Type == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
 				}
 				else
-					channel = next.Value;
+					CurrentChannel = next.Value;
 
 				rowHeight = imageSize.Height;
 				p = int2.Zero;
 			}
 
-			var rect = new Sprite(current, new Rectangle(p.X + margin, p.Y + margin, imageSize.Width, imageSize.Height), zRamp, spriteOffset, channel, BlendMode.Alpha, scale);
+			var rect = new Sprite(Current, new Rectangle(p.X + margin, p.Y + margin, imageSize.Width, imageSize.Height), zRamp, spriteOffset, CurrentChannel, BlendMode.Alpha, scale);
 			p += new int2(imageSize.Width + margin, 0);
 
 			return rect;
 		}
 
-		public Sheet Current => current;
-		public TextureChannel CurrentChannel => channel;
-		public IEnumerable<Sheet> AllSheets => sheets;
-
 		public void Dispose()
 		{
 			foreach (var sheet in sheets)

OpenRA.Game/Graphics/Sprite.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -42,11 +42,11 @@ namespace OpenRA.Graphics
 			// in rendering a line of texels that sample outside the sprite rectangle.
 			// Insetting the texture coordinates by a small fraction of a pixel avoids this
 			// with negligible impact on the 1:1 rendering case.
-			var inset = 1 / 128f;
-			Left = (Math.Min(bounds.Left, bounds.Right) + inset) / sheet.Size.Width;
-			Top = (Math.Min(bounds.Top, bounds.Bottom) + inset) / sheet.Size.Height;
-			Right = (Math.Max(bounds.Left, bounds.Right) - inset) / sheet.Size.Width;
-			Bottom = (Math.Max(bounds.Top, bounds.Bottom) - inset) / sheet.Size.Height;
+			const float Inset = 1 / 128f;
+			Left = (Math.Min(bounds.Left, bounds.Right) + Inset) / sheet.Size.Width;
+			Top = (Math.Min(bounds.Top, bounds.Bottom) + Inset) / sheet.Size.Height;
+			Right = (Math.Max(bounds.Left, bounds.Right) - Inset) / sheet.Size.Width;
+			Bottom = (Math.Max(bounds.Top, bounds.Bottom) - Inset) / sheet.Size.Height;
 		}
 	}
 

OpenRA.Game/Graphics/SpriteCache.cs

@@ -0,0 +1,170 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using OpenRA.FileSystem;
+using OpenRA.Primitives;
+
+namespace OpenRA.Graphics
+{
+	public sealed class SpriteCache : IDisposable
+	{
+		public readonly Dictionary<SheetType, SheetBuilder> SheetBuilders;
+		readonly ISpriteLoader[] loaders;
+		readonly IReadOnlyFileSystem fileSystem;
+
+		readonly Dictionary<int, (int[] Frames, MiniYamlNode.SourceLocation Location, Func<ISpriteFrame, ISpriteFrame> AdjustFrame, bool Premultiplied)> spriteReservations = new();
+		readonly Dictionary<string, List<int>> reservationsByFilename = new();
+
+		readonly Dictionary<int, Sprite[]> resolvedSprites = new();
+
+		readonly Dictionary<int, (string Filename, MiniYamlNode.SourceLocation Location)> missingFiles = new();
+
+		int nextReservationToken = 1;
+
+		public SpriteCache(IReadOnlyFileSystem fileSystem, ISpriteLoader[] loaders, int bgraSheetSize, int indexedSheetSize, int bgraSheetMargin = 1, int indexedSheetMargin = 1)
+		{
+			SheetBuilders = new Dictionary<SheetType, SheetBuilder>
+			{
+				{ SheetType.Indexed, new SheetBuilder(SheetType.Indexed, indexedSheetSize, indexedSheetMargin) },
+				{ SheetType.BGRA, new SheetBuilder(SheetType.BGRA, bgraSheetSize, bgraSheetMargin) }
+			};
+
+			this.fileSystem = fileSystem;
+			this.loaders = loaders;
+		}
+
+		public int ReserveSprites(string filename, IEnumerable<int> frames, MiniYamlNode.SourceLocation location, Func<ISpriteFrame, ISpriteFrame> adjustFrame = null, bool premultiplied = false)
+		{
+			var token = nextReservationToken++;
+			spriteReservations[token] = (frames?.ToArray(), location, adjustFrame, premultiplied);
+			reservationsByFilename.GetOrAdd(filename, _ => new List<int>()).Add(token);
+			return token;
+		}
+
+		static ISpriteFrame[] GetFrames(IReadOnlyFileSystem fileSystem, string filename, ISpriteLoader[] loaders, out TypeDictionary metadata)
+		{
+			metadata = null;
+			if (!fileSystem.TryOpen(filename, out var stream))
+				return null;
+
+			using (stream)
+			{
+				foreach (var loader in loaders)
+					if (loader.TryParseSprite(stream, filename, out var frames, out metadata))
+						return frames;
+
+				return null;
+			}
+		}
+
+		public void LoadReservations(ModData modData)
+		{
+			foreach (var sb in SheetBuilders.Values)
+				sb.Current.CreateBuffer();
+
+			var pendingResolve = new List<(
+				string Filename,
+				int FrameIndex,
+				bool Premultiplied,
+				Func<ISpriteFrame, ISpriteFrame> AdjustFrame,
+				ISpriteFrame Frame,
+				Sprite[] SpritesForToken)>();
+			foreach (var (filename, tokens) in reservationsByFilename)
+			{
+				modData.LoadScreen?.Display();
+				var loadedFrames = GetFrames(fileSystem, filename, loaders, out _);
+				foreach (var token in tokens)
+				{
+					if (spriteReservations.TryGetValue(token, out var rs))
+					{
+						if (loadedFrames != null)
+						{
+							var resolved = new Sprite[loadedFrames.Length];
+							resolvedSprites[token] = resolved;
+							var frames = rs.Frames ?? Enumerable.Range(0, loadedFrames.Length);
+
+							foreach (var i in frames)
+							{
+								var frame = loadedFrames[i];
+								if (rs.AdjustFrame != null)
+									frame = rs.AdjustFrame(frame);
+								pendingResolve.Add((filename, i, rs.Premultiplied, rs.AdjustFrame, frame, resolved));
+							}
+						}
+						else
+						{
+							resolvedSprites[token] = null;
+							missingFiles[token] = (filename, rs.Location);
+						}
+					}
+				}
+			}
+
+			spriteReservations.Clear();
+			spriteReservations.TrimExcess();
+			reservationsByFilename.Clear();
+			reservationsByFilename.TrimExcess();
+
+			// When the sheet builder is adding sprites, it reserves height for the tallest sprite seen along the row.
+			// We can achieve better sheet packing by keeping sprites with similar heights together.
+			var orderedPendingResolve = pendingResolve.OrderBy(x => x.Frame.Size.Height);
+
+			var spriteCache = new Dictionary<(
+				string Filename,
+				int FrameIndex,
+				bool Premultiplied,
+				Func<ISpriteFrame, ISpriteFrame> AdjustFrame),
+				Sprite>(pendingResolve.Count);
+			foreach (var (filename, frameIndex, premultiplied, adjustFrame, frame, spritesForToken) in orderedPendingResolve)
+			{
+				// Premultiplied and non-premultiplied sprites must be cached separately
+				// to cover the case where the same image is requested in both versions.
+				spritesForToken[frameIndex] = spriteCache.GetOrAdd(
+					(filename, frameIndex, premultiplied, adjustFrame),
+					_ =>
+					{
+						var sheetBuilder = SheetBuilders[SheetBuilder.FrameTypeToSheetType(frame.Type)];
+						return sheetBuilder.Add(frame, premultiplied);
+					});
+
+				modData.LoadScreen?.Display();
+			}
+
+			foreach (var sb in SheetBuilders.Values)
+				sb.Current.ReleaseBuffer();
+		}
+
+		public Sprite[] ResolveSprites(int token)
+		{
+			if (!resolvedSprites.Remove(token, out var resolved))
+				throw new InvalidOperationException($"{nameof(token)} {token} has either already been resolved, or was never reserved via {nameof(ReserveSprites)}");
+
+			resolvedSprites.TrimExcess();
+
+			if (missingFiles.TryGetValue(token, out var r))
+				throw new FileNotFoundException($"{r.Location}: {r.Filename} not found", r.Filename);
+
+			return resolved;
+		}
+
+		public IEnumerable<(string Filename, MiniYamlNode.SourceLocation Location)> MissingFiles => missingFiles.Values.ToHashSet();
+
+		public void Dispose()
+		{
+			foreach (var sb in SheetBuilders.Values)
+				sb.Dispose();
+		}
+	}
+}

OpenRA.Game/Graphics/SpriteFont.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -123,7 +123,7 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		float2 Rotate(float2 v, float sina, float cosa, float2 offset)
+		static float2 Rotate(float2 v, float sina, float cosa, float2 offset)
 		{
 			return new float2(
 				v.X * cosa - v.Y * sina + offset.X,
@@ -427,7 +427,7 @@ namespace OpenRA.Graphics
 		}
 	}
 
-	class GlyphInfo
+	sealed class GlyphInfo
 	{
 		public float Advance;
 		public int2 Offset;

OpenRA.Game/Graphics/SpriteLoader.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -9,10 +9,7 @@
  */
 #endregion
 
-using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using OpenRA.FileSystem;
 using OpenRA.Primitives;
 
@@ -21,24 +18,34 @@ namespace OpenRA.Graphics
 	/// <summary>
 	/// Describes the format of the pixel data in a ISpriteFrame.
 	/// Note that the channel order is defined for little-endian bytes, so BGRA corresponds
-	/// to a 32bit ARGB value, such as that returned by Color.ToArgb()!
+	/// to a 32bit ARGB value, such as that returned by Color.ToArgb().
 	/// </summary>
 	public enum SpriteFrameType
 	{
-		// 8 bit index into an external palette
+		/// <summary>
+		/// 8 bit index into an external palette.
+		/// </summary>
 		Indexed8,
 
-		// 32 bit color such as returned by Color.ToArgb() or the bmp file format
-		// (remember that little-endian systems place the little bits in the first byte!)
+		/// <summary>
+		/// 32 bit color such as returned by Color.ToArgb() or the bmp file format
+		/// (remember that little-endian systems place the little bits in the first byte).
+		/// </summary>
 		Bgra32,
 
-		// Like BGRA, but without an alpha channel
+		/// <summary>
+		/// Like BGRA, but without an alpha channel.
+		/// </summary>
 		Bgr24,
 
-		// 32 bit color in big-endian format, like png
+		/// <summary>
+		/// 32 bit color in big-endian format, like png.
+		/// </summary>
 		Rgba32,
 
-		// Like RGBA, but without an alpha channel
+		/// <summary>
+		/// Like RGBA, but without an alpha channel.
+		/// </summary>
 		Rgb24
 	}
 
@@ -67,94 +74,6 @@ namespace OpenRA.Graphics
 		bool DisableExportPadding { get; }
 	}
 
-	public class SpriteCache
-	{
-		public readonly Cache<SheetType, SheetBuilder> SheetBuilders;
-		readonly ISpriteLoader[] loaders;
-		readonly IReadOnlyFileSystem fileSystem;
-
-		readonly Dictionary<string, List<Sprite[]>> sprites = new Dictionary<string, List<Sprite[]>>();
-		readonly Dictionary<string, ISpriteFrame[]> unloadedFrames = new Dictionary<string, ISpriteFrame[]>();
-		readonly Dictionary<string, TypeDictionary> metadata = new Dictionary<string, TypeDictionary>();
-
-		public SpriteCache(IReadOnlyFileSystem fileSystem, ISpriteLoader[] loaders)
-		{
-			SheetBuilders = new Cache<SheetType, SheetBuilder>(t => new SheetBuilder(t));
-
-			this.fileSystem = fileSystem;
-			this.loaders = loaders;
-		}
-
-		/// <summary>
-		/// Returns the first set of sprites with the given filename.
-		/// If getUsedFrames is defined then the indices returned by the function call
-		/// are guaranteed to be loaded.  The value of other indices in the returned
-		/// array are undefined and should never be accessed.
-		/// </summary>
-		public Sprite[] this[string filename, Func<int, IEnumerable<int>> getUsedFrames = null]
-		{
-			get
-			{
-				var allSprites = sprites.GetOrAdd(filename);
-				var sprite = allSprites.FirstOrDefault();
-
-				if (!unloadedFrames.TryGetValue(filename, out var unloaded))
-					unloaded = null;
-
-				// This is the first time that the file has been requested
-				// Load all of the frames into the unused buffer and initialize
-				// the loaded cache (initially empty)
-				if (sprite == null)
-				{
-					unloaded = FrameLoader.GetFrames(fileSystem, filename, loaders, out var fileMetadata);
-					unloadedFrames[filename] = unloaded;
-					metadata[filename] = fileMetadata;
-
-					sprite = new Sprite[unloaded.Length];
-					allSprites.Add(sprite);
-				}
-
-				// HACK: The sequence code relies on side-effects from getUsedFrames
-				var indices = getUsedFrames != null ? getUsedFrames(sprite.Length) :
-					Enumerable.Range(0, sprite.Length);
-
-				// Load any unused frames into the SheetBuilder
-				if (unloaded != null)
-				{
-					foreach (var i in indices)
-					{
-						if (unloaded[i] != null)
-						{
-							sprite[i] = SheetBuilders[SheetBuilder.FrameTypeToSheetType(unloaded[i].Type)].Add(unloaded[i]);
-							unloaded[i] = null;
-						}
-					}
-
-					// All frames have been loaded
-					if (unloaded.All(f => f == null))
-						unloadedFrames.Remove(filename);
-				}
-
-				return sprite;
-			}
-		}
-
-		/// <summary>
-		/// Returns a TypeDictionary containing any metadata defined by the frame
-		/// or null if the frame does not define metadata.
-		/// </summary>
-		public TypeDictionary FrameMetadata(string filename)
-		{
-			if (!metadata.TryGetValue(filename, out var fileMetadata))
-			{
-				FrameLoader.GetFrames(fileSystem, filename, loaders, out fileMetadata);
-				metadata[filename] = fileMetadata;
-			}
-
-			return fileMetadata;
-		}
-	}
-
 	public class FrameCache
 	{
 		readonly Cache<string, ISpriteFrame[]> frames;

OpenRA.Game/Graphics/SpriteRenderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -21,102 +21,95 @@ namespace OpenRA.Graphics
 
 		readonly Sprite sprite;
 		readonly WPos pos;
-		readonly WVec offset;
-		readonly int zOffset;
-		readonly PaletteReference palette;
 		readonly float scale;
 		readonly WAngle rotation = WAngle.Zero;
-		readonly float3 tint;
-		readonly TintModifiers tintModifiers;
-		readonly float alpha;
-		readonly bool isDecoration;
 
 		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, float alpha,
 			float3 tint, TintModifiers tintModifiers, bool isDecoration, WAngle rotation)
 		{
 			this.sprite = sprite;
 			this.pos = pos;
-			this.offset = offset;
-			this.zOffset = zOffset;
-			this.palette = palette;
+			Offset = offset;
+			ZOffset = zOffset;
+			Palette = palette;
 			this.scale = scale;
 			this.rotation = rotation;
-			this.tint = tint;
-			this.isDecoration = isDecoration;
-			this.tintModifiers = tintModifiers;
-			this.alpha = alpha;
+			Tint = tint;
+			IsDecoration = isDecoration;
+			TintModifiers = tintModifiers;
+			Alpha = alpha;
 
 			// PERF: Remove useless palette assignments for RGBA sprites
 			// HACK: This is working around the fact that palettes are defined on traits rather than sequences
 			// and can be removed once this has been fixed
 			if (sprite.Channel == TextureChannel.RGBA && !(palette?.HasColorShift ?? false))
-				this.palette = null;
+				Palette = null;
 		}
 
 		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, float alpha,
 			float3 tint, TintModifiers tintModifiers, bool isDecoration)
 			: this(sprite, pos, offset, zOffset, palette, scale, alpha, tint, tintModifiers, isDecoration, WAngle.Zero) { }
 
-		public WPos Pos => pos + offset;
-		public WVec Offset => offset;
-		public PaletteReference Palette => palette;
-		public int ZOffset => zOffset;
-		public bool IsDecoration => isDecoration;
+		public WPos Pos => pos + Offset;
+		public WVec Offset { get; }
+		public PaletteReference Palette { get; }
+		public int ZOffset { get; }
+		public bool IsDecoration { get; }
 
-		public float Alpha => alpha;
-		public float3 Tint => tint;
-		public TintModifiers TintModifiers => tintModifiers;
+		public float Alpha { get; }
+		public float3 Tint { get; }
+		public TintModifiers TintModifiers { get; }
 
 		public IPalettedRenderable WithPalette(PaletteReference newPalette)
 		{
-			return new SpriteRenderable(sprite, pos, offset, zOffset, newPalette, scale, alpha, tint, tintModifiers, isDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, Offset, ZOffset, newPalette, scale, Alpha, Tint, TintModifiers, IsDecoration, rotation);
 		}
 
 		public IRenderable WithZOffset(int newOffset)
 		{
-			return new SpriteRenderable(sprite, pos, offset, newOffset, palette, scale, alpha, tint, tintModifiers, isDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, Offset, newOffset, Palette, scale, Alpha, Tint, TintModifiers, IsDecoration, rotation);
 		}
 
 		public IRenderable OffsetBy(in WVec vec)
 		{
-			return new SpriteRenderable(sprite, pos + vec, offset, zOffset, palette, scale, alpha, tint, tintModifiers, isDecoration, rotation);
+			return new SpriteRenderable(sprite, pos + vec, Offset, ZOffset, Palette, scale, Alpha, Tint, TintModifiers, IsDecoration, rotation);
 		}
 
 		public IRenderable AsDecoration()
 		{
-			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, alpha, tint, tintModifiers, true, rotation);
+			return new SpriteRenderable(sprite, pos, Offset, ZOffset, Palette, scale, Alpha, Tint, TintModifiers, true, rotation);
 		}
 
 		public IModifyableRenderable WithAlpha(float newAlpha)
 		{
-			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, newAlpha, tint, tintModifiers, isDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, Offset, ZOffset, Palette, scale, newAlpha, Tint, TintModifiers, IsDecoration, rotation);
 		}
 
 		public IModifyableRenderable WithTint(in float3 newTint, TintModifiers newTintModifiers)
 		{
-			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, alpha, newTint, newTintModifiers, isDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, Offset, ZOffset, Palette, scale, Alpha, newTint, newTintModifiers, IsDecoration, rotation);
 		}
 
 		float3 ScreenPosition(WorldRenderer wr)
 		{
 			var s = 0.5f * scale * sprite.Size;
-			return wr.Screen3DPxPosition(pos) + wr.ScreenPxOffset(offset) - new float3((int)s.X, (int)s.Y, s.Z);
+			return wr.Screen3DPxPosition(pos) + wr.ScreenPxOffset(Offset) - new float3((int)s.X, (int)s.Y, s.Z);
 		}
 
 		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }
 		public void Render(WorldRenderer wr)
 		{
 			var wsr = Game.Renderer.WorldSpriteRenderer;
-			var t = alpha * tint;
-			if (wr.TerrainLighting != null && (tintModifiers & TintModifiers.IgnoreWorldTint) == 0)
+			var t = Alpha * Tint;
+			if (wr.TerrainLighting != null && (TintModifiers & TintModifiers.IgnoreWorldTint) == 0)
 				t *= wr.TerrainLighting.TintAt(pos);
 
 			// Shader interprets negative alpha as a flag to use the tint colour directly instead of multiplying the sprite colour
-			var a = alpha;
-			if ((tintModifiers & TintModifiers.ReplaceColor) != 0)
+			var a = Alpha;
+			if ((TintModifiers & TintModifiers.ReplaceColor) != 0)
 				a *= -1;
 
-			wsr.DrawSprite(sprite, palette, ScreenPosition(wr), scale, t, a, rotation.RendererRadians());
+			wsr.DrawSprite(sprite, Palette, ScreenPosition(wr), scale, t, a, rotation.RendererRadians());
 		}
 
 		public void RenderDebugGeometry(WorldRenderer wr)

OpenRA.Game/Graphics/SpriteRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -11,6 +11,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Runtime.InteropServices;
 using OpenRA.Primitives;
 
 namespace OpenRA.Graphics
@@ -19,6 +20,7 @@ namespace OpenRA.Graphics
 	{
 		public const int SheetCount = 8;
 		static readonly string[] SheetIndexToTextureName = Exts.MakeArray(SheetCount, i => $"Texture{i}");
+		static readonly int UintSize = Marshal.SizeOf(typeof(uint));
 
 		readonly Renderer renderer;
 		readonly IShader shader;
@@ -27,21 +29,21 @@ namespace OpenRA.Graphics
 		readonly Sheet[] sheets = new Sheet[SheetCount];
 
 		BlendMode currentBlend = BlendMode.Alpha;
-		int nv = 0;
-		int ns = 0;
+		int vertexCount = 0;
+		int sheetCount = 0;
 
 		public SpriteRenderer(Renderer renderer, IShader shader)
 		{
 			this.renderer = renderer;
 			this.shader = shader;
-			vertices = renderer.Context.CreateVertices(renderer.TempBufferSize);
+			vertices = renderer.Context.CreateVertices<Vertex>(renderer.TempVertexBufferSize);
 		}
 
 		public void Flush()
 		{
-			if (nv > 0)
+			if (vertexCount > 0)
 			{
-				for (var i = 0; i < ns; i++)
+				for (var i = 0; i < sheetCount; i++)
 				{
 					shader.SetTexture(SheetIndexToTextureName[i], sheets[i].GetTexture());
 					sheets[i] = null;
@@ -50,12 +52,11 @@ namespace OpenRA.Graphics
 				renderer.Context.SetBlendMode(currentBlend);
 				shader.PrepareRender();
 
-				// PERF: The renderer may choose to replace vertices with a different temporary buffer.
-				renderer.DrawBatch(ref vertices, nv, PrimitiveType.TriangleList);
+				renderer.DrawQuadBatch(ref vertices, shader, vertexCount);
 				renderer.Context.SetBlendMode(BlendMode.None);
 
-				nv = 0;
-				ns = 0;
+				vertexCount = 0;
+				sheetCount = 0;
 			}
 		}
 
@@ -63,7 +64,7 @@ namespace OpenRA.Graphics
 		{
 			renderer.CurrentBatchRenderer = this;
 
-			if (s.BlendMode != currentBlend || nv + 6 > renderer.TempBufferSize)
+			if (s.BlendMode != currentBlend || vertexCount + 4 > renderer.TempVertexBufferSize)
 				Flush();
 
 			currentBlend = s.BlendMode;
@@ -71,7 +72,7 @@ namespace OpenRA.Graphics
 			// Check if the sheet (or secondary data sheet) have already been mapped
 			var sheet = s.Sheet;
 			var sheetIndex = 0;
-			for (; sheetIndex < ns; sheetIndex++)
+			for (; sheetIndex < sheetCount; sheetIndex++)
 				if (sheets[sheetIndex] == sheet)
 					break;
 
@@ -80,7 +81,7 @@ namespace OpenRA.Graphics
 			if (ss != null)
 			{
 				var secondarySheet = ss.SecondarySheet;
-				for (; secondarySheetIndex < ns; secondarySheetIndex++)
+				for (; secondarySheetIndex < sheetCount; secondarySheetIndex++)
 					if (sheets[secondarySheetIndex] == secondarySheet)
 						break;
 
@@ -99,22 +100,22 @@ namespace OpenRA.Graphics
 				secondarySheetIndex = ss != null && ss.SecondarySheet != sheet ? 1 : 0;
 			}
 
-			if (sheetIndex >= ns)
+			if (sheetIndex >= sheetCount)
 			{
 				sheets[sheetIndex] = sheet;
-				ns++;
+				sheetCount++;
 			}
 
-			if (secondarySheetIndex >= ns && ss != null)
+			if (secondarySheetIndex >= sheetCount && ss != null)
 			{
 				sheets[secondarySheetIndex] = ss.SecondarySheet;
-				ns++;
+				sheetCount++;
 			}
 
 			return new int2(sheetIndex, secondarySheetIndex);
 		}
 
-		float ResolveTextureIndex(Sprite s, PaletteReference pal)
+		static int ResolveTextureIndex(Sprite s, PaletteReference pal)
 		{
 			if (pal == null)
 				return 0;
@@ -128,20 +129,20 @@ namespace OpenRA.Graphics
 			return pal.TextureIndex;
 		}
 
-		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, in float3 scale, float rotation = 0f)
+		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 location, in float3 scale, float rotation = 0f)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, float3.Ones,
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, vertexCount, scale * s.Size, float3.Ones,
 								1f, rotation);
-			nv += 6;
+			vertexCount += 4;
 		}
 
-		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, float scale, float rotation = 0f)
+		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 location, float scale, float rotation = 0f)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, float3.Ones,
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, vertexCount, scale * s.Size, float3.Ones,
 								1f, rotation);
-			nv += 6;
+			vertexCount += 4;
 		}
 
 		public void DrawSprite(Sprite s, PaletteReference pal, in float3 location, float scale = 1f, float rotation = 0f)
@@ -149,13 +150,13 @@ namespace OpenRA.Graphics
 			DrawSprite(s, ResolveTextureIndex(s, pal), location, scale, rotation);
 		}
 
-		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, float scale, in float3 tint, float alpha,
+		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 location, float scale, in float3 tint, float alpha,
 			float rotation = 0f)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, tint, alpha,
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, vertexCount, scale * s.Size, tint, alpha,
 								rotation);
-			nv += 6;
+			vertexCount += 4;
 		}
 
 		public void DrawSprite(Sprite s, PaletteReference pal, in float3 location, float scale, in float3 tint, float alpha,
@@ -164,14 +165,14 @@ namespace OpenRA.Graphics
 			DrawSprite(s, ResolveTextureIndex(s, pal), location, scale, tint, alpha, rotation);
 		}
 
-		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 a, in float3 b, in float3 c, in float3 d, in float3 tint, float alpha)
+		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 a, in float3 b, in float3 c, in float3 d, in float3 tint, float alpha)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, a, b, c, d, s, samplers, paletteTextureIndex, tint, alpha, nv);
-			nv += 6;
+			Util.FastCreateQuad(vertices, a, b, c, d, s, samplers, paletteTextureIndex, tint, alpha, vertexCount);
+			vertexCount += 4;
 		}
 
-		public void DrawVertexBuffer(IVertexBuffer<Vertex> buffer, int start, int length, PrimitiveType type, IEnumerable<Sheet> sheets, BlendMode blendMode)
+		public void DrawVertexBuffer(IVertexBuffer<Vertex> buffer, IIndexBuffer indices, int start, int length, IEnumerable<Sheet> sheets, BlendMode blendMode)
 		{
 			var i = 0;
 			foreach (var s in sheets)
@@ -185,7 +186,7 @@ namespace OpenRA.Graphics
 
 			renderer.Context.SetBlendMode(blendMode);
 			shader.PrepareRender();
-			renderer.DrawBatch(buffer, start, length, type);
+			renderer.DrawQuadBatch(buffer, indices, shader, length, UintSize * start);
 			renderer.Context.SetBlendMode(BlendMode.None);
 		}
 
@@ -196,29 +197,32 @@ namespace OpenRA.Graphics
 		}
 
 		// For RGBAColorRenderer
-		internal void DrawRGBAVertices(Vertex[] v, BlendMode blendMode)
+		internal void DrawRGBAQuad(Vertex[] v, BlendMode blendMode)
 		{
 			renderer.CurrentBatchRenderer = this;
 
-			if (currentBlend != blendMode || nv + v.Length > renderer.TempBufferSize)
+			if (currentBlend != blendMode || vertexCount + 4 > renderer.TempVertexBufferSize)
 				Flush();
 
 			currentBlend = blendMode;
-			Array.Copy(v, 0, vertices, nv, v.Length);
-			nv += v.Length;
+
+			Array.Copy(v, 0, vertices, vertexCount, v.Length);
+			vertexCount += 4;
 		}
 
-		public void SetPalette(ITexture palette, ITexture colorShifts)
+		public void SetPalette(HardwarePalette palette)
 		{
-			shader.SetTexture("Palette", palette);
-			shader.SetTexture("ColorShifts", colorShifts);
+			shader.SetTexture("Palette", palette.Texture);
+			shader.SetTexture("ColorShifts", palette.ColorShifts);
+			shader.SetVec("PaletteRows", palette.Height);
 		}
 
 		public void SetViewportParams(Size sheetSize, int downscale, float depthMargin, int2 scroll)
 		{
-			// Calculate the scale (r1) and offset (r2) that convert from OpenRA viewport pixels
-			// to OpenGL normalized device coordinates (NDC). OpenGL expects coordinates to vary from [-1, 1],
-			// so we rescale viewport pixels to the range [0, 2] using r1 then subtract 1 using r2.
+			// OpenGL only renders x and y coordinates inside [-1, 1] range. We project world coordinates
+			// using p1 to values [0, 2] and then subtract by 1 using p2, where p stands for projection. It's
+			// standard practice for shaders to use a projection matrix, but as we project orthographically
+			// we are able to send less data to the GPU.
 			var width = 2f / (downscale * sheetSize.Width);
 			var height = 2f / (downscale * sheetSize.Height);
 
@@ -239,8 +243,8 @@ namespace OpenRA.Graphics
 			var depth = depthMargin != 0f ? 2f / (downscale * (sheetSize.Height + depthMargin)) : 0;
 			shader.SetVec("DepthTextureScale", 128 * depth);
 			shader.SetVec("Scroll", scroll.X, scroll.Y, depthMargin != 0f ? scroll.Y : 0);
-			shader.SetVec("r1", width, height, -depth);
-			shader.SetVec("r2", -1, -1, depthMargin != 0f ? 1 : 0);
+			shader.SetVec("p1", width, height, -depth);
+			shader.SetVec("p2", -1, -1, depthMargin != 0f ? 1 : 0);
 		}
 
 		public void SetDepthPreview(bool enabled, float contrast, float offset)

OpenRA.Game/Graphics/TargetLineRenderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/TerrainSpriteLayer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -12,12 +12,15 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.CompilerServices;
 
 namespace OpenRA.Graphics
 {
 	public sealed class TerrainSpriteLayer : IDisposable
 	{
-		static readonly int[] CornerVertexMap = { 0, 1, 2, 2, 3, 0 };
+		// PERF: we can reuse the IndexBuffer as all layers have the same size.
+		static readonly ConditionalWeakTable<World, IndexBufferRc> IndexBuffers = new();
+		readonly IndexBufferRc indexBufferWrapper;
 
 		public readonly BlendMode BlendMode;
 
@@ -27,8 +30,9 @@ namespace OpenRA.Graphics
 		readonly IVertexBuffer<Vertex> vertexBuffer;
 		readonly Vertex[] vertices;
 		readonly bool[] ignoreTint;
-		readonly HashSet<int> dirtyRows = new HashSet<int>();
-		readonly int rowStride;
+		readonly HashSet<int> dirtyRows = new();
+		readonly int indexRowStride;
+		readonly int vertexRowStride;
 		readonly bool restrictToBounds;
 
 		readonly WorldRenderer worldRenderer;
@@ -43,19 +47,25 @@ namespace OpenRA.Graphics
 			this.emptySprite = emptySprite;
 			sheets = new Sheet[SpriteRenderer.SheetCount];
 			BlendMode = blendMode;
-
 			map = world.Map;
-			rowStride = 6 * map.MapSize.X;
 
-			vertices = new Vertex[rowStride * map.MapSize.Y];
+			vertexRowStride = 4 * map.MapSize.X;
+			vertices = new Vertex[vertexRowStride * map.MapSize.Y];
+			vertexBuffer = Game.Renderer.Context.CreateVertexBuffer<Vertex>(vertices.Length);
+
+			indexRowStride = 6 * map.MapSize.X;
+			lock (IndexBuffers)
+			{
+				indexBufferWrapper = IndexBuffers.GetValue(world, world => new IndexBufferRc(world));
+				indexBufferWrapper.AddRef();
+			}
+
 			palettes = new PaletteReference[map.MapSize.X * map.MapSize.Y];
-			vertexBuffer = Game.Renderer.Context.CreateVertexBuffer(vertices.Length);
-
 			wr.PaletteInvalidated += UpdatePaletteIndices;
 
 			if (wr.TerrainLighting != null)
 			{
-				ignoreTint = new bool[rowStride * map.MapSize.Y];
+				ignoreTint = new bool[vertexRowStride * map.MapSize.Y];
 				wr.TerrainLighting.CellChanged += UpdateTint;
 			}
 		}
@@ -65,8 +75,9 @@ namespace OpenRA.Graphics
 			for (var i = 0; i < vertices.Length; i++)
 			{
 				var v = vertices[i];
-				var p = palettes[i / 6]?.TextureIndex ?? 0;
-				vertices[i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, p, v.C, v.R, v.G, v.B, v.A);
+				var p = palettes[i / 4]?.TextureIndex ?? 0;
+				var c = (uint)((p & 0xFFFF) << 16) | (v.C & 0xFFFF);
+				vertices[i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, c, v.R, v.G, v.B, v.A);
 			}
 
 			for (var row = 0; row < map.MapSize.Y; row++)
@@ -97,13 +108,13 @@ namespace OpenRA.Graphics
 
 		void UpdateTint(MPos uv)
 		{
-			var offset = rowStride * uv.V + 6 * uv.U;
+			var offset = vertexRowStride * uv.V + 4 * uv.U;
 			if (ignoreTint[offset])
 			{
-				for (var i = 0; i < 6; i++)
+				for (var i = 0; i < 4; i++)
 				{
 					var v = vertices[offset + i];
-					vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.P, v.C, v.A * float3.Ones, v.A);
+					vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.C, v.A * float3.Ones, v.A);
 				}
 
 				return;
@@ -114,7 +125,7 @@ namespace OpenRA.Graphics
 			// transparent for isometric tiles
 			var tl = worldRenderer.TerrainLighting;
 			var pos = map.CenterOfCell(uv.ToCPos(map));
-			var step = map.Grid.Type == MapGridType.RectangularIsometric ? 724 : 512;
+			var step = map.Grid.TileScale / 2;
 			var weights = new[]
 			{
 				tl.TintAt(pos + new WVec(-step, -step, 0)),
@@ -125,10 +136,10 @@ namespace OpenRA.Graphics
 
 			// Apply tint directly to the underlying vertices
 			// This saves us from having to re-query the sprite information, which has not changed
-			for (var i = 0; i < 6; i++)
+			for (var i = 0; i < 4; i++)
 			{
 				var v = vertices[offset + i];
-				vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.P, v.C, v.A * weights[CornerVertexMap[i]], v.A);
+				vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.C, v.A * weights[i], v.A);
 			}
 
 			dirtyRows.Add(uv.V);
@@ -180,7 +191,7 @@ namespace OpenRA.Graphics
 			if (!map.Tiles.Contains(uv))
 				return;
 
-			var offset = rowStride * uv.V + 6 * uv.U;
+			var offset = vertexRowStride * uv.V + 4 * uv.U;
 			Util.FastCreateQuad(vertices, pos, sprite, samplers, palette?.TextureIndex ?? 0, offset, scale * sprite.Size, alpha * float3.Ones, alpha);
 			palettes[uv.V * map.MapSize.X + uv.U] = palette;
 
@@ -209,13 +220,13 @@ namespace OpenRA.Graphics
 				if (!dirtyRows.Remove(row))
 					continue;
 
-				var rowOffset = rowStride * row;
-				vertexBuffer.SetData(vertices, rowOffset, rowOffset, rowStride);
+				var rowOffset = vertexRowStride * row;
+				vertexBuffer.SetData(vertices, rowOffset, rowOffset, vertexRowStride);
 			}
 
 			Game.Renderer.WorldSpriteRenderer.DrawVertexBuffer(
-				vertexBuffer, rowStride * firstRow, rowStride * (lastRow - firstRow),
-				PrimitiveType.TriangleList, sheets, BlendMode);
+				vertexBuffer, indexBufferWrapper.Buffer, indexRowStride * firstRow,
+				indexRowStride * (lastRow - firstRow), sheets, BlendMode);
 
 			Game.Renderer.Flush();
 		}
@@ -227,6 +238,29 @@ namespace OpenRA.Graphics
 				worldRenderer.TerrainLighting.CellChanged -= UpdateTint;
 
 			vertexBuffer.Dispose();
+
+			lock (IndexBuffers)
+				indexBufferWrapper.Dispose();
+		}
+
+		sealed class IndexBufferRc : IDisposable
+		{
+			public IIndexBuffer Buffer;
+			int count;
+
+			public IndexBufferRc(World world)
+			{
+				Buffer = Game.Renderer.Context.CreateIndexBuffer(Util.CreateQuadIndices(world.Map.MapSize.X * world.Map.MapSize.Y));
+			}
+
+			public void AddRef() { count++; }
+
+			public void Dispose()
+			{
+				count--;
+				if (count == 0)
+					Buffer.Dispose();
+			}
 		}
 	}
 }

OpenRA.Game/Graphics/UISpriteRenderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -16,10 +16,7 @@ namespace OpenRA.Graphics
 	public class UISpriteRenderable : IRenderable, IPalettedRenderable, IFinalizedRenderable
 	{
 		readonly Sprite sprite;
-		readonly WPos effectiveWorldPos;
 		readonly int2 screenPos;
-		readonly int zOffset;
-		readonly PaletteReference palette;
 		readonly float scale;
 		readonly float alpha;
 		readonly float rotation = 0f;
@@ -27,10 +24,10 @@ namespace OpenRA.Graphics
 		public UISpriteRenderable(Sprite sprite, WPos effectiveWorldPos, int2 screenPos, int zOffset, PaletteReference palette, float scale = 1f, float alpha = 1f, float rotation = 0f)
 		{
 			this.sprite = sprite;
-			this.effectiveWorldPos = effectiveWorldPos;
+			Pos = effectiveWorldPos;
 			this.screenPos = screenPos;
-			this.zOffset = zOffset;
-			this.palette = palette;
+			ZOffset = zOffset;
+			Palette = palette;
 			this.scale = scale;
 			this.alpha = alpha;
 			this.rotation = rotation;
@@ -39,18 +36,18 @@ namespace OpenRA.Graphics
 			// HACK: This is working around the fact that palettes are defined on traits rather than sequences
 			// and can be removed once this has been fixed
 			if (sprite.Channel == TextureChannel.RGBA && !(palette?.HasColorShift ?? false))
-				this.palette = null;
+				Palette = null;
 		}
 
 		// Does not exist in the world, so a world positions don't make sense
-		public WPos Pos => effectiveWorldPos;
+		public WPos Pos { get; }
 		public WVec Offset => WVec.Zero;
 		public bool IsDecoration => true;
 
-		public PaletteReference Palette => palette;
-		public int ZOffset => zOffset;
+		public PaletteReference Palette { get; }
+		public int ZOffset { get; }
 
-		public IPalettedRenderable WithPalette(PaletteReference newPalette) { return new UISpriteRenderable(sprite, effectiveWorldPos, screenPos, zOffset, newPalette, scale, alpha, rotation); }
+		public IPalettedRenderable WithPalette(PaletteReference newPalette) { return new UISpriteRenderable(sprite, Pos, screenPos, ZOffset, newPalette, scale, alpha, rotation); }
 		public IRenderable WithZOffset(int newOffset) { return this; }
 		public IRenderable OffsetBy(in WVec vec) { return this; }
 		public IRenderable AsDecoration() { return this; }
@@ -58,7 +55,7 @@ namespace OpenRA.Graphics
 		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }
 		public void Render(WorldRenderer wr)
 		{
-			Game.Renderer.SpriteRenderer.DrawSprite(sprite, palette, screenPos, scale, float3.Ones, alpha, rotation);
+			Game.Renderer.SpriteRenderer.DrawSprite(sprite, Palette, screenPos, scale, float3.Ones, alpha, rotation);
 		}
 
 		public void RenderDebugGeometry(WorldRenderer wr)

OpenRA.Game/Graphics/Util.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -10,6 +10,7 @@
 #endregion
 
 using System;
+using System.Runtime.InteropServices;
 using OpenRA.FileFormats;
 using OpenRA.Primitives;
 
@@ -20,7 +21,17 @@ namespace OpenRA.Graphics
 		// yes, our channel order is nuts.
 		static readonly int[] ChannelMasks = { 2, 1, 0, 3 };
 
-		public static void FastCreateQuad(Vertex[] vertices, in float3 o, Sprite r, int2 samplers, float paletteTextureIndex, int nv,
+		public static uint[] CreateQuadIndices(int quads)
+		{
+			var indices = new uint[quads * 6];
+			ReadOnlySpan<uint> cornerVertexMap = stackalloc uint[] { 0, 1, 2, 2, 3, 0 };
+			for (var i = 0; i < indices.Length; i++)
+				indices[i] = cornerVertexMap[i % 6] + (uint)(4 * (i / 6));
+
+			return indices;
+		}
+
+		public static void FastCreateQuad(Vertex[] vertices, in float3 o, Sprite r, int2 samplers, int paletteTextureIndex, int nv,
 			in float3 size, in float3 tint, float alpha, float rotation = 0f)
 		{
 			float3 a, b, c, d;
@@ -62,7 +73,7 @@ namespace OpenRA.Graphics
 
 		public static void FastCreateQuad(Vertex[] vertices,
 			in float3 a, in float3 b, in float3 c, in float3 d,
-			Sprite r, int2 samplers, float paletteTextureIndex,
+			Sprite r, int2 samplers, int paletteTextureIndex,
 			in float3 tint, float alpha, int nv)
 		{
 			float sl = 0;
@@ -84,76 +95,33 @@ namespace OpenRA.Graphics
 				attribC |= samplers.Y << 9;
 			}
 
-			var fAttribC = (float)attribC;
-			vertices[nv] = new Vertex(a, r.Left, r.Top, sl, st, paletteTextureIndex, fAttribC, tint, alpha);
-			vertices[nv + 1] = new Vertex(b, r.Right, r.Top, sr, st, paletteTextureIndex, fAttribC, tint, alpha);
-			vertices[nv + 2] = new Vertex(c, r.Right, r.Bottom, sr, sb, paletteTextureIndex, fAttribC, tint, alpha);
-			vertices[nv + 3] = new Vertex(c, r.Right, r.Bottom, sr, sb, paletteTextureIndex, fAttribC, tint, alpha);
-			vertices[nv + 4] = new Vertex(d, r.Left, r.Bottom, sl, sb, paletteTextureIndex, fAttribC, tint, alpha);
-			vertices[nv + 5] = new Vertex(a, r.Left, r.Top, sl, st, paletteTextureIndex, fAttribC, tint, alpha);
+			attribC |= (paletteTextureIndex & 0xFFFF) << 16;
+
+			var uAttribC = (uint)attribC;
+			vertices[nv] = new Vertex(a, r.Left, r.Top, sl, st, uAttribC, tint, alpha);
+			vertices[nv + 1] = new Vertex(b, r.Right, r.Top, sr, st, uAttribC, tint, alpha);
+			vertices[nv + 2] = new Vertex(c, r.Right, r.Bottom, sr, sb, uAttribC, tint, alpha);
+			vertices[nv + 3] = new Vertex(d, r.Left, r.Bottom, sl, sb, uAttribC, tint, alpha);
 		}
 
-		public static void FastCopyIntoChannel(Sprite dest, byte[] src, SpriteFrameType srcType)
+		public static void FastCopyIntoChannel(Sprite dest, byte[] src, SpriteFrameType srcType, bool premultiplied = false)
 		{
 			var destData = dest.Sheet.GetData();
+			var stride = dest.Sheet.Size.Width;
+			var x = dest.Bounds.Left;
+			var y = dest.Bounds.Top;
 			var width = dest.Bounds.Width;
 			var height = dest.Bounds.Height;
 
 			if (dest.Channel == TextureChannel.RGBA)
 			{
-				var destStride = dest.Sheet.Size.Width;
-				unsafe
-				{
-					// Cast the data to an int array so we can copy the src data directly
-					fixed (byte* bd = &destData[0])
-					{
-						var data = (int*)bd;
-						var x = dest.Bounds.Left;
-						var y = dest.Bounds.Top;
-
-						var k = 0;
-						for (var j = 0; j < height; j++)
-						{
-							for (var i = 0; i < width; i++)
-							{
-								byte r, g, b, a;
-								switch (srcType)
-								{
-									case SpriteFrameType.Bgra32:
-									case SpriteFrameType.Bgr24:
-									{
-										b = src[k++];
-										g = src[k++];
-										r = src[k++];
-										a = srcType == SpriteFrameType.Bgra32 ? src[k++] : (byte)255;
-										break;
-									}
-
-									case SpriteFrameType.Rgba32:
-									case SpriteFrameType.Rgb24:
-									{
-										r = src[k++];
-										g = src[k++];
-										b = src[k++];
-										a = srcType == SpriteFrameType.Rgba32 ? src[k++] : (byte)255;
-										break;
-									}
-
-									default:
-										throw new InvalidOperationException($"Unknown SpriteFrameType {srcType}");
-								}
-
-								var cc = Color.FromArgb(a, r, g, b);
-								data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();
-							}
-						}
-					}
-				}
+				CopyIntoRgba(src, srcType, premultiplied, destData, x, y, width, height, stride);
 			}
 			else
 			{
-				var destStride = dest.Sheet.Size.Width * 4;
-				var destOffset = destStride * dest.Bounds.Top + dest.Bounds.Left * 4 + ChannelMasks[(int)dest.Channel];
+				// Copy into single channel of destination.
+				var destStride = stride * 4;
+				var destOffset = destStride * y + x * 4 + ChannelMasks[(int)dest.Channel];
 				var destSkip = destStride - 4 * width;
 
 				var srcOffset = 0;
@@ -170,64 +138,127 @@ namespace OpenRA.Graphics
 			}
 		}
 
+		static void CopyIntoRgba(
+			byte[] src, SpriteFrameType srcType, bool premultiplied, byte[] dest, int x, int y, int width, int height, int stride)
+		{
+			var si = 0;
+			var di = y * stride + x;
+			var d = MemoryMarshal.Cast<byte, uint>(dest);
+
+			// SpriteFrameType.Brga32 is a common source format, and it matches the destination format.
+			// Provide a fast past that just performs memory copies.
+			if (srcType == SpriteFrameType.Bgra32)
+			{
+				var s = MemoryMarshal.Cast<byte, uint>(src);
+				for (var h = 0; h < height; h++)
+				{
+					s[si..(si + width)].CopyTo(d[di..(di + width)]);
+
+					if (!premultiplied)
+					{
+						for (var w = 0; w < width; w++)
+						{
+							d[di] = PremultiplyAlpha(Color.FromArgb(d[di])).ToArgb();
+							di++;
+						}
+
+						di -= width;
+					}
+
+					si += width;
+					di += stride;
+				}
+
+				return;
+			}
+
+			for (var h = 0; h < height; h++)
+			{
+				for (var w = 0; w < width; w++)
+				{
+					byte r, g, b, a;
+					switch (srcType)
+					{
+						case SpriteFrameType.Bgra32:
+						case SpriteFrameType.Bgr24:
+							b = src[si++];
+							g = src[si++];
+							r = src[si++];
+							a = srcType == SpriteFrameType.Bgra32 ? src[si++] : byte.MaxValue;
+							break;
+
+						case SpriteFrameType.Rgba32:
+						case SpriteFrameType.Rgb24:
+							r = src[si++];
+							g = src[si++];
+							b = src[si++];
+							a = srcType == SpriteFrameType.Rgba32 ? src[si++] : byte.MaxValue;
+							break;
+
+						default:
+							throw new InvalidOperationException($"Unknown SpriteFrameType {srcType}");
+					}
+
+					var c = Color.FromArgb(a, r, g, b);
+					if (!premultiplied)
+						c = PremultiplyAlpha(c);
+					d[di++] = c.ToArgb();
+				}
+
+				di += stride - width;
+			}
+		}
+
 		public static void FastCopyIntoSprite(Sprite dest, Png src)
 		{
 			var destData = dest.Sheet.GetData();
-			var destStride = dest.Sheet.Size.Width;
+			var stride = dest.Sheet.Size.Width;
+			var x = dest.Bounds.Left;
+			var y = dest.Bounds.Top;
 			var width = dest.Bounds.Width;
 			var height = dest.Bounds.Height;
 
-			unsafe
+			var si = 0;
+			var di = y * stride + x;
+			var d = MemoryMarshal.Cast<byte, uint>(destData);
+
+			for (var h = 0; h < height; h++)
 			{
-				// Cast the data to an int array so we can copy the src data directly
-				fixed (byte* bd = &destData[0])
+				for (var w = 0; w < width; w++)
 				{
-					var data = (int*)bd;
-					var x = dest.Bounds.Left;
-					var y = dest.Bounds.Top;
-
-					var k = 0;
-					for (var j = 0; j < height; j++)
+					Color c;
+					switch (src.Type)
 					{
-						for (var i = 0; i < width; i++)
-						{
-							Color cc;
-							switch (src.Type)
-							{
-								case SpriteFrameType.Indexed8:
-								{
-									cc = src.Palette[src.Data[k++]];
-									break;
-								}
+						case SpriteFrameType.Indexed8:
+							c = src.Palette[src.Data[si++]];
+							break;
 
-								case SpriteFrameType.Rgba32:
-								case SpriteFrameType.Rgb24:
-								{
-									var r = src.Data[k++];
-									var g = src.Data[k++];
-									var b = src.Data[k++];
-									var a = src.Type == SpriteFrameType.Rgba32 ? src.Data[k++] : (byte)255;
-									cc = Color.FromArgb(a, r, g, b);
-									break;
-								}
+						case SpriteFrameType.Rgba32:
+						case SpriteFrameType.Rgb24:
+							var r = src.Data[si++];
+							var g = src.Data[si++];
+							var b = src.Data[si++];
+							var a = src.Type == SpriteFrameType.Rgba32 ? src.Data[si++] : byte.MaxValue;
+							c = Color.FromArgb(a, r, g, b);
+							break;
 
-								// Pngs don't support BGR[A], so no need to include them here
-								default:
-									throw new InvalidOperationException($"Unknown SpriteFrameType {src.Type}");
-							}
-
-							data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();
-						}
+						// PNGs don't support BGR[A], so no need to include them here
+						default:
+							throw new InvalidOperationException($"Unknown SpriteFrameType {src.Type}");
 					}
+
+					d[di++] = PremultiplyAlpha(c).ToArgb();
 				}
+
+				di += stride - width;
 			}
 		}
 
 		/// <summary>Rotates a quad about its center in the x-y plane.</summary>
-		/// <param name="tl">The top left vertex of the quad</param>
-		/// <param name="size">A float3 containing the X, Y, and Z lengths of the quad</param>
-		/// <param name="rotation">The number of radians to rotate by</param>
-		/// <returns>An array of four vertices representing the rotated quad (top-left, top-right, bottom-right, bottom-left)</returns>
+		/// <param name="tl">The top left vertex of the quad.</param>
+		/// <param name="size">A float3 containing the X, Y, and Z lengths of the quad.</param>
+		/// <param name="rotation">The number of radians to rotate by.</param>
+		/// <returns>An array of four vertices representing the rotated quad (top-left, top-right, bottom-right, bottom-left).</returns>
 		public static float3[] RotateQuad(float3 tl, float3 size, float rotation)
 		{
 			var center = tl + 0.5f * size;
@@ -258,15 +289,15 @@ namespace OpenRA.Graphics
 		/// <summary>
 		/// Returns the bounds of an object. Used for determining which objects need to be rendered on screen, and which do not.
 		/// </summary>
-		/// <param name="offset">The top left vertex of the object</param>
-		/// <param name="size">A float 3 containing the X, Y, and Z lengths of the object</param>
-		/// <param name="rotation">The angle to rotate the object by (use 0f if there is no rotation)</param>
+		/// <param name="offset">The top left vertex of the object.</param>
+		/// <param name="size">A float 3 containing the X, Y, and Z lengths of the object.</param>
+		/// <param name="rotation">The angle to rotate the object by (use 0f if there is no rotation).</param>
 		public static Rectangle BoundingRectangle(float3 offset, float3 size, float rotation)
 		{
 			if (rotation == 0f)
 				return new Rectangle((int)offset.X, (int)offset.Y, (int)size.X, (int)size.Y);
 
-			var rotatedQuad = Util.RotateQuad(offset, size, rotation);
+			var rotatedQuad = RotateQuad(offset, size, rotation);
 			var minX = rotatedQuad[0].X;
 			var maxX = rotatedQuad[0].X;
 			var minY = rotatedQuad[0].Y;
@@ -305,239 +336,5 @@ namespace OpenRA.Graphics
 				(int)((byte)(t * a2 * c2.G + 0.5f) + (1 - t) * (byte)(a1 * c1.G + 0.5f)),
 				(int)((byte)(t * a2 * c2.B + 0.5f) + (1 - t) * (byte)(a1 * c1.B + 0.5f))));
 		}
-
-		public static float[] IdentityMatrix()
-		{
-			return Exts.MakeArray(16, j => (j % 5 == 0) ? 1.0f : 0);
-		}
-
-		public static float[] ScaleMatrix(float sx, float sy, float sz)
-		{
-			var mtx = IdentityMatrix();
-			mtx[0] = sx;
-			mtx[5] = sy;
-			mtx[10] = sz;
-			return mtx;
-		}
-
-		public static float[] TranslationMatrix(float x, float y, float z)
-		{
-			var mtx = IdentityMatrix();
-			mtx[12] = x;
-			mtx[13] = y;
-			mtx[14] = z;
-			return mtx;
-		}
-
-		public static float[] MatrixMultiply(float[] lhs, float[] rhs)
-		{
-			var mtx = new float[16];
-			for (var i = 0; i < 4; i++)
-				for (var j = 0; j < 4; j++)
-				{
-					mtx[4 * i + j] = 0;
-					for (var k = 0; k < 4; k++)
-						mtx[4 * i + j] += lhs[4 * k + j] * rhs[4 * i + k];
-				}
-
-			return mtx;
-		}
-
-		public static float[] MatrixVectorMultiply(float[] mtx, float[] vec)
-		{
-			var ret = new float[4];
-			for (var j = 0; j < 4; j++)
-			{
-				ret[j] = 0;
-				for (var k = 0; k < 4; k++)
-					ret[j] += mtx[4 * k + j] * vec[k];
-			}
-
-			return ret;
-		}
-
-		public static float[] MatrixInverse(float[] m)
-		{
-			var mtx = new float[16];
-
-			mtx[0] = m[5] * m[10] * m[15] -
-				m[5] * m[11] * m[14] -
-				m[9] * m[6] * m[15] +
-				m[9] * m[7] * m[14] +
-				m[13] * m[6] * m[11] -
-				m[13] * m[7] * m[10];
-
-			mtx[4] = -m[4] * m[10] * m[15] +
-				m[4] * m[11] * m[14] +
-				m[8] * m[6] * m[15] -
-				m[8] * m[7] * m[14] -
-				m[12] * m[6] * m[11] +
-				m[12] * m[7] * m[10];
-
-			mtx[8] = m[4] * m[9] * m[15] -
-				m[4] * m[11] * m[13] -
-				m[8] * m[5] * m[15] +
-				m[8] * m[7] * m[13] +
-				m[12] * m[5] * m[11] -
-				m[12] * m[7] * m[9];
-
-			mtx[12] = -m[4] * m[9] * m[14] +
-				m[4] * m[10] * m[13] +
-				m[8] * m[5] * m[14] -
-				m[8] * m[6] * m[13] -
-				m[12] * m[5] * m[10] +
-				m[12] * m[6] * m[9];
-
-			mtx[1] = -m[1] * m[10] * m[15] +
-				m[1] * m[11] * m[14] +
-				m[9] * m[2] * m[15] -
-				m[9] * m[3] * m[14] -
-				m[13] * m[2] * m[11] +
-				m[13] * m[3] * m[10];
-
-			mtx[5] = m[0] * m[10] * m[15] -
-				m[0] * m[11] * m[14] -
-				m[8] * m[2] * m[15] +
-				m[8] * m[3] * m[14] +
-				m[12] * m[2] * m[11] -
-				m[12] * m[3] * m[10];
-
-			mtx[9] = -m[0] * m[9] * m[15] +
-				m[0] * m[11] * m[13] +
-				m[8] * m[1] * m[15] -
-				m[8] * m[3] * m[13] -
-				m[12] * m[1] * m[11] +
-				m[12] * m[3] * m[9];
-
-			mtx[13] = m[0] * m[9] * m[14] -
-				m[0] * m[10] * m[13] -
-				m[8] * m[1] * m[14] +
-				m[8] * m[2] * m[13] +
-				m[12] * m[1] * m[10] -
-				m[12] * m[2] * m[9];
-
-			mtx[2] = m[1] * m[6] * m[15] -
-				m[1] * m[7] * m[14] -
-				m[5] * m[2] * m[15] +
-				m[5] * m[3] * m[14] +
-				m[13] * m[2] * m[7] -
-				m[13] * m[3] * m[6];
-
-			mtx[6] = -m[0] * m[6] * m[15] +
-				m[0] * m[7] * m[14] +
-				m[4] * m[2] * m[15] -
-				m[4] * m[3] * m[14] -
-				m[12] * m[2] * m[7] +
-				m[12] * m[3] * m[6];
-
-			mtx[10] = m[0] * m[5] * m[15] -
-				m[0] * m[7] * m[13] -
-				m[4] * m[1] * m[15] +
-				m[4] * m[3] * m[13] +
-				m[12] * m[1] * m[7] -
-				m[12] * m[3] * m[5];
-
-			mtx[14] = -m[0] * m[5] * m[14] +
-				m[0] * m[6] * m[13] +
-				m[4] * m[1] * m[14] -
-				m[4] * m[2] * m[13] -
-				m[12] * m[1] * m[6] +
-				m[12] * m[2] * m[5];
-
-			mtx[3] = -m[1] * m[6] * m[11] +
-				m[1] * m[7] * m[10] +
-				m[5] * m[2] * m[11] -
-				m[5] * m[3] * m[10] -
-				m[9] * m[2] * m[7] +
-				m[9] * m[3] * m[6];
-
-			mtx[7] = m[0] * m[6] * m[11] -
-				m[0] * m[7] * m[10] -
-				m[4] * m[2] * m[11] +
-				m[4] * m[3] * m[10] +
-				m[8] * m[2] * m[7] -
-				m[8] * m[3] * m[6];
-
-			mtx[11] = -m[0] * m[5] * m[11] +
-				m[0] * m[7] * m[9] +
-				m[4] * m[1] * m[11] -
-				m[4] * m[3] * m[9] -
-				m[8] * m[1] * m[7] +
-				m[8] * m[3] * m[5];
-
-			mtx[15] = m[0] * m[5] * m[10] -
-				m[0] * m[6] * m[9] -
-				m[4] * m[1] * m[10] +
-				m[4] * m[2] * m[9] +
-				m[8] * m[1] * m[6] -
-				m[8] * m[2] * m[5];
-
-			var det = m[0] * mtx[0] + m[1] * mtx[4] + m[2] * mtx[8] + m[3] * mtx[12];
-			if (det == 0)
-				return null;
-
-			for (var i = 0; i < 16; i++)
-				mtx[i] *= 1 / det;
-
-			return mtx;
-		}
-
-		public static float[] MakeFloatMatrix(Int32Matrix4x4 imtx)
-		{
-			var multipler = 1f / imtx.M44;
-			return new[]
-			{
-				imtx.M11 * multipler,
-				imtx.M12 * multipler,
-				imtx.M13 * multipler,
-				imtx.M14 * multipler,
-
-				imtx.M21 * multipler,
-				imtx.M22 * multipler,
-				imtx.M23 * multipler,
-				imtx.M24 * multipler,
-
-				imtx.M31 * multipler,
-				imtx.M32 * multipler,
-				imtx.M33 * multipler,
-				imtx.M34 * multipler,
-
-				imtx.M41 * multipler,
-				imtx.M42 * multipler,
-				imtx.M43 * multipler,
-				imtx.M44 * multipler,
-			};
-		}
-
-		public static float[] MatrixAABBMultiply(float[] mtx, float[] bounds)
-		{
-			// Corner offsets
-			var ix = new uint[] { 0, 0, 0, 0, 3, 3, 3, 3 };
-			var iy = new uint[] { 1, 1, 4, 4, 1, 1, 4, 4 };
-			var iz = new uint[] { 2, 5, 2, 5, 2, 5, 2, 5 };
-
-			// Vectors to opposing corner
-			var ret = new[]
-			{
-				float.MaxValue, float.MaxValue, float.MaxValue,
-				float.MinValue, float.MinValue, float.MinValue
-			};
-
-			// Transform vectors and find new bounding box
-			for (var i = 0; i < 8; i++)
-			{
-				var vec = new[] { bounds[ix[i]], bounds[iy[i]], bounds[iz[i]], 1 };
-				var tvec = MatrixVectorMultiply(mtx, vec);
-
-				ret[0] = Math.Min(ret[0], tvec[0] / tvec[3]);
-				ret[1] = Math.Min(ret[1], tvec[1] / tvec[3]);
-				ret[2] = Math.Min(ret[2], tvec[2] / tvec[3]);
-				ret[3] = Math.Max(ret[3], tvec[0] / tvec[3]);
-				ret[4] = Math.Max(ret[4], tvec[1] / tvec[3]);
-				ret[5] = Math.Max(ret[5], tvec[2] / tvec[3]);
-			}
-
-			return ret;
-		}
 	}
 }

OpenRA.Game/Graphics/Vertex.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -23,27 +23,42 @@ namespace OpenRA.Graphics
 		public readonly float S, T, U, V;
 
 		// Palette and channel flags
-		public readonly float P, C;
+		public readonly uint C;
 
 		// Color tint
 		public readonly float R, G, B, A;
 
-		public Vertex(in float3 xyz, float s, float t, float u, float v, float p, float c)
-			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, p, c, float3.Ones, 1f) { }
+		public Vertex(in float3 xyz, float s, float t, float u, float v, uint c)
+			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, c, float3.Ones, 1f) { }
 
-		public Vertex(in float3 xyz, float s, float t, float u, float v, float p, float c, in float3 tint, float a)
-			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, p, c, tint.X, tint.Y, tint.Z, a) { }
+		public Vertex(in float3 xyz, float s, float t, float u, float v, uint c, in float3 tint, float a)
+			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, c, tint.X, tint.Y, tint.Z, a) { }
 
-		public Vertex(float x, float y, float z, float s, float t, float u, float v, float p, float c, in float3 tint, float a)
-			: this(x, y, z, s, t, u, v, p, c, tint.X, tint.Y, tint.Z, a) { }
+		public Vertex(float x, float y, float z, float s, float t, float u, float v, uint c, in float3 tint, float a)
+			: this(x, y, z, s, t, u, v, c, tint.X, tint.Y, tint.Z, a) { }
 
-		public Vertex(float x, float y, float z, float s, float t, float u, float v, float p, float c, float r, float g, float b, float a)
+		public Vertex(float x, float y, float z, float s, float t, float u, float v, uint c, float r, float g, float b, float a)
 		{
 			X = x; Y = y; Z = z;
 			S = s; T = t;
 			U = u; V = v;
-			P = p; C = c;
+			C = c;
 			R = r; G = g; B = b; A = a;
 		}
 	}
+
+	public sealed class CombinedShaderBindings : ShaderBindings
+	{
+		public CombinedShaderBindings()
+			: base("combined")
+		{ }
+
+		public override ShaderVertexAttribute[] Attributes { get; } = new[]
+		{
+			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 3, 0),
+			new ShaderVertexAttribute("aVertexTexCoord", ShaderVertexAttributeType.Float, 4, 12),
+			new ShaderVertexAttribute("aVertexAttributes", ShaderVertexAttributeType.UInt, 1, 28),
+			new ShaderVertexAttribute("aVertexTint", ShaderVertexAttributeType.Float, 4, 32)
+		};
+	}
 }

OpenRA.Game/Graphics/Video.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/VideoLoader.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Graphics/Viewport.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -53,7 +53,7 @@ namespace OpenRA.Graphics
 
 		public WPos CenterPosition => worldRenderer.ProjectedPosition(CenterLocation);
 
-		public Rectangle Rectangle => new Rectangle(TopLeft, new Size(viewportSize.X, viewportSize.Y));
+		public Rectangle Rectangle => new(TopLeft, new Size(viewportSize.X, viewportSize.Y));
 		public int2 TopLeft => CenterLocation - viewportSize / 2;
 		public int2 BottomRight => CenterLocation + viewportSize / 2;
 		int2 viewportSize;
@@ -66,9 +66,6 @@ namespace OpenRA.Graphics
 		WorldViewport lastViewportDistance;
 
 		float zoom = 1f;
-		float minZoom = 1f;
-		float maxZoom = 2f;
-
 		bool unlockMinZoom;
 		float unlockedMinZoomScale;
 		float unlockedMinZoom = 1f;
@@ -86,12 +83,13 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		public float MinZoom => minZoom;
+		public float MinZoom { get; private set; } = 1f;
+		public float MaxZoom { get; private set; } = 2f;
 
 		public void AdjustZoom(float dz)
 		{
 			// Exponential ensures that equal positive and negative steps have the same effect
-			Zoom = (zoom * (float)Math.Exp(dz)).Clamp(unlockMinZoom ? unlockedMinZoom : minZoom, maxZoom);
+			Zoom = (zoom * (float)Math.Exp(dz)).Clamp(unlockMinZoom ? unlockedMinZoom : MinZoom, MaxZoom);
 		}
 
 		public void AdjustZoom(float dz, int2 center)
@@ -105,10 +103,10 @@ namespace OpenRA.Graphics
 		public void ToggleZoom()
 		{
 			// Unlocked zooms always reset to the default zoom
-			if (zoom < minZoom)
-				Zoom = minZoom;
+			if (zoom < MinZoom)
+				Zoom = MinZoom;
 			else
-				Zoom = zoom > minZoom ? minZoom : maxZoom;
+				Zoom = zoom > MinZoom ? MinZoom : MaxZoom;
 		}
 
 		public void UnlockMinimumZoom(float scale)
@@ -121,23 +119,6 @@ namespace OpenRA.Graphics
 		public static long LastMoveRunTime = 0;
 		public static int2 LastMousePos;
 
-		float ClosestTo(float[] collection, float target)
-		{
-			var closestValue = collection.First();
-			var subtractResult = Math.Abs(closestValue - target);
-
-			foreach (var element in collection)
-			{
-				if (Math.Abs(element - target) < subtractResult)
-				{
-					subtractResult = Math.Abs(element - target);
-					closestValue = element;
-				}
-			}
-
-			return closestValue;
-		}
-
 		public ScrollDirection GetBlockedDirections()
 		{
 			var ret = ScrollDirection.None;
@@ -191,7 +172,7 @@ namespace OpenRA.Graphics
 				UpdateViewportZooms();
 		}
 
-		float CalculateMinimumZoom(float minHeight, float maxHeight)
+		static float CalculateMinimumZoom(float minHeight, float maxHeight)
 		{
 			var h = Game.Renderer.NativeResolution.Height;
 
@@ -227,14 +208,14 @@ namespace OpenRA.Graphics
 
 			var vd = graphicSettings.ViewportDistance;
 			if (viewportSizes.AllowNativeZoom && vd == WorldViewport.Native)
-				minZoom = 1;
+				MinZoom = viewportSizes.DefaultScale;
 			else
 			{
 				var range = viewportSizes.GetSizeRange(vd);
-				minZoom = CalculateMinimumZoom(range.X, range.Y);
+				MinZoom = CalculateMinimumZoom(range.X, range.Y) * viewportSizes.DefaultScale;
 			}
 
-			maxZoom = Math.Min(minZoom * viewportSizes.MaxZoomScale, Game.Renderer.NativeResolution.Height * 1f / viewportSizes.MaxZoomWindowHeight);
+			MaxZoom = Math.Min(MinZoom * viewportSizes.MaxZoomScale, Game.Renderer.NativeResolution.Height * viewportSizes.DefaultScale / viewportSizes.MaxZoomWindowHeight);
 
 			if (unlockMinZoom)
 			{
@@ -242,19 +223,19 @@ namespace OpenRA.Graphics
 				// TODO: Allow zooming out until the full map is visible
 				// We need to improve our viewport scroll handling to center the map as we zoom out
 				// before this will work well enough to enable
-				unlockedMinZoom = minZoom * unlockedMinZoomScale;
+				unlockedMinZoom = MinZoom * unlockedMinZoomScale;
 			}
 
 			if (resetCurrentZoom)
-				Zoom = minZoom;
+				Zoom = MinZoom;
 			else
-				Zoom = Zoom.Clamp(minZoom, maxZoom);
+				Zoom = Zoom.Clamp(MinZoom, MaxZoom);
 
-			var maxSize = (1f / (unlockMinZoom ? unlockedMinZoom : minZoom) * new float2(Game.Renderer.NativeResolution));
+			var maxSize = 1f / (unlockMinZoom ? unlockedMinZoom : MinZoom) * new float2(Game.Renderer.NativeResolution);
 			Game.Renderer.SetMaximumViewportSize(new Size((int)maxSize.X, (int)maxSize.Y));
 
 			foreach (var t in worldRenderer.World.WorldActor.TraitsImplementing<INotifyViewportZoomExtentsChanged>())
-				t.ViewportZoomExtentsChanged(minZoom, maxZoom);
+				t.ViewportZoomExtentsChanged(MinZoom, MaxZoom);
 		}
 
 		public CPos ViewToWorld(int2 view)
@@ -297,15 +278,27 @@ namespace OpenRA.Graphics
 			return worldRenderer.World.Map.CellContaining(worldRenderer.ProjectedPosition(ViewToWorldPx(view)));
 		}
 
-		/// <summary> Returns an unfiltered list of all cells that could potentially contain the mouse cursor</summary>
+		/// <summary>Returns an unfiltered list of all cells that could potentially contain the mouse cursor.</summary>
 		IEnumerable<MPos> CandidateMouseoverCells(int2 world)
 		{
 			var map = worldRenderer.World.Map;
+			var tileScale = map.Grid.TileScale / 2;
 			var minPos = worldRenderer.ProjectedPosition(world);
 
-			// Find all the cells that could potentially have been clicked
-			var a = map.CellContaining(minPos - new WVec(1024, 0, 0)).ToMPos(map.Grid.Type);
-			var b = map.CellContaining(minPos + new WVec(512, 512 * map.Grid.MaximumTerrainHeight, 0)).ToMPos(map.Grid.Type);
+			// Find all the cells that could potentially have been clicked.
+			MPos a;
+			MPos b;
+			if (map.Grid.Type == MapGridType.RectangularIsometric)
+			{
+				// TODO: this generates too many cells.
+				a = map.CellContaining(minPos - new WVec(tileScale, 0, 0)).ToMPos(map.Grid.Type);
+				b = map.CellContaining(minPos + new WVec(tileScale, tileScale * map.Grid.MaximumTerrainHeight, 0)).ToMPos(map.Grid.Type);
+			}
+			else
+			{
+				a = map.CellContaining(minPos).ToMPos(map.Grid.Type);
+				b = map.CellContaining(minPos + new WVec(0, tileScale * map.Grid.MaximumTerrainHeight, 0)).ToMPos(map.Grid.Type);
+			}
 
 			for (var v = b.V; v >= a.V; v--)
 				for (var u = b.U; u >= a.U; u--)
@@ -313,15 +306,18 @@ namespace OpenRA.Graphics
 		}
 
 		public int2 ViewToWorldPx(int2 view) { return (graphicSettings.UIScale / Zoom * view.ToFloat2()).ToInt2() + TopLeft; }
-		public int2 WorldToViewPx(int2 world) { return ((Zoom / graphicSettings.UIScale) * (world - TopLeft).ToFloat2()).ToInt2(); }
-		public int2 WorldToViewPx(in float3 world) { return ((Zoom / graphicSettings.UIScale) * (world - TopLeft).XY).ToInt2(); }
+		public int2 WorldToViewPx(int2 world) { return (Zoom / graphicSettings.UIScale * (world - TopLeft).ToFloat2()).ToInt2(); }
+		public int2 WorldToViewPx(in float3 world) { return (Zoom / graphicSettings.UIScale * (world - TopLeft).XY).ToInt2(); }
 
 		public void Center(IEnumerable<Actor> actors)
 		{
-			if (!actors.Any())
+			var actorsCollection = actors as IReadOnlyCollection<Actor>;
+			actorsCollection ??= actors.ToList();
+
+			if (actorsCollection.Count == 0)
 				return;
 
-			Center(actors.Select(a => a.CenterPosition).Average());
+			Center(actorsCollection.Select(a => a.CenterPosition).Average());
 		}
 
 		public void Center(WPos pos)

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -31,25 +31,27 @@ namespace OpenRA.Graphics
 
 		public event Action PaletteInvalidated = null;
 
-		readonly HashSet<Actor> onScreenActors = new HashSet<Actor>();
-		readonly HardwarePalette palette = new HardwarePalette();
-		readonly Dictionary<string, PaletteReference> palettes = new Dictionary<string, PaletteReference>();
+		readonly HashSet<Actor> onScreenActors = new();
+		readonly HardwarePalette palette = new();
+		readonly Dictionary<string, PaletteReference> palettes = new();
 		readonly IRenderTerrain terrainRenderer;
 		readonly Lazy<DebugVisualizations> debugVis;
 		readonly Func<string, PaletteReference> createPaletteReference;
 		readonly bool enableDepthBuffer;
 
-		readonly List<IFinalizedRenderable> preparedRenderables = new List<IFinalizedRenderable>();
-		readonly List<IFinalizedRenderable> preparedOverlayRenderables = new List<IFinalizedRenderable>();
-		readonly List<IFinalizedRenderable> preparedAnnotationRenderables = new List<IFinalizedRenderable>();
+		readonly List<IFinalizedRenderable> preparedRenderables = new();
+		readonly List<IFinalizedRenderable> preparedOverlayRenderables = new();
+		readonly List<IFinalizedRenderable> preparedAnnotationRenderables = new();
 
-		readonly List<IRenderable> renderablesBuffer = new List<IRenderable>();
+		readonly List<IRenderable> renderablesBuffer = new();
+		readonly IRenderer[] renderers;
+		readonly IRenderPostProcessPass[] postProcessPasses;
 
 		internal WorldRenderer(ModData modData, World world)
 		{
 			World = world;
 			TileSize = World.Map.Grid.TileSize;
-			TileScale = World.Map.Grid.Type == MapGridType.RectangularIsometric ? 1448 : 1024;
+			TileScale = World.Map.Grid.TileScale;
 			Viewport = new Viewport(this, world.Map);
 
 			createPaletteReference = CreatePaletteReference;
@@ -66,9 +68,24 @@ namespace OpenRA.Graphics
 			palette.Initialize();
 
 			TerrainLighting = world.WorldActor.TraitOrDefault<ITerrainLighting>();
+			renderers = world.WorldActor.TraitsImplementing<IRenderer>().ToArray();
 			terrainRenderer = world.WorldActor.TraitOrDefault<IRenderTerrain>();
 
 			debugVis = Exts.Lazy(() => world.WorldActor.TraitOrDefault<DebugVisualizations>());
+
+			postProcessPasses = world.WorldActor.TraitsImplementing<IRenderPostProcessPass>().ToArray();
+		}
+
+		public void BeginFrame()
+		{
+			foreach (var r in renderers)
+				r.BeginFrame();
+		}
+
+		public void EndFrame()
+		{
+			foreach (var r in renderers)
+				r.EndFrame();
 		}
 
 		public void UpdatePalettesForPlayer(string internalName, Color color, bool replaceExisting)
@@ -87,7 +104,7 @@ namespace OpenRA.Graphics
 		{
 			// HACK: This is working around the fact that palettes are defined on traits rather than sequences
 			// and can be removed once this has been fixed.
-			return name == null ? null : palettes.GetOrAdd(name, createPaletteReference);
+			return string.IsNullOrEmpty(name) ? null : palettes.GetOrAdd(name, createPaletteReference);
 		}
 
 		public void AddPalette(string name, ImmutablePalette pal, bool allowModifiers = false, bool allowOverwrite = false)
@@ -109,13 +126,13 @@ namespace OpenRA.Graphics
 			palette.ReplacePalette(name, pal);
 
 			// Update cached PlayerReference if one exists
-			if (palettes.ContainsKey(name))
-				palettes[name].Palette = pal;
+			if (palettes.TryGetValue(name, out var paletteReference))
+				paletteReference.Palette = pal;
 		}
 
-		public void SetPaletteColorShift(string name, float hueOffset, float satOffset, float minHue, float maxHue)
+		public void SetPaletteColorShift(string name, float hueOffset, float satOffset, float valueModifier, float minHue, float maxHue)
 		{
-			palette.SetColorShift(name, hueOffset, satOffset, minHue, maxHue);
+			palette.SetColorShift(name, hueOffset, satOffset, valueModifier, minHue, maxHue);
 		}
 
 		// PERF: Avoid LINQ.
@@ -177,7 +194,7 @@ namespace OpenRA.Graphics
 
 			foreach (var e in World.Effects)
 			{
-				if (!(e is IEffectAboveShroud ea))
+				if (e is not IEffectAboveShroud ea)
 					continue;
 
 				foreach (var renderable in ea.RenderAboveShroud(this))
@@ -218,7 +235,7 @@ namespace OpenRA.Graphics
 
 			foreach (var e in World.Effects)
 			{
-				if (!(e is IEffectAnnotation ea))
+				if (e is not IEffectAnnotation ea)
 					continue;
 
 				foreach (var renderAnnotation in ea.RenderAnnotation(this))
@@ -270,6 +287,8 @@ namespace OpenRA.Graphics
 			if (enableDepthBuffer)
 				Game.Renderer.ClearDepthBuffer();
 
+			ApplyPostProcessing(PostProcessPassType.AfterActors);
+
 			World.ApplyToActorsWithTrait<IRenderAboveWorld>((actor, trait) =>
 			{
 				if (actor.IsInWorld && !actor.Disposed)
@@ -279,6 +298,8 @@ namespace OpenRA.Graphics
 			if (enableDepthBuffer)
 				Game.Renderer.ClearDepthBuffer();
 
+			ApplyPostProcessing(PostProcessPassType.AfterWorld);
+
 			World.ApplyToActorsWithTrait<IRenderShroud>((actor, trait) => trait.RenderShroud(this));
 
 			if (enableDepthBuffer)
@@ -292,9 +313,23 @@ namespace OpenRA.Graphics
 				foreach (var r in g)
 					r.Render(this);
 
+			ApplyPostProcessing(PostProcessPassType.AfterShroud);
+
 			Game.Renderer.Flush();
 		}
 
+		void ApplyPostProcessing(PostProcessPassType type)
+		{
+			foreach (var pass in postProcessPasses)
+			{
+				if (pass.Type != type || !pass.Enabled)
+					continue;
+
+				Game.Renderer.Flush();
+				pass.Draw(this);
+			}
+		}
+
 		public void DrawAnnotations()
 		{
 			Game.Renderer.EnableAntialiasingFilter();

OpenRA.Game/HotkeyDefinition.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -10,7 +10,6 @@
 #endregion
 
 using System.Collections.Generic;
-using System.Linq;
 
 namespace OpenRA
 {
@@ -19,8 +18,8 @@ namespace OpenRA
 		public readonly string Name;
 		public readonly Hotkey Default = Hotkey.Invalid;
 		public readonly string Description = "";
-		public readonly HashSet<string> Types = new HashSet<string>();
-		public readonly HashSet<string> Contexts = new HashSet<string>();
+		public readonly HashSet<string> Types = new();
+		public readonly HashSet<string> Contexts = new();
 		public readonly bool Readonly = false;
 		public bool HasDuplicates { get; internal set; }
 
@@ -31,29 +30,26 @@ namespace OpenRA
 			if (!string.IsNullOrEmpty(node.Value))
 				Default = FieldLoader.GetValue<Hotkey>("value", node.Value);
 
-			var descriptionNode = node.Nodes.FirstOrDefault(n => n.Key == "Description");
-			if (descriptionNode != null)
-				Description = descriptionNode.Value.Value;
+			var nodeDict = node.ToDictionary();
 
-			var typesNode = node.Nodes.FirstOrDefault(n => n.Key == "Types");
-			if (typesNode != null)
-				Types = FieldLoader.GetValue<HashSet<string>>("Types", typesNode.Value.Value);
+			if (nodeDict.TryGetValue("Description", out var descriptionYaml))
+				Description = descriptionYaml.Value;
 
-			var contextsNode = node.Nodes.FirstOrDefault(n => n.Key == "Contexts");
-			if (contextsNode != null)
-				Contexts = FieldLoader.GetValue<HashSet<string>>("Contexts", contextsNode.Value.Value);
+			if (nodeDict.TryGetValue("Types", out var typesYaml))
+				Types = FieldLoader.GetValue<HashSet<string>>("Types", typesYaml.Value);
 
-			var platformNode = node.Nodes.FirstOrDefault(n => n.Key == "Platform");
-			if (platformNode != null)
+			if (nodeDict.TryGetValue("Contexts", out var contextYaml))
+				Contexts = FieldLoader.GetValue<HashSet<string>>("Contexts", contextYaml.Value);
+
+			if (nodeDict.TryGetValue("Platform", out var platformYaml))
 			{
-				var platformOverride = platformNode.Value.Nodes.FirstOrDefault(n => n.Key == Platform.CurrentPlatform.ToString());
+				var platformOverride = platformYaml.NodeWithKeyOrDefault(Platform.CurrentPlatform.ToString());
 				if (platformOverride != null)
 					Default = FieldLoader.GetValue<Hotkey>("value", platformOverride.Value.Value);
 			}
 
-			var readonlyNode = node.Nodes.FirstOrDefault(n => n.Key == "Readonly");
-			if (readonlyNode != null)
-				Readonly = FieldLoader.GetValue<bool>("Readonly", readonlyNode.Value.Value);
+			if (nodeDict.TryGetValue("Readonly", out var readonlyYaml))
+				Readonly = FieldLoader.GetValue<bool>("Readonly", readonlyYaml.Value);
 		}
 	}
 }

OpenRA.Game/HotkeyManager.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -18,8 +18,8 @@ namespace OpenRA
 	public sealed class HotkeyManager
 	{
 		readonly Dictionary<string, Hotkey> settings;
-		readonly Dictionary<string, HotkeyDefinition> definitions = new Dictionary<string, HotkeyDefinition>();
-		readonly Dictionary<string, Hotkey> keys = new Dictionary<string, Hotkey>();
+		readonly Dictionary<string, HotkeyDefinition> definitions = new();
+		readonly Dictionary<string, Hotkey> keys = new();
 
 		public HotkeyManager(IReadOnlyFileSystem fileSystem, Dictionary<string, Hotkey> settings, Manifest manifest)
 		{
@@ -35,7 +35,7 @@ namespace OpenRA
 
 			foreach (var kv in settings)
 			{
-				if (definitions.ContainsKey(kv.Key) && !definitions[kv.Key].Readonly)
+				if (definitions.TryGetValue(kv.Key, out var definition) && !definition.Readonly)
 					keys[kv.Key] = kv.Value;
 			}
 
@@ -43,6 +43,9 @@ namespace OpenRA
 				hd.Value.HasDuplicates = GetFirstDuplicate(hd.Value, this[hd.Value.Name].GetValue()) != null;
 		}
 
+		[System.Diagnostics.CodeAnalysis.SuppressMessage(
+			"Performance", "CA1854:Prefer the 'IDictionary.TryGetValue(TKey, out TValue)' method",
+			Justification = "Func must perform a live lookup in the collection, as the lookup value can change.")]
 		internal Func<Hotkey> GetHotkeyReference(string name)
 		{
 			// Is this a mod-defined hotkey?
@@ -102,7 +105,7 @@ namespace OpenRA
 			return null;
 		}
 
-		public HotkeyReference this[string name] => new HotkeyReference(GetHotkeyReference(name));
+		public HotkeyReference this[string name] => new(GetHotkeyReference(name));
 
 		public IEnumerable<HotkeyDefinition> Definitions => definitions.Values;
 	}

OpenRA.Game/HttpExtension.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/IUtilityCommand.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -9,12 +9,41 @@
  */
 #endregion
 
+using System;
+using System.Reflection;
+using OpenRA.Primitives;
 using OpenRA.Traits;
 
 namespace OpenRA
 {
 	public class Utility
 	{
+		static readonly ConcurrentCache<Type, FieldInfo[]> TypeFields =
+			new(type => type.GetFields());
+
+		static readonly ConcurrentCache<(MemberInfo Member, Type AttributeType), bool> MemberHasAttribute =
+			new(x => Attribute.IsDefined(x.Member, x.AttributeType));
+
+		static readonly ConcurrentCache<(MemberInfo Member, Type AttributeType, bool Inherit), object[]> MemberCustomAttributes =
+			new(x => x.Member.GetCustomAttributes(x.AttributeType, x.Inherit));
+
+		public static FieldInfo[] GetFields(Type type)
+		{
+			return TypeFields[type];
+		}
+
+		public static bool HasAttribute<TAttribute>(MemberInfo member)
+			where TAttribute : Attribute
+		{
+			return MemberHasAttribute[(member, typeof(TAttribute))];
+		}
+
+		public static TAttribute[] GetCustomAttributes<TAttribute>(MemberInfo member, bool inherit)
+			where TAttribute : Attribute
+		{
+			return (TAttribute[])MemberCustomAttributes[(member, typeof(TAttribute), inherit)];
+		}
+
 		public readonly ModData ModData;
 		public readonly InstalledMods Mods;
 

OpenRA.Game/Input/Hotkey.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -15,7 +15,7 @@ namespace OpenRA
 {
 	public readonly struct Hotkey : IEquatable<Hotkey>
 	{
-		public static Hotkey Invalid = new Hotkey(Keycode.UNKNOWN, Modifiers.None);
+		public static Hotkey Invalid = new(Keycode.UNKNOWN, Modifiers.None);
 		public bool IsValid()
 		{
 			return Key != Keycode.UNKNOWN;
@@ -42,7 +42,7 @@ namespace OpenRA
 			var mods = Modifiers.None;
 			if (parts.Length >= 2)
 			{
-				var modString = s.Substring(s.IndexOf(' '));
+				var modString = s[s.IndexOf(' ')..];
 				if (!Enum<Modifiers>.TryParse(modString, true, out mods))
 					return false;
 			}
@@ -84,7 +84,7 @@ namespace OpenRA
 			return obj is Hotkey o && (Hotkey?)o == this;
 		}
 
-		public override string ToString() { return $"{Key} {Modifiers.ToString("F")}"; }
+		public override string ToString() { return $"{Key} {Modifiers:F}"; }
 
 		public string DisplayString()
 		{

OpenRA.Game/Input/HotkeyReference.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -14,7 +14,7 @@ using System;
 namespace OpenRA
 {
 	/// <summary>
-	/// A reference to either a named hotkey (defined in the game settings) or a statically assigned hotkey
+	/// A reference to either a named hotkey (defined in the game settings) or a statically assigned hotkey.
 	/// </summary>
 	public class HotkeyReference
 	{

OpenRA.Game/Input/IInputHandler.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Input/InputHandler.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of

OpenRA.Game/Input/Keycode.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -13,7 +13,8 @@ using System.Collections.Generic;
 
 namespace OpenRA
 {
-	// List of keycodes, duplicated from SDL 2.0.1
+	// List of keycodes. Duplicated from SDL 2.0.1, with the addition
+	// of MOUSE4 and MOUSE5.
 	public enum Keycode
 	{
 		UNKNOWN = 0,
@@ -252,11 +253,13 @@ namespace OpenRA
 		KBDILLUMUP = 280 | (1 << 30),
 		EJECT = 281 | (1 << 30),
 		SLEEP = 282 | (1 << 30),
+		MOUSE4 = 283 | (1 << 30),
+		MOUSE5 = 284 | (1 << 30)
 	}
 
 	public static class KeycodeExts
 	{
-		static readonly Dictionary<Keycode, string> KeyNames = new Dictionary<Keycode, string>
+		static readonly Dictionary<Keycode, string> KeyNames = new()
 		{
 			{ Keycode.UNKNOWN, "Undefined" },
 			{ Keycode.RETURN, "Return" },
@@ -494,6 +497,8 @@ namespace OpenRA
 			{ Keycode.KBDILLUMUP, "KBDIllumUp" },
 			{ Keycode.EJECT, "Eject" },
 			{ Keycode.SLEEP, "Sleep" },
+			{ Keycode.MOUSE4, "Mouse 4" },
+			{ Keycode.MOUSE5, "Mouse 5" },
 		};
 
 		public static string DisplayString(Keycode k)

OpenRA.Game/InstalledMods.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -54,7 +54,7 @@ namespace OpenRA
 			return mods;
 		}
 
-		Manifest LoadMod(string id, string path)
+		static Manifest LoadMod(string id, string path)
 		{
 			IReadOnlyPackage package = null;
 			try
@@ -79,7 +79,7 @@ namespace OpenRA
 			return null;
 		}
 
-		Dictionary<string, Manifest> GetInstalledMods(IEnumerable<string> searchPaths, IEnumerable<string> explicitPaths)
+		static Dictionary<string, Manifest> GetInstalledMods(IEnumerable<string> searchPaths, IEnumerable<string> explicitPaths)
 		{
 			var ret = new Dictionary<string, Manifest>();
 			var candidates = GetCandidateMods(searchPaths)

OpenRA.Game/LocalPlayerProfile.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -66,8 +66,10 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Console.WriteLine("Failed to load keys: {0}", e);
-				Log.Write("debug", "Failed to load player keypair from `{0}` with exception: {1}", filePath, e);
+				Console.WriteLine("Failed to load keys:");
+				Console.WriteLine(e);
+				Log.Write("debug", $"Failed to load player keypair from `{filePath}` with exception:");
+				Log.Write("debug", e);
 			}
 		}
 
@@ -82,16 +84,17 @@ namespace OpenRA
 				{
 					var client = HttpClientFactory.Create();
 
-					var httpResponseMessage = await client.GetAsync(playerDatabase.Profile + Fingerprint);
+					var url = playerDatabase.Profile + Fingerprint;
+					var httpResponseMessage = await client.GetAsync(url);
 					var result = await httpResponseMessage.Content.ReadAsStreamAsync();
 
-					var yaml = MiniYaml.FromStream(result).First();
+					var yaml = MiniYaml.FromStream(result, url).First();
 					if (yaml.Key == "Player")
 					{
 						innerData = FieldLoader.Load<PlayerProfile>(yaml.Value);
 						if (innerData.KeyRevoked)
 						{
-							Log.Write("debug", "Revoking key with fingerprint {0}", Fingerprint);
+							Log.Write("debug", $"Revoking key with fingerprint {Fingerprint}");
 							DeleteKeypair();
 						}
 						else
@@ -102,7 +105,8 @@ namespace OpenRA
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", "Failed to parse player data result with exception: {0}", e);
+					Log.Write("debug", "Failed to parse player data result with exception:");
+					Log.Write("debug", e);
 					innerState = LinkState.ConnectionFailed;
 				}
 				finally
@@ -136,8 +140,10 @@ namespace OpenRA
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", "Failed to generate keypair with exception: {1}", e);
-					Console.WriteLine("Key generation failed: {0}", e);
+					Log.Write("debug", "Failed to generate keypair with exception:");
+					Log.Write("debug", e);
+					Console.WriteLine("Key generation failed:");
+					Console.WriteLine(e);
 
 					innerState = LinkState.Uninitialized;
 				}
@@ -152,8 +158,10 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to delete keypair with exception: {1}", e);
-				Console.WriteLine("Key deletion failed: {0}", e);
+				Log.Write("debug", "Failed to delete keypair with exception:");
+				Log.Write("debug", e);
+				Console.WriteLine("Key deletion failed:");
+				Console.WriteLine(e);
 			}
 
 			innerState = LinkState.Uninitialized;

OpenRA.Game/MPos.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -19,7 +19,7 @@ namespace OpenRA
 		public readonly int U, V;
 
 		public MPos(int u, int v) { U = u; V = v; }
-		public static readonly MPos Zero = new MPos(0, 0);
+		public static readonly MPos Zero = new(0, 0);
 
 		public static bool operator ==(MPos me, MPos other) { return me.U == other.U && me.V == other.V; }
 		public static bool operator !=(MPos me, MPos other) { return !(me == other); }
@@ -27,7 +27,7 @@ namespace OpenRA
 		public override int GetHashCode() { return U.GetHashCode() ^ V.GetHashCode(); }
 
 		public bool Equals(MPos other) { return other == this; }
-		public override bool Equals(object obj) { return obj is MPos && Equals((MPos)obj); }
+		public override bool Equals(object obj) { return obj is MPos uv && Equals(uv); }
 
 		public MPos Clamp(Rectangle r)
 		{
@@ -64,14 +64,14 @@ namespace OpenRA
 	}
 
 	/// <summary>
-	/// Projected map position
+	/// Projected map position.
 	/// </summary>
 	public readonly struct PPos : IEquatable<PPos>
 	{
 		public readonly int U, V;
 
 		public PPos(int u, int v) { U = u; V = v; }
-		public static readonly PPos Zero = new PPos(0, 0);
+		public static readonly PPos Zero = new(0, 0);
 
 		public static bool operator ==(PPos me, PPos other) { return me.U == other.U && me.V == other.V; }
 		public static bool operator !=(PPos me, PPos other) { return !(me == other); }
@@ -88,7 +88,7 @@ namespace OpenRA
 		public override int GetHashCode() { return U.GetHashCode() ^ V.GetHashCode(); }
 
 		public bool Equals(PPos other) { return other == this; }
-		public override bool Equals(object obj) { return obj is PPos && Equals((PPos)obj); }
+		public override bool Equals(object obj) { return obj is PPos puv && Equals(puv); }
 
 		public override string ToString() { return U + "," + V; }
 	}

OpenRA.Game/Manifest.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -43,17 +43,6 @@ namespace OpenRA
 		}
 	}
 
-	public sealed class ModelSequenceFormat : IGlobalModData
-	{
-		public readonly string Type;
-		public readonly IReadOnlyDictionary<string, MiniYaml> Metadata;
-		public ModelSequenceFormat(MiniYaml yaml)
-		{
-			Type = yaml.Value;
-			Metadata = new ReadOnlyDictionary<string, MiniYaml>(yaml.ToDictionary());
-		}
-	}
-
 	public class ModMetadata
 	{
 		public string Title;
@@ -64,8 +53,8 @@ namespace OpenRA
 		public bool Hidden;
 	}
 
-	/// <summary> Describes what is to be loaded in order to run a mod. </summary>
-	public class Manifest : IDisposable
+	/// <summary>Describes what is to be loaded in order to run a mod.</summary>
+	public sealed class Manifest : IDisposable
 	{
 		public readonly string Id;
 		public readonly IReadOnlyPackage Package;
@@ -95,7 +84,7 @@ namespace OpenRA
 			"RequiresMods", "PackageFormats"
 		};
 
-		readonly TypeDictionary modules = new TypeDictionary();
+		readonly TypeDictionary modules = new();
 		readonly Dictionary<string, MiniYaml> yaml;
 
 		bool customDataLoaded;
@@ -105,7 +94,8 @@ namespace OpenRA
 			Id = modId;
 			Package = package;
 
-			var nodes = MiniYaml.FromStream(package.GetStream("mod.yaml"), "mod.yaml");
+			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
+			var nodes = MiniYaml.FromStream(package.GetStream("mod.yaml"), $"{package.Name}:mod.yaml", stringPool: stringPool);
 			for (var i = nodes.Count - 1; i >= 0; i--)
 			{
 				if (nodes[i].Key != "Include")
@@ -118,7 +108,7 @@ namespace OpenRA
 					throw new YamlException($"{nodes[i].Location}: File `{filename}` not found.");
 
 				nodes.RemoveAt(i);
-				nodes.InsertRange(i, MiniYaml.FromStream(contents, filename));
+				nodes.InsertRange(i, MiniYaml.FromStream(contents, $"{package.Name}:{filename}", stringPool: stringPool));
 			}
 
 			// Merge inherited overrides
@@ -157,25 +147,25 @@ namespace OpenRA
 			// Allow inherited mods to import parent maps.
 			var compat = new List<string> { Id };
 
-			if (yaml.ContainsKey("SupportsMapsFrom"))
-				compat.AddRange(yaml["SupportsMapsFrom"].Value.Split(',').Select(c => c.Trim()));
+			if (yaml.TryGetValue("SupportsMapsFrom", out var entry))
+				compat.AddRange(entry.Value.Split(',').Select(c => c.Trim()));
 
 			MapCompatibility = compat.ToArray();
 
-			if (yaml.ContainsKey("DefaultOrderGenerator"))
-				DefaultOrderGenerator = yaml["DefaultOrderGenerator"].Value;
+			if (yaml.TryGetValue("DefaultOrderGenerator", out entry))
+				DefaultOrderGenerator = entry.Value;
 
-			if (yaml.ContainsKey("PackageFormats"))
-				PackageFormats = FieldLoader.GetValue<string[]>("PackageFormats", yaml["PackageFormats"].Value);
+			if (yaml.TryGetValue("PackageFormats", out entry))
+				PackageFormats = FieldLoader.GetValue<string[]>("PackageFormats", entry.Value);
 
-			if (yaml.ContainsKey("SoundFormats"))
-				SoundFormats = FieldLoader.GetValue<string[]>("SoundFormats", yaml["SoundFormats"].Value);
+			if (yaml.TryGetValue("SoundFormats", out entry))
+				SoundFormats = FieldLoader.GetValue<string[]>("SoundFormats", entry.Value);
 
-			if (yaml.ContainsKey("SpriteFormats"))
-				SpriteFormats = FieldLoader.GetValue<string[]>("SpriteFormats", yaml["SpriteFormats"].Value);
+			if (yaml.TryGetValue("SpriteFormats", out entry))
+				SpriteFormats = FieldLoader.GetValue<string[]>("SpriteFormats", entry.Value);
 
-			if (yaml.ContainsKey("VideoFormats"))
-				VideoFormats = FieldLoader.GetValue<string[]>("VideoFormats", yaml["VideoFormats"].Value);
+			if (yaml.TryGetValue("VideoFormats", out entry))
+				VideoFormats = FieldLoader.GetValue<string[]>("VideoFormats", entry.Value);
 		}
 
 		public void LoadCustomData(ObjectCreator oc)
@@ -211,18 +201,18 @@ namespace OpenRA
 
 		static string[] YamlList(Dictionary<string, MiniYaml> yaml, string key)
 		{
-			if (!yaml.ContainsKey(key))
+			if (!yaml.TryGetValue(key, out var value))
 				return Array.Empty<string>();
 
-			return yaml[key].ToDictionary().Keys.ToArray();
+			return value.Nodes.Select(n => n.Key).ToArray();
 		}
 
 		static IReadOnlyDictionary<string, string> YamlDictionary(Dictionary<string, MiniYaml> yaml, string key)
 		{
-			if (!yaml.ContainsKey(key))
+			if (!yaml.TryGetValue(key, out var value))
 				return new Dictionary<string, string>();
 
-			return yaml[key].ToDictionary(my => my.Value);
+			return value.ToDictionary(my => my.Value);
 		}
 
 		public bool Contains<T>() where T : IGlobalModData

OpenRA.Game/Map/ActorInitializer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -54,7 +54,7 @@ namespace OpenRA
 			// Traits tagged with an instance name prefer inits with the same name.
 			// If a more specific init is not available, fall back to an unnamed init.
 			// If duplicate inits are defined, take the last to match standard yaml override expectations
-			if (info != null && !string.IsNullOrEmpty(info.InstanceName))
+			if (!string.IsNullOrEmpty(info?.InstanceName))
 				return inits.LastOrDefault(i => i.InstanceName == info.InstanceName) ??
 					inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));
 
@@ -159,9 +159,9 @@ namespace OpenRA
 
 		public virtual void Initialize(T value)
 		{
-			var field = typeof(ValueActorInit<T>).GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance);
-			if (field != null)
-				field.SetValue(this, value);
+			typeof(ValueActorInit<T>)
+				.GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance)
+				?.SetValue(this, value);
 		}
 
 		public override MiniYaml Save()
@@ -175,8 +175,7 @@ namespace OpenRA
 		protected CompositeActorInit(TraitInfo info)
 			: base(info.InstanceName) { }
 
-		protected CompositeActorInit()
-			: base() { }
+		protected CompositeActorInit() { }
 
 		public virtual void Initialize(MiniYaml yaml)
 		{
@@ -246,16 +245,16 @@ namespace OpenRA
 
 		public void Initialize(MiniYaml yaml)
 		{
-			var field = typeof(OwnerInit).GetField(nameof(InternalName), BindingFlags.Public | BindingFlags.Instance);
-			if (field != null)
-				field.SetValue(this, yaml.Value);
+			typeof(OwnerInit)
+				.GetField(nameof(InternalName), BindingFlags.Public | BindingFlags.Instance)
+				?.SetValue(this, yaml.Value);
 		}
 
 		public void Initialize(Player player)
 		{
-			var field = typeof(OwnerInit).GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance);
-			if (field != null)
-				field.SetValue(this, player);
+			typeof(OwnerInit)
+				.GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance)
+				?.SetValue(this, player);
 		}
 
 		public override MiniYaml Save()

OpenRA.Game/Map/ActorReference.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -22,7 +22,7 @@ namespace OpenRA
 {
 	public interface ISuppressInitExport { }
 
-	public class ActorReference : IEnumerable
+	public class ActorReference : IEnumerable<object>
 	{
 		public string Type;
 		readonly Lazy<TypeDictionary> initDict;
@@ -84,27 +84,29 @@ namespace OpenRA
 
 		public MiniYaml Save(Func<ActorInit, bool> initFilter = null)
 		{
-			var ret = new MiniYaml(Type);
+			var nodes = new List<MiniYamlNode>();
 			foreach (var o in initDict.Value)
 			{
-				if (!(o is ActorInit init) || o is ISuppressInitExport)
+				if (o is not ActorInit init || o is ISuppressInitExport)
 					continue;
 
 				if (initFilter != null && !initFilter(init))
 					continue;
 
 				var initTypeName = init.GetType().Name;
-				var initName = initTypeName.Substring(0, initTypeName.Length - 4);
+				var initName = initTypeName[..^4];
 				if (!string.IsNullOrEmpty(init.InstanceName))
 					initName += ActorInfo.TraitInstanceSeparator + init.InstanceName;
 
-				ret.Nodes.Add(new MiniYamlNode(initName, init.Save()));
+				nodes.Add(new MiniYamlNode(initName, init.Save()));
 			}
 
-			return ret;
+			return new MiniYaml(Type, nodes);
 		}
 
-		public IEnumerator GetEnumerator() { return initDict.Value.GetEnumerator(); }
+		public IEnumerator<object> GetEnumerator() { return initDict.Value.GetEnumerator(); }
+
+		IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); }
 
 		public ActorReference Clone()
 		{
@@ -137,7 +139,7 @@ namespace OpenRA
 			return removed;
 		}
 
-		public IEnumerable<T> GetAll<T>() where T : ActorInit
+		public IReadOnlyCollection<T> GetAll<T>() where T : ActorInit
 		{
 			return initDict.Value.WithInterface<T>();
 		}
@@ -150,8 +152,9 @@ namespace OpenRA
 			// If a more specific init is not available, fall back to an unnamed init.
 			// If duplicate inits are defined, take the last to match standard yaml override expectations
 			if (info != null && !string.IsNullOrEmpty(info.InstanceName))
-				return inits.LastOrDefault(i => i.InstanceName == info.InstanceName) ??
-				       inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));
+				return
+					inits.LastOrDefault(i => i.InstanceName == info.InstanceName) ??
+					inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));
 
 			// Untagged traits will only use untagged inits
 			return inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));

OpenRA.Game/Map/CellCoordsRegion.cs

@@ -0,0 +1,90 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Collections;
+using System.Collections.Generic;
+
+namespace OpenRA
+{
+	public readonly struct CellCoordsRegion : IEnumerable<CPos>
+	{
+		public struct CellCoordsEnumerator : IEnumerator<CPos>
+		{
+			readonly CellCoordsRegion r;
+
+			public CellCoordsEnumerator(CellCoordsRegion region)
+				: this()
+			{
+				r = region;
+				Reset();
+			}
+
+			public bool MoveNext()
+			{
+				var x = Current.X + 1;
+				var y = Current.Y;
+
+				// Check for column overflow.
+				if (x > r.BottomRight.X)
+				{
+					y++;
+					x = r.TopLeft.X;
+
+					// Check for row overflow.
+					if (y > r.BottomRight.Y)
+						return false;
+				}
+
+				Current = new CPos(x, y);
+				return true;
+			}
+
+			public void Reset()
+			{
+				Current = new CPos(r.TopLeft.X - 1, r.TopLeft.Y);
+			}
+
+			public CPos Current { get; private set; }
+
+			readonly object IEnumerator.Current => Current;
+			public readonly void Dispose() { }
+		}
+
+		public CellCoordsRegion(CPos topLeft, CPos bottomRight)
+		{
+			TopLeft = topLeft;
+			BottomRight = bottomRight;
+		}
+
+		public override string ToString()
+		{
+			return $"{TopLeft}->{BottomRight}";
+		}
+
+		public CellCoordsEnumerator GetEnumerator()
+		{
+			return new CellCoordsEnumerator(this);
+		}
+
+		IEnumerator<CPos> IEnumerable<CPos>.GetEnumerator()
+		{
+			return GetEnumerator();
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return GetEnumerator();
+		}
+
+		public CPos TopLeft { get; }
+		public CPos BottomRight { get; }
+	}
+}

OpenRA.Game/Map/CellLayer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -72,7 +72,7 @@ namespace OpenRA
 			return uv.V * Size.Width + uv.U;
 		}
 
-		/// <summary>Gets or sets the <see cref="CellLayer"/> using cell coordinates</summary>
+		/// <summary>Gets or sets the <see cref="CellLayer"/> using cell coordinates.</summary>
 		public T this[CPos cell]
 		{
 			get => Entries[Index(cell)];
@@ -85,7 +85,7 @@ namespace OpenRA
 			}
 		}
 
-		/// <summary>Gets or sets the layer contents using raw map coordinates (not CPos!)</summary>
+		/// <summary>Gets or sets the layer contents using raw map coordinates (not CPos!).</summary>
 		public T this[MPos uv]
 		{
 			get => Entries[Index(uv)];

OpenRA.Game/Map/CellLayerBase.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -24,10 +24,10 @@ namespace OpenRA
 		protected readonly T[] Entries;
 		protected readonly Rectangle Bounds;
 
-		public CellLayerBase(Map map)
+		protected CellLayerBase(Map map)
 			: this(map.Grid.Type, new Size(map.MapSize.X, map.MapSize.Y)) { }
 
-		public CellLayerBase(MapGridType gridType, Size size)
+		protected CellLayerBase(MapGridType gridType, Size size)
 		{
 			Size = size;
 			Bounds = new Rectangle(0, 0, Size.Width, Size.Height);
@@ -43,13 +43,13 @@ namespace OpenRA
 			Array.Copy(anotherLayer.Entries, Entries, Entries.Length);
 		}
 
-		/// <summary>Clears the layer contents with their default value</summary>
+		/// <summary>Clears the layer contents with their default value.</summary>
 		public virtual void Clear()
 		{
 			Array.Clear(Entries, 0, Entries.Length);
 		}
 
-		/// <summary>Clears the layer contents with a known value</summary>
+		/// <summary>Clears the layer contents with a known value.</summary>
 		public virtual void Clear(T clearValue)
 		{
 			Array.Fill(Entries, clearValue);

OpenRA.Game/Map/CellRegion.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -12,7 +12,6 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
-using System.Linq;
 
 namespace OpenRA
 {
@@ -64,9 +63,9 @@ namespace OpenRA
 		}
 
 		/// <summary>Returns the minimal region that covers at least the specified cells.</summary>
-		public static CellRegion BoundingRegion(MapGridType shape, IEnumerable<CPos> cells)
+		public static CellRegion BoundingRegion(MapGridType shape, IReadOnlyCollection<CPos> cells)
 		{
-			if (cells == null || !cells.Any())
+			if (cells == null || cells.Count == 0)
 				throw new ArgumentException("cells must not be null or empty.", nameof(cells));
 
 			var minU = int.MaxValue;
@@ -102,7 +101,8 @@ namespace OpenRA
 			return uv.U >= mapTopLeft.U && uv.U <= mapBottomRight.U && uv.V >= mapTopLeft.V && uv.V <= mapBottomRight.V;
 		}
 
-		public MapCoordsRegion MapCoords => new MapCoordsRegion(mapTopLeft, mapBottomRight);
+		public MapCoordsRegion MapCoords => new(mapTopLeft, mapBottomRight);
+		public CellCoordsRegion CellCoords => new(TopLeft, BottomRight);
 
 		public CellRegionEnumerator GetEnumerator()
 		{
@@ -126,25 +126,22 @@ namespace OpenRA
 			// Current position, in map coordinates
 			int u, v;
 
-			// Current position, in cell coordinates
-			CPos current;
-
 			public CellRegionEnumerator(CellRegion region)
 				: this()
 			{
 				r = region;
 				Reset();
-				current = new MPos(u, v).ToCPos(r.gridType);
+				Current = new MPos(u, v).ToCPos(r.gridType);
 			}
 
 			public bool MoveNext()
 			{
-				u += 1;
+				u++;
 
 				// Check for column overflow
 				if (u > r.mapBottomRight.U)
 				{
-					v += 1;
+					v++;
 					u = r.mapTopLeft.U;
 
 					// Check for row overflow
@@ -152,7 +149,8 @@ namespace OpenRA
 						return false;
 				}
 
-				current = new MPos(u, v).ToCPos(r.gridType);
+				// Current position, in cell coordinates
+				Current = new MPos(u, v).ToCPos(r.gridType);
 				return true;
 			}
 
@@ -163,9 +161,9 @@ namespace OpenRA
 				v = r.mapTopLeft.V;
 			}
 
-			public CPos Current => current;
-			object IEnumerator.Current => Current;
-			public void Dispose() { }
+			public CPos Current { get; private set; }
+			readonly object IEnumerator.Current => Current;
+			public readonly void Dispose() { }
 		}
 	}
 }

OpenRA.Game/Map/Map.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -11,6 +11,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -65,7 +66,7 @@ namespace OpenRA
 		MissionSelector = 4
 	}
 
-	class MapField
+	sealed class MapField
 	{
 		enum Type { Normal, NodeList, MiniYaml }
 		readonly FieldInfo field;
@@ -90,13 +91,13 @@ namespace OpenRA
 				throw new InvalidOperationException("Map does not have a field/property " + fieldName);
 
 			var t = field != null ? field.FieldType : property.PropertyType;
-			type = t == typeof(List<MiniYamlNode>) ? Type.NodeList :
+			type = t == typeof(IReadOnlyCollection<MiniYamlNode>) ? Type.NodeList :
 				t == typeof(MiniYaml) ? Type.MiniYaml : Type.Normal;
 		}
 
-		public void Deserialize(Map map, List<MiniYamlNode> nodes)
+		public void Deserialize(Map map, MiniYaml yaml)
 		{
-			var node = nodes.FirstOrDefault(n => n.Key == key);
+			var node = yaml.NodeWithKeyOrDefault(key);
 			if (node == null)
 			{
 				if (required)
@@ -130,14 +131,14 @@ namespace OpenRA
 			var value = field != null ? field.GetValue(map) : property.GetValue(map, null);
 			if (type == Type.NodeList)
 			{
-				var listValue = (List<MiniYamlNode>)value;
+				var listValue = (IReadOnlyCollection<MiniYamlNode>)value;
 				if (required || listValue.Count > 0)
 					nodes.Add(new MiniYamlNode(key, null, listValue));
 			}
 			else if (type == Type.MiniYaml)
 			{
 				var yamlValue = (MiniYaml)value;
-				if (required || (yamlValue != null && (yamlValue.Value != null || yamlValue.Nodes.Count > 0)))
+				if (required || (yamlValue != null && (yamlValue.Value != null || yamlValue.Nodes.Length > 0)))
 					nodes.Add(new MiniYamlNode(key, yamlValue));
 			}
 			else
@@ -149,35 +150,35 @@ namespace OpenRA
 		}
 	}
 
-	public class Map : IReadOnlyFileSystem
+	public sealed class Map : IReadOnlyFileSystem, IDisposable
 	{
 		public const int SupportedMapFormat = 11;
 		public const int CurrentMapFormat = 12;
 		const short InvalidCachedTerrainIndex = -1;
 
-		/// <summary>Defines the order of the fields in map.yaml</summary>
+		/// <summary>Defines the order of the fields in map.yaml.</summary>
 		static readonly MapField[] YamlFields =
 		{
-			new MapField("MapFormat"),
-			new MapField("RequiresMod"),
-			new MapField("Title"),
-			new MapField("Author"),
-			new MapField("Tileset"),
-			new MapField("MapSize"),
-			new MapField("Bounds"),
-			new MapField("Visibility"),
-			new MapField("Categories"),
-			new MapField("Translations", required: false, ignoreIfValue: ""),
-			new MapField("LockPreview", required: false, ignoreIfValue: "False"),
-			new MapField("Players", "PlayerDefinitions"),
-			new MapField("Actors", "ActorDefinitions"),
-			new MapField("Rules", "RuleDefinitions", required: false),
-			new MapField("Sequences", "SequenceDefinitions", required: false),
-			new MapField("ModelSequences", "ModelSequenceDefinitions", required: false),
-			new MapField("Weapons", "WeaponDefinitions", required: false),
-			new MapField("Voices", "VoiceDefinitions", required: false),
-			new MapField("Music", "MusicDefinitions", required: false),
-			new MapField("Notifications", "NotificationDefinitions", required: false),
+			new("MapFormat"),
+			new("RequiresMod"),
+			new("Title"),
+			new("Author"),
+			new("Tileset"),
+			new("MapSize"),
+			new("Bounds"),
+			new("Visibility"),
+			new("Categories"),
+			new("LockPreview", required: false, ignoreIfValue: "False"),
+			new("Players", "PlayerDefinitions"),
+			new("Actors", "ActorDefinitions"),
+			new("Rules", "RuleDefinitions", required: false),
+			new("Translations", "TranslationDefinitions", required: false),
+			new("Sequences", "SequenceDefinitions", required: false),
+			new("ModelSequences", "ModelSequenceDefinitions", required: false),
+			new("Weapons", "WeaponDefinitions", required: false),
+			new("Voices", "VoiceDefinitions", required: false),
+			new("Music", "MusicDefinitions", required: false),
+			new("Notifications", "NotificationDefinitions", required: false),
 		};
 
 		// Format versions
@@ -193,24 +194,24 @@ namespace OpenRA
 		public Rectangle Bounds;
 		public MapVisibility Visibility = MapVisibility.Lobby;
 		public string[] Categories = { "Conquest" };
-		public string[] Translations;
 
 		public int2 MapSize { get; private set; }
 
 		// Player and actor yaml. Public for access by the map importers and lint checks.
-		public List<MiniYamlNode> PlayerDefinitions = new List<MiniYamlNode>();
-		public List<MiniYamlNode> ActorDefinitions = new List<MiniYamlNode>();
+		public IReadOnlyCollection<MiniYamlNode> PlayerDefinitions = ImmutableArray<MiniYamlNode>.Empty;
+		public IReadOnlyCollection<MiniYamlNode> ActorDefinitions = ImmutableArray<MiniYamlNode>.Empty;
 
 		// Custom map yaml. Public for access by the map importers and lint checks
-		public readonly MiniYaml RuleDefinitions;
-		public readonly MiniYaml SequenceDefinitions;
-		public readonly MiniYaml ModelSequenceDefinitions;
-		public readonly MiniYaml WeaponDefinitions;
-		public readonly MiniYaml VoiceDefinitions;
-		public readonly MiniYaml MusicDefinitions;
-		public readonly MiniYaml NotificationDefinitions;
+		public MiniYaml RuleDefinitions;
+		public MiniYaml TranslationDefinitions;
+		public MiniYaml SequenceDefinitions;
+		public MiniYaml ModelSequenceDefinitions;
+		public MiniYaml WeaponDefinitions;
+		public MiniYaml VoiceDefinitions;
+		public MiniYaml MusicDefinitions;
+		public MiniYaml NotificationDefinitions;
 
-		public readonly Dictionary<CPos, TerrainTile> ReplacedInvalidTerrainTiles = new Dictionary<CPos, TerrainTile>();
+		public readonly Dictionary<CPos, TerrainTile> ReplacedInvalidTerrainTiles = new();
 
 		// Generated data
 		public readonly MapGrid Grid;
@@ -218,6 +219,8 @@ namespace OpenRA
 		public string Uid { get; private set; }
 
 		public Ruleset Rules { get; private set; }
+		public SequenceSet Sequences { get; private set; }
+
 		public bool InvalidCustomRules { get; private set; }
 		public Exception InvalidCustomRulesException { get; private set; }
 
@@ -243,6 +246,8 @@ namespace OpenRA
 		public CellRegion AllCells { get; private set; }
 		public List<CPos> AllEdgeCells { get; private set; }
 
+		public event Action<CPos> CellProjectionChanged;
+
 		// Internal data
 		readonly ModData modData;
 		CellLayer<short> cachedTerrainIndexes;
@@ -252,8 +257,6 @@ namespace OpenRA
 		CellLayer<byte> projectedHeight;
 		Rectangle projectionSafeBounds;
 
-		internal Translation Translation;
-
 		public static string ComputeUID(IReadOnlyPackage package)
 		{
 			return ComputeUID(package, GetMapFormat(package));
@@ -272,7 +275,10 @@ namespace OpenRA
 			try
 			{
 				foreach (var filename in contents)
-					if (filename.EndsWith(".yaml") || filename.EndsWith(".bin") || filename.EndsWith(".lua") || (format >= 12 && filename == "map.png"))
+					if (filename.EndsWith(".yaml", StringComparison.Ordinal) ||
+						filename.EndsWith(".bin", StringComparison.Ordinal) ||
+						filename.EndsWith(".lua", StringComparison.Ordinal) ||
+						(format >= 12 && filename == "map.png"))
 						streams.Add(package.GetStream(filename));
 
 				// Take the SHA1
@@ -336,11 +342,12 @@ namespace OpenRA
 			Height = new CellLayer<byte>(Grid.Type, size);
 			Ramp = new CellLayer<byte>(Grid.Type, size);
 			Tiles.Clear(terrainInfo.DefaultTerrainTile);
+
 			if (Grid.MaximumTerrainHeight > 0)
 			{
-				Height.CellEntryChanged += UpdateProjection;
-				Tiles.CellEntryChanged += UpdateProjection;
 				Tiles.CellEntryChanged += UpdateRamp;
+				Tiles.CellEntryChanged += UpdateProjection;
+				Height.CellEntryChanged += UpdateProjection;
 			}
 
 			PostInit();
@@ -354,15 +361,15 @@ namespace OpenRA
 			if (!Package.Contains("map.yaml") || !Package.Contains("map.bin"))
 				throw new InvalidDataException($"Not a valid map\n File: {package.Name}");
 
-			var yaml = new MiniYaml(null, MiniYaml.FromStream(Package.GetStream("map.yaml"), package.Name));
+			var yaml = new MiniYaml(null, MiniYaml.FromStream(Package.GetStream("map.yaml"), $"{package.Name}:map.yaml"));
 			foreach (var field in YamlFields)
-				field.Deserialize(this, yaml.Nodes);
+				field.Deserialize(this, yaml);
 
 			if (MapFormat < SupportedMapFormat)
 				throw new InvalidDataException($"Map format {MapFormat} is not supported.\n File: {package.Name}");
 
-			PlayerDefinitions = MiniYaml.NodesOrEmpty(yaml, "Players");
-			ActorDefinitions = MiniYaml.NodesOrEmpty(yaml, "Actors");
+			PlayerDefinitions = yaml.NodeWithKeyOrDefault("Players")?.Value.Nodes ?? ImmutableArray<MiniYamlNode>.Empty;
+			ActorDefinitions = yaml.NodeWithKeyOrDefault("Actors")?.Value.Nodes ?? ImmutableArray<MiniYamlNode>.Empty;
 
 			Grid = modData.Manifest.Get<MapGrid>();
 
@@ -387,7 +394,7 @@ namespace OpenRA
 
 							// TODO: Remember to remove this when rewriting tile variants / PickAny
 							if (index == byte.MaxValue)
-								index = (byte)(i % 4 + (j % 4) * 4);
+								index = (byte)(i % 4 + j % 4 * 4);
 
 							Tiles[new MPos(i, j)] = new TerrainTile(tile, index);
 						}
@@ -434,19 +441,18 @@ namespace OpenRA
 			try
 			{
 				Rules = Ruleset.Load(modData, this, Tileset, RuleDefinitions, WeaponDefinitions,
-					VoiceDefinitions, NotificationDefinitions, MusicDefinitions, SequenceDefinitions, ModelSequenceDefinitions);
+					VoiceDefinitions, NotificationDefinitions, MusicDefinitions, ModelSequenceDefinitions);
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to load rules for {0} with error {1}", Title, e);
+				Log.Write("debug", $"Failed to load rules for {Title} with error");
+				Log.Write("debug", e);
 				InvalidCustomRules = true;
 				InvalidCustomRulesException = e;
 				Rules = Ruleset.LoadDefaultsForTileSet(modData, Tileset);
 			}
 
-			Rules.Sequences.Preload();
-
-			Translation = new Translation(Game.Settings.Player.Language, Translations, this);
+			Sequences = new SequenceSet(this, modData, Tileset, SequenceDefinitions);
 
 			var tl = new MPos(0, 0).ToCPos(this);
 			var br = new MPos(MapSize.X - 1, MapSize.Y - 1).ToCPos(this);
@@ -477,17 +483,17 @@ namespace OpenRA
 			AllEdgeCells = UpdateEdgeCells();
 
 			// Invalidate the entry for a cell if anything could cause the terrain index to change.
-			Action<CPos> invalidateTerrainIndex = c =>
+			void InvalidateTerrainIndex(CPos c)
 			{
 				if (cachedTerrainIndexes != null)
 					cachedTerrainIndexes[c] = InvalidCachedTerrainIndex;
-			};
+			}
 
 			// Even though the cache is lazily initialized, we must attach these event handlers on init.
 			// This ensures our handler to invalidate the cache runs first,
 			// so other listeners to these same events will get correct data when calling GetTerrainIndex.
-			CustomTerrain.CellEntryChanged += invalidateTerrainIndex;
-			Tiles.CellEntryChanged += invalidateTerrainIndex;
+			CustomTerrain.CellEntryChanged += InvalidateTerrainIndex;
+			Tiles.CellEntryChanged += InvalidateTerrainIndex;
 		}
 
 		void UpdateRamp(CPos cell)
@@ -530,6 +536,7 @@ namespace OpenRA
 				var inverse = inverseCellProjection[uv];
 				inverse.Clear();
 				inverse.Add(uv);
+				CellProjectionChanged?.Invoke(cell);
 				return;
 			}
 
@@ -567,6 +574,8 @@ namespace OpenRA
 					projectedHeight[temp] = height;
 				}
 			}
+
+			CellProjectionChanged?.Invoke(cell);
 		}
 
 		byte ProjectedCellHeightInner(PPos puv)
@@ -602,7 +611,7 @@ namespace OpenRA
 
 			// Odd-height ramps get bumped up a level to the next even height layer
 			if ((height & 1) == 1 && Ramp[uv] != 0)
-				height += 1;
+				height++;
 
 			var candidates = new List<PPos>();
 
@@ -641,13 +650,25 @@ namespace OpenRA
 				foreach (var file in Package.Contents)
 					toPackage.Update(file, Package.GetStream(file).ReadAllBytes());
 
+			void UpdatePackage(string filename, byte[] data)
+			{
+				if (Package != toPackage)
+					toPackage.Update(filename, data);
+				else
+				{
+					var stream = Package.GetStream(filename);
+					if (stream == null || !Enumerable.SequenceEqual(data, stream.ReadAllBytes()))
+						toPackage.Update(filename, data);
+				}
+			}
+
 			if (!LockPreview)
-				toPackage.Update("map.png", SavePreview());
+				UpdatePackage("map.png", SavePreview());
 
 			// Update the package with the new map data
-			var s = root.WriteToString();
-			toPackage.Update("map.yaml", Encoding.UTF8.GetBytes(s));
-			toPackage.Update("map.bin", SaveBinaryData());
+			UpdatePackage("map.yaml", Encoding.UTF8.GetBytes(root.WriteToString()));
+			UpdatePackage("map.bin", SaveBinaryData());
+
 			Package = toPackage;
 
 			// Update UID to match the newly saved data
@@ -667,16 +688,16 @@ namespace OpenRA
 				writer.Write((ushort)MapSize.Y);
 
 				// Data offsets
-				var tilesOffset = 17;
+				const int TilesOffset = 17;
 				var heightsOffset = Grid.MaximumTerrainHeight > 0 ? 3 * MapSize.X * MapSize.Y + 17 : 0;
 				var resourcesOffset = (Grid.MaximumTerrainHeight > 0 ? 4 : 3) * MapSize.X * MapSize.Y + 17;
 
-				writer.Write((uint)tilesOffset);
+				writer.Write((uint)TilesOffset);
 				writer.Write((uint)heightsOffset);
 				writer.Write((uint)resourcesOffset);
 
 				// Tile data
-				if (tilesOffset != 0)
+				if (TilesOffset != 0)
 				{
 					for (var i = 0; i < MapSize.X; i++)
 					{
@@ -733,8 +754,8 @@ namespace OpenRA
 		public byte[] SavePreview()
 		{
 			var actorTypes = Rules.Actors.Values.Where(a => a.HasTraitInfo<IMapPreviewSignatureInfo>());
-			var actors = ActorDefinitions.Where(a => actorTypes.Where(ai => ai.Name == a.Value.Value).Any());
-			var positions = new List<(MPos Position, Color Color)>();
+			var actors = ActorDefinitions.Where(a => actorTypes.Any(ai => ai.Name == a.Value.Value));
+			var positions = new List<(MPos Uv, Color Color)>();
 			foreach (var actor in actors)
 			{
 				var s = new ActorReference(actor.Value.Value, actor.Value.ToDictionary());
@@ -758,19 +779,10 @@ namespace OpenRA
 
 			if (Grid.MaximumTerrainHeight > 0)
 			{
-				// The minimap is drawn in cell space, so we need to
-				// unproject the PPos bounds to find the MPos boundaries.
-				// This matches the calculation in RadarWidget that is used ingame
-				for (var x = Bounds.Left; x < Bounds.Right; x++)
-				{
-					var allTop = Unproject(new PPos(x, Bounds.Top));
-					var allBottom = Unproject(new PPos(x, Bounds.Bottom));
-					if (allTop.Count > 0)
-						top = Math.Min(top, allTop.MinBy(uv => uv.V).V);
+				(top, bottom) = GetCellSpaceBounds();
 
-					if (allBottom.Count > 0)
-						bottom = Math.Max(bottom, allBottom.MaxBy(uv => uv.V).V);
-				}
+				if (top == int.MaxValue || bottom == int.MinValue)
+					throw new InvalidDataException("The map has invalid boundaries");
 			}
 			else
 			{
@@ -787,18 +799,21 @@ namespace OpenRA
 				bitmapWidth = 2 * bitmapWidth - 1;
 
 			var stride = bitmapWidth * 4;
-			var pxStride = 4;
+			const int PxStride = 4;
 			var minimapData = new byte[stride * height];
 			(Color Left, Color Right) terrainColor = default;
 
+			var colorsByPosition = positions
+				.GroupBy(p => p.Uv)
+				.ToDictionary(g => g.Key, g => g.First().Color);
 			for (var y = 0; y < height; y++)
 			{
 				for (var x = 0; x < width; x++)
 				{
 					var uv = new MPos(x + Bounds.Left, y + top);
 
-					// FirstOrDefault will return a (MPos.Zero, Color.Transparent) if positions is empty
-					var actorColor = positions.FirstOrDefault(ap => ap.Position == uv).Color;
+					// TryGetValue will return Color.Transparent if not found
+					colorsByPosition.TryGetValue(uv, out var actorColor);
 					if (actorColor.A == 0)
 						terrainColor = GetTerrainColorPair(uv);
 
@@ -806,10 +821,10 @@ namespace OpenRA
 					{
 						// Odd rows are shifted right by 1px
 						var dx = uv.V & 1;
-						var xOffset = pxStride * (2 * x + dx);
+						var xOffset = PxStride * (2 * x + dx);
 						if (x + dx > 0)
 						{
-							var z = y * stride + xOffset - pxStride;
+							var z = y * stride + xOffset - PxStride;
 							var c = actorColor.A == 0 ? terrainColor.Left : actorColor;
 							minimapData[z++] = c.R;
 							minimapData[z++] = c.G;
@@ -829,7 +844,7 @@ namespace OpenRA
 					}
 					else
 					{
-						var z = y * stride + pxStride * x;
+						var z = y * stride + PxStride * x;
 						var c = actorColor.A == 0 ? terrainColor.Left : actorColor;
 						minimapData[z++] = c.R;
 						minimapData[z++] = c.G;
@@ -843,6 +858,28 @@ namespace OpenRA
 			return png.Save();
 		}
 
+		public (int Top, int Bottom) GetCellSpaceBounds()
+		{
+			var top = int.MaxValue;
+			var bottom = int.MinValue;
+
+			// The minimap is drawn in cell space, so we need to
+			// unproject the PPos bounds to find the MPos boundaries.
+			// This matches the calculation in RadarWidget that is used ingame
+			for (var x = Bounds.Left; x < Bounds.Right; x++)
+			{
+				var allTop = Unproject(new PPos(x, Bounds.Top));
+				var allBottom = Unproject(new PPos(x, Bounds.Bottom));
+				if (allTop.Count > 0)
+					top = Math.Min(top, allTop.MinBy(uv => uv.V).V);
+
+				if (allBottom.Count > 0)
+					bottom = Math.Max(bottom, allBottom.MaxBy(uv => uv.V).V);
+			}
+
+			return (top, bottom);
+		}
+
 		public bool Contains(CPos cell)
 		{
 			if (Grid.Type == MapGridType.RectangularIsometric)
@@ -977,11 +1014,11 @@ namespace OpenRA
 		}
 
 		/// <summary>
-		/// The size of the map Height step in world units
+		/// The size of the map Height step in world units.
 		/// </summary>
 		/// RectangularIsometric defines 1024 units along the diagonal axis,
 		/// giving a half-tile height step of sqrt(2) * 512
-		public WDist CellHeightStep => new WDist(Grid.Type == MapGridType.RectangularIsometric ? 724 : 512);
+		public WDist CellHeightStep => new(Grid.Type == MapGridType.RectangularIsometric ? 724 : 512);
 
 		public CPos CellContaining(WPos pos)
 		{
@@ -1163,7 +1200,7 @@ namespace OpenRA
 			// Project this guessed cell and take the first available cell
 			// If it is projected outside the layer, then make another guess.
 			var allProjected = ProjectedCellsCovering(uv);
-			var projected = allProjected.Length > 0 ? allProjected.First()
+			var projected = allProjected.Length > 0 ? allProjected[0]
 				: new PPos(uv.U, uv.V.Clamp(Bounds.Top, Bounds.Bottom));
 
 			// Clamp the projected cell to the map area
@@ -1191,7 +1228,7 @@ namespace OpenRA
 				// This shouldn't happen.  But if it does, return the original value and hope the caller doesn't explode.
 				if (unProjected.Count == 0)
 				{
-					Log.Write("debug", "Failed to clamp map cell {0} to map bounds", uv);
+					Log.Write("debug", $"Failed to clamp map cell {uv} to map bounds");
 					return uv;
 				}
 			}
@@ -1232,9 +1269,9 @@ namespace OpenRA
 			PPos edge;
 			if (allProjected.Length > 0)
 			{
-				var puv = allProjected.First();
-				var horizontalBound = ((puv.U - Bounds.Left) < Bounds.Width / 2) ? Bounds.Left : Bounds.Right;
-				var verticalBound = ((puv.V - Bounds.Top) < Bounds.Height / 2) ? Bounds.Top : Bounds.Bottom;
+				var puv = allProjected[0];
+				var horizontalBound = (puv.U - Bounds.Left < Bounds.Width / 2) ? Bounds.Left : Bounds.Right;
+				var verticalBound = (puv.V - Bounds.Top < Bounds.Height / 2) ? Bounds.Top : Bounds.Bottom;
 
 				var du = Math.Abs(horizontalBound - puv.U);
 				var dv = Math.Abs(verticalBound - puv.V);
@@ -1263,7 +1300,7 @@ namespace OpenRA
 				// This shouldn't happen.  But if it does, return the original value and hope the caller doesn't explode.
 				if (unProjected.Count == 0)
 				{
-					Log.Write("debug", "Failed to find closest edge for map cell {0}", uv);
+					Log.Write("debug", $"Failed to find closest edge for map cell {uv}");
 					return uv;
 				}
 			}
@@ -1332,13 +1369,18 @@ namespace OpenRA
 				throw new ArgumentOutOfRangeException(nameof(maxRange),
 					$"The requested range ({maxRange}) cannot exceed the value of MaximumTileSearchRange ({Grid.MaximumTileSearchRange})");
 
-			for (var i = minRange; i <= maxRange; i++)
+			return FindTilesInAnnulus();
+
+			IEnumerable<CPos> FindTilesInAnnulus()
 			{
-				foreach (var offset in Grid.TilesByDistance[i])
+				for (var i = minRange; i <= maxRange; i++)
 				{
-					var t = offset + center;
-					if (allowOutsideBounds ? Tiles.Contains(t) : Contains(t))
-						yield return t;
+					foreach (var offset in Grid.TilesByDistance[i])
+					{
+						var t = offset + center;
+						if (allowOutsideBounds ? Tiles.Contains(t) : Contains(t))
+							yield return t;
+					}
 				}
 			}
 		}
@@ -1394,12 +1436,9 @@ namespace OpenRA
 			return false;
 		}
 
-		public string Translate(string key, IDictionary<string, object> args = null)
+		public void Dispose()
 		{
-			if (Translation.TryGetString(key, out var message, args))
-				return message;
-
-			return modData.Translation.GetString(key, args);
+			Sequences.Dispose();
 		}
 	}
 }

OpenRA.Game/Map/MapCache.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -25,32 +25,33 @@ namespace OpenRA
 {
 	public sealed class MapCache : IEnumerable<MapPreview>, IDisposable
 	{
-		public static readonly MapPreview UnknownMap = new MapPreview(null, null, MapGridType.Rectangular, null);
+		public static readonly MapPreview UnknownMap = new(null, null, MapGridType.Rectangular, null);
 		public IReadOnlyDictionary<IReadOnlyPackage, MapClassification> MapLocations => mapLocations;
-		readonly Dictionary<IReadOnlyPackage, MapClassification> mapLocations = new Dictionary<IReadOnlyPackage, MapClassification>();
+		readonly Dictionary<IReadOnlyPackage, MapClassification> mapLocations = new();
+		public bool LoadPreviewImages = true;
 
 		readonly Cache<string, MapPreview> previews;
 		readonly ModData modData;
 		readonly SheetBuilder sheetBuilder;
 		Thread previewLoaderThread;
 		bool previewLoaderThreadShutDown = true;
-		readonly object syncRoot = new object();
-		readonly Queue<MapPreview> generateMinimap = new Queue<MapPreview>();
+		readonly object syncRoot = new();
+		readonly Queue<MapPreview> generateMinimap = new();
 
-		public Dictionary<string, string> StringPool { get; } = new Dictionary<string, string>();
+		public HashSet<string> StringPool { get; } = new();
 
-		readonly List<MapDirectoryTracker> mapDirectoryTrackers = new List<MapDirectoryTracker>();
+		readonly List<MapDirectoryTracker> mapDirectoryTrackers = new();
 
 		/// <summary>
-		/// The most recenly modified or loaded map at runtime
+		/// The most recently modified or loaded map at runtime.
 		/// </summary>
 		public string LastModifiedMap { get; private set; } = null;
-		readonly Dictionary<string, string> mapUpdates = new Dictionary<string, string>();
+		readonly Dictionary<string, string> mapUpdates = new();
 
 		string lastLoadedLastModifiedMap;
 
 		/// <summary>
-		/// If LastModifiedMap was picked already, returns a null
+		/// If LastModifiedMap was picked already, returns a null.
 		/// </summary>
 		public string PickLastModifiedMap(MapVisibility visibility)
 		{
@@ -96,16 +97,16 @@ namespace OpenRA
 					? MapClassification.Unknown : Enum<MapClassification>.Parse(kv.Value);
 
 				IReadOnlyPackage package;
-				var optional = name.StartsWith("~", StringComparison.Ordinal);
+				var optional = name.StartsWith('~');
 				if (optional)
-					name = name.Substring(1);
+					name = name[1..];
 
 				try
 				{
 					// HACK: If the path is inside the support directory then we may need to create it
 					// Assume that the path is a directory if there is not an existing file with the same name
 					var resolved = Platform.ResolvePath(name);
-					if (resolved.StartsWith(Platform.SupportDir) && !File.Exists(resolved))
+					if (resolved.StartsWith(Platform.SupportDir, StringComparison.Ordinal) && !File.Exists(resolved))
 						Directory.CreateDirectory(resolved);
 
 					package = modData.ModFiles.OpenPackage(name);
@@ -122,10 +123,15 @@ namespace OpenRA
 				mapDirectoryTrackers.Add(new MapDirectoryTracker(mapGrid, package, classification));
 			}
 
+			// PERF: Load the mod YAML once outside the loop, and reuse it when resolving each maps custom YAML.
+			var modDataRules = modData.GetRulesYaml();
 			foreach (var kv in MapLocations)
 			{
 				foreach (var map in kv.Key.Contents)
-					LoadMap(map, kv.Key, kv.Value, mapGrid, null);
+				{
+					LoadMapInternal(map, kv.Key, kv.Value, mapGrid, null, modDataRules);
+					GC.Collect();
+				}
 			}
 
 			// We only want to track maps in runtime, not at loadtime
@@ -133,17 +139,27 @@ namespace OpenRA
 		}
 
 		public void LoadMap(string map, IReadOnlyPackage package, MapClassification classification, MapGrid mapGrid, string oldMap)
+		{
+			LoadMapInternal(map, package, classification, mapGrid, oldMap, null);
+		}
+
+		void LoadMapInternal(string map, IReadOnlyPackage package, MapClassification classification, MapGrid mapGrid, string oldMap, IEnumerable<List<MiniYamlNode>> modDataRules)
 		{
 			IReadOnlyPackage mapPackage = null;
 			try
 			{
-				using (new Support.PerfTimer(map))
+				using (new PerfTimer(map))
 				{
 					mapPackage = package.OpenPackage(map, modData.ModFiles);
+					Log.Write("debug", $"Loading Map: {map} FROM {mapPackage.Name}");
+					Console.WriteLine($"Loading Map: {map} FROM {mapPackage.Name}");
 					if (mapPackage != null)
 					{
 						var uid = Map.ComputeUID(mapPackage);
-						previews[uid].UpdateFromMap(mapPackage, package, classification, modData.Manifest.MapCompatibility, mapGrid.Type);
+						previews[uid].UpdateFromMap(mapPackage, package, classification, modData.Manifest.MapCompatibility, mapGrid.Type, modDataRules);
+
+						// Freeing the package to save memory if there is a lot of Maps
+						previews[uid].PackageDispose();
 
 						if (oldMap != uid)
 						{
@@ -157,10 +173,16 @@ namespace OpenRA
 			catch (Exception e)
 			{
 				mapPackage?.Dispose();
-				Console.WriteLine("Failed to load map: {0}", map);
-				Console.WriteLine("Details: {0}", e);
-				Log.Write("debug", "Failed to load map: {0}", map);
-				Log.Write("debug", "Details: {0}", e);
+				Console.WriteLine($"Failed to load map: {map}");
+				Console.WriteLine("Details:");
+				Console.WriteLine(e);
+				Console.WriteLine("StackTrace:");
+				Console.WriteLine(System.Environment.StackTrace);
+				Log.Write("debug", $"Failed to load map: {map}");
+				Log.Write("debug", "Details:");
+				Log.Write("debug", e);
+				Log.Write("debug", "StackTrace:");
+				Log.Write("debug", System.Environment.StackTrace);
 			}
 		}
 
@@ -180,13 +202,13 @@ namespace OpenRA
 					continue;
 
 				var name = kv.Key;
-				var optional = name.StartsWith("~", StringComparison.Ordinal);
+				var optional = name.StartsWith('~');
 				if (optional)
-					name = name.Substring(1);
+					name = name[1..];
 
 				// Don't try to open the map directory in the support directory if it doesn't exist
 				var resolved = Platform.ResolvePath(name);
-				if (resolved.StartsWith(Platform.SupportDir) && (!Directory.Exists(resolved) || !File.Exists(resolved)))
+				if (resolved.StartsWith(Platform.SupportDir, StringComparison.Ordinal) && (!Directory.Exists(resolved) || !File.Exists(resolved)))
 					continue;
 
 				using (var package = (IReadWritePackage)modData.ModFiles.OpenPackage(name))
@@ -194,7 +216,7 @@ namespace OpenRA
 			}
 		}
 
-		public IEnumerable<(IReadWritePackage package, string map)> EnumerateMapDirPackagesAndNames(MapClassification classification = MapClassification.System)
+		public IEnumerable<(IReadWritePackage Package, string Map)> EnumerateMapDirPackagesAndNames(MapClassification classification = MapClassification.System)
 		{
 			var mapDirPackages = EnumerateMapDirPackages(classification);
 
@@ -213,12 +235,6 @@ namespace OpenRA
 						yield return mapPackage;
 		}
 
-		public IEnumerable<Map> EnumerateMapsWithoutCaching(MapClassification classification = MapClassification.System)
-		{
-			foreach (var mapPackage in EnumerateMapPackagesWithoutCaching(classification))
-				yield return new Map(modData, mapPackage);
-		}
-
 		public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids, Action<MapPreview> mapDetailsReceived = null, Action<MapPreview> mapQueryFailed = null)
 		{
 			var queryUids = uids.Distinct()
@@ -229,11 +245,12 @@ namespace OpenRA
 				.ToList();
 
 			foreach (var uid in queryUids)
-				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null);
+				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null, null);
 
 			Task.Run(async () =>
 			{
 				var client = HttpClientFactory.Create();
+				var stringPool = new HashSet<string>(); // Reuse common strings in YAML
 
 				// Limit each query to 50 maps at a time to avoid request size limits
 				for (var i = 0; i < queryUids.Count; i += 50)
@@ -245,26 +262,27 @@ namespace OpenRA
 						var httpResponseMessage = await client.GetAsync(url);
 						var result = await httpResponseMessage.Content.ReadAsStreamAsync();
 
-						var yaml = MiniYaml.FromStream(result);
+						var yaml = MiniYaml.FromStream(result, url, stringPool: stringPool);
 						foreach (var kv in yaml)
-							previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, mapDetailsReceived);
+							previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, modData.Manifest.MapCompatibility, mapDetailsReceived);
 
 						foreach (var uid in batchUids)
 						{
 							var p = previews[uid];
 							if (p.Status != MapStatus.DownloadAvailable)
-								p.UpdateRemoteSearch(MapStatus.Unavailable, null);
+								p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
 						}
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", "Remote map query failed with error: {0}", e);
-						Log.Write("debug", "URL was: {0}", url);
+						Log.Write("debug", "Remote map query failed with error:");
+						Log.Write("debug", e);
+						Log.Write("debug", $"URL was: {url}");
 
 						foreach (var uid in batchUids)
 						{
 							var p = previews[uid];
-							p.UpdateRemoteSearch(MapStatus.Unavailable, null);
+							p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
 							mapQueryFailed?.Invoke(p);
 						}
 					}
@@ -277,11 +295,11 @@ namespace OpenRA
 			Log.Write("debug", "MapCache.LoadAsyncInternal started");
 
 			// Milliseconds to wait on one loop when nothing to do
-			var emptyDelay = 50;
+			const int EmptyDelay = 50;
 
 			// Keep the thread alive for at least 5 seconds after the last minimap generation
-			var maxKeepAlive = 5000 / emptyDelay;
-			var keepAlive = maxKeepAlive;
+			const int MaxKeepAlive = 5000 / EmptyDelay;
+			var keepAlive = MaxKeepAlive;
 
 			while (true)
 			{
@@ -301,11 +319,11 @@ namespace OpenRA
 
 				if (todo.Count == 0)
 				{
-					Thread.Sleep(emptyDelay);
+					Thread.Sleep(EmptyDelay);
 					continue;
 				}
 				else
-					keepAlive = maxKeepAlive;
+					keepAlive = MaxKeepAlive;
 
 				// Render the minimap into the shared sheet
 				foreach (var p in todo)
@@ -320,7 +338,8 @@ namespace OpenRA
 							}
 							catch (Exception e)
 							{
-								Log.Write("debug", "Failed to load minimap with exception: {0}", e);
+								Log.Write("debug", "Failed to load minimap with exception:");
+								Log.Write("debug", e);
 							}
 						});
 					}
@@ -342,8 +361,8 @@ namespace OpenRA
 
 			while (this[uid].Status != MapStatus.Available)
 			{
-				if (mapUpdates.ContainsKey(uid))
-					uid = mapUpdates[uid];
+				if (mapUpdates.TryGetValue(uid, out var newUid))
+					uid = newUid;
 				else
 					return null;
 			}
@@ -366,7 +385,6 @@ namespace OpenRA
 				{
 					// Wait for any existing thread to exit before starting a new one.
 					previewLoaderThread?.Join();
-
 					previewLoaderThread = new Thread(LoadAsyncInternal)
 					{
 						Name = "Map Preview Loader",

OpenRA.Game/Map/MapCoordsRegion.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2022 The OpenRA Developers (see AUTHORS)
+ * Copyright (c) The OpenRA Developers and Contributors
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation, either version 3 of
@@ -19,7 +19,6 @@ namespace OpenRA
 		public struct MapCoordsEnumerator : IEnumerator<MPos>
 		{
 			readonly MapCoordsRegion r;
-			MPos current;
 
 			public MapCoordsEnumerator(MapCoordsRegion region)
 				: this()
@@ -30,41 +29,38 @@ namespace OpenRA
 
 			public bool MoveNext()
 			{
-				var u = current.U + 1;
-				var v = current.V;
+				var u = Current.U + 1;
+				var v = Current.V;
 
 				// Check for column overflow
-				if (u > r.bottomRight.U)
+				if (u > r.BottomRight.U)
 				{
-					v += 1;
-					u = r.topLeft.U;
+					v++;
+					u = r.TopLeft.U;
 
 					// Check for row overflow
-					if (v > r.bottomRight.V)
+					if (v > r.BottomRight.V)
 						return false;
 				}
 
-				current = new MPos(u, v);
+				Current = new MPos(u, v);
 				return true;
 			}
 
 			public void Reset()
 			{
-				current = new MPos(r.topLeft.U - 1, r.topLeft.V);
+				Current = new MPos(r.TopLeft.U - 1, r.TopLeft.V);
 			}
 
-			public MPos Current => current;
-			object IEnumerator.Current => Current;
-			public void Dispose() { }
+			public MPos Current { get; private set; }
+			readonly object IEnumerator.Current => Current;
+			public readonly void Dispose() { }
 		}
 
-		readonly MPos topLeft;
-		readonly MPos bottomRight;
-
 		public MapCoordsRegion(MPos mapTopLeft, MPos mapBottomRight)
 		{
-			topLeft = mapTopLeft;
-			bottomRight = mapBottomRight;
+			TopLeft = mapTopLeft;
+			BottomRight = mapBottomRight;
 		}
 
 		public override string ToString()
@@ -87,7 +83,7 @@ namespace OpenRA
 			return GetEnumerator();
 		}
 
-		public MPos TopLeft => topLeft;
-		public MPos BottomRight => bottomRight;
+		public MPos TopLeft { get; }
+		public MPos BottomRight { get; }
 	}
 }