Mention infrastructure Patreon account.

and stop the LAN beacon.

.editorconfig

@@ -55,6 +55,8 @@ dotnet_naming_symbols.types.applicable_accessibilities = public, internal, priva
 dotnet_naming_symbols.non_field_members.applicable_kinds = property, event, method
 dotnet_naming_symbols.non_field_members.applicable_accessibilities = public, internal, private, protected, protected_internal
 
+dotnet_naming_symbols.parameters.applicable_kinds = parameter
+
 # Naming rules
 
 dotnet_naming_rule.non_field_members_should_be_pascal_case.severity = warning
@@ -78,6 +80,10 @@ dotnet_naming_rule.private_or_internal_field_should_be_camel_case.severity = war
 dotnet_naming_rule.private_or_internal_field_should_be_camel_case.symbols = private_or_internal_field
 dotnet_naming_rule.private_or_internal_field_should_be_camel_case.style = camel_case
 
+dotnet_naming_rule.parameters.severity = warning
+dotnet_naming_rule.parameters.symbols = parameters
+dotnet_naming_rule.parameters.style = camel_case
+
 # Naming rules
 
 #require a space before the colon for bases or interfaces in a type declaration
@@ -100,6 +106,9 @@ dotnet_style_predefined_type_for_member_access = true:suggestion
 #prefer the language keyword for local variables, method parameters, and class members, instead of the type name, for types that have a keyword to represent them
 dotnet_style_predefined_type_for_locals_parameters_members = true:suggestion
 
+#don't prefer braces (for one liners)
+dotnet_diagnostic.IDE0011.severity = none
+
 ; 4-column tab indentation
 [*.yaml]
 indent_style = tab

.github/FUNDING.yml

@@ -0,0 +1 @@
+patreon: orahosting

.github/workflows/ci.yaml

@@ -6,6 +6,29 @@ on:
     branches: [ bleed ]
 
 jobs:
+  linux:
+    name: Linux (.NET 5.0)
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Clone Repository
+        uses: actions/checkout@v2
+
+      - name: Install .NET 5
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: '5.0.x'
+
+      - name: Check Code
+        run: |
+          make check
+
+      - name: Check Mods
+        run: |
+          sudo apt-get install lua5.1
+          make check-scripts
+          make test
+
   linux-mono:
     name: Linux (mono)
     runs-on: ubuntu-20.04
@@ -17,28 +40,34 @@ jobs:
       - name: Check Code
         run: |
           mono --version
-          make check
-          mono ~/.nuget/packages/nunit.consolerunner/3.11.1/tools/nunit3-console.exe --noresult bin/OpenRA.Test.dll
+          make RUNTIME=mono check
 
       - name: Check Mods
         run: |
-          sudo apt-get install lua5.1
-          make check-scripts
-          make test
+          # check-scripts does not depend on .net/mono, so is not needed here
+          make RUNTIME=mono test
 
   windows:
-    name: Windows (Framework 4.7)
+    name: Windows (.NET 5.0)
     runs-on: windows-2019
 
     steps:
       - name: Clone Repository
         uses: actions/checkout@v2
 
+      - name: Install .NET 5
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: '5.0.x'
+
       - name: Check Code
         shell: powershell
         run: |
+          # 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
-          Invoke-Expression "$home\.nuget\packages\nunit.consolerunner\3.11.1\tools\nunit3-console.exe --noresult bin/OpenRA.Test.dll"
+          dotnet build OpenRA.Test\OpenRA.Test.csproj -c Debug --nologo -p:TargetPlatform=win-x64
+          dotnet test bin\OpenRA.Test.dll --test-adapter-path:.
 
       - name: Check Mods
         run: |

.github/workflows/itch.yml

@@ -15,17 +15,15 @@ jobs:
     if: github.repository == 'openra/openra'
     steps:
       - name: Download Packages
-        env:
-          GIT_TAG: ${{ github.event.inputs.tag }}
         run: |
-          wget -q "https://github.com/${{ github.repository }}/releases/download/${GIT_TAG}/OpenRA-${GIT_TAG}-x64.exe"
-          wget -q "https://github.com/${{ github.repository }}/releases/download/${GIT_TAG}/OpenRA-${GIT_TAG}-x64-winportable.zip" -O "OpenRA-${GIT_TAG}-x64-win-itch.zip"
-          wget -q "https://github.com${{ github.repository }}/releases/download/${GIT_TAG}/OpenRA-${GIT_TAG}.dmg"
-          wget -q "https://github.com/${{ github.repository }}/releases/download/${GIT_TAG}/OpenRA-Dune-2000-x86_64.AppImage"
-          wget -q "https://github.com/${{ github.repository }}/releases/download/${GIT_TAG}/OpenRA-Red-Alert-x86_64.AppImage"
-          wget -q "https://github.com/${{ github.repository }}/releases/download/${GIT_TAG}/OpenRA-Tiberian-Dawn-x86_64.AppImage"
-          wget -q "https://raw.githubusercontent.com/${{ github.repository }}/${GIT_TAG}/packaging/.itch.toml"
-          zip -u "OpenRA-${GIT_TAG}-x64-win-itch.zip" .itch.toml
+          wget -q "https://github.com/${{ github.repository }}/releases/download/${{ github.event.inputs.tag }}/OpenRA-${{ github.event.inputs.tag }}-x64.exe"
+          wget -q "https://github.com/${{ github.repository }}/releases/download/${{ github.event.inputs.tag }}/OpenRA-${{ github.event.inputs.tag }}-x64-winportable.zip" -O "OpenRA-${{ github.event.inputs.tag }}-x64-win-itch.zip"
+          wget -q "https://github.com/${{ github.repository }}/releases/download/${{ github.event.inputs.tag }}/OpenRA-${{ github.event.inputs.tag }}.dmg"
+          wget -q "https://github.com/${{ github.repository }}/releases/download/${{ github.event.inputs.tag }}/OpenRA-Dune-2000-x86_64.AppImage"
+          wget -q "https://github.com/${{ github.repository }}/releases/download/${{ github.event.inputs.tag }}/OpenRA-Red-Alert-x86_64.AppImage"
+          wget -q "https://github.com/${{ github.repository }}/releases/download/${{ github.event.inputs.tag }}/OpenRA-Tiberian-Dawn-x86_64.AppImage"
+          wget -q "https://raw.githubusercontent.com/${{ github.repository }}/${{ github.event.inputs.tag }}/packaging/.itch.toml"
+          zip -u "OpenRA-${{ github.event.inputs.tag }}-x64-win-itch.zip" .itch.toml
 
       - name: Publish Windows Installer
         uses: josephbmanley/butler-publish-itchio-action@master
@@ -33,9 +31,9 @@ jobs:
           BUTLER_CREDENTIALS: ${{ secrets.BUTLER_CREDENTIALS }}
           CHANNEL: win
           ITCH_GAME: openra
-          ITCH_USER: openra-developers
+          ITCH_USER: openra
           VERSION: ${{ github.event.inputs.tag }}
-          PACKAGE: OpenRA-${{ github.event.inputs.tag }}}-x64.exe"
+          PACKAGE: OpenRA-${{ github.event.inputs.tag }}-x64.exe
 
       - name: Publish Windows Itch Bundle
         uses: josephbmanley/butler-publish-itchio-action@master
@@ -43,7 +41,7 @@ jobs:
           BUTLER_CREDENTIALS: ${{ secrets.BUTLER_CREDENTIALS }}
           CHANNEL: itch
           ITCH_GAME: openra
-          ITCH_USER: openra-developers
+          ITCH_USER: openra
           VERSION: ${{ github.event.inputs.tag }}
           PACKAGE: OpenRA-${{ github.event.inputs.tag }}-x64-win-itch.zip
 
@@ -53,9 +51,9 @@ jobs:
           BUTLER_CREDENTIALS: ${{ secrets.BUTLER_CREDENTIALS }}
           CHANNEL: macos
           ITCH_GAME: openra
-          ITCH_USER: openra-developers
+          ITCH_USER: openra
           VERSION: ${{ github.event.inputs.tag }}
-          PACKAGE: OpenRA-${{ github.event.inputs.tag }}}.dmg"
+          PACKAGE: OpenRA-${{ github.event.inputs.tag }}.dmg
 
       - name: Publish RA AppImage
         uses: josephbmanley/butler-publish-itchio-action@master
@@ -63,7 +61,7 @@ jobs:
           BUTLER_CREDENTIALS: ${{ secrets.BUTLER_CREDENTIALS }}
           CHANNEL: linux-ra
           ITCH_GAME: openra
-          ITCH_USER: openra-developers
+          ITCH_USER: openra
           VERSION: ${{ github.event.inputs.tag }}
           PACKAGE: OpenRA-Red-Alert-x86_64.AppImage
 
@@ -73,7 +71,7 @@ jobs:
           BUTLER_CREDENTIALS: ${{ secrets.BUTLER_CREDENTIALS }}
           CHANNEL: linux-cnc
           ITCH_GAME: openra
-          ITCH_USER: openra-developers
+          ITCH_USER: openra
           VERSION: ${{ github.event.inputs.tag }}
           PACKAGE: OpenRA-Tiberian-Dawn-x86_64.AppImage
 
@@ -83,6 +81,6 @@ jobs:
           BUTLER_CREDENTIALS: ${{ secrets.BUTLER_CREDENTIALS }}
           CHANNEL: linux-d2k
           ITCH_GAME: openra
-          ITCH_USER: openra-developers
+          ITCH_USER: openra
           VERSION: ${{ github.event.inputs.tag }}
           PACKAGE: OpenRA-Dune-2000-x86_64.AppImage

.github/workflows/packaging.yml

@@ -8,6 +8,30 @@ on:
     - 'devtest-*'
 
 jobs:
+  source:
+    name: Source Tarball
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Clone Repository
+        uses: actions/checkout@v2
+
+      - name: Prepare Environment
+        run: echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> ${GITHUB_ENV}
+
+      - name: Package Source
+        run: |
+          mkdir -p build/source
+          ./packaging/source/buildpackage.sh "${GIT_TAG}" "${PWD}/build/source"
+
+      - name: Upload Packages
+        uses: svenstaro/upload-release-action@v2
+        with:
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          tag: ${{ github.ref }}
+          overwrite: true
+          file_glob: true
+          file: build/source/*
+
   linux:
     name: Linux AppImages
     runs-on: ubuntu-20.04
@@ -15,6 +39,11 @@ jobs:
       - name: Clone Repository
         uses: actions/checkout@v2
 
+      - name: Install .NET 5
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: '5.0.x'
+
       - name: Prepare Environment
         run: echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> ${GITHUB_ENV}
 
@@ -39,6 +68,11 @@ jobs:
       - name: Clone Repository
         uses: actions/checkout@v2
 
+      - name: Install .NET 5
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: '5.0.x'
+
       - name: Prepare Environment
         run: echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> ${GITHUB_ENV}
 
@@ -69,10 +103,16 @@ jobs:
       - name: Clone Repository
         uses: actions/checkout@v2
 
+      - name: Install .NET 5
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: '5.0.x'
+
       - name: Prepare Environment
         run: |
           echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> ${GITHUB_ENV}
-          sudo apt install nsis
+          sudo apt-get update
+          sudo apt-get install nsis wine64
 
       - name: Package Installers
         run: |

.vscode/launch.json

@@ -3,62 +3,46 @@
 	"configurations": [
 		{
 			"name": "Launch (TD)",
-			"type": "clr",
-			"linux": {
-				"type": "mono"
-			},
-			"osx": {
-				"type": "mono"
-			},
+			"type": "coreclr",
 			"request": "launch",
-			"program": "${workspaceRoot}/OpenRA.Game.exe",
-			"cwd": "${workspaceRoot}",
-			"args": ["Game.Mod=cnc"],
+			"program": "${workspaceRoot}/bin/OpenRA.dll",
+			"windows": {
+				"program": "${workspaceRoot}/bin/OpenRA.exe",
+			},
+			"args": ["Game.Mod=cnc", "Engine.EngineDir=.."],
 			"preLaunchTask": "build",
 		},
 		{
 			"name": "Launch (RA)",
-			"type": "clr",
-			"linux": {
-				"type": "mono"
-			},
-			"osx": {
-				"type": "mono"
-			},
+			"type": "coreclr",
 			"request": "launch",
-			"program": "${workspaceRoot}/OpenRA.Game.exe",
-			"cwd": "${workspaceRoot}",
-			"args": ["Game.Mod=ra"],
+			"program": "${workspaceRoot}/bin/OpenRA.dll",
+			"windows": {
+				"program": "${workspaceRoot}/bin/OpenRA.exe",
+			},
+			"args": ["Game.Mod=ra", "Engine.EngineDir=.."],
 			"preLaunchTask": "build",
 		},
 		{
 			"name": "Launch (D2k)",
-			"type": "clr",
-			"linux": {
-				"type": "mono"
-			},
-			"osx": {
-				"type": "mono"
-			},
+			"type": "coreclr",
 			"request": "launch",
-			"program": "${workspaceRoot}/OpenRA.Game.exe",
-			"cwd": "${workspaceRoot}",
-			"args": ["Game.Mod=d2k"],
+			"program": "${workspaceRoot}/bin/OpenRA.dll",
+			"windows": {
+				"program": "${workspaceRoot}/bin/OpenRA.exe",
+			},
+			"args": ["Game.Mod=d2k", "Engine.EngineDir=.."],
 			"preLaunchTask": "build",
 		},
 		{
 			"name": "Launch (TS)",
-			"type": "clr",
-			"linux": {
-				"type": "mono"
-			},
-			"osx": {
-				"type": "mono"
-			},
+			"type": "coreclr",
 			"request": "launch",
-			"program": "${workspaceRoot}/OpenRA.Game.exe",
-			"cwd": "${workspaceRoot}",
-			"args": ["Game.Mod=ts"],
+			"program": "${workspaceRoot}/bin/OpenRA.dll",
+			"windows": {
+				"program": "${workspaceRoot}/bin/OpenRA.exe",
+			},
+			"args": ["Game.Mod=ts", "Engine.EngineDir=.."],
 			"preLaunchTask": "build",
 		},
 	]

.vscode/tasks.json

@@ -4,7 +4,7 @@
 		{
 			"label": "build",
 			"command": "make",
-			"args": ["all"],
+			"args": ["all", "CONFIGURATION=Debug"],
 			"windows": {
 				"command": "make.cmd"
 			}

AUTHORS

@@ -4,6 +4,7 @@ hard work of many contributors.
 The OpenRA developers are:
     * Chris Forbes (chrisf)
     * Lukas Franke (abcdefg30)
+    * Matthias Mailänder (Mailaender)
     * Paul Chote (pchote)
     * Reaperrr
 
@@ -13,7 +14,6 @@ Previous developers included:
     * Curtis Shmyr (hamb)
     * Daniel Hernandez (Mancano)
     * Igor Popov (ihptru)
-    * Matthias Mailänder (Mailaender)
     * Megan Bowra-Dean (beedee)
     * Mike Bundy (kehaar)
     * Oliver Brakmann (obrakmann)
@@ -173,9 +173,17 @@ under the MIT license.
 Using FuzzyLogicLibrary (fuzzynet) by Dmitry
 Kaluzhny and released under the GNU GPL terms.
 
-Using Open.Nat by Lucas Ontivero, based on the work
-of Alan McGovern and Ben Motmans and distributed
-under the MIT license.
+Using Mono.Nat by Alan McGovern, Ben Motmans,
+Nicholas Terry distributed under the MIT license.
+
+Using MP3Sharp by Robert Bruke and Zane Wagner
+licensed under the GNU LGPL Version 3.
+
+Using TagLib# by Stephen Shaw licensed under the
+GNU LGPL Version 2.1.
+
+Using NVorbis by Andrew Ward distributed under
+the MIT license.
 
 Using ICSharpCode.SharpZipLib initially by Mike
 Krueger and distributed under the GNU GPL terms.
@@ -191,6 +199,9 @@ distributed under MIT License.
 
 Using ANGLE distributed under the BS3 3-Clause license.
 
+Using Pfim developed by Nick Babcock
+distributed under the MIT license.
+
 This site or product includes IP2Location LITE data
 available from http://www.ip2location.com.
 

Directory.Build.props

@@ -0,0 +1,54 @@
+<Project>
+  <PropertyGroup>
+    <OutputType>Library</OutputType>
+    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
+    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <Optimize>true</Optimize>
+    <LangVersion>7.3</LangVersion>
+    <DebugSymbols>true</DebugSymbols>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <EngineRootPath Condition="'$(EngineRootPath)' == ''">..</EngineRootPath>
+    <OutputPath>$(EngineRootPath)/bin</OutputPath>
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <ExternalConsole>false</ExternalConsole>
+    <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
+    <CodeAnalysisRuleSet>$(EngineRootPath)/OpenRA.ruleset</CodeAnalysisRuleSet>
+    <Nullable>disable</Nullable>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <TargetFramework Condition="'$(Mono)' == ''">net5.0</TargetFramework>
+    <TargetFramework Condition="'$(Mono)' != ''">netstandard2.1</TargetFramework>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <TargetPlatform Condition="$([MSBuild]::IsOsPlatform('Windows'))">win-x64</TargetPlatform>
+    <TargetPlatform Condition="$([MSBuild]::IsOsPlatform('Linux'))">linux-x64</TargetPlatform>
+    <TargetPlatform Condition="$([MSBuild]::IsOsPlatform('OSX'))">osx-x64</TargetPlatform>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)' == 'Debug'">
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <Optimize>false</Optimize>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <!-- Work around an issue where Rider does not detect files in the project root using the default glob -->
+    <Compile Include="**/*.cs" Exclude="$(DefaultItemExcludes)" />
+  </ItemGroup>
+
+  <Target Name="DisableAnalyzers" BeforeTargets="CoreCompile" Condition="'$(Configuration)'=='Release'">
+    <!-- Disable code style analysis on Release builds to improve compile-time performance -->
+    <ItemGroup Condition="'$(Configuration)'=='Release'">
+      <Analyzer Remove="@(Analyzer)" />
+    </ItemGroup>
+  </Target>
+
+  <!-- StyleCop -->
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
+    <PackageReference Include="StyleCop.Analyzers" Version="1.1.118" PrivateAssets="All" />
+    <AdditionalFiles Include="$(EngineRootPath)/stylecop.json" />
+  </ItemGroup>
+</Project>

INSTALL.md

@@ -8,104 +8,76 @@ Windows
 
 Compiling OpenRA requires the following dependencies:
 * [Windows PowerShell >= 4.0](http://microsoft.com/powershell) (included by default in recent Windows 10 versions)
-* [.NET Framework 4.7.2 (Developer Pack)](https://dotnet.microsoft.com/download/dotnet-framework/net472) (or via Visual Studio 2017)
-* [.NET Core 2.2 SDK](https://dotnet.microsoft.com/download/dotnet-core/2.2) (or via Visual Studio 2017)
+* [.NET 5 SDK](https://dotnet.microsoft.com/download/dotnet/5.0) (or via Visual Studio)
 
-
-To compile OpenRA, open the `OpenRA.sln` solution in the main folder, build it from the command-line with MSBuild or use the Makefile analogue command `make all` scripted in PowerShell syntax.
+To compile OpenRA, open the `OpenRA.sln` solution in the main folder, build it from the command-line with `dotnet` or use the Makefile analogue command `make all` scripted in PowerShell syntax.
 
 Run the game with `launch-game.cmd`. It can be handed arguments that specify the exact mod one wishes to run, for example, run `launch-game.cmd Game.Mod=ra` to launch Red Alert, `launch-game.cmd Game.Mod=cnc` to start Tiberian dawn or `launch-game.cmd Game.Mod=d2k` to launch Dune 2000.
 
 Linux
 =====
 
-Mono, version 5.18 or later, is required to compile OpenRA. You can add the [upstream mono repository](https://www.mono-project.com/download/stable/#download-lin) for your distro to obtain the latest version if your system packages are not sufficient.
+.NET 5 or Mono (version 6.4 or later) is required to compile OpenRA. We recommend using .NET 5 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.
 
-To compile OpenRA, run `make` from the command line. After this one can run the game with `./launch-game.sh`. It is also possible to specify the mod you wish to run from the command line, e.g. with `./launch-game.sh Game.Mod=ts` if you wish to try the experimental Tiberian Sun mod.
+The [.NET 5 download page](https://dotnet.microsoft.com/download/dotnet/5.0) 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.
+
+To compile OpenRA, run `make` from the command line (or `make RUNTIME=mono` if using Mono). After this one can run the game with `./launch-game.sh`. It is also possible to specify the mod you wish to run from the command line, e.g. with `./launch-game.sh Game.Mod=ts` if you wish to try the experimental Tiberian Sun mod.
 
 The default behaviour on the x86_64 architecture is to download several pre-compiled native libraries using the Nuget packaging manager. If you prefer to use system libraries, compile instead using `make TARGETPLATFORM=unix-generic`.
 
-If you choose to use system libraries, or your system is not x86_64, you will need to install the following using your system package manager:
-* [SDL 2](http://www.libsdl.org/download-2.0.php)
-* [FreeType](http://gnuwin32.sourceforge.net/packages/freetype.htm)
-* [OpenAL](http://kcat.strangesoft.net/openal.html)
-* [liblua 5.1](http://luabinaries.sourceforge.net/download.html)
+If you choose to use system libraries, or your system is not x86_64, you will need to install [SDL 2](https://www.libsdl.org/download-2.0.php), [FreeType](http://gnuwin32.sourceforge.net/packages/freetype.htm), [OpenAL](https://openal-soft.org/), and [liblua 5.1](http://luabinaries.sourceforge.net/download.html) before compiling OpenRA.
 
-Type `sudo make install` for system-wide installation. Run `sudo make install-linux-shortcuts` to get startup scripts, icons and desktop files. You can then run the Red Alert by executing the `openra-ra` command, the Dune 2000 mod by running the `openra-d2k` command and Tiberian Dawn by the `openra-cnc` command. Alternatively, you can also run these mods by clicking on their desktop shortcuts if you ran `sudo make install-linux-shortcuts`.
+These can be installed using your package manager on various distros:
 
-Arch Linux
-----------
-
-It is important to note there is an unofficial [`openra-git`](https://aur.archlinux.org/packages/openra-git) package in the Arch User Repository (AUR) of Arch Linux. If manually compiling is the way you wish to go the build and runtime dependencies can be installed with:
+<details><summary>Arch Linux</summary>
 
 ```
-sudo pacman -S mono openal libgl freetype2 sdl2 lua51 xdg-utils zenity
+sudo pacman -S openal libgl freetype2 sdl2 lua51
 ```
-
-Debian/Ubuntu
--------------
-
-:warning: The `mono` packages in the Ubuntu < 19.04 and Debian < 10 repositories are too old to support OpenRA. :warning:
-
-See the instructions under the *Linux* section above to upgrade `mono` using the upstream releases if needed.
+</details>
+<details><summary>Debian/Ubuntu</summary>
 
 ```
-sudo apt install mono-devel libfreetype6 libopenal1 liblua5.1-0 libsdl2-2.0-0 xdg-utils zenity wget
+sudo apt install libfreetype6 libopenal1 liblua5.1-0 libsdl2-2.0-0
 ```
-
-Fedora
-------
-
-:warning: The `mono` packages in the Fedora repositories are too old to support OpenRA. :warning:
-
-See the instructions under the *Linux* section above to upgrade `mono` using the upstream releases.
-
+</details>
+<details><summary>Fedora</summary>
 
 ```
-sudo dnf install "pkgconfig(mono)" SDL2 freetype "lua = 5.1" openal-soft xdg-utils zenity
+sudo dnf install SDL2 freetype "lua = 5.1" openal-soft
 ```
-
-Gentoo
-------
+</details>
+<details><summary>Gentoo</summary>
 
 ```
-sudo emerge -av dev-lang/mono dev-dotnet/libgdiplus media-libs/freetype:2 media-libs/libsdl2 media-libs/openal virtual/jpeg virtual/opengl '=dev-lang/lua-5.1.5*' x11-misc/xdg-utils gnome-extra/zenity
+sudo emerge -av media-libs/freetype:2 media-libs/libsdl2 media-libs/openal virtual/opengl '=dev-lang/lua-5.1.5*'
 ```
-
-Mageia
-------
+</details>
+<details><summary>Mageia</summary>
 
 ```
-sudo dnf install "pkgconfig(mono)" SDL2 freetype "lib*lua5.1" "lib*freetype2" "lib*sdl2.0_0" openal-soft xdg-utils zenity
+sudo dnf install SDL2 freetype "lib*lua5.1" "lib*freetype2" "lib*sdl2.0_0" openal-soft
 ```
-
-openSUSE
---------
+</details>
+<details><summary>openSUSE</summary>
 
 ```
-sudo zypper in mono-devel openal-soft freetype2 SDL2 lua51 xdg-utils zenity
+sudo zypper in openal-soft freetype2 SDL2 lua51
 ```
-
-Red Hat Enterprise Linux (and rebuilds, e.g. CentOS)
-----------------------------------------------------
-
+</details>
+<details><summary>Red Hat Enterprise Linux (and rebuilds, e.g. CentOS)</summary>
 The EPEL repository is required in order for the following command to run properly.
 
 ```
-sudo yum install "pkgconfig(mono)" SDL2 freetype "lua = 5.1" openal-soft xdg-utils zenity
+sudo yum install SDL2 freetype "lua = 5.1" openal-soft
 ```
+</details>
+
+Type `sudo make install` for system-wide installation. Run `sudo make install-linux-shortcuts` to get startup scripts, icons and desktop files. You can then run the Red Alert by executing the `openra-ra` command, the Dune 2000 mod by running the `openra-d2k` command and Tiberian Dawn by the `openra-cnc` command. Alternatively, you can also run these mods by clicking on their desktop shortcuts if you ran `sudo make install-linux-shortcuts`.
 
 macOS
 =====
 
-Before compiling OpenRA you must install the following dependencies:
-* [Mono >= 5.18](https://www.mono-project.com/download/stable/#download-mac)
-
-To compile OpenRA, run `make` from the command line. Run with `./launch-game.sh`.
-
-The default behaviour is to download several pre-compiled native libraries using the Nuget packaging manager. If you prefer to use system libraries, compile instead using `make TARGETPLATFORM=unix-generic`. If you choose to use system libraries you will need to install:
-* [SDL 2](http://www.libsdl.org/download-2.0.php) (`brew install sdl2`)
-* [FreeType](http://gnuwin32.sourceforge.net/packages/freetype.htm) (`brew install freetype`)
-* [OpenAL](http://kcat.strangesoft.net/openal.html) (`brew install openal-soft`)
-* [liblua 5.1](http://luabinaries.sourceforge.net/download.html) (`brew install lua@5.1`)
+[.NET 5](https://dotnet.microsoft.com/download/dotnet/5.0) 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 5 unless you are running a very old version of macOS (10.9 through 10.12).
 
+To compile OpenRA, run `make` from the command line (or `make RUNTIME=mono` if using Mono). Run with `./launch-game.sh`.

Makefile

@@ -1,19 +1,26 @@
 ############################# INSTRUCTIONS #############################
 #
 # to compile, run:
-#   make [DEBUG=true]
+#   make
+#
+# to compile using Mono (version 6.4 or greater) instead of .NET 5, run:
+#   make RUNTIME=mono
 #
 # to compile using system libraries for native dependencies, run:
-#   make [DEBUG=true] TARGETPLATFORM=unix-generic
+#   make [RUNTIME=net5] TARGETPLATFORM=unix-generic
 #
 # to check the official mods for erroneous yaml files, run:
-#   make test
+#   make [RUNTIME=net5] test
 #
 # to check the engine and official mod dlls for code style violations, run:
-#   make check
+#   make [RUNTIME=net5] check
 #
 # to compile and install Red Alert, Tiberian Dawn, and Dune 2000, run:
-#   make [prefix=/foo] [bindir=/bar/bin] install
+#   make [RUNTIME=net5] [prefix=/foo] [bindir=/bar/bin] install
+#
+# to compile and install Red Alert, Tiberian Dawn, and Dune 2000
+# using system libraries for native dependencies, run:
+#   make [prefix=/foo] [bindir=/bar/bin] TARGETPLATFORM=unix-generic install
 #
 # to install Linux startup scripts, desktop files, icons, and MIME metadata
 #   make install-linux-shortcuts
@@ -25,18 +32,6 @@
 #   make help
 #
 
-############################## TOOLCHAIN ###############################
-#
-# List of .NET assemblies that we can guarantee exist
-WHITELISTED_OPENRA_ASSEMBLIES = OpenRA.exe OpenRA.Utility.exe OpenRA.Server.exe OpenRA.Platforms.Default.dll OpenRA.Game.dll OpenRA.Mods.Common.dll OpenRA.Mods.Cnc.dll OpenRA.Mods.D2k.dll
-
-# These are explicitly shipped alongside our core files by the packaging script
-WHITELISTED_THIRDPARTY_ASSEMBLIES = ICSharpCode.SharpZipLib.dll FuzzyLogicLibrary.dll Eluant.dll BeaconLib.dll Open.Nat.dll SDL2-CS.dll OpenAL-CS.Core.dll DiscordRPC.dll Newtonsoft.Json.dll
-
-# These are shipped in our custom minimal mono runtime and also available in the full system-installed .NET/mono stack
-# This list *must* be kept in sync with the files packaged by the AppImageSupport and OpenRALauncherOSX repositories
-WHITELISTED_CORE_ASSEMBLIES = mscorlib.dll System.dll System.Configuration.dll System.Core.dll System.Numerics.dll System.Security.dll System.Xml.dll Mono.Security.dll netstandard.dll
-
 ######################### UTILITIES/SETTINGS ###########################
 #
 # Install locations for local installs and downstream packaging
@@ -48,20 +43,21 @@ bindir ?= $(prefix)/bin
 libdir ?= $(prefix)/lib
 gameinstalldir ?= $(libdir)/openra
 
-BIN_INSTALL_DIR = $(DESTDIR)$(bindir)
-DATA_INSTALL_DIR = $(DESTDIR)$(datadir)
-OPENRA_INSTALL_DIR = $(DESTDIR)$(gameinstalldir)
-
 # Toolchain
 CWD = $(shell pwd)
 MSBUILD = msbuild -verbosity:m -nologo
+DOTNET = dotnet
 MONO = mono
 RM = rm
 RM_R = $(RM) -r
 RM_F = $(RM) -f
 RM_RF = $(RM) -rf
 
-VERSION = $(shell git name-rev --name-only --tags --no-undefined HEAD 2>/dev/null || echo git-`git rev-parse --short HEAD`)
+RUNTIME ?= net5
+CONFIGURATION ?= Release
+
+# 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))
 
 # Detect target platform for dependencies if not given by the user
 ifndef TARGETPLATFORM
@@ -78,36 +74,44 @@ endif
 endif
 endif
 
-OPENRA_UTILITY = ENGINE_DIR=".." $(MONO) --debug bin/OpenRA.Utility.exe
-
 ##################### DEVELOPMENT BUILDS AND TESTS #####################
 #
 all:
-	@command -v $(firstword $(MSBUILD)) >/dev/null || (echo "OpenRA requires the '$(MSBUILD)' tool provided by Mono >= 5.18."; exit 1)
-	@$(MSBUILD) -t:Build -restore -p:Configuration=Release -p:TargetPlatform=$(TARGETPLATFORM)
+	@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)
+	@$(MSBUILD) -t:Build -restore -p:Configuration=${CONFIGURATION} -p:TargetPlatform=$(TARGETPLATFORM) -p:Mono=true
+else
+	@$(DOTNET) build -c ${CONFIGURATION} -nologo -p:TargetPlatform=$(TARGETPLATFORM)
+endif
 ifeq ($(TARGETPLATFORM), unix-generic)
 	@./configure-system-libraries.sh
 endif
 	@./fetch-geoip.sh
 
+# dotnet clean and msbuild -t:Clean leave files that cause problems when switching between mono/dotnet
+# Deleting the intermediate / output directories ensures the build directory is actually clean
 clean:
-	@-$(RM_RF) ./bin ./*/bin ./*/obj
-	@$(MSBUILD) -t:Clean
+	@-$(RM_RF) ./bin ./*/obj
 	@-$(RM_F) IP2LOCATION-LITE-DB1.IPV6.BIN.ZIP
 
 check:
 	@echo
 	@echo "Compiling in debug mode..."
-	@$(MSBUILD) -t:build -restore -p:Configuration=Debug
-	@echo
-	@echo "Checking runtime assemblies..."
-	@$(OPENRA_UTILITY) all --check-runtime-assemblies $(WHITELISTED_OPENRA_ASSEMBLIES) $(WHITELISTED_THIRDPARTY_ASSEMBLIES) $(WHITELISTED_CORE_ASSEMBLIES)
+ifeq ($(RUNTIME), mono)
+	@$(MSBUILD) -t:build -restore -p:Configuration=Debug -p:TargetPlatform=$(TARGETPLATFORM) -p:Mono=true
+else
+	@$(DOTNET) build -c Debug -nologo -p:TargetPlatform=$(TARGETPLATFORM)
+endif
+ifeq ($(TARGETPLATFORM), unix-generic)
+	@./configure-system-libraries.sh
+endif
 	@echo
 	@echo "Checking for explicit interface violations..."
-	@$(OPENRA_UTILITY) all --check-explicit-interfaces
+	@./utility.sh all --check-explicit-interfaces
 	@echo
 	@echo "Checking for incorrect conditional trait interface overrides..."
-	@$(OPENRA_UTILITY) all --check-conditional-trait-interface-overrides
+	@./utility.sh all --check-conditional-trait-interface-overrides
 
 check-scripts:
 	@echo
@@ -119,48 +123,58 @@ check-scripts:
 test: all
 	@echo
 	@echo "Testing Tiberian Sun mod MiniYAML..."
-	@$(OPENRA_UTILITY) ts --check-yaml
+	@./utility.sh ts --check-yaml
 	@echo
 	@echo "Testing Dune 2000 mod MiniYAML..."
-	@$(OPENRA_UTILITY) d2k --check-yaml
+	@./utility.sh d2k --check-yaml
 	@echo
 	@echo "Testing Tiberian Dawn mod MiniYAML..."
-	@$(OPENRA_UTILITY) cnc --check-yaml
+	@./utility.sh cnc --check-yaml
 	@echo
 	@echo "Testing Red Alert mod MiniYAML..."
-	@$(OPENRA_UTILITY) ra --check-yaml
+	@./utility.sh ra --check-yaml
 
 ############# 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
-	@sh -c '. ./packaging/functions.sh; set_engine_version $(VERSION) .'
-	@sh -c '. ./packaging/functions.sh; set_mod_version $(VERSION) mods/ra/mod.yaml mods/cnc/mod.yaml mods/d2k/mod.yaml mods/ts/mod.yaml mods/modcontent/mod.yaml mods/all/mod.yaml'
+ifeq ($(VERSION),)
+	$(error Unable to determine new version (requires git or override of variable VERSION))
+endif
+	@sh -c '. ./packaging/functions.sh; set_engine_version "$(VERSION)" .'
+	@sh -c '. ./packaging/functions.sh; set_mod_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'
 
 install:
-	@sh -c '. ./packaging/functions.sh; install_assemblies_mono $(CWD) $(OPENRA_INSTALL_DIR) $(TARGETPLATFORM) True True True'
-	@sh -c '. ./packaging/functions.sh; install_data $(CWD) $(OPENRA_INSTALL_DIR) cnc d2k ra'
+	@sh -c '. ./packaging/functions.sh; install_assemblies $(CWD) $(DESTDIR)$(gameinstalldir) $(TARGETPLATFORM) $(RUNTIME) True True True'
+	@sh -c '. ./packaging/functions.sh; install_data $(CWD) $(DESTDIR)$(gameinstalldir) cnc d2k ra'
 
 install-linux-shortcuts:
-	@sh -c '. ./packaging/functions.sh; install_linux_shortcuts $(CWD) $(OPENRA_INSTALL_DIR) $(BIN_INSTALL_DIR) $(DATA_INSTALL_DIR) $(VERSION) cnc d2k ra'
+	@sh -c '. ./packaging/functions.sh; install_linux_shortcuts $(CWD) "$(DESTDIR)" "$(gameinstalldir)" "$(bindir)" "$(datadir)" "$(shell head -n1 VERSION)" cnc d2k ra'
 
 install-linux-appdata:
-	@sh -c '. ./packaging/functions.sh; install_linux_appdata $(CWD) $(DATA_INSTALL_DIR) cnc d2k ra'
+	@sh -c '. ./packaging/functions.sh; install_linux_appdata $(CWD) "$(DESTDIR)" "$(datadir)" cnc d2k ra'
 
 help:
 	@echo 'to compile, run:'
-	@echo '  make [DEBUG=true]'
+	@echo '  make'
+	@echo
+	@echo 'to compile using Mono (version 6.4 or greater) instead of .NET 5, run:'
+	@echo '  make RUNTIME=mono'
 	@echo
 	@echo 'to compile using system libraries for native dependencies, run:'
-	@echo '  make [DEBUG=true] TARGETPLATFORM=unix-generic'
+	@echo '  make [RUNTIME=net5] TARGETPLATFORM=unix-generic'
 	@echo
 	@echo 'to check the official mods for erroneous yaml files, run:'
-	@echo '  make test'
+	@echo '  make [RUNTIME=net5] test'
 	@echo
 	@echo 'to check the engine and official mod dlls for code style violations, run:'
-	@echo '  make test'
+	@echo '  make [RUNTIME=net5] check'
 	@echo
 	@echo 'to compile and install Red Alert, Tiberian Dawn, and Dune 2000 run:'
-	@echo '  make [prefix=/foo] install'
+	@echo '  make [RUNTIME=net5] [prefix=/foo] [TARGETPLATFORM=unix-generic] install'
+	@echo
+	@echo 'to compile and install Red Alert, Tiberian Dawn, and Dune 2000'
+	@echo 'using system libraries for native dependencies, run:'
+	@echo '   make [RUNTIME=net5] [prefix=/foo] [bindir=/bar/bin] TARGETPLATFORM=unix-generic install'
 	@echo
 	@echo 'to install Linux startup scripts, desktop files, icons, and MIME metadata'
 	@echo '  make install-linux-shortcuts'

OpenRA.Game/Activities/Activity.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -53,15 +53,15 @@ namespace OpenRA.Activities
 		Activity childActivity;
 		protected Activity ChildActivity
 		{
-			get { return SkipDoneActivities(childActivity); }
-			private set { childActivity = value; }
+			get => SkipDoneActivities(childActivity);
+			private set => childActivity = value;
 		}
 
 		Activity nextActivity;
 		public Activity NextActivity
 		{
-			get { return SkipDoneActivities(nextActivity); }
-			private set { nextActivity = value; }
+			get => SkipDoneActivities(nextActivity);
+			private set => nextActivity = value;
 		}
 
 		internal static Activity SkipDoneActivities(Activity first)
@@ -74,14 +74,14 @@ namespace OpenRA.Activities
 			// drop valid activities queued after it. Walk the queue until we find a valid activity or
 			// (more likely) run out of activities.
 			while (first != null && first.State == ActivityState.Done)
-				first = first.NextActivity;
+				first = first.nextActivity;
 
 			return first;
 		}
 
 		public bool IsInterruptible { get; protected set; }
 		public bool ChildHasPriority { get; protected set; }
-		public bool IsCanceling { get { return State == ActivityState.Canceling; } }
+		public bool IsCanceling => State == ActivityState.Canceling;
 		bool finishing;
 		bool firstRunCompleted;
 		bool lastRun;
@@ -95,7 +95,7 @@ namespace OpenRA.Activities
 		public Activity TickOuter(Actor self)
 		{
 			if (State == ActivityState.Done)
-				throw new InvalidOperationException("Actor {0} attempted to tick activity {1} after it had already completed.".F(self, GetType()));
+				throw new InvalidOperationException($"Actor {self} attempted to tick activity {GetType()} after it had already completed.");
 
 			if (State == ActivityState.Queued)
 			{
@@ -105,7 +105,7 @@ namespace OpenRA.Activities
 			}
 
 			if (!firstRunCompleted)
-				throw new InvalidOperationException("Actor {0} attempted to tick activity {1} before running its OnFirstRun method.".F(self, GetType()));
+				throw new InvalidOperationException($"Actor {self} attempted to tick activity {GetType()} before running its OnFirstRun method.");
 
 			// Only run the parent tick when the child is done.
 			// We must always let the child finish on its own before continuing.
@@ -120,7 +120,8 @@ namespace OpenRA.Activities
 				lastRun = Tick(self);
 
 			// Avoid a single tick delay if the childactivity was just queued.
-			if (ChildActivity != null && ChildActivity.State == ActivityState.Queued)
+			var ca = ChildActivity;
+			if (ca != null && ca.State == ActivityState.Queued)
 			{
 				if (ChildHasPriority)
 					lastRun = TickChild(self) && finishing;
@@ -206,18 +207,18 @@ namespace OpenRA.Activities
 
 		public void Queue(Activity activity)
 		{
-			if (NextActivity != null)
-				NextActivity.Queue(activity);
-			else
-				NextActivity = activity;
+			var it = this;
+			while (it.nextActivity != null)
+				it = it.nextActivity;
+			it.nextActivity = activity;
 		}
 
 		public void QueueChild(Activity activity)
 		{
-			if (ChildActivity != null)
-				ChildActivity.Queue(activity);
+			if (childActivity != null)
+				childActivity.Queue(activity);
 			else
-				ChildActivity = activity;
+				childActivity = activity;
 		}
 
 		/// <summary>
@@ -269,15 +270,21 @@ namespace OpenRA.Activities
 
 		public IEnumerable<T> ActivitiesImplementing<T>(bool includeChildren = true) where T : IActivityInterface
 		{
-			if (includeChildren && ChildActivity != null)
-				foreach (var a in ChildActivity.ActivitiesImplementing<T>())
-					yield return a;
+			// Skips Done child and next activities
+			if (includeChildren)
+			{
+				var ca = ChildActivity;
+				if (ca != null)
+					foreach (var a in ca.ActivitiesImplementing<T>())
+						yield return a;
+			}
 
 			if (this is T)
 				yield return (T)(object)this;
 
-			if (NextActivity != null)
-				foreach (var a in NextActivity.ActivitiesImplementing<T>())
+			var na = NextActivity;
+			if (na != null)
+				foreach (var a in na.ActivitiesImplementing<T>())
 					yield return a;
 		}
 	}

OpenRA.Game/Activities/CallFunc.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -26,7 +26,7 @@ namespace OpenRA.Activities
 
 		public override bool Tick(Actor self)
 		{
-			a?.Invoke();
+			a.Invoke();
 			return true;
 		}
 	}

OpenRA.Game/Actor.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -11,6 +11,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
 using Eluant;
@@ -23,9 +24,18 @@ using OpenRA.Traits;
 
 namespace OpenRA
 {
+	[Flags]
+	public enum SystemActors
+	{
+		Player = 0,
+		EditorPlayer = 1,
+		World = 2,
+		EditorWorld = 4
+	}
+
 	public sealed class Actor : IScriptBindable, IScriptNotifyBind, ILuaTableBinding, ILuaEqualityBinding, ILuaToStringBinding, IEquatable<Actor>, IDisposable
 	{
-		internal struct SyncHash
+		internal readonly struct SyncHash
 		{
 			public readonly ISync Trait;
 			readonly Func<object, int> hashFunction;
@@ -48,8 +58,8 @@ namespace OpenRA
 		Activity currentActivity;
 		public Activity CurrentActivity
 		{
-			get { return Activity.SkipDoneActivities(currentActivity); }
-			private set { currentActivity = value; }
+			get => Activity.SkipDoneActivities(currentActivity);
+			private set => currentActivity = value;
 		}
 
 		public int Generation;
@@ -59,19 +69,13 @@ namespace OpenRA
 		public IOccupySpace OccupiesSpace { get; private set; }
 		public ITargetable[] Targetables { get; private set; }
 
-		public bool IsIdle { get { return CurrentActivity == null; } }
-		public bool IsDead { get { return Disposed || (health != null && health.IsDead); } }
+		public bool IsIdle => CurrentActivity == null;
+		public bool IsDead => Disposed || (health != null && health.IsDead);
 
-		public CPos Location { get { return OccupiesSpace.TopLeft; } }
-		public WPos CenterPosition { get { return OccupiesSpace.CenterPosition; } }
+		public CPos Location => OccupiesSpace.TopLeft;
+		public WPos CenterPosition => OccupiesSpace.CenterPosition;
 
-		public WRot Orientation
-		{
-			get
-			{
-				return facing != null ? facing.Orientation : WRot.None;
-			}
-		}
+		public WRot Orientation => facing?.Orientation ?? WRot.None;
 
 		/// <summary>Value used to represent an invalid token.</summary>
 		public static readonly int InvalidConditionToken = -1;
@@ -121,7 +125,7 @@ namespace OpenRA
 				.FirstOrDefault(i => i.Count() > 1);
 
 			if (duplicateInit != null)
-				throw new InvalidDataException("Duplicate initializer '{0}'".F(duplicateInit.Key.Name));
+				throw new InvalidDataException($"Duplicate initializer '{duplicateInit.Key.Name}'");
 
 			var init = new ActorInitializer(this, initDict);
 
@@ -246,7 +250,7 @@ namespace OpenRA
 					continue;
 
 				if (creationActivity != null)
-					throw new InvalidOperationException("More than one enabled ICreationActivity trait: {0} and {1}".F(creationActivity.GetType().Name, ica.GetType().Name));
+					throw new InvalidOperationException($"More than one enabled ICreationActivity trait: {creationActivity.GetType().Name} and {ica.GetType().Name}");
 
 				var activity = ica.GetCreationActivity();
 				if (activity == null)
@@ -365,8 +369,7 @@ namespace OpenRA
 
 		public override bool Equals(object obj)
 		{
-			var o = obj as Actor;
-			return o != null && Equals(o);
+			return obj is Actor o && Equals(o);
 		}
 
 		public bool Equals(Actor other)
@@ -528,7 +531,7 @@ namespace OpenRA
 		{
 			// PERF: Avoid LINQ.
 			foreach (var targetable in Targetables)
-				if (targetable.IsTraitEnabled() && targetable.TargetableBy(this, byActor))
+				if (targetable.TargetableBy(this, byActor))
 					return true;
 
 			return false;
@@ -589,7 +592,7 @@ namespace OpenRA
 		public int RevokeCondition(int token)
 		{
 			if (!conditionTokens.TryGetValue(token, out var condition))
-				throw new InvalidOperationException("Attempting to revoke condition with invalid token {0} for {1}.".F(token, this));
+				throw new InvalidOperationException($"Attempting to revoke condition with invalid token {token} for {this}.");
 
 			conditionTokens.Remove(token);
 			UpdateConditionState(condition, token, true);
@@ -615,8 +618,8 @@ namespace OpenRA
 
 		public LuaValue this[LuaRuntime runtime, LuaValue keyValue]
 		{
-			get { return luaInterface.Value[runtime, keyValue]; }
-			set { luaInterface.Value[runtime, keyValue] = value; }
+			get => luaInterface.Value[runtime, keyValue];
+			set => luaInterface.Value[runtime, keyValue] = value;
 		}
 
 		public LuaValue Equals(LuaRuntime runtime, LuaValue left, LuaValue right)
@@ -629,7 +632,7 @@ namespace OpenRA
 
 		public LuaValue ToString(LuaRuntime runtime)
 		{
-			return "Actor ({0})".F(this);
+			return $"Actor ({this})";
 		}
 
 		public bool HasScriptProperty(string name)

OpenRA.Game/CPos.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -16,7 +16,7 @@ using OpenRA.Scripting;
 
 namespace OpenRA
 {
-	public struct CPos : IScriptBindable, ILuaAdditionBinding, ILuaSubtractionBinding, ILuaEqualityBinding, ILuaTableBinding, IEquatable<CPos>
+	public readonly struct CPos : IScriptBindable, ILuaAdditionBinding, ILuaSubtractionBinding, ILuaEqualityBinding, ILuaTableBinding, IEquatable<CPos>
 	{
 		// Coordinates are packed in a 32 bit signed int
 		// X and Y are 12 bits (signed): -2048...2047
@@ -25,13 +25,13 @@ namespace OpenRA
 		public readonly int Bits;
 
 		// X is padded to MSB, so bit shift does the correct sign extension
-		public int X { get { return Bits >> 20; } }
+		public int X => Bits >> 20;
 
 		// Align Y with a short, cast, then shift the rest of the way
 		// The signed short bit shift does the correct sign extension
-		public int Y { get { return ((short)(Bits >> 4)) >> 4; } }
+		public int Y => ((short)(Bits >> 4)) >> 4;
 
-		public byte Layer { get { return (byte)Bits; } }
+		public byte Layer => (byte)Bits;
 
 		public CPos(int bits) { Bits = bits; }
 		public CPos(int x, int y)
@@ -90,7 +90,7 @@ namespace OpenRA
 		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out CPos a) || !right.TryGetClrValue(out CVec b))
-				throw new LuaException("Attempted to call CPos.Add(CPos, CVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call CPos.Add(CPos, CVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a + b);
 		}
@@ -99,7 +99,7 @@ namespace OpenRA
 		{
 			var rightType = right.WrappedClrType();
 			if (!left.TryGetClrValue(out CPos a))
-				throw new LuaException("Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, rightType.Name));
+				throw new LuaException($"Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({left.WrappedClrType().Name}, {rightType.Name})");
 
 			if (rightType == typeof(CPos))
 			{
@@ -112,7 +112,7 @@ namespace OpenRA
 				return new LuaCustomClrObject(a - b);
 			}
 
-			throw new LuaException("Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, rightType.Name));
+			throw new LuaException($"Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({left.WrappedClrType().Name}, {rightType.Name})");
 		}
 
 		public LuaValue Equals(LuaRuntime runtime, LuaValue left, LuaValue right)
@@ -132,14 +132,11 @@ namespace OpenRA
 					case "X": return X;
 					case "Y": return Y;
 					case "Layer": return Layer;
-					default: throw new LuaException("CPos does not define a member '{0}'".F(key));
+					default: throw new LuaException($"CPos does not define a member '{key}'");
 				}
 			}
 
-			set
-			{
-				throw new LuaException("CPos is read-only. Use CPos.New to create a new value");
-			}
+			set => throw new LuaException("CPos is read-only. Use CPos.New to create a new value");
 		}
 
 		#endregion

OpenRA.Game/CVec.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -17,7 +17,7 @@ using OpenRA.Scripting;
 
 namespace OpenRA
 {
-	public struct CVec : IScriptBindable, ILuaAdditionBinding, ILuaSubtractionBinding, ILuaUnaryMinusBinding, ILuaEqualityBinding, ILuaTableBinding, IEquatable<CVec>
+	public readonly struct CVec : IScriptBindable, ILuaAdditionBinding, ILuaSubtractionBinding, ILuaUnaryMinusBinding, ILuaEqualityBinding, ILuaTableBinding, IEquatable<CVec>
 	{
 		public readonly int X, Y;
 
@@ -42,8 +42,8 @@ namespace OpenRA
 
 		public CVec Sign() { return new CVec(Math.Sign(X), Math.Sign(Y)); }
 		public CVec Abs() { return new CVec(Math.Abs(X), Math.Abs(Y)); }
-		public int LengthSquared { get { return X * X + Y * Y; } }
-		public int Length { get { return Exts.ISqrt(LengthSquared); } }
+		public int LengthSquared => X * X + Y * Y;
+		public int Length => Exts.ISqrt(LengthSquared);
 
 		public CVec Clamp(Rectangle r)
 		{
@@ -76,7 +76,7 @@ namespace OpenRA
 		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out CVec a) || !right.TryGetClrValue(out CVec b))
-				throw new LuaException("Attempted to call CVec.Add(CVec, CVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call CVec.Add(CVec, CVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a + b);
 		}
@@ -84,7 +84,7 @@ namespace OpenRA
 		public LuaValue Subtract(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out CVec a) || !right.TryGetClrValue(out CVec b))
-				throw new LuaException("Attempted to call CVec.Subtract(CVec, CVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call CVec.Subtract(CVec, CVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a - b);
 		}
@@ -110,14 +110,11 @@ namespace OpenRA
 				{
 					case "X": return X;
 					case "Y": return Y;
-					default: throw new LuaException("CVec does not define a member '{0}'".F(key));
+					default: throw new LuaException($"CVec does not define a member '{key}'");
 				}
 			}
 
-			set
-			{
-				throw new LuaException("CVec is read-only. Use CVec.New to create a new value");
-			}
+			set => throw new LuaException("CVec is read-only. Use CVec.New to create a new value");
 		}
 
 		#endregion

OpenRA.Game/CacheStorage.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/CryptoUtil.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/DefaultPlayer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -15,6 +15,6 @@ namespace OpenRA
 {
 	public class DefaultPlayer : IGlobalModData
 	{
-		public readonly Color Color = Color.FromAhsl(0, 0, 238);
+		public readonly Color Color = Color.FromArgb(0xEE, 0xEE, 0xEE);
 	}
 }

OpenRA.Game/Download.cs

@@ -1,96 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright 2007-2020 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.ComponentModel;
-using System.Net;
-
-namespace OpenRA
-{
-	public class Download
-	{
-		readonly object syncObject = new object();
-		WebClient wc;
-
-		public static string FormatErrorMessage(Exception e)
-		{
-			var ex = e as WebException;
-			if (ex == null)
-				return e.Message;
-
-			switch (ex.Status)
-			{
-				case WebExceptionStatus.RequestCanceled:
-					return "Cancelled";
-				case WebExceptionStatus.NameResolutionFailure:
-					return "DNS lookup failed";
-				case WebExceptionStatus.Timeout:
-					return "Connection timeout";
-				case WebExceptionStatus.ConnectFailure:
-					return "Cannot connect to remote server";
-				case WebExceptionStatus.ProtocolError:
-					return "File not found on remote server";
-				default:
-					return ex.Message;
-			}
-		}
-
-		void EnableTLS12OnWindows()
-		{
-			// Enable TLS 1.2 on Windows: .NET 4.7 on Windows 10 only supports obsolete protocols by default
-			// SecurityProtocolType.Tls12 is not defined in the .NET 4.5 reference dlls used by mono,
-			// so we must use the enum's constant value directly
-			if (Platform.CurrentPlatform == PlatformType.Windows)
-				ServicePointManager.SecurityProtocol |= (SecurityProtocolType)3072;
-		}
-
-		public Download(string url, string path, Action<DownloadProgressChangedEventArgs> onProgress, Action<AsyncCompletedEventArgs> onComplete)
-		{
-			EnableTLS12OnWindows();
-
-			lock (syncObject)
-			{
-				wc = new WebClient { Proxy = null };
-				wc.DownloadProgressChanged += (_, a) => onProgress(a);
-				wc.DownloadFileCompleted += (_, a) => { DisposeWebClient(); onComplete(a); };
-				wc.DownloadFileAsync(new Uri(url), path);
-			}
-		}
-
-		public Download(string url, Action<DownloadProgressChangedEventArgs> onProgress, Action<DownloadDataCompletedEventArgs> onComplete)
-		{
-			EnableTLS12OnWindows();
-
-			lock (syncObject)
-			{
-				wc = new WebClient { Proxy = null };
-				wc.DownloadProgressChanged += (_, a) => onProgress(a);
-				wc.DownloadDataCompleted += (_, a) => { DisposeWebClient(); onComplete(a); };
-				wc.DownloadDataAsync(new Uri(url));
-			}
-		}
-
-		void DisposeWebClient()
-		{
-			lock (syncObject)
-			{
-				wc.Dispose();
-				wc = null;
-			}
-		}
-
-		public void CancelAsync()
-		{
-			lock (syncObject)
-				wc?.CancelAsync();
-		}
-	}
-}

OpenRA.Game/Effects/AsyncAction.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/Effects/DelayedAction.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/Effects/DelayedImpact.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/Effects/IEffect.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/ExternalMods.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -290,10 +290,15 @@ namespace OpenRA
 			}
 		}
 
-		public ExternalMod this[string key] { get { return mods[key]; } }
-		public int Count { get { return mods.Count; } }
-		public ICollection<string> Keys { get { return mods.Keys; } }
-		public ICollection<ExternalMod> Values { get { return mods.Values; } }
+		public ExternalMod this[string key] => mods[key];
+		public int Count => mods.Count;
+		public ICollection<string> Keys => mods.Keys;
+		public ICollection<ExternalMod> Values => mods.Values;
+
+		IEnumerable<string> IReadOnlyDictionary<string, ExternalMod>.Keys => ((IReadOnlyDictionary<string, ExternalMod>)mods).Keys;
+
+		IEnumerable<ExternalMod> IReadOnlyDictionary<string, ExternalMod>.Values => ((IReadOnlyDictionary<string, ExternalMod>)mods).Values;
+
 		public bool ContainsKey(string key) { return mods.ContainsKey(key); }
 		public IEnumerator<KeyValuePair<string, ExternalMod>> GetEnumerator() { return mods.GetEnumerator(); }
 		public bool TryGetValue(string key, out ExternalMod value) { return mods.TryGetValue(key, out value); }

OpenRA.Game/Exts.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -159,7 +159,7 @@ namespace OpenRA
 			if (xs.Count == 0)
 			{
 				if (throws)
-					throw new ArgumentException("Collection must not be empty.", "ts");
+					throw new ArgumentException("Collection must not be empty.", nameof(ts));
 				else
 					return default(T);
 			}
@@ -236,7 +236,7 @@ namespace OpenRA
 			{
 				if (!e.MoveNext())
 					if (throws)
-						throw new ArgumentException("Collection must not be empty.", "ts");
+						throw new ArgumentException("Collection must not be empty.", nameof(ts));
 					else
 						return default(T);
 				t = e.Current;
@@ -278,7 +278,7 @@ namespace OpenRA
 		public static int ISqrt(int number, ISqrtRoundMode round = ISqrtRoundMode.Floor)
 		{
 			if (number < 0)
-				throw new InvalidOperationException("Attempted to calculate the square root of a negative integer: {0}".F(number));
+				throw new InvalidOperationException($"Attempted to calculate the square root of a negative integer: {number}");
 
 			return (int)ISqrt((uint)number, round);
 		}
@@ -319,7 +319,7 @@ namespace OpenRA
 		public static long ISqrt(long number, ISqrtRoundMode round = ISqrtRoundMode.Floor)
 		{
 			if (number < 0)
-				throw new InvalidOperationException("Attempted to calculate the square root of a negative integer: {0}".F(number));
+				throw new InvalidOperationException($"Attempted to calculate the square root of a negative integer: {number}");
 
 			return (long)ISqrt((ulong)number, round);
 		}
@@ -429,8 +429,8 @@ namespace OpenRA
 			// If any duplicates were found, throw a descriptive error
 			if (dupKeys.Count > 0)
 			{
-				var badKeysFormatted = string.Join(", ", dupKeys.Select(p => "{0}: [{1}]".F(logKey(p.Key), string.Join(",", p.Value))));
-				var msg = "{0}, duplicate values found for the following keys: {1}".F(debugName, badKeysFormatted);
+				var badKeysFormatted = string.Join(", ", dupKeys.Select(p => $"{logKey(p.Key)}: [{string.Join(",", p.Value)}]"));
+				var msg = $"{debugName}, duplicate values found for the following keys: {badKeysFormatted}";
 				throw new ArgumentException(msg);
 			}
 
@@ -511,8 +511,7 @@ namespace OpenRA
 
 		public static bool IsTraitEnabled<T>(this T trait)
 		{
-			var disabledTrait = trait as IDisabledTrait;
-			return disabledTrait == null || !disabledTrait.IsTraitDisabled;
+			return !(trait is IDisabledTrait disabledTrait) || !disabledTrait.IsTraitDisabled;
 		}
 
 		public static T FirstEnabledTraitOrDefault<T>(this IEnumerable<T> ts)
@@ -534,6 +533,50 @@ namespace OpenRA
 
 			return default(T);
 		}
+
+		public static LineSplitEnumerator SplitLines(this string str, char separator)
+		{
+			return new LineSplitEnumerator(str.AsSpan(), separator);
+		}
+	}
+
+	public ref struct LineSplitEnumerator
+	{
+		ReadOnlySpan<char> str;
+		readonly char separator;
+
+		public LineSplitEnumerator(ReadOnlySpan<char> str, char separator)
+		{
+			this.str = str;
+			this.separator = separator;
+			Current = default;
+		}
+
+		public LineSplitEnumerator GetEnumerator() => this;
+
+		public bool MoveNext()
+		{
+			var span = str;
+
+			// Reach the end of the string
+			if (span.Length == 0)
+				return false;
+
+			var index = span.IndexOf(separator);
+			if (index == -1)
+			{
+				// The remaining string is an empty string
+				str = ReadOnlySpan<char>.Empty;
+				Current = span;
+				return true;
+			}
+
+			Current = span.Slice(0, index);
+			str = span.Slice(index + 1);
+			return true;
+		}
+
+		public ReadOnlySpan<char> Current { get; private set; }
 	}
 
 	public static class Enum<T>

OpenRA.Game/FieldLoader.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -25,6 +25,8 @@ namespace OpenRA
 {
 	public static class FieldLoader
 	{
+		const char SplitComma = ',';
+
 		[Serializable]
 		public class MissingFieldsException : YamlException
 		{
@@ -56,26 +58,465 @@ namespace OpenRA
 
 		public static Func<string, Type, string, object> InvalidValueAction = (s, t, f) =>
 		{
-			throw new YamlException("FieldLoader: Cannot parse `{0}` into `{1}.{2}` ".F(s, f, t));
+			throw new YamlException($"FieldLoader: Cannot parse `{s}` into `{f}.{t}` ");
 		};
 
 		public static Action<string, Type> UnknownFieldAction = (s, f) =>
 		{
-			throw new NotImplementedException("FieldLoader: Missing field `{0}` on `{1}`".F(s, f.Name));
+			throw new NotImplementedException($"FieldLoader: Missing field `{s}` on `{f.Name}`");
 		};
 
 		static readonly ConcurrentCache<Type, FieldLoadInfo[]> TypeLoadInfo =
 			new ConcurrentCache<Type, FieldLoadInfo[]>(BuildTypeLoadInfo);
-		static readonly ConcurrentCache<MemberInfo, bool> MemberHasTranslateAttribute =
-			new ConcurrentCache<MemberInfo, bool>(member => member.HasAttribute<TranslateAttribute>());
-
 		static readonly ConcurrentCache<string, BooleanExpression> BooleanExpressionCache =
 			new ConcurrentCache<string, BooleanExpression>(expression => new BooleanExpression(expression));
 		static readonly ConcurrentCache<string, IntegerExpression> IntegerExpressionCache =
 			new ConcurrentCache<string, IntegerExpression>(expression => new IntegerExpression(expression));
 
-		static readonly object TranslationsLock = new object();
-		static Dictionary<string, string> translations;
+		static readonly Dictionary<Type, Func<string, Type, string, MemberInfo, object>> TypeParsers =
+			new Dictionary<Type, Func<string, Type, string, MemberInfo, object>>()
+			{
+				{ typeof(int), ParseInt },
+				{ typeof(ushort), ParseUShort },
+				{ typeof(long), ParseLong },
+				{ typeof(float), ParseFloat },
+				{ typeof(decimal), ParseDecimal },
+				{ typeof(string), ParseString },
+				{ typeof(Color), ParseColor },
+				{ typeof(Hotkey), ParseHotkey },
+				{ typeof(HotkeyReference), ParseHotkeyReference },
+				{ typeof(WDist), ParseWDist },
+				{ typeof(WVec), ParseWVec },
+				{ typeof(WVec[]), ParseWVecArray },
+				{ typeof(WPos), ParseWPos },
+				{ typeof(WAngle), ParseWAngle },
+				{ typeof(WRot), ParseWRot },
+				{ typeof(CPos), ParseCPos },
+				{ typeof(CVec), ParseCVec },
+				{ typeof(CVec[]), ParseCVecArray },
+				{ typeof(BooleanExpression), ParseBooleanExpression },
+				{ typeof(IntegerExpression), ParseIntegerExpression },
+				{ typeof(Enum), ParseEnum },
+				{ typeof(bool), ParseBool },
+				{ typeof(int2[]), ParseInt2Array },
+				{ typeof(Size), ParseSize },
+				{ typeof(int2), ParseInt2 },
+				{ typeof(float2), ParseFloat2 },
+				{ typeof(float3), ParseFloat3 },
+				{ typeof(Rectangle), ParseRectangle },
+				{ typeof(DateTime), ParseDateTime }
+			};
+
+		static readonly Dictionary<Type, Func<string, Type, string, MiniYaml, MemberInfo, object>> GenericTypeParsers =
+			new Dictionary<Type, Func<string, Type, string, MiniYaml, MemberInfo, object>>()
+			{
+				{ typeof(HashSet<>), ParseHashSetOrList },
+				{ typeof(List<>), ParseHashSetOrList },
+				{ typeof(Dictionary<,>), ParseDictionary },
+				{ typeof(BitSet<>), ParseBitSet },
+				{ typeof(Nullable<>), ParseNullable },
+			};
+
+		static object ParseInt(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (Exts.TryParseIntegerInvariant(value, out var res))
+				return res;
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseUShort(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (ushort.TryParse(value, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out var res))
+				return res;
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseLong(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (long.TryParse(value, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out var res))
+				return res;
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseFloat(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null && float.TryParse(value.Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var res))
+				return res * (value.Contains('%') ? 0.01f : 1f);
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseDecimal(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null && decimal.TryParse(value.Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var res))
+				return res * (value.Contains('%') ? 0.01m : 1m);
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseString(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			return value;
+		}
+
+		static object ParseColor(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null && Color.TryParse(value, out var color))
+					return color;
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseHotkey(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (Hotkey.TryParse(value, out var res))
+				return res;
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseHotkeyReference(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			return Game.ModData.Hotkeys[value];
+		}
+
+		static object ParseWDist(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (WDist.TryParse(value, out var res))
+				return res;
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseWVec(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			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);
+				}
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseWVecArray(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma);
+
+				if (parts.Length % 3 != 0)
+					return InvalidValueAction(value, fieldType, fieldName);
+
+				var vecs = new WVec[parts.Length / 3];
+
+				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))
+						vecs[i] = new WVec(rx, ry, rz);
+				}
+
+				return vecs;
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseWPos(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			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);
+				}
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseWAngle(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (Exts.TryParseIntegerInvariant(value, out var res))
+				return new WAngle(res);
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseWRot(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			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));
+				}
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseCPos(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				return new CPos(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseCVec(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				return new CVec(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseCVecArray(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 CVec[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 CVec(rx, ry);
+				}
+
+				return vecs;
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseBooleanExpression(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				try
+				{
+					return BooleanExpressionCache[value];
+				}
+				catch (InvalidDataException e)
+				{
+					throw new YamlException(e.Message);
+				}
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseIntegerExpression(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				try
+				{
+					return IntegerExpressionCache[value];
+				}
+				catch (InvalidDataException e)
+				{
+					throw new YamlException(e.Message);
+				}
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseEnum(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			try
+			{
+				return Enum.Parse(fieldType, value, true);
+			}
+			catch (ArgumentException)
+			{
+				return InvalidValueAction(value, fieldType, fieldName);
+			}
+		}
+
+		static object ParseBool(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (bool.TryParse(value.ToLowerInvariant(), out var result))
+				return result;
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseInt2Array(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				if (parts.Length % 2 != 0)
+					return InvalidValueAction(value, fieldType, fieldName);
+
+				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]));
+
+				return ints;
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseSize(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				return new Size(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseInt2(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				if (parts.Length != 2)
+					return InvalidValueAction(value, fieldType, fieldName);
+
+				return new int2(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseFloat2(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				float xx = 0;
+				float yy = 0;
+				if (float.TryParse(parts[0].Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var res))
+					xx = res * (parts[0].Contains('%') ? 0.01f : 1f);
+				if (float.TryParse(parts[1].Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out res))
+					yy = res * (parts[1].Contains('%') ? 0.01f : 1f);
+				return new float2(xx, yy);
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseFloat3(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				float.TryParse(parts[0], NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var x);
+				float.TryParse(parts[1], NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var y);
+
+				// z component is optional for compatibility with older float2 definitions
+				float z = 0;
+				if (parts.Length > 2)
+					float.TryParse(parts[2], NumberStyles.Float, NumberFormatInfo.InvariantInfo, out z);
+
+				return new float3(x, y, z);
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseRectangle(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (value != null)
+			{
+				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]));
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseDateTime(string fieldName, Type fieldType, string value, MemberInfo field)
+		{
+			if (DateTime.TryParseExact(value, "yyyy-MM-dd HH-mm-ss", CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal, out var dt))
+				return dt;
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseHashSetOrList(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
+		{
+			var set = Activator.CreateInstance(fieldType);
+			if (value == null)
+				return set;
+
+			var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+			var addMethod = fieldType.GetMethod("Add", fieldType.GetGenericArguments());
+			for (var i = 0; i < parts.Length; i++)
+				addMethod.Invoke(set, new[] { GetValue(fieldName, fieldType.GetGenericArguments()[0], parts[i].Trim(), field) });
+			return set;
+		}
+
+		static object ParseDictionary(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
+		{
+			var dict = Activator.CreateInstance(fieldType);
+			var arguments = fieldType.GetGenericArguments();
+			var addMethod = fieldType.GetMethod("Add", arguments);
+
+			foreach (var node in yaml.Nodes)
+			{
+				var key = GetValue(fieldName, arguments[0], node.Key, field);
+				var val = GetValue(fieldName, arguments[1], node.Value, field);
+				addMethod.Invoke(dict, new[] { key, val });
+			}
+
+			return dict;
+		}
+
+		static object ParseBitSet(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
+		{
+			if (value != null)
+			{
+				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
+				var ctor = fieldType.GetConstructor(new[] { typeof(string[]) });
+				return ctor.Invoke(new object[] { parts.Select(p => p.Trim()).ToArray() });
+			}
+
+			return InvalidValueAction(value, fieldType, fieldName);
+		}
+
+		static object ParseNullable(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
+		{
+			if (string.IsNullOrEmpty(value))
+				return null;
+
+			var innerType = fieldType.GetGenericArguments().First();
+			var innerValue = GetValue("Nullable<T>", innerType, value, field);
+			return fieldType.GetConstructor(new[] { innerType }).Invoke(new[] { innerValue });
+		}
 
 		public static void Load(object self, MiniYaml my)
 		{
@@ -180,402 +621,46 @@ namespace OpenRA
 		public static object GetValue(string fieldName, Type fieldType, MiniYaml yaml, MemberInfo field)
 		{
 			var value = yaml.Value?.Trim();
+			if (fieldType.IsGenericType)
+			{
+				if (GenericTypeParsers.TryGetValue(fieldType.GetGenericTypeDefinition(), out var parseFuncGeneric))
+					return parseFuncGeneric(fieldName, fieldType, value, yaml, field);
+			}
+			else
+			{
+				if (TypeParsers.TryGetValue(fieldType, out var parseFunc))
+					return parseFunc(fieldName, fieldType, value, field);
 
-			if (fieldType == typeof(int))
-			{
-				if (Exts.TryParseIntegerInvariant(value, out var res))
-					return res;
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(ushort))
-			{
-				if (ushort.TryParse(value, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out var res))
-					return res;
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-
-			if (fieldType == typeof(long))
-			{
-				if (long.TryParse(value, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out var res))
-					return res;
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(float))
-			{
-				if (value != null && float.TryParse(value.Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var res))
-					return res * (value.Contains('%') ? 0.01f : 1f);
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(decimal))
-			{
-				if (value != null && decimal.TryParse(value.Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var res))
-					return res * (value.Contains('%') ? 0.01m : 1m);
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(string))
-			{
-				if (field != null && MemberHasTranslateAttribute[field] && value != null)
-					return Regex.Replace(value, "@[^@]+@", m => Translate(m.Value.Substring(1, m.Value.Length - 2)), RegexOptions.Compiled);
-				return value;
-			}
-			else if (fieldType == typeof(Color))
-			{
-				if (value != null && Color.TryParse(value, out var color))
-					return color;
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(Hotkey))
-			{
-				if (Hotkey.TryParse(value, out var res))
-					return res;
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(HotkeyReference))
-			{
-				return Game.ModData.Hotkeys[value];
-			}
-			else if (fieldType == typeof(WDist))
-			{
-				if (WDist.TryParse(value, out var res))
-					return res;
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(WVec))
-			{
-				if (value != null)
+				if (fieldType.IsArray && fieldType.GetArrayRank() == 1)
 				{
-					var parts = value.Split(',');
-					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 (value == null)
+						return Array.CreateInstance(fieldType.GetElementType(), 0);
+
+					var options = field != null && field.HasAttribute<AllowEmptyEntriesAttribute>() ?
+						StringSplitOptions.None : StringSplitOptions.RemoveEmptyEntries;
+					var parts = value.Split(SplitComma, options);
+
+					var ret = Array.CreateInstance(fieldType.GetElementType(), parts.Length);
+					for (var i = 0; i < parts.Length; i++)
+						ret.SetValue(GetValue(fieldName, fieldType.GetElementType(), parts[i].Trim(), field), i);
+					return ret;
 				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
 			}
-			else if (fieldType == typeof(WVec[]))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(',');
 
-					if (parts.Length % 3 != 0)
-						return InvalidValueAction(value, fieldType, fieldName);
-
-					var vecs = new WVec[parts.Length / 3];
-
-					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))
-							vecs[i] = new WVec(rx, ry, rz);
-					}
-
-					return vecs;
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(WPos))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(',');
-					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);
-					}
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(WAngle))
-			{
-				if (Exts.TryParseIntegerInvariant(value, out var res))
-					return new WAngle(res);
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(WRot))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(',');
-					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));
-					}
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(CPos))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					return new CPos(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(CVec))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					return new CVec(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(CVec[]))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(',');
-
-					if (parts.Length % 2 != 0)
-						return InvalidValueAction(value, fieldType, fieldName);
-
-					var vecs = new CVec[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 CVec(rx, ry);
-					}
-
-					return vecs;
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(BooleanExpression))
-			{
-				if (value != null)
-				{
-					try
-					{
-						return BooleanExpressionCache[value];
-					}
-					catch (InvalidDataException e)
-					{
-						throw new YamlException(e.Message);
-					}
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(IntegerExpression))
-			{
-				if (value != null)
-				{
-					try
-					{
-						return IntegerExpressionCache[value];
-					}
-					catch (InvalidDataException e)
-					{
-						throw new YamlException(e.Message);
-					}
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType.IsEnum)
+			var conv = TypeDescriptor.GetConverter(fieldType);
+			if (conv.CanConvertFrom(typeof(string)))
 			{
 				try
 				{
-					return Enum.Parse(fieldType, value, true);
+					return conv.ConvertFromInvariantString(value);
 				}
-				catch (ArgumentException)
+				catch
 				{
 					return InvalidValueAction(value, fieldType, fieldName);
 				}
 			}
-			else if (fieldType == typeof(bool))
-			{
-				if (bool.TryParse(value.ToLowerInvariant(), out var result))
-					return result;
 
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(int2[]))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					if (parts.Length % 2 != 0)
-						return InvalidValueAction(value, fieldType, fieldName);
-
-					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]));
-
-					return ints;
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType.IsArray && fieldType.GetArrayRank() == 1)
-			{
-				if (value == null)
-					return Array.CreateInstance(fieldType.GetElementType(), 0);
-
-				var options = field != null && field.HasAttribute<AllowEmptyEntriesAttribute>() ?
-					StringSplitOptions.None : StringSplitOptions.RemoveEmptyEntries;
-				var parts = value.Split(new char[] { ',' }, options);
-
-				var ret = Array.CreateInstance(fieldType.GetElementType(), parts.Length);
-				for (var i = 0; i < parts.Length; i++)
-					ret.SetValue(GetValue(fieldName, fieldType.GetElementType(), parts[i].Trim(), field), i);
-				return ret;
-			}
-			else if (fieldType.IsGenericType && (fieldType.GetGenericTypeDefinition() == typeof(HashSet<>) || fieldType.GetGenericTypeDefinition() == typeof(List<>)))
-			{
-				var set = Activator.CreateInstance(fieldType);
-				if (value == null)
-					return set;
-
-				var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-				var addMethod = fieldType.GetMethod("Add", fieldType.GetGenericArguments());
-				for (var i = 0; i < parts.Length; i++)
-					addMethod.Invoke(set, new[] { GetValue(fieldName, fieldType.GetGenericArguments()[0], parts[i].Trim(), field) });
-				return set;
-			}
-			else if (fieldType.IsGenericType && fieldType.GetGenericTypeDefinition() == typeof(Dictionary<,>))
-			{
-				var dict = Activator.CreateInstance(fieldType);
-				var arguments = fieldType.GetGenericArguments();
-				var addMethod = fieldType.GetMethod("Add", arguments);
-
-				foreach (var node in yaml.Nodes)
-				{
-					var key = GetValue(fieldName, arguments[0], node.Key, field);
-					var val = GetValue(fieldName, arguments[1], node.Value, field);
-					addMethod.Invoke(dict, new[] { key, val });
-				}
-
-				return dict;
-			}
-			else if (fieldType == typeof(Size))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					return new Size(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(int2))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					if (parts.Length != 2)
-						return InvalidValueAction(value, fieldType, fieldName);
-
-					return new int2(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(float2))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					float xx = 0;
-					float yy = 0;
-					if (float.TryParse(parts[0].Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var res))
-						xx = res * (parts[0].Contains('%') ? 0.01f : 1f);
-					if (float.TryParse(parts[1].Replace("%", ""), NumberStyles.Float, NumberFormatInfo.InvariantInfo, out res))
-						yy = res * (parts[1].Contains('%') ? 0.01f : 1f);
-					return new float2(xx, yy);
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(float3))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					float.TryParse(parts[0], NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var x);
-					float.TryParse(parts[1], NumberStyles.Float, NumberFormatInfo.InvariantInfo, out var y);
-
-					// z component is optional for compatibility with older float2 definitions
-					float z = 0;
-					if (parts.Length > 2)
-						float.TryParse(parts[2], NumberStyles.Float, NumberFormatInfo.InvariantInfo, out z);
-
-					return new float3(x, y, z);
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType == typeof(Rectangle))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					return new Rectangle(
-						Exts.ParseIntegerInvariant(parts[0]),
-						Exts.ParseIntegerInvariant(parts[1]),
-						Exts.ParseIntegerInvariant(parts[2]),
-						Exts.ParseIntegerInvariant(parts[3]));
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType.IsGenericType && fieldType.GetGenericTypeDefinition() == typeof(BitSet<>))
-			{
-				if (value != null)
-				{
-					var parts = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-					var ctor = fieldType.GetConstructor(new[] { typeof(string[]) });
-					return ctor.Invoke(new object[] { parts.Select(p => p.Trim()).ToArray() });
-				}
-
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else if (fieldType.IsGenericType && fieldType.GetGenericTypeDefinition() == typeof(Nullable<>))
-			{
-				if (string.IsNullOrEmpty(value))
-					return null;
-
-				var innerType = fieldType.GetGenericArguments().First();
-				var innerValue = GetValue("Nullable<T>", innerType, value, field);
-				return fieldType.GetConstructor(new[] { innerType }).Invoke(new[] { innerValue });
-			}
-			else if (fieldType == typeof(DateTime))
-			{
-				if (DateTime.TryParseExact(value, "yyyy-MM-dd HH-mm-ss", CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal, out var dt))
-					return dt;
-				return InvalidValueAction(value, fieldType, fieldName);
-			}
-			else
-			{
-				var conv = TypeDescriptor.GetConverter(fieldType);
-				if (conv.CanConvertFrom(typeof(string)))
-				{
-					try
-					{
-						return conv.ConvertFromInvariantString(value);
-					}
-					catch
-					{
-						return InvalidValueAction(value, fieldType, fieldName);
-					}
-				}
-			}
-
-			UnknownFieldAction("[Type] {0}".F(value), fieldType);
+			UnknownFieldAction($"[Type] {value}", fieldType);
 			return null;
 		}
 
@@ -661,7 +746,7 @@ namespace OpenRA
 		{
 			public static readonly SerializeAttribute Default = new SerializeAttribute(true);
 
-			public bool IsDefault { get { return this == Default; } }
+			public bool IsDefault => this == Default;
 
 			public readonly bool Serialize;
 			public string YamlName;
@@ -686,7 +771,7 @@ namespace OpenRA
 				{
 					var method = type.GetMethod(Loader, Flags);
 					if (method == null)
-						throw new InvalidOperationException("{0} does not specify a loader function '{1}'".F(type.Name, Loader));
+						throw new InvalidOperationException($"{type.Name} does not specify a loader function '{Loader}'");
 
 					return (Func<MiniYaml, object>)Delegate.CreateDelegate(typeof(Func<MiniYaml, object>), method);
 				}
@@ -694,34 +779,8 @@ namespace OpenRA
 				return null;
 			}
 		}
-
-		public static string Translate(string key)
-		{
-			if (string.IsNullOrEmpty(key))
-				return key;
-
-			lock (TranslationsLock)
-			{
-				if (translations == null)
-					return key;
-
-				if (!translations.TryGetValue(key, out var value))
-					return key;
-
-				return value;
-			}
-		}
-
-		public static void SetTranslations(IDictionary<string, string> translations)
-		{
-			lock (TranslationsLock)
-				FieldLoader.translations = new Dictionary<string, string>(translations);
-		}
 	}
 
-	[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
-	public sealed class TranslateAttribute : Attribute { }
-
 	[AttributeUsage(AttributeTargets.Field)]
 	public sealed class FieldFromYamlKeyAttribute : FieldLoader.SerializeAttribute
 	{

OpenRA.Game/FieldSaver.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -72,32 +72,14 @@ namespace OpenRA
 				return "";
 
 			var t = v.GetType();
-
-			if (t == typeof(Color))
-			{
-				return ((Color)v).ToString();
-			}
-
-			if (t == typeof(Rectangle))
-			{
-				var r = (Rectangle)v;
-				return "{0},{1},{2},{3}".F(r.X, r.Y, r.Width, r.Height);
-			}
-
 			if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(BitSet<>))
-			{
 				return ((IEnumerable<string>)v).Select(FormatValue).JoinWith(", ");
-			}
 
 			if (t.IsArray && t.GetArrayRank() == 1)
-			{
 				return ((Array)v).Cast<object>().Select(FormatValue).JoinWith(", ");
-			}
 
 			if (t.IsGenericType && (t.GetGenericTypeDefinition() == typeof(HashSet<>) || t.GetGenericTypeDefinition() == typeof(List<>)))
-			{
 				return ((System.Collections.IEnumerable)v).Cast<object>().Select(FormatValue).JoinWith(", ");
-			}
 
 			// This is only for documentation generation
 			if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Dictionary<,>))
@@ -112,17 +94,14 @@ namespace OpenRA
 					var formattedKey = FormatValue(key);
 					var formattedValue = FormatValue(value);
 
-					result += "{0}: {1}{2}".F(formattedKey, formattedValue, Environment.NewLine);
+					result += $"{formattedKey}: {formattedValue}{Environment.NewLine}";
 				}
 
 				return result;
 			}
 
-			if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Primitives.Cache<,>))
-				return ""; // TODO
-
-			if (t == typeof(DateTime))
-				return ((DateTime)v).ToString("yyyy-MM-dd HH-mm-ss", CultureInfo.InvariantCulture);
+			if (v is DateTime d)
+				return d.ToString("yyyy-MM-dd HH-mm-ss", CultureInfo.InvariantCulture);
 
 			// Try the TypeConverter
 			var conv = TypeDescriptor.GetConverter(t);

OpenRA.Game/FileFormats/Png.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -17,6 +17,7 @@ using System.Net;
 using System.Text;
 using ICSharpCode.SharpZipLib.Checksum;
 using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
+using OpenRA.Graphics;
 using OpenRA.Primitives;
 
 namespace OpenRA.FileFormats
@@ -25,12 +26,15 @@ namespace OpenRA.FileFormats
 	{
 		static readonly byte[] Signature = { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a };
 
-		public int Width { get; set; }
-		public int Height { get; set; }
-		public Color[] Palette { get; set; }
-		public byte[] Data { get; set; }
+		public int Width { get; private set; }
+		public int Height { get; private set; }
+		public Color[] Palette { get; private set; }
+		public byte[] Data { get; private set; }
+		public SpriteFrameType Type { get; private set; }
 		public Dictionary<string, string> EmbeddedData = new Dictionary<string, string>();
 
+		public int PixelStride => Type == SpriteFrameType.Indexed8 ? 1 : Type == SpriteFrameType.Rgb24 ? 3 : 4;
+
 		public Png(Stream s)
 		{
 			if (!Verify(s))
@@ -38,9 +42,8 @@ namespace OpenRA.FileFormats
 
 			s.Position += 8;
 			var headerParsed = false;
-			var isPaletted = false;
-			var is24Bit = false;
 			var data = new List<byte>();
+			Type = SpriteFrameType.Rgba32;
 
 			while (true)
 			{
@@ -65,14 +68,12 @@ namespace OpenRA.FileFormats
 
 							var bitDepth = ms.ReadUInt8();
 							var colorType = (PngColorType)ms.ReadByte();
-							isPaletted = IsPaletted(bitDepth, colorType);
-							is24Bit = colorType == PngColorType.Color;
+							if (IsPaletted(bitDepth, colorType))
+								Type = SpriteFrameType.Indexed8;
+							else if (colorType == PngColorType.Color)
+								Type = SpriteFrameType.Rgb24;
 
-							var dataLength = Width * Height;
-							if (!isPaletted)
-								dataLength *= 4;
-
-							Data = new byte[dataLength];
+							Data = new byte[Width * Height * PixelStride];
 
 							var compression = ms.ReadByte();
 							/*var filter = */ms.ReadByte();
@@ -133,39 +134,28 @@ namespace OpenRA.FileFormats
 							{
 								using (var ds = new InflaterInputStream(ns))
 								{
-									var pxStride = isPaletted ? 1 : is24Bit ? 3 : 4;
-									var srcStride = Width * pxStride;
-									var destStride = Width * (isPaletted ? 1 : 4);
+									var pxStride = PixelStride;
+									var rowStride = Width * pxStride;
 
-									var prevLine = new byte[srcStride];
+									var prevLine = new byte[rowStride];
 									for (var y = 0; y < Height; y++)
 									{
 										var filter = (PngFilter)ds.ReadByte();
-										var line = ds.ReadBytes(srcStride);
+										var line = ds.ReadBytes(rowStride);
 
-										for (var i = 0; i < srcStride; i++)
+										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 (is24Bit)
-										{
-											// Fold alpha channel into RGB data
-											for (var i = 0; i < line.Length / 3; i++)
-											{
-												Array.Copy(line, 3 * i, Data, y * destStride + 4 * i, 3);
-												Data[y * destStride + 4 * i + 3] = 255;
-											}
-										}
-										else
-											Array.Copy(line, 0, Data, y * destStride, line.Length);
+										Array.Copy(line, 0, Data, y * rowStride, rowStride);
 
 										prevLine = line;
 									}
 								}
 							}
 
-							if (isPaletted && Palette == null)
+							if (Type == SpriteFrameType.Indexed8 && Palette == null)
 								throw new InvalidDataException("Non-Palette indexed PNG are not supported.");
 
 							return;
@@ -175,7 +165,7 @@ namespace OpenRA.FileFormats
 			}
 		}
 
-		public Png(byte[] data, int width, int height, Color[] palette = null,
+		public Png(byte[] data, SpriteFrameType type, int width, int height, Color[] palette = null,
 			Dictionary<string, string> embeddedData = null)
 		{
 			var expectLength = width * height;
@@ -185,11 +175,46 @@ namespace OpenRA.FileFormats
 			if (data.Length != expectLength)
 				throw new InvalidDataException("Input data does not match expected length");
 
+			Type = type;
 			Width = width;
 			Height = height;
 
-			Palette = palette;
-			Data = data;
+			switch (type)
+			{
+				case SpriteFrameType.Indexed8:
+				case SpriteFrameType.Rgba32:
+				case SpriteFrameType.Rgb24:
+				{
+					// Data is already in a compatible format
+					Data = data;
+					if (type == SpriteFrameType.Indexed8)
+						Palette = palette;
+
+					break;
+				}
+
+				case SpriteFrameType.Bgra32:
+				case SpriteFrameType.Bgr24:
+				{
+					// Convert to big endian
+					Data = new byte[data.Length];
+					var stride = PixelStride;
+					for (var i = 0; i < width * height; i++)
+					{
+						Data[stride * i] = data[stride * i + 2];
+						Data[stride * i + 1] = data[stride * i + 1];
+						Data[stride * i + 2] = data[stride * i + 0];
+
+						if (type == SpriteFrameType.Bgra32)
+							Data[stride * i + 3] = data[stride * i + 3];
+					}
+
+					break;
+				}
+
+				default:
+					throw new InvalidDataException($"Unhandled SpriteFrameType {type}");
+			}
 
 			if (embeddedData != null)
 				EmbeddedData = embeddedData;
@@ -274,9 +299,8 @@ namespace OpenRA.FileFormats
 					header.Write(IPAddress.HostToNetworkOrder(Height));
 					header.WriteByte(8); // Bit depth
 
-					var colorType = Palette != null
-						? PngColorType.Indexed | PngColorType.Color
-						: PngColorType.Color | PngColorType.Alpha;
+					var colorType = Type == SpriteFrameType.Indexed8 ? PngColorType.Indexed | PngColorType.Color :
+						Type == SpriteFrameType.Rgb24 ? PngColorType.Color : PngColorType.Color | PngColorType.Alpha;
 					header.WriteByte((byte)colorType);
 
 					header.WriteByte(0); // Compression
@@ -286,7 +310,7 @@ namespace OpenRA.FileFormats
 					WritePngChunk(output, "IHDR", header);
 				}
 
-				bool alphaPalette = false;
+				var alphaPalette = false;
 				if (Palette != null)
 				{
 					using (var palette = new MemoryStream())
@@ -318,12 +342,12 @@ namespace OpenRA.FileFormats
 				{
 					using (var compressed = new DeflaterOutputStream(data))
 					{
-						var stride = Width * (Palette != null ? 1 : 4);
+						var rowStride = Width * PixelStride;
 						for (var y = 0; y < Height; y++)
 						{
 							// Write uncompressed scanlines for simplicity
 							compressed.WriteByte(0);
-							compressed.Write(Data, y * stride, stride);
+							compressed.Write(Data, y * rowStride, rowStride);
 						}
 
 						compressed.Flush();

OpenRA.Game/FileFormats/ReplayMetadata.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -28,7 +28,7 @@ namespace OpenRA.FileFormats
 		public ReplayMetadata(GameInformation info)
 		{
 			if (info == null)
-				throw new ArgumentNullException("info");
+				throw new ArgumentNullException(nameof(info));
 
 			GameInfo = info;
 		}
@@ -44,7 +44,7 @@ namespace OpenRA.FileFormats
 			// Read version
 			var version = fs.ReadInt32();
 			if (version != MetaVersion)
-				throw new NotSupportedException("Metadata version {0} is not supported".F(version));
+				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);

OpenRA.Game/FileSystem/FileSystem.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -28,7 +28,7 @@ namespace OpenRA.FileSystem
 
 	public class FileSystem : IReadOnlyFileSystem
 	{
-		public IEnumerable<IReadOnlyPackage> MountedPackages { get { return mountedPackages.Keys; } }
+		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 string modID;
@@ -95,7 +95,7 @@ namespace OpenRA.FileSystem
 					name = name.Substring(1);
 
 					if (!installedMods.TryGetValue(name, out var mod))
-						throw new InvalidOperationException("Could not load mod '{0}'. Available mods: {1}".F(name, installedMods.Keys.JoinWith(", ")));
+						throw new InvalidOperationException($"Could not load mod '{name}'. Available mods: {installedMods.Keys.JoinWith(", ")}");
 
 					package = mod.Package;
 					modPackages.Add(package);
@@ -104,7 +104,7 @@ namespace OpenRA.FileSystem
 				{
 					package = OpenPackage(name);
 					if (package == null)
-						throw new InvalidOperationException("Could not open package '{0}', file not found or its format is not supported.".F(name));
+						throw new InvalidOperationException($"Could not open package '{name}', file not found or its format is not supported.");
 				}
 
 				Mount(package, explicitName);
@@ -203,7 +203,7 @@ namespace OpenRA.FileSystem
 		public Stream Open(string filename)
 		{
 			if (!TryOpen(filename, out var s))
-				throw new FileNotFoundException("File not found: {0}".F(filename), filename);
+				throw new FileNotFoundException($"File not found: {filename}", filename);
 
 			return s;
 		}

OpenRA.Game/FileSystem/Folder.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -27,7 +27,7 @@ namespace OpenRA.FileSystem
 				Directory.CreateDirectory(path);
 		}
 
-		public string Name { get { return path; } }
+		public string Name => path;
 
 		public IEnumerable<string> Contents
 		{

OpenRA.Game/FileSystem/IPackage.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/FileSystem/ZipFile.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -141,7 +141,7 @@ namespace OpenRA.FileSystem
 
 		sealed class ZipFolder : IReadOnlyPackage
 		{
-			public string Name { get { return path; } }
+			public string Name => path;
 			public ReadOnlyZipFile Parent { get; private set; }
 			readonly string path;
 

OpenRA.Game/Fonts.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -22,7 +22,7 @@ namespace OpenRA
 
 	public class Fonts : IGlobalModData
 	{
-		[FieldLoader.LoadUsing("LoadFonts")]
+		[FieldLoader.LoadUsing(nameof(LoadFonts))]
 		public readonly Dictionary<string, FontData> FontList;
 
 		static object LoadFonts(MiniYaml y)

OpenRA.Game/Game.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -19,7 +19,6 @@ using System.Net;
 using System.Reflection;
 using System.Runtime;
 using System.Threading;
-using System.Threading.Tasks;
 using OpenRA.Graphics;
 using OpenRA.Network;
 using OpenRA.Primitives;
@@ -32,7 +31,6 @@ namespace OpenRA
 	public static class Game
 	{
 		public const int NetTickScale = 3; // 120 ms net tick for 40 ms local tick
-		public const int Timestep = 40;
 		public const int TimestepJankThreshold = 250; // Don't catch up for delays larger than 250ms
 
 		public static InstalledMods Mods { get; private set; }
@@ -42,6 +40,7 @@ namespace OpenRA
 		public static Settings Settings;
 		public static CursorManager Cursor;
 		public static bool HideCursor;
+
 		static WorldRenderer worldRenderer;
 		static string modLaunchWrapper;
 
@@ -56,7 +55,6 @@ namespace OpenRA
 		public static string EngineVersion { get; private set; }
 		public static LocalPlayerProfile LocalPlayerProfile;
 
-		static Task discoverNat;
 		static bool takeScreenshot = false;
 		static Benchmark benchmark = null;
 
@@ -64,12 +62,18 @@ namespace OpenRA
 
 		public static OrderManager JoinServer(ConnectionTarget endpoint, string password, bool recordReplay = true)
 		{
-			var connection = new NetworkConnection(endpoint);
+			var newConnection = new NetworkConnection(endpoint);
 			if (recordReplay)
-				connection.StartRecording(() => { return TimestampedFilename(); });
+				newConnection.StartRecording(() => { return TimestampedFilename(); });
 
-			var om = new OrderManager(endpoint, password, connection);
+			var om = new OrderManager(newConnection);
 			JoinInner(om);
+			CurrentServerSettings.Password = password;
+			CurrentServerSettings.Target = endpoint;
+
+			lastConnectionState = ConnectionState.PreConnecting;
+			ConnectionStateChanged(OrderManager, password, newConnection);
+
 			return om;
 		}
 
@@ -81,34 +85,53 @@ namespace OpenRA
 
 		static void JoinInner(OrderManager om)
 		{
-			OrderManager?.Dispose();
+			// 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
+			// a lobby, while keeping the OrderManager that runs the shellmap intact.
+			// A matching check in World.Dispose (which is called by WorldRenderer.Dispose) makes sure that we dispose
+			// the shellmap's OM when a lobby game actually starts.
+			if (OrderManager?.World == null || OrderManager.World.Type != WorldType.Shellmap)
+				OrderManager?.Dispose();
+
 			OrderManager = om;
-			lastConnectionState = ConnectionState.PreConnecting;
-			ConnectionStateChanged(OrderManager);
 		}
 
 		public static void JoinReplay(string replayFile)
 		{
-			JoinInner(new OrderManager(new ConnectionTarget(), "", new ReplayConnection(replayFile)));
+			JoinInner(new OrderManager(new ReplayConnection(replayFile)));
 		}
 
 		static void JoinLocal()
 		{
-			JoinInner(new OrderManager(new ConnectionTarget(), "", new EchoConnection()));
+			JoinInner(new OrderManager(new EchoConnection()));
+
+			// Add a spectator client for the local player
+			// On the shellmap this player is controlling the map via scripted orders
+			OrderManager.LobbyInfo.Clients.Add(new Session.Client
+			{
+				Index = OrderManager.Connection.LocalClientId,
+				Name = Settings.Player.Name,
+				PreferredColor = Settings.Player.Color,
+				Color = Settings.Player.Color,
+				Faction = "Random",
+				SpawnPoint = 0,
+				Team = 0,
+				State = Session.ClientState.Ready
+			});
 		}
 
 		// More accurate replacement for Environment.TickCount
 		static Stopwatch stopwatch = Stopwatch.StartNew();
-		public static long RunTime { get { return stopwatch.ElapsedMilliseconds; } }
+		public static long RunTime => stopwatch.ElapsedMilliseconds;
 
 		public static int RenderFrame = 0;
-		public static int NetFrameNumber { get { return OrderManager.NetFrameNumber; } }
-		public static int LocalTick { get { return OrderManager.LocalFrameNumber; } }
+		public static int NetFrameNumber => OrderManager.NetFrameNumber;
+		public static int LocalTick => OrderManager.LocalFrameNumber;
 
 		public static event Action<ConnectionTarget> OnRemoteDirectConnect = _ => { };
-		public static event Action<OrderManager> ConnectionStateChanged = _ => { };
+		public static event Action<OrderManager, string, NetworkConnection> ConnectionStateChanged = (om, pass, conn) => { };
 		static ConnectionState lastConnectionState = ConnectionState.PreConnecting;
-		public static int LocalClientId { get { return OrderManager.Connection.LocalClientId; } }
+		public static int LocalClientId => OrderManager.Connection.LocalClientId;
 
 		public static void RemoteDirectConnect(ConnectionTarget endpoint)
 		{
@@ -164,6 +187,7 @@ namespace OpenRA
 
 			using (new PerfTimer("PrepareMap"))
 				map = ModData.PrepareMap(mapUID);
+
 			using (new PerfTimer("NewWorld"))
 				OrderManager.World = new World(ModData, map, OrderManager, type);
 
@@ -186,11 +210,9 @@ namespace OpenRA
 			Ui.MouseFocusWidget = null;
 			Ui.KeyboardFocusWidget = null;
 
-			OrderManager.LocalFrameNumber = 0;
-			OrderManager.LastTickTime = RunTime;
 			OrderManager.StartGame();
 			worldRenderer.RefreshPalette();
-			Cursor.SetCursor("default");
+			Cursor.SetCursor(ChromeMetrics.Get<string>("DefaultCursor"));
 
 			// Now loading is completed, now is the ideal time to run a GC and compact the LOH.
 			// - All the temporary garbage created during loading can be collected.
@@ -206,7 +228,7 @@ namespace OpenRA
 		public static void RestartGame()
 		{
 			var replay = OrderManager.Connection as ReplayConnection;
-			var replayName = replay != null ? replay.Filename : null;
+			var replayName = replay?.Filename;
 			var lobbyInfo = OrderManager.LobbyInfo;
 
 			// Reseed the RNG so this isn't an exact repeat of the last game
@@ -214,7 +236,7 @@ namespace OpenRA
 
 			var orders = new[]
 			{
-					Order.Command("sync_lobby {0}".F(lobbyInfo.Serialize())),
+					Order.Command($"sync_lobby {lobbyInfo.Serialize()}"),
 					Order.Command("startgame")
 			};
 
@@ -297,6 +319,7 @@ namespace OpenRA
 				EngineVersion = "Unknown";
 
 			Console.WriteLine("Engine version is {0}", EngineVersion);
+			Console.WriteLine("Runtime: {0}", Platform.RuntimeVersion);
 
 			// Special case handling of Game.Mod argument: if it matches a real filesystem path
 			// then we use this to override the mod search path, and replace it with the mod id
@@ -329,9 +352,16 @@ namespace OpenRA
 				try
 				{
 					var rendererPath = Path.Combine(Platform.BinDir, "OpenRA.Platforms." + p + ".dll");
-					var assembly = Assembly.LoadFile(rendererPath);
 
+#if !MONO
+					var loader = new AssemblyLoader(rendererPath);
+					var platformType = loader.LoadDefaultAssembly().GetTypes().SingleOrDefault(t => typeof(IPlatform).IsAssignableFrom(t));
+
+#else
+					var assembly = Assembly.LoadFile(rendererPath);
 					var platformType = assembly.GetTypes().SingleOrDefault(t => typeof(IPlatform).IsAssignableFrom(t));
+#endif
+
 					if (platformType == null)
 						throw new InvalidOperationException("Platform dll must include exactly one IPlatform implementation.");
 
@@ -352,8 +382,7 @@ namespace OpenRA
 				}
 			}
 
-			if (Settings.Server.DiscoverNatDevices)
-				discoverNat = UPnP.DiscoverNatDevices(Settings.Server.NatDiscoveryTimeout);
+			Nat.Initialize();
 
 			var modSearchArg = args.GetValue("Engine.ModSearchPaths", null);
 			var modSearchPaths = modSearchArg != null ?
@@ -399,13 +428,14 @@ namespace OpenRA
 				Console.WriteLine("\t{0}: {1} ({2})", mod.Key, mod.Value.Title, mod.Value.Version);
 
 			InitializeMod(modID, args);
+			Ui.InitializeTranslation();
 		}
 
 		public static void InitializeMod(string mod, Arguments args)
 		{
 			// Clear static state if we have switched mods
 			LobbyInfoChanged = () => { };
-			ConnectionStateChanged = om => { };
+			ConnectionStateChanged = (om, p, conn) => { };
 			BeforeGameStart = () => { };
 			OnRemoteDirectConnect = endpoint => { };
 			delayedActions = new ActionQueue();
@@ -429,7 +459,7 @@ namespace OpenRA
 				throw new InvalidOperationException("Game.Mod argument missing.");
 
 			if (!Mods.ContainsKey(mod))
-				throw new InvalidOperationException("Unknown or invalid mod '{0}'.".F(mod));
+				throw new InvalidOperationException($"Unknown or invalid mod '{mod}'.");
 
 			Console.WriteLine("Loading mod: {0}", mod);
 
@@ -442,19 +472,22 @@ namespace OpenRA
 			if (!ModData.LoadScreen.BeforeLoad())
 				return;
 
-			using (new PerfTimer("LoadMaps"))
-				ModData.MapCache.LoadMaps();
-
 			ModData.InitializeLoaders(ModData.DefaultFileSystem);
 			Renderer.InitializeFonts(ModData);
 
+			using (new PerfTimer("LoadMaps"))
+				ModData.MapCache.LoadMaps();
+
 			var grid = ModData.Manifest.Contains<MapGrid>() ? ModData.Manifest.Get<MapGrid>() : null;
 			Renderer.InitializeDepthBuffer(grid);
 
 			Cursor?.Dispose();
-
 			Cursor = new CursorManager(ModData.CursorProvider);
 
+			var metadata = ModData.Manifest.Metadata;
+			if (!string.IsNullOrEmpty(metadata.WindowTitle))
+				Renderer.Window.SetWindowTitle(metadata.WindowTitle);
+
 			PerfHistory.Items["render"].HasNormalTick = false;
 			PerfHistory.Items["batches"].HasNormalTick = false;
 			PerfHistory.Items["render_world"].HasNormalTick = false;
@@ -464,31 +497,18 @@ namespace OpenRA
 
 			JoinLocal();
 
-			try
-			{
-				discoverNat?.Wait();
-			}
-			catch (Exception e)
-			{
-				Console.WriteLine("NAT discovery failed: {0}", e.Message);
-				Log.Write("nat", e.ToString());
-			}
-
-			ChromeMetrics.TryGet("ChatMessageColor", out chatMessageColor);
-			ChromeMetrics.TryGet("SystemMessageColor", out systemMessageColor);
-
 			ModData.LoadScreen.StartGame(args);
 		}
 
 		public static void LoadEditor(string mapUid)
 		{
+			JoinLocal();
 			StartGame(mapUid, WorldType.Editor);
 		}
 
 		public static void LoadShellMap()
 		{
 			var shellmap = ChooseShellmap();
-
 			using (new PerfTimer("StartGame"))
 			{
 				StartGame(shellmap, WorldType.Shellmap);
@@ -543,8 +563,7 @@ 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 Color systemMessageColor = Color.White;
-		static Color chatMessageColor = Color.White;
+
 		public static void RunAfterTick(Action a) { delayedActions.Add(a, RunTime); }
 		public static void RunAfterDelay(int delayMilliseconds, Action a) { delayedActions.Add(a, RunTime + delayMilliseconds); }
 
@@ -561,7 +580,7 @@ namespace OpenRA
 				Log.Write("debug", "Taking screenshot " + path);
 
 				Renderer.SaveScreenshot(path);
-				Debug("Saved screenshot " + filename);
+				TextNotificationsManager.Debug("Saved screenshot " + filename);
 			}
 		}
 
@@ -571,48 +590,29 @@ namespace OpenRA
 
 			var world = orderManager.World;
 
-			var uiTickDelta = tick - Ui.LastTickTime;
-			if (uiTickDelta >= Timestep)
+			if (Ui.LastTickTime.ShouldAdvance(tick))
 			{
-				// Explained below for the world tick calculation
-				var integralTickTimestep = (uiTickDelta / Timestep) * Timestep;
-				Ui.LastTickTime += integralTickTimestep >= TimestepJankThreshold ? integralTickTimestep : Timestep;
-
-				Sync.RunUnsynced(Settings.Debug.SyncCheckUnsyncedCode, world, Ui.Tick);
+				Ui.LastTickTime.AdvanceTickTime(tick);
+				Sync.RunUnsynced(world, Ui.Tick);
 				Cursor.Tick();
 			}
 
-			var worldTimestep = world == null ? Timestep : world.IsLoadingGameSave ? 1 : world.Timestep;
-			var worldTickDelta = tick - orderManager.LastTickTime;
-			if (worldTimestep != 0 && worldTickDelta >= worldTimestep)
+			if (orderManager.LastTickTime.ShouldAdvance(tick))
 			{
 				using (new PerfSample("tick_time"))
 				{
-					// Tick the world to advance the world time to match real time:
-					//    If dt < TickJankThreshold then we should try and catch up by repeatedly ticking
-					//    If dt >= TickJankThreshold then we should accept the jank and progress at the normal rate
-					// dt is rounded down to an integer tick count in order to preserve fractional tick components.
-					var integralTickTimestep = (worldTickDelta / worldTimestep) * worldTimestep;
-					orderManager.LastTickTime += integralTickTimestep >= TimestepJankThreshold ? integralTickTimestep : worldTimestep;
+					orderManager.LastTickTime.AdvanceTickTime(tick);
 
 					Sound.Tick();
-					Sync.RunUnsynced(Settings.Debug.SyncCheckUnsyncedCode, world, orderManager.TickImmediate);
+
+					Sync.RunUnsynced(world, orderManager.TickImmediate);
 
 					if (world == null)
 						return;
 
-					var isNetTick = LocalTick % NetTickScale == 0;
-
-					if (!isNetTick || orderManager.IsReadyForNextFrame)
+					if (orderManager.TryTick())
 					{
-						++orderManager.LocalFrameNumber;
-
-						Log.Write("debug", "--Tick: {0} ({1})", LocalTick, isNetTick ? "net" : "local");
-
-						if (isNetTick)
-							orderManager.Tick();
-
-						Sync.RunUnsynced(Settings.Debug.SyncCheckUnsyncedCode, world, () =>
+						Sync.RunUnsynced(world, () =>
 						{
 							world.OrderGenerator.Tick(world);
 						});
@@ -621,12 +621,10 @@ namespace OpenRA
 
 						PerfHistory.Tick();
 					}
-					else if (orderManager.NetFrameNumber == 0)
-						orderManager.LastTickTime = RunTime;
 
 					// Wait until we have done our first world Tick before TickRendering
 					if (orderManager.LocalFrameNumber > 0)
-						Sync.RunUnsynced(Settings.Debug.SyncCheckUnsyncedCode, world, () => world.TickRender(worldRenderer));
+						Sync.RunUnsynced(world, () => world.TickRender(worldRenderer));
 				}
 
 				benchmark?.Tick(LocalTick);
@@ -637,10 +635,10 @@ namespace OpenRA
 		{
 			PerformDelayedActions();
 
-			if (OrderManager.Connection.ConnectionState != lastConnectionState)
+			if (OrderManager.Connection is NetworkConnection nc && nc.ConnectionState != lastConnectionState)
 			{
-				lastConnectionState = OrderManager.Connection.ConnectionState;
-				ConnectionStateChanged(OrderManager);
+				lastConnectionState = nc.ConnectionState;
+				ConnectionStateChanged(OrderManager, null, nc);
 			}
 
 			InnerLogicTick(OrderManager);
@@ -777,9 +775,14 @@ namespace OpenRA
 
 			while (state == RunStatus.Running)
 			{
-				// Ideal time between logic updates. Timestep = 0 means the game is paused
-				// but we still call LogicTick() because it handles pausing internally.
-				var logicInterval = worldRenderer != null && worldRenderer.World.Timestep != 0 ? worldRenderer.World.Timestep : Timestep;
+				var logicInterval = Ui.Timestep;
+				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))
+					logicInterval = logicWorld.IsLoadingGameSave ? 1 :
+						logicWorld.IsReplay ? logicWorld.ReplayTimestep :
+						logicWorld.Timestep;
 
 				// Ideal time between screen updates
 				var maxFramerate = Settings.Graphics.CapFramerate ? Settings.Graphics.MaxFramerate.Clamp(1, 1000) : 1000;
@@ -817,8 +820,7 @@ namespace OpenRA
 
 					var haveSomeTimeUntilNextLogic = now < nextLogic;
 					var isTimeToRender = now >= nextRender;
-
-					if ((isTimeToRender && haveSomeTimeUntilNextLogic) || forceRender)
+					if (!Renderer.WindowIsSuspended && ((isTimeToRender && haveSomeTimeUntilNextLogic) || forceRender))
 					{
 						nextRender = now + renderInterval;
 
@@ -833,6 +835,19 @@ namespace OpenRA
 						RenderTick();
 						renderBeforeNextTick = false;
 					}
+
+					// Simulate a render tick if it was time to render but we skip actually rendering
+					if (Renderer.WindowIsSuspended && isTimeToRender)
+					{
+						// Make sure that nextUpdate is set to a proper minimum interval
+						nextRender = now + renderInterval;
+
+						// Still process SDL events to allow a restore to come through
+						Renderer.Window.PumpInput(new NullInputHandler());
+
+						// Ensure that we still logic tick despite not rendering
+						renderBeforeNextTick = false;
+					}
 				}
 				else
 					Thread.Sleep((int)(nextUpdate - now));
@@ -874,26 +889,6 @@ namespace OpenRA
 			state = RunStatus.Success;
 		}
 
-		public static void AddSystemLine(string text)
-		{
-			AddSystemLine("Battlefield Control", text);
-		}
-
-		public static void AddSystemLine(string name, string text)
-		{
-			OrderManager.AddChatLine(name, systemMessageColor, text, systemMessageColor);
-		}
-
-		public static void AddChatLine(string name, Color nameColor, string text)
-		{
-			OrderManager.AddChatLine(name, nameColor, text, chatMessageColor);
-		}
-
-		public static void Debug(string s, params object[] args)
-		{
-			AddSystemLine("Debug", string.Format(s, args));
-		}
-
 		public static void Disconnect()
 		{
 			OrderManager.World?.TraitDict.PrintReport();
@@ -965,8 +960,8 @@ namespace OpenRA
 		{
 			var orders = new List<Order>
 			{
-				Order.Command("option gamespeed {0}".F("default")),
-				Order.Command("state {0}".F(Session.ClientState.Ready))
+				Order.Command("option gamespeed default"),
+				Order.Command($"state {Session.ClientState.Ready}")
 			};
 
 			var path = Platform.ResolvePath(launchMap);
@@ -974,7 +969,7 @@ namespace OpenRA
 				ModData.MapCache.SingleOrDefault(m => m.Package.Name == path);
 
 			if (map == null)
-				throw new InvalidOperationException("Could not find map '{0}'.".F(launchMap));
+				throw new InvalidOperationException($"Could not find map '{launchMap}'.");
 
 			CreateAndStartLocalServer(map.Uid, orders);
 		}
@@ -988,4 +983,11 @@ namespace OpenRA
 			}
 		}
 	}
+
+	public static class CurrentServerSettings
+	{
+		public static string Password;
+		public static ConnectionTarget Target;
+		public static ExternalMod ServerExternalMod;
+	}
 }

OpenRA.Game/GameInformation.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -33,12 +33,13 @@ namespace OpenRA
 		public DateTime EndTimeUtc;
 
 		/// <summary>Gets the game's duration, from the time the game started until the replay recording stopped.</summary>
-		public TimeSpan Duration { get { return EndTimeUtc > StartTimeUtc ? EndTimeUtc - StartTimeUtc : TimeSpan.Zero; } }
+		public TimeSpan Duration => EndTimeUtc > StartTimeUtc ? EndTimeUtc - StartTimeUtc : TimeSpan.Zero;
+
 		public IList<Player> Players { get; private set; }
 		public HashSet<int> DisabledSpawnPoints = new HashSet<int>();
-		public MapPreview MapPreview { get { return Game.ModData.MapCache[MapUid]; } }
+		public MapPreview MapPreview => Game.ModData.MapCache[MapUid];
 		public IEnumerable<Player> HumanPlayers { get { return Players.Where(p => p.IsHuman); } }
-		public bool IsSinglePlayer { get { return HumanPlayers.Count() == 1; } }
+		public bool IsSinglePlayer => HumanPlayers.Count() == 1;
 
 		readonly Dictionary<OpenRA.Player, Player> playersByRuntime;
 
@@ -75,7 +76,7 @@ namespace OpenRA
 			}
 			catch (YamlException)
 			{
-				Log.Write("debug", "GameInformation deserialized invalid MiniYaml:\n{0}".F(data));
+				Log.Write("debug", $"GameInformation deserialized invalid MiniYaml:\n{data}");
 				throw;
 			}
 		}
@@ -88,7 +89,7 @@ namespace OpenRA
 			};
 
 			for (var i = 0; i < Players.Count; i++)
-				nodes.Add(new MiniYamlNode("Player@{0}".F(i), FieldSaver.Save(Players[i])));
+				nodes.Add(new MiniYamlNode($"Player@{i}", FieldSaver.Save(Players[i])));
 
 			return nodes.WriteToString();
 		}
@@ -97,10 +98,10 @@ namespace OpenRA
 		public void AddPlayer(OpenRA.Player runtimePlayer, Session lobbyInfo)
 		{
 			if (runtimePlayer == null)
-				throw new ArgumentNullException("runtimePlayer");
+				throw new ArgumentNullException(nameof(runtimePlayer));
 
 			if (lobbyInfo == null)
-				throw new ArgumentNullException("lobbyInfo");
+				throw new ArgumentNullException(nameof(lobbyInfo));
 
 			// We don't care about spectators and map players
 			if (runtimePlayer.NonCombatant || !runtimePlayer.Playable)
@@ -123,6 +124,7 @@ namespace OpenRA
 				DisplayFactionId = runtimePlayer.DisplayFaction.InternalName,
 				Color = runtimePlayer.Color,
 				Team = client.Team,
+				Handicap = client.Handicap,
 				SpawnPoint = runtimePlayer.SpawnPoint,
 				IsRandomFaction = runtimePlayer.Faction.InternalName != client.Faction,
 				IsRandomSpawnPoint = runtimePlayer.DisplaySpawnPoint == 0,
@@ -166,6 +168,7 @@ namespace OpenRA
 			/// <summary>The team ID on start-up, or 0 if the player is not part of a team.</summary>
 			public int Team;
 			public int SpawnPoint;
+			public int Handicap;
 
 			/// <summary>True if the faction was chosen at random; otherwise, false.</summary>
 			public bool IsRandomFaction;

OpenRA.Game/GameRules/ActorInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -61,7 +61,7 @@ namespace OpenRA
 			}
 			catch (YamlException e)
 			{
-				throw new YamlException("Actor type {0}: {1}".F(name, e.Message));
+				throw new YamlException($"Actor type {name}: {e.Message}");
 			}
 		}
 
@@ -76,8 +76,7 @@ namespace OpenRA
 		static TraitInfo LoadTraitInfo(ObjectCreator creator, string traitName, MiniYaml my)
 		{
 			if (!string.IsNullOrEmpty(my.Value))
-				throw new YamlException("Junk value `{0}` on trait node {1}"
-				.F(my.Value, traitName));
+				throw new YamlException($"Junk value `{my.Value}` on trait node {traitName}");
 
 			// HACK: The linter does not want to crash when a trait doesn't exist but only print an error instead
 			// ObjectCreator will only return null to signal us to abort here if the linter is running
@@ -89,7 +88,7 @@ namespace OpenRA
 			try
 			{
 				if (traitInstance.Length > 1)
-					info.GetType().GetField("InstanceName").SetValue(info, traitInstance[1]);
+					info.GetType().GetField(nameof(info.InstanceName)).SetValue(info, traitInstance[1]);
 
 				FieldLoader.Load(info, my);
 			}

OpenRA.Game/GameRules/MusicInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/GameRules/Ruleset.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -22,12 +22,12 @@ namespace OpenRA
 {
 	public class Ruleset
 	{
-		public readonly IReadOnlyDictionary<string, ActorInfo> Actors;
+		public readonly ActorInfoDictionary Actors;
 		public readonly IReadOnlyDictionary<string, WeaponInfo> Weapons;
 		public readonly IReadOnlyDictionary<string, SoundInfo> Voices;
 		public readonly IReadOnlyDictionary<string, SoundInfo> Notifications;
 		public readonly IReadOnlyDictionary<string, MusicInfo> Music;
-		public readonly TileSet TileSet;
+		public readonly ITerrainInfo TerrainInfo;
 		public readonly SequenceProvider Sequences;
 		public readonly IReadOnlyDictionary<string, MiniYamlNode> ModelSequences;
 
@@ -37,16 +37,16 @@ namespace OpenRA
 			IReadOnlyDictionary<string, SoundInfo> voices,
 			IReadOnlyDictionary<string, SoundInfo> notifications,
 			IReadOnlyDictionary<string, MusicInfo> music,
-			TileSet tileSet,
+			ITerrainInfo terrainInfo,
 			SequenceProvider sequences,
 			IReadOnlyDictionary<string, MiniYamlNode> modelSequences)
 		{
-			Actors = actors;
+			Actors = new ActorInfoDictionary(actors);
 			Weapons = weapons;
 			Voices = voices;
 			Notifications = notifications;
 			Music = music;
-			TileSet = tileSet;
+			TerrainInfo = terrainInfo;
 			Sequences = sequences;
 			ModelSequences = modelSequences;
 
@@ -60,15 +60,14 @@ namespace OpenRA
 					}
 					catch (YamlException e)
 					{
-						throw new YamlException("Actor type {0}: {1}".F(a.Name, e.Message));
+						throw new YamlException($"Actor type {a.Name}: {e.Message}");
 					}
 				}
 			}
 
 			foreach (var weapon in Weapons)
 			{
-				var projectileLoaded = weapon.Value.Projectile as IRulesetLoaded<WeaponInfo>;
-				if (projectileLoaded != null)
+				if (weapon.Value.Projectile is IRulesetLoaded<WeaponInfo> projectileLoaded)
 				{
 					try
 					{
@@ -76,14 +75,13 @@ namespace OpenRA
 					}
 					catch (YamlException e)
 					{
-						throw new YamlException("Projectile type {0}: {1}".F(weapon.Key, e.Message));
+						throw new YamlException($"Projectile type {weapon.Key}: {e.Message}");
 					}
 				}
 
 				foreach (var warhead in weapon.Value.Warheads)
 				{
-					var cacher = warhead as IRulesetLoaded<WeaponInfo>;
-					if (cacher != null)
+					if (warhead is IRulesetLoaded<WeaponInfo> cacher)
 					{
 						try
 						{
@@ -91,7 +89,7 @@ namespace OpenRA
 						}
 						catch (YamlException e)
 						{
-							throw new YamlException("Weapon type {0}: {1}".F(weapon.Key, e.Message));
+							throw new YamlException($"Weapon type {weapon.Key}: {e.Message}");
 						}
 					}
 				}
@@ -117,7 +115,7 @@ namespace OpenRA
 			if (filterNode != null)
 				yamlNodes = yamlNodes.Where(k => !filterNode(k));
 
-			return new ReadOnlyDictionary<string, T>(yamlNodes.ToDictionaryWithConflictLog(k => k.Key.ToLowerInvariant(), makeObject, "LoadFromManifest<" + name + ">"));
+			return yamlNodes.ToDictionaryWithConflictLog(k => k.Key.ToLowerInvariant(), makeObject, "LoadFromManifest<" + name + ">");
 		}
 
 		public static Ruleset LoadDefaults(ModData modData)
@@ -171,10 +169,10 @@ namespace OpenRA
 		public static Ruleset LoadDefaultsForTileSet(ModData modData, string tileSet)
 		{
 			var dr = modData.DefaultRules;
-			var ts = modData.DefaultTileSets[tileSet];
+			var terrainInfo = modData.DefaultTerrainInfo[tileSet];
 			var sequences = modData.DefaultSequences[tileSet];
 
-			return new Ruleset(dr.Actors, dr.Weapons, dr.Voices, dr.Notifications, dr.Music, ts, sequences, dr.ModelSequences);
+			return new Ruleset(dr.Actors, dr.Weapons, dr.Voices, dr.Notifications, dr.Music, terrainInfo, sequences, dr.ModelSequences);
 		}
 
 		public static Ruleset Load(ModData modData, IReadOnlyFileSystem fileSystem, string tileSet,
@@ -203,8 +201,8 @@ namespace OpenRA
 				var music = MergeOrDefault("Music", fileSystem, m.Music, mapMusic, dr.Music,
 					k => new MusicInfo(k.Key, k.Value));
 
-				// TODO: Add support for merging custom tileset modifications
-				var ts = modData.DefaultTileSets[tileSet];
+				// 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] :
@@ -215,7 +213,7 @@ namespace OpenRA
 					modelSequences = MergeOrDefault("ModelSequences", fileSystem, m.ModelSequences, mapModelSequences, dr.ModelSequences,
 						k => k);
 
-				ruleset = new Ruleset(actors, weapons, voices, notifications, music, ts, sequences, modelSequences);
+				ruleset = new Ruleset(actors, weapons, voices, notifications, music, terrainInfo, sequences, modelSequences);
 			};
 
 			if (modData.IsOnMainThread)

OpenRA.Game/GameRules/SoundInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/GameRules/WeaponInfo.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -121,10 +121,10 @@ namespace OpenRA.GameRules
 		[Desc("Does this weapon aim at the target's center regardless of other targetable offsets?")]
 		public readonly bool TargetActorCenter = false;
 
-		[FieldLoader.LoadUsing("LoadProjectile")]
+		[FieldLoader.LoadUsing(nameof(LoadProjectile))]
 		public readonly IProjectileInfo Projectile;
 
-		[FieldLoader.LoadUsing("LoadWarheads")]
+		[FieldLoader.LoadUsing(nameof(LoadWarheads))]
 		public readonly List<IWarhead> Warheads = new List<IWarhead>();
 
 		public WeaponInfo(string name, MiniYaml content)

OpenRA.Game/GameSpeed.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -10,27 +10,49 @@
 #endregion
 
 using System.Collections.Generic;
+using System.Linq;
 
 namespace OpenRA
 {
 	public class GameSpeed
 	{
-		[Translate]
-		public readonly string Name = "Default";
-		public readonly int Timestep = 40;
-		public readonly int OrderLatency = 3;
+		[FieldLoader.Require]
+		public readonly string Name;
+
+		[FieldLoader.Require]
+		public readonly int Timestep;
+
+		[FieldLoader.Require]
+		public readonly int OrderLatency;
 	}
 
 	public class GameSpeeds : IGlobalModData
 	{
-		[FieldLoader.LoadUsing("LoadSpeeds")]
+		[FieldLoader.Require]
+		public readonly string DefaultSpeed;
+
+		[FieldLoader.LoadUsing(nameof(LoadSpeeds))]
 		public readonly Dictionary<string, GameSpeed> Speeds;
 
 		static object LoadSpeeds(MiniYaml y)
 		{
 			var ret = new Dictionary<string, GameSpeed>();
-			foreach (var node in y.Nodes)
-				ret.Add(node.Key, FieldLoader.Load<GameSpeed>(node.Value));
+			var speedsNode = y.Nodes.FirstOrDefault(n => n.Key == "Speeds");
+			if (speedsNode == null)
+				throw new YamlException("Error parsing GameSpeeds: Missing Speeds node!");
+
+			foreach (var node in speedsNode.Value.Nodes)
+			{
+				try
+				{
+					ret.Add(node.Key, FieldLoader.Load<GameSpeed>(node.Value));
+				}
+				catch (FieldLoader.MissingFieldsException e)
+				{
+					var label = e.Missing.Length > 1 ? "Required properties missing" : "Required property missing";
+					throw new YamlException($"Error parsing GameSpeed {node.Key}: {label}: {e.Missing.JoinWith(", ")}");
+				}
+			}
 
 			return ret;
 		}

OpenRA.Game/Graphics/Animation.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -49,28 +49,32 @@ namespace OpenRA.Graphics
 			this.paused = paused;
 		}
 
-		public int CurrentFrame { get { return backwards ? CurrentSequence.Length - frame - 1 : frame; } }
-		public Sprite Image { get { return CurrentSequence.GetSprite(CurrentFrame, facingFunc()); } }
+		public int CurrentFrame => backwards ? CurrentSequence.Length - frame - 1 : frame;
+		public Sprite Image => CurrentSequence.GetSprite(CurrentFrame, facingFunc());
 
-		public IRenderable[] Render(WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale)
+		public IRenderable[] Render(WPos pos, in WVec offset, int zOffset, PaletteReference palette)
 		{
-			var imageRenderable = new SpriteRenderable(Image, pos, offset, CurrentSequence.ZOffset + zOffset, palette, scale, IsDecoration, CurrentSequence.IgnoreWorldTint);
+			var tintModifiers = CurrentSequence.IgnoreWorldTint ? TintModifiers.IgnoreWorldTint : TintModifiers.None;
+			var alpha = CurrentSequence.GetAlpha(CurrentFrame);
+			var imageRenderable = new SpriteRenderable(Image, pos, offset, CurrentSequence.ZOffset + zOffset, palette, CurrentSequence.Scale, alpha, float3.Ones, tintModifiers, IsDecoration);
 
 			if (CurrentSequence.ShadowStart >= 0)
 			{
 				var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
-				var shadowRenderable = new SpriteRenderable(shadow, pos, offset, CurrentSequence.ShadowZOffset + zOffset, palette, scale, true, CurrentSequence.IgnoreWorldTint);
+				var shadowRenderable = new SpriteRenderable(shadow, pos, offset, CurrentSequence.ShadowZOffset + zOffset, palette, CurrentSequence.Scale, 1f, float3.Ones, tintModifiers, true);
 				return new IRenderable[] { shadowRenderable, imageRenderable };
 			}
 
 			return new IRenderable[] { imageRenderable };
 		}
 
-		public IRenderable[] RenderUI(WorldRenderer wr, int2 pos, WVec offset, int zOffset, PaletteReference palette, float scale)
+		public IRenderable[] RenderUI(WorldRenderer wr, int2 pos, in WVec offset, int zOffset, PaletteReference palette, float scale = 1f)
 		{
+			scale *= CurrentSequence.Scale;
 			var screenOffset = (scale * wr.ScreenVectorComponents(offset)).XY.ToInt2();
 			var imagePos = pos + screenOffset - new int2((int)(scale * Image.Size.X / 2), (int)(scale * Image.Size.Y / 2));
-			var imageRenderable = new UISpriteRenderable(Image, WPos.Zero + offset, imagePos, CurrentSequence.ZOffset + zOffset, palette, scale);
+			var alpha = CurrentSequence.GetAlpha(CurrentFrame);
+			var imageRenderable = new UISpriteRenderable(Image, WPos.Zero + offset, imagePos, CurrentSequence.ZOffset + zOffset, palette, scale, alpha);
 
 			if (CurrentSequence.ShadowStart >= 0)
 			{
@@ -83,8 +87,9 @@ namespace OpenRA.Graphics
 			return new IRenderable[] { imageRenderable };
 		}
 
-		public Rectangle ScreenBounds(WorldRenderer wr, WPos pos, WVec offset, float scale)
+		public Rectangle ScreenBounds(WorldRenderer wr, WPos pos, in WVec offset)
 		{
+			var scale = CurrentSequence.Scale;
 			var xy = wr.ScreenPxPosition(pos) + wr.ScreenPxOffset(offset);
 			var cb = CurrentSequence.Bounds;
 			return Rectangle.FromLTRB(
@@ -96,7 +101,7 @@ namespace OpenRA.Graphics
 
 		public IRenderable[] Render(WPos pos, PaletteReference palette)
 		{
-			return Render(pos, WVec.Zero, 0, palette, 1f);
+			return Render(pos, WVec.Zero, 0, palette);
 		}
 
 		public void Play(string sequenceName)
@@ -107,7 +112,7 @@ namespace OpenRA.Graphics
 		int CurrentSequenceTickOrDefault()
 		{
 			const int DefaultTick = 40; // 25 fps == 40 ms
-			return CurrentSequence != null ? CurrentSequence.Tick : DefaultTick;
+			return CurrentSequence?.Tick ?? DefaultTick;
 		}
 
 		void PlaySequence(string sequenceName)

OpenRA.Game/Graphics/AnimationWithOffset.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -35,21 +35,21 @@ namespace OpenRA.Graphics
 			ZOffset = zOffset;
 		}
 
-		public IRenderable[] Render(Actor self, WorldRenderer wr, PaletteReference pal, float scale)
+		public IRenderable[] Render(Actor self, WorldRenderer wr, PaletteReference pal)
 		{
 			var center = self.CenterPosition;
-			var offset = OffsetFunc != null ? OffsetFunc() : WVec.Zero;
+			var offset = OffsetFunc?.Invoke() ?? WVec.Zero;
 
-			var z = (ZOffset != null) ? ZOffset(center + offset) : 0;
-			return Animation.Render(center, offset, z, pal, scale);
+			var z = ZOffset?.Invoke(center + offset) ?? 0;
+			return Animation.Render(center, offset, z, pal);
 		}
 
-		public Rectangle ScreenBounds(Actor self, WorldRenderer wr, float scale)
+		public Rectangle ScreenBounds(Actor self, WorldRenderer wr)
 		{
 			var center = self.CenterPosition;
-			var offset = OffsetFunc != null ? OffsetFunc() : WVec.Zero;
+			var offset = OffsetFunc?.Invoke() ?? WVec.Zero;
 
-			return Animation.ScreenBounds(wr, center, offset, scale);
+			return Animation.ScreenBounds(wr, center, offset);
 		}
 
 		public static implicit operator AnimationWithOffset(Animation a)

OpenRA.Game/Graphics/ChromeProvider.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -52,7 +52,7 @@ namespace OpenRA.Graphics
 			public readonly Dictionary<string, Rectangle> Regions = new Dictionary<string, Rectangle>();
 		}
 
-		public static IReadOnlyDictionary<string, Collection> Collections { get; private set; }
+		public static IReadOnlyDictionary<string, Collection> Collections => collections;
 		static Dictionary<string, Collection> collections;
 		static Dictionary<string, (Sheet Sheet, int Density)> cachedSheets;
 		static Dictionary<string, Dictionary<string, Sprite>> cachedSprites;
@@ -77,8 +77,6 @@ namespace OpenRA.Graphics
 			cachedPanelSprites = new Dictionary<string, Sprite[]>();
 			cachedCollectionSheets = new Dictionary<Collection, (Sheet, int)>();
 
-			Collections = new ReadOnlyDictionary<string, Collection>(collections);
-
 			var chrome = MiniYaml.Merge(modData.Manifest.Chrome
 				.Select(s => MiniYaml.FromStream(fileSystem.Open(s), s)));
 

OpenRA.Game/Graphics/CursorManager.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -69,9 +69,16 @@ namespace OpenRA.Graphics
 					// Hotspot is specified relative to the center of the frame
 					var hotspot = f.Offset.ToInt2() - kv.Value.Hotspot - new int2(f.Size) / 2;
 
-					// SheetBuilder expects data in BGRA
-					var data = FrameToBGRA(kv.Key, f, palette);
-					c.Sprites[c.Length++] = sheetBuilder.Add(data, f.Size, 0, hotspot);
+					// Resolve indexed data to real colours
+					var data = f.Data;
+					var type = f.Type;
+					if (type == SpriteFrameType.Indexed8)
+					{
+						data = ConvertIndexedToBgra(kv.Key, f, palette);
+						type = SpriteFrameType.Bgra32;
+					}
+
+					c.Sprites[c.Length++] = sheetBuilder.Add(data, type, f.Size, 0, hotspot);
 
 					// Bounds relative to the hotspot
 					c.Bounds = Rectangle.Union(c.Bounds, new Rectangle(hotspot, f.Size));
@@ -99,34 +106,28 @@ namespace OpenRA.Graphics
 			// Dispose any existing cursors to avoid leaking native resources
 			ClearHardwareCursors();
 
-			try
+			foreach (var kv in cursors)
 			{
-				foreach (var kv in cursors)
+				var template = kv.Value;
+				for (var i = 0; i < template.Sprites.Length; i++)
 				{
-					var template = kv.Value;
-					for (var i = 0; i < template.Sprites.Length; i++)
+					if (template.Cursors[i] != null)
+						template.Cursors[i].Dispose();
+
+					// Calculate the padding to position the frame within sequenceBounds
+					var paddingTL = -(template.Bounds.Location - template.Sprites[i].Offset.XY.ToInt2());
+					var paddingBR = template.PaddedSize - new int2(template.Sprites[i].Bounds.Size) - paddingTL;
+
+					var hardwareCursor = CreateHardwareCursor(kv.Key, template.Sprites[i], paddingTL, paddingBR, -template.Bounds.Location);
+					if (hardwareCursor != null)
+						template.Cursors[i] = hardwareCursor;
+					else
 					{
-						if (template.Cursors[i] != null)
-							template.Cursors[i].Dispose();
-
-						// Calculate the padding to position the frame within sequenceBounds
-						var paddingTL = -(template.Bounds.Location - template.Sprites[i].Offset.XY.ToInt2());
-						var paddingBR = template.PaddedSize - new int2(template.Sprites[i].Bounds.Size) - paddingTL;
-
-						template.Cursors[i] = CreateHardwareCursor(kv.Key, template.Sprites[i], paddingTL, paddingBR, -template.Bounds.Location);
+						Log.Write("debug", $"Failed to initialize hardware cursor for {template.Name}.");
+						Console.WriteLine($"Failed to initialize hardware cursor for {template.Name}.");
 					}
 				}
 			}
-			catch (Exception e)
-			{
-				Log.Write("debug", "Failed to initialize hardware cursors. Falling back to software cursors.");
-				Log.Write("debug", "Error was: " + e.Message);
-
-				Console.WriteLine("Failed to initialize hardware cursors. Falling back to software cursors.");
-				Console.WriteLine("Error was: " + e.Message);
-
-				ClearHardwareCursors();
-			}
 
 			hardwareCursorsDoubled = graphicSettings.CursorDouble;
 		}
@@ -170,10 +171,11 @@ namespace OpenRA.Graphics
 			if (cursor != null && frame >= cursor.Cursors.Length)
 				frame %= cursor.Cursors.Length;
 
-			if (cursor == null || isLocked)
+			var hardwareCursor = cursor?.Cursors[frame];
+			if (hardwareCursor == null || isLocked)
 				Game.Renderer.Window.SetHardwareCursor(null);
 			else
-				Game.Renderer.Window.SetHardwareCursor(cursor.Cursors[frame]);
+				Game.Renderer.Window.SetHardwareCursor(hardwareCursor);
 		}
 
 		public void Render(Renderer renderer)
@@ -189,17 +191,17 @@ namespace OpenRA.Graphics
 			// Render cursor in software
 			var doubleCursor = graphicSettings.CursorDouble;
 			var cursorSprite = cursor.Sprites[frame % cursor.Length];
-			var cursorSize = doubleCursor ? 2.0f * cursorSprite.Size : cursorSprite.Size;
+			var cursorScale = doubleCursor ? 2 : 1;
 
 			// Cursor is rendered in native window coordinates
 			// Apply same scaling rules as hardware cursors
 			if (Game.Renderer.NativeWindowScale > 1.5f)
-				cursorSize = 2 * cursorSize;
+				cursorScale *= 2;
 
 			var mousePos = isLocked ? lockedPosition : Viewport.LastMousePos;
 			renderer.RgbaSpriteRenderer.DrawSprite(cursorSprite,
 				mousePos,
-				cursorSize / Game.Renderer.WindowScale);
+				cursorScale / Game.Renderer.WindowScale);
 		}
 
 		public void Lock()
@@ -217,33 +219,27 @@ namespace OpenRA.Graphics
 			Update();
 		}
 
-		public static byte[] FrameToBGRA(string name, ISpriteFrame frame, ImmutablePalette palette)
+		public static byte[] ConvertIndexedToBgra(string name, ISpriteFrame frame, ImmutablePalette palette)
 		{
-			// Data is already in BGRA format
-			if (frame.Type == SpriteFrameType.BGRA)
-				return frame.Data;
+			if (frame.Type != SpriteFrameType.Indexed8)
+				throw new ArgumentException("ConvertIndexedToBgra requires input frames to be indexed.", nameof(frame));
 
-			// Cursors may be either native BGRA or Indexed.
-			// Indexed sprites are converted to BGRA using the referenced palette.
 			// All palettes must be explicitly referenced, even if they are embedded in the sprite.
-			if (frame.Type == SpriteFrameType.Indexed && palette == null)
-				throw new InvalidOperationException("Cursor sequence `{0}` attempted to load an indexed sprite but does not define Palette".F(name));
+			if (palette == null)
+				throw new InvalidOperationException($"Cursor sequence `{name}` attempted to load an indexed sprite but does not define Palette");
 
 			var width = frame.Size.Width;
 			var height = frame.Size.Height;
 			var data = new byte[4 * width * height];
-			for (var j = 0; j < height; j++)
+			unsafe
 			{
-				for (var i = 0; i < width; i++)
+				// Cast the data to an int array so we can copy the src data directly
+				fixed (byte* bd = &data[0])
 				{
-					var rgba = palette[frame.Data[j * width + i]];
-					var k = 4 * (j * width + i);
-
-					// Convert RGBA to BGRA
-					data[k] = (byte)(rgba >> 16);
-					data[k + 1] = (byte)(rgba >> 8);
-					data[k + 2] = (byte)(rgba >> 0);
-					data[k + 3] = (byte)(rgba >> 24);
+					var rgba = (uint*)bd;
+					for (var j = 0; j < height; j++)
+						for (var i = 0; i < width; i++)
+							rgba[j * width + i] = palette[frame.Data[j * width + i]];
 				}
 			}
 

OpenRA.Game/Graphics/CursorProvider.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -31,15 +31,14 @@ namespace OpenRA.Graphics
 
 			// Overwrite previous definitions if there are duplicates
 			var pals = new Dictionary<string, IProvidesCursorPaletteInfo>();
-			foreach (var p in modData.DefaultRules.Actors["world"].TraitInfos<IProvidesCursorPaletteInfo>())
+			foreach (var p in modData.DefaultRules.Actors[SystemActors.World].TraitInfos<IProvidesCursorPaletteInfo>())
 				if (p.Palette != null)
 					pals[p.Palette] = p;
 
 			Palettes = nodesDict["Cursors"].Nodes.Select(n => n.Value.Value)
 				.Where(p => p != null)
 				.Distinct()
-				.ToDictionary(p => p, p => pals[p].ReadPalette(modData.DefaultFileSystem))
-				.AsReadOnly();
+				.ToDictionary(p => p, p => pals[p].ReadPalette(modData.DefaultFileSystem));
 
 			var frameCache = new FrameCache(fileSystem, modData.SpriteLoaders);
 			var cursors = new Dictionary<string, CursorSequence>();
@@ -47,7 +46,7 @@ namespace OpenRA.Graphics
 				foreach (var sequence in s.Value.Nodes)
 					cursors.Add(sequence.Key, new CursorSequence(frameCache, sequence.Key, s.Key, s.Value.Value, sequence.Value));
 
-			Cursors = cursors.AsReadOnly();
+			Cursors = cursors;
 		}
 
 		public bool HasCursorSequence(string cursor)
@@ -60,7 +59,7 @@ namespace OpenRA.Graphics
 			try { return Cursors[cursor]; }
 			catch (KeyNotFoundException)
 			{
-				throw new InvalidOperationException("Cursor does not have a sequence `{0}`".F(cursor));
+				throw new InvalidOperationException($"Cursor does not have a sequence `{cursor}`");
 			}
 		}
 	}

OpenRA.Game/Graphics/CursorSequence.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/Graphics/HardwarePalette.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -18,72 +18,93 @@ namespace OpenRA.Graphics
 	public sealed class HardwarePalette : IDisposable
 	{
 		public ITexture Texture { get; private set; }
+		public ITexture ColorShifts { get; private set; }
+
 		public int Height { get; private set; }
 		readonly Dictionary<string, ImmutablePalette> palettes = new Dictionary<string, ImmutablePalette>();
-		readonly Dictionary<string, MutablePalette> modifiablePalettes = new Dictionary<string, MutablePalette>();
-		readonly IReadOnlyDictionary<string, MutablePalette> readOnlyModifiablePalettes;
+		readonly Dictionary<string, MutablePalette> mutablePalettes = new Dictionary<string, MutablePalette>();
 		readonly Dictionary<string, int> indices = new Dictionary<string, int>();
 		byte[] buffer = new byte[0];
+		float[] colorShiftBuffer = new float[0];
 
 		public HardwarePalette()
 		{
 			Texture = Game.Renderer.Context.CreateTexture();
-			readOnlyModifiablePalettes = modifiablePalettes.AsReadOnly();
+			ColorShifts = Game.Renderer.Context.CreateTexture();
 		}
 
 		public bool Contains(string name)
 		{
-			return modifiablePalettes.ContainsKey(name) || palettes.ContainsKey(name);
+			return mutablePalettes.ContainsKey(name) || palettes.ContainsKey(name);
 		}
 
 		public IPalette GetPalette(string name)
 		{
-			if (modifiablePalettes.TryGetValue(name, out var mutable))
+			if (mutablePalettes.TryGetValue(name, out var mutable))
 				return mutable.AsReadOnly();
 			if (palettes.TryGetValue(name, out var immutable))
 				return immutable;
-			throw new InvalidOperationException("Palette `{0}` does not exist".F(name));
+			throw new InvalidOperationException($"Palette `{name}` does not exist");
 		}
 
 		public int GetPaletteIndex(string name)
 		{
 			if (!indices.TryGetValue(name, out var ret))
-				throw new InvalidOperationException("Palette `{0}` does not exist".F(name));
+				throw new InvalidOperationException($"Palette `{name}` does not exist");
 			return ret;
 		}
 
 		public void AddPalette(string name, ImmutablePalette p, bool allowModifiers)
 		{
 			if (palettes.ContainsKey(name))
-				throw new InvalidOperationException("Palette {0} has already been defined".F(name));
+				throw new InvalidOperationException($"Palette {name} has already been defined");
 
-			int index = palettes.Count;
+			// PERF: the first row in the palette textures is reserved as a placeholder for non-indexed sprites
+			// that do not have a color-shift applied. This provides a quick shortcut to avoid querying the
+			// color-shift texture for every pixel only to find that most are not shifted.
+			var index = palettes.Count + 1;
 			indices.Add(name, index);
 			palettes.Add(name, p);
 
-			if (palettes.Count > Height)
+			if (index >= Height)
 			{
-				Height = Exts.NextPowerOf2(palettes.Count);
+				Height = Exts.NextPowerOf2(index + 1);
 				Array.Resize(ref buffer, Height * Palette.Size * 4);
+				Array.Resize(ref colorShiftBuffer, Height * 4);
 			}
 
 			if (allowModifiers)
-				modifiablePalettes.Add(name, new MutablePalette(p));
+				mutablePalettes.Add(name, new MutablePalette(p));
 			else
 				CopyPaletteToBuffer(index, p);
 		}
 
 		public void ReplacePalette(string name, IPalette p)
 		{
-			if (modifiablePalettes.ContainsKey(name))
-				CopyPaletteToBuffer(indices[name], modifiablePalettes[name] = new MutablePalette(p));
+			if (mutablePalettes.ContainsKey(name))
+				CopyPaletteToBuffer(indices[name], mutablePalettes[name] = new MutablePalette(p));
 			else if (palettes.ContainsKey(name))
 				CopyPaletteToBuffer(indices[name], palettes[name] = new ImmutablePalette(p));
 			else
-				throw new InvalidOperationException("Palette `{0}` does not exist".F(name));
+				throw new InvalidOperationException($"Palette `{name}` does not exist");
 			CopyBufferToTexture();
 		}
 
+		public void SetColorShift(string name, float hueOffset, float satOffset, 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;
+		}
+
+		public bool HasColorShift(string name)
+		{
+			var index = GetPaletteIndex(name);
+			return colorShiftBuffer[4 * index + 2] != 0 || colorShiftBuffer[4 * index + 3] != 0;
+		}
+
 		public void Initialize()
 		{
 			CopyModifiablePalettesToBuffer();
@@ -97,26 +118,27 @@ namespace OpenRA.Graphics
 
 		void CopyModifiablePalettesToBuffer()
 		{
-			foreach (var kvp in modifiablePalettes)
+			foreach (var kvp in mutablePalettes)
 				CopyPaletteToBuffer(indices[kvp.Key], kvp.Value);
 		}
 
 		void CopyBufferToTexture()
 		{
 			Texture.SetData(buffer, Palette.Size, Height);
+			ColorShifts.SetFloatData(colorShiftBuffer, 1, Height);
 		}
 
 		public void ApplyModifiers(IEnumerable<IPaletteModifier> paletteMods)
 		{
 			foreach (var mod in paletteMods)
-				mod.AdjustPalette(readOnlyModifiablePalettes);
+				mod.AdjustPalette(mutablePalettes);
 
 			// Update our texture with the changes.
 			CopyModifiablePalettesToBuffer();
 			CopyBufferToTexture();
 
 			// Reset modified palettes back to their original colors, ready for next time.
-			foreach (var kvp in modifiablePalettes)
+			foreach (var kvp in mutablePalettes)
 			{
 				var originalPalette = palettes[kvp.Key];
 				var modifiedPalette = kvp.Value;
@@ -127,6 +149,7 @@ namespace OpenRA.Graphics
 		public void Dispose()
 		{
 			Texture.Dispose();
+			ColorShifts.Dispose();
 		}
 	}
 }

OpenRA.Game/Graphics/Model.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -10,6 +10,7 @@
 #endregion
 
 using System;
+using System.Collections.Generic;
 using OpenRA.FileSystem;
 using OpenRA.Primitives;
 
@@ -29,7 +30,7 @@ namespace OpenRA.Graphics
 		Rectangle AggregateBounds { get; }
 	}
 
-	public struct ModelRenderData
+	public readonly struct ModelRenderData
 	{
 		public readonly int Start;
 		public readonly int Count;
@@ -45,6 +46,7 @@ namespace OpenRA.Graphics
 
 	public interface IModelCache : IDisposable
 	{
+		IModel GetModel(string model);
 		IModel GetModelSequence(string model, string sequence);
 		bool HasModelSequence(string model, string sequence);
 		IVertexBuffer<Vertex> VertexBuffer { get; }
@@ -62,10 +64,15 @@ namespace OpenRA.Graphics
 
 		class PlaceholderModelCache : IModelCache
 		{
-			public IVertexBuffer<Vertex> VertexBuffer { get { throw new NotImplementedException(); } }
+			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();

OpenRA.Game/Graphics/ModelAnimation.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -14,7 +14,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Graphics
 {
-	public struct ModelAnimation
+	public readonly struct ModelAnimation
 	{
 		public readonly IModel Model;
 		public readonly Func<WVec> OffsetFunc;
@@ -46,12 +46,6 @@ namespace OpenRA.Graphics
 				xy.Y + (int)(r.Bottom * scale));
 		}
 
-		public bool IsVisible
-		{
-			get
-			{
-				return DisableFunc == null || !DisableFunc();
-			}
-		}
+		public bool IsVisible => DisableFunc == null || !DisableFunc();
 	}
 }

OpenRA.Game/Graphics/ModelRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -42,6 +42,7 @@ namespace OpenRA.Graphics
 		static readonly float[] ZVector = new float[] { 0, 0, 1, 1 };
 		static readonly float[] FlipMtx = Util.ScaleMatrix(1, -1, 1);
 		static readonly float[] ShadowScaleFlipMtx = Util.ScaleMatrix(2, -2, 2);
+		static readonly float[] GroundNormal = { 0, 0, 1, 1 };
 
 		readonly Renderer renderer;
 		readonly IShader shader;
@@ -80,7 +81,7 @@ namespace OpenRA.Graphics
 
 		public ModelRenderProxy RenderAsync(
 			WorldRenderer wr, IEnumerable<ModelAnimation> models, in WRot camera, float scale,
-			float[] groundNormal, in WRot lightSource, float[] lightAmbientColor, float[] lightDiffuseColor,
+			in WRot groundOrientation, in WRot lightSource, float[] lightAmbientColor, float[] lightDiffuseColor,
 			PaletteReference color, PaletteReference normals, PaletteReference shadowPalette)
 		{
 			if (!isInFrame)
@@ -92,7 +93,10 @@ namespace OpenRA.Graphics
 			// Correct for bogus light source definition
 			var lightYaw = Util.MakeFloatMatrix(new WRot(WAngle.Zero, WAngle.Zero, -lightSource.Yaw).AsMatrix());
 			var lightPitch = Util.MakeFloatMatrix(new WRot(WAngle.Zero, -lightSource.Pitch, WAngle.Zero).AsMatrix());
-			var shadowTransform = Util.MatrixMultiply(lightPitch, lightYaw);
+			var ground = Util.MakeFloatMatrix(groundOrientation.AsMatrix());
+			var shadowTransform = Util.MatrixMultiply(Util.MatrixMultiply(lightPitch, lightYaw), Util.MatrixInverse(ground));
+
+			var groundNormal = Util.MatrixVectorMultiply(ground, GroundNormal);
 
 			var invShadowTransform = Util.MatrixInverse(shadowTransform);
 			var cameraTransform = Util.MakeFloatMatrix(camera.AsMatrix());
@@ -205,7 +209,7 @@ namespace OpenRA.Graphics
 						var t = m.Model.TransformationMatrix(i, frame);
 						var it = Util.MatrixInverse(t);
 						if (it == null)
-							throw new InvalidOperationException("Failed to invert the transformed matrix of frame {0} during RenderAsync.".F(i));
+							throw new InvalidOperationException($"Failed to invert the transformed matrix of frame {i} during RenderAsync.");
 
 						// Transform light vector from shadow -> world -> limb coords
 						var lightDirection = ExtractRotationVector(Util.MatrixMultiply(it, lightTransform));

OpenRA.Game/Graphics/Palette.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -44,7 +44,8 @@ namespace OpenRA.Graphics
 		{
 			IPalette palette;
 			public ReadOnlyPalette(IPalette palette) { this.palette = palette; }
-			public uint this[int index] { get { return palette[index]; } }
+			public uint this[int index] => palette[index];
+
 			public void CopyToArray(Array destination, int destinationOffset)
 			{
 				palette.CopyToArray(destination, destinationOffset);
@@ -56,28 +57,25 @@ namespace OpenRA.Graphics
 	{
 		readonly uint[] colors = new uint[Palette.Size];
 
-		public uint this[int index]
-		{
-			get { return colors[index]; }
-		}
+		public uint this[int index] => colors[index];
 
 		public void CopyToArray(Array destination, int destinationOffset)
 		{
 			Buffer.BlockCopy(colors, 0, destination, destinationOffset * 4, Palette.Size * 4);
 		}
 
-		public ImmutablePalette(string filename, int[] remap)
+		public ImmutablePalette(string filename, int[] remapTransparent, int[] remap)
 		{
 			using (var s = File.OpenRead(filename))
-				LoadFromStream(s, remap);
+				LoadFromStream(s, remapTransparent, remap);
 		}
 
-		public ImmutablePalette(Stream s, int[] remapShadow)
+		public ImmutablePalette(Stream s, int[] remapTransparent, int[] remapShadow)
 		{
-			LoadFromStream(s, remapShadow);
+			LoadFromStream(s, remapTransparent, remapShadow);
 		}
 
-		void LoadFromStream(Stream s, int[] remapShadow)
+		void LoadFromStream(Stream s, int[] remapTransparent, int[] remapShadow)
 		{
 			using (var reader = new BinaryReader(s))
 				for (var i = 0; i < Palette.Size; i++)
@@ -94,7 +92,9 @@ namespace OpenRA.Graphics
 					colors[i] = (uint)((255 << 24) | (r << 16) | (g << 8) | b);
 				}
 
-			colors[0] = 0; // Convert black background to transparency.
+			foreach (var i in remapTransparent)
+				colors[i] = 0;
+
 			foreach (var i in remapShadow)
 				colors[i] = 140u << 24;
 		}
@@ -126,8 +126,8 @@ namespace OpenRA.Graphics
 
 		public uint this[int index]
 		{
-			get { return colors[index]; }
-			set { colors[index] = value; }
+			get => colors[index];
+			set => colors[index] = value;
 		}
 
 		public void CopyToArray(Array destination, int destinationOffset)

OpenRA.Game/Graphics/PaletteReference.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -18,8 +18,8 @@ namespace OpenRA.Graphics
 
 		public readonly string Name;
 		public IPalette Palette { get; internal set; }
-		public float TextureIndex { get { return index / hardwarePalette.Height; } }
-		public float TextureMidIndex { get { return (index + 0.5f) / hardwarePalette.Height; } }
+		public float TextureIndex => index / hardwarePalette.Height;
+		public float TextureMidIndex => (index + 0.5f) / hardwarePalette.Height;
 
 		public PaletteReference(string name, int index, IPalette palette, HardwarePalette hardwarePalette)
 		{
@@ -28,5 +28,7 @@ namespace OpenRA.Graphics
 			this.index = index;
 			this.hardwarePalette = hardwarePalette;
 		}
+
+		public bool HasColorShift => hardwarePalette.HasColorShift(Name);
 	}
 }

OpenRA.Game/Graphics/PlatformInterfaces.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -59,6 +59,7 @@ namespace OpenRA
 		int DisplayCount { get; }
 		int CurrentDisplay { get; }
 		bool HasInputFocus { get; }
+		bool IsSuspended { get; }
 
 		event Action<float, float, float, float> OnWindowScaleChanged;
 
@@ -71,6 +72,7 @@ namespace OpenRA
 
 		IHardwareCursor CreateHardwareCursor(string name, Size size, byte[] data, int2 hotspot, bool pixelDouble);
 		void SetHardwareCursor(IHardwareCursor cursor);
+		void SetWindowTitle(string title);
 		void SetRelativeMouseMode(bool mode);
 		void SetScaleModifier(float scale);
 
@@ -124,6 +126,7 @@ namespace OpenRA
 	{
 		void SetData(uint[,] colors);
 		void SetData(byte[] colors, int width, int height);
+		void SetFloatData(float[] data, int width, int height);
 		byte[] GetData();
 		Size Size { get; }
 		TextureScaleFilter ScaleFilter { get; set; }
@@ -145,7 +148,7 @@ namespace OpenRA
 		TriangleList,
 	}
 
-	public struct Range<T>
+	public readonly struct Range<T>
 	{
 		public readonly T Start, End;
 		public Range(T start, T end) { Start = start; End = end; }

OpenRA.Game/Graphics/PlayerColorRemap.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -18,43 +18,35 @@ namespace OpenRA.Graphics
 {
 	public class PlayerColorRemap : IPaletteRemap
 	{
-		Dictionary<int, Color> remapColors;
+		readonly int[] remapIndices;
+		readonly float hue;
+		readonly float saturation;
 
-		public static int GetRemapIndex(int[] ramp, int i)
+		public PlayerColorRemap(int[] remapIndices, float hue, float saturation)
 		{
-			return ramp[i];
-		}
-
-		public PlayerColorRemap(int[] ramp, Color c, float rampFraction)
-		{
-			var h = c.GetHue() / 360.0f;
-			var s = c.GetSaturation();
-			var l = c.GetBrightness();
-
-			// Increase luminosity if required to represent the full ramp
-			var rampRange = (byte)((1 - rampFraction) * l);
-			var c1 = Color.FromAhsl(h, s, Math.Max(rampRange, l));
-			var c2 = Color.FromAhsl(h, s, (byte)Math.Max(0, l - rampRange));
-			var baseIndex = ramp[0];
-			var remapRamp = ramp.Select(r => r - ramp[0]);
-			var rampMaxIndex = ramp.Length - 1;
-
-			// reversed remapping
-			if (ramp[0] > ramp[rampMaxIndex])
-			{
-				baseIndex = ramp[rampMaxIndex];
-				for (var i = rampMaxIndex; i > 0; i--)
-					remapRamp = ramp.Select(r => r - ramp[rampMaxIndex]);
-			}
-
-			remapColors = remapRamp.Select((x, i) => (baseIndex + i, Exts.ColorLerp(x / (float)ramp.Length, c1, c2)))
-				.ToDictionary(u => u.Item1, u => u.Item2);
+			this.remapIndices = remapIndices;
+			this.hue = hue;
+			this.saturation = saturation;
 		}
 
 		public Color GetRemappedColor(Color original, int index)
 		{
-			return remapColors.TryGetValue(index, out var c)
-				? c : original;
+			if (!remapIndices.Contains(index))
+				return original;
+
+			// Color remapping is applied in a linear color space, so start
+			// by undoing the pre-multiplied alpha and gamma corrections
+			var (r, g, b) = original.ToLinear();
+
+			// Calculate the brightness (i.e HSV value) of the original colour
+			// This inlines the single line of Color.RgbToHsv() that we need
+			var value = Math.Max(Math.Max(r, g), b);
+
+			// Construct the new RGB color
+			(r, g, b) = Color.HsvToRgb(hue, saturation, value);
+
+			// Convert linear back to SRGB and pre-multiply by the alpha
+			return Color.FromLinear(original.A, r, g, b);
 		}
 	}
 }

OpenRA.Game/Graphics/Renderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Primitives;
 
 namespace OpenRA.Graphics
@@ -16,21 +17,38 @@ namespace OpenRA.Graphics
 	public interface IRenderable
 	{
 		WPos Pos { get; }
-		PaletteReference Palette { get; }
 		int ZOffset { get; }
 		bool IsDecoration { get; }
 
-		IRenderable WithPalette(PaletteReference newPalette);
 		IRenderable WithZOffset(int newOffset);
-		IRenderable OffsetBy(WVec offset);
+		IRenderable OffsetBy(in WVec offset);
 		IRenderable AsDecoration();
 
 		IFinalizedRenderable PrepareRender(WorldRenderer wr);
 	}
 
-	public interface ITintableRenderable
+	public interface IPalettedRenderable : IRenderable
 	{
-		IRenderable WithTint(in float3 newTint);
+		PaletteReference Palette { get; }
+		IPalettedRenderable WithPalette(PaletteReference newPalette);
+	}
+
+	[Flags]
+	public enum TintModifiers
+	{
+		None = 0,
+		IgnoreWorldTint = 1,
+		ReplaceColor = 2
+	}
+
+	public interface IModifyableRenderable : IRenderable
+	{
+		float Alpha { get; }
+		float3 Tint { get; }
+		TintModifiers TintModifiers { get; }
+
+		IModifyableRenderable WithAlpha(float newAlpha);
+		IModifyableRenderable WithTint(in float3 newTint, TintModifiers newTintModifiers);
 	}
 
 	public interface IFinalizedRenderable

OpenRA.Game/Graphics/RgbaColorRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -28,7 +28,7 @@ namespace OpenRA.Graphics
 			this.parent = parent;
 		}
 
-		public void DrawLine(in float3 start, in float3 end, float width, Color startColor, Color endColor)
+		public void DrawLine(in float3 start, in float3 end, float width, Color startColor, Color endColor, BlendMode blendMode = BlendMode.Alpha)
 		{
 			var delta = (end - start) / (end - start).XY.Length;
 			var corner = width / 2 * new float3(-delta.Y, delta.X, delta.Z);
@@ -52,10 +52,10 @@ namespace OpenRA.Graphics
 			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);
 
-			parent.DrawRGBAVertices(vertices);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}
 
-		public void DrawLine(in float3 start, in float3 end, float width, Color color)
+		public void DrawLine(in float3 start, in float3 end, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
 		{
 			var delta = (end - start) / (end - start).XY.Length;
 			var corner = width / 2 * new float2(-delta.Y, delta.X);
@@ -72,7 +72,7 @@ namespace OpenRA.Graphics
 			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);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}
 
 		/// <summary>
@@ -90,7 +90,7 @@ namespace OpenRA.Graphics
 			return new float3(x / d, y / d, 0.5f * (a.Z + b.Z));
 		}
 
-		void DrawDisconnectedLine(IEnumerable<float3> points, float width, Color color)
+		void DrawDisconnectedLine(IEnumerable<float3> points, float width, Color color, BlendMode blendMode)
 		{
 			using (var e = points.GetEnumerator())
 			{
@@ -101,13 +101,13 @@ namespace OpenRA.Graphics
 				while (e.MoveNext())
 				{
 					var point = e.Current;
-					DrawLine(lastPoint, point, width, color);
+					DrawLine(lastPoint, point, width, color, blendMode);
 					lastPoint = point;
 				}
 			}
 		}
 
-		void DrawConnectedLine(float3[] points, float width, Color color, bool closed)
+		void DrawConnectedLine(float3[] points, float width, Color color, bool closed, BlendMode blendMode)
 		{
 			// Not a line
 			if (points.Length < 2)
@@ -116,7 +116,7 @@ namespace OpenRA.Graphics
 			// Single segment
 			if (points.Length == 2)
 			{
-				DrawLine(points[0], points[1], width, color);
+				DrawLine(points[0], points[1], width, color, blendMode);
 				return;
 			}
 
@@ -163,7 +163,7 @@ namespace OpenRA.Graphics
 				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);
+				parent.DrawRGBAVertices(vertices, blendMode);
 
 				// Advance line segment
 				end = next;
@@ -175,32 +175,32 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		public void DrawLine(IEnumerable<float3> points, float width, Color color, bool connectSegments = false)
+		public void DrawLine(IEnumerable<float3> points, float width, Color color, bool connectSegments = false, BlendMode blendMode = BlendMode.Alpha)
 		{
 			if (!connectSegments)
-				DrawDisconnectedLine(points, width, color);
+				DrawDisconnectedLine(points, width, color, blendMode);
 			else
-				DrawConnectedLine(points as float3[] ?? points.ToArray(), width, color, false);
+				DrawConnectedLine(points as float3[] ?? points.ToArray(), width, color, false, blendMode);
 		}
 
-		public void DrawPolygon(float3[] vertices, float width, Color color)
+		public void DrawPolygon(float3[] vertices, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
 		{
-			DrawConnectedLine(vertices, width, color, true);
+			DrawConnectedLine(vertices, width, color, true, blendMode);
 		}
 
-		public void DrawPolygon(float2[] vertices, float width, Color color)
+		public void DrawPolygon(float2[] vertices, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
 		{
-			DrawConnectedLine(vertices.Select(v => new float3(v, 0)).ToArray(), width, color, true);
+			DrawConnectedLine(vertices.Select(v => new float3(v, 0)).ToArray(), width, color, true, blendMode);
 		}
 
-		public void DrawRect(in float3 tl, in float3 br, float width, Color color)
+		public void DrawRect(in float3 tl, in float3 br, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
 		{
 			var tr = new float3(br.X, tl.Y, tl.Z);
 			var bl = new float3(tl.X, br.Y, br.Z);
-			DrawPolygon(new[] { tl, tr, br, bl }, width, color);
+			DrawPolygon(new[] { tl, tr, br, bl }, width, color, blendMode);
 		}
 
-		public void FillTriangle(in float3 a, in float3 b, in float3 c, Color color)
+		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;
@@ -211,17 +211,17 @@ namespace OpenRA.Graphics
 			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);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}
 
-		public void FillRect(in float3 tl, in float3 br, Color color)
+		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);
 			var bl = new float3(tl.X, br.Y, br.Z);
-			FillRect(tl, tr, br, bl, color);
+			FillRect(tl, tr, br, bl, color, blendMode);
 		}
 
-		public void FillRect(in float3 a, in float3 b, in float3 c, in float3 d, Color color)
+		public void FillRect(in float3 a, in float3 b, in float3 c, in float3 d, Color color, BlendMode blendMode = BlendMode.Alpha)
 		{
 			color = Util.PremultiplyAlpha(color);
 			var cr = color.R / 255.0f;
@@ -235,10 +235,10 @@ namespace OpenRA.Graphics
 			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);
+			parent.DrawRGBAVertices(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)
+		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)
 		{
 			vertices[0] = VertexWithColor(a + Offset, topLeftColor);
 			vertices[1] = VertexWithColor(b + Offset, topRightColor);
@@ -247,7 +247,7 @@ namespace OpenRA.Graphics
 			vertices[4] = VertexWithColor(d + Offset, bottomLeftColor);
 			vertices[5] = VertexWithColor(a + Offset, topLeftColor);
 
-			parent.DrawRGBAVertices(vertices);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}
 
 		static Vertex VertexWithColor(in float3 xyz, Color color)
@@ -261,7 +261,7 @@ namespace OpenRA.Graphics
 			return new Vertex(xyz, cr, cg, cb, ca, 0, 0);
 		}
 
-		public void FillEllipse(in float3 tl, in float3 br, Color color, int vertices = 32)
+		public void FillEllipse(in float3 tl, in float3 br, Color color, int vertices = 32, BlendMode blendMode = BlendMode.Alpha)
 		{
 			// TODO: Create an ellipse polygon instead
 			var a = (br.X - tl.X) / 2;
@@ -272,7 +272,7 @@ namespace OpenRA.Graphics
 			{
 				var z = float2.Lerp(tl.Z, br.Z, (y - tl.Y) / (br.Y - tl.Y));
 				var dx = a * (float)Math.Sqrt(1 - (y - yc) * (y - yc) / b / b);
-				DrawLine(new float3(xc - dx, y, z), new float3(xc + dx, y, z), 1, color);
+				DrawLine(new float3(xc - dx, y, z), new float3(xc + dx, y, z), 1, color, blendMode);
 			}
 		}
 	}

OpenRA.Game/Graphics/RgbaSpriteRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -22,44 +22,36 @@ namespace OpenRA.Graphics
 			this.parent = parent;
 		}
 
-		public void DrawSprite(Sprite s, in float3 location, in float3 size)
+		public void DrawSprite(Sprite s, in float3 location, in float3 scale)
 		{
 			if (s.Channel != TextureChannel.RGBA)
 				throw new InvalidOperationException("DrawRGBASprite requires a RGBA sprite.");
 
-			parent.DrawSprite(s, location, 0, size);
+			parent.DrawSprite(s, 0, location, scale);
 		}
 
-		public void DrawSprite(Sprite s, in float3 location)
+		public void DrawSprite(Sprite s, in float3 location, float scale = 1f)
 		{
 			if (s.Channel != TextureChannel.RGBA)
 				throw new InvalidOperationException("DrawRGBASprite requires a RGBA sprite.");
 
-			parent.DrawSprite(s, location, 0, s.Size);
+			parent.DrawSprite(s, 0, location, scale);
 		}
 
-		public void DrawSprite(Sprite s, in float3 a, in float3 b, in float3 c, in float3 d)
+		public void DrawSprite(Sprite s, in float3 location, float scale, in float3 tint, float alpha)
 		{
 			if (s.Channel != TextureChannel.RGBA)
 				throw new InvalidOperationException("DrawRGBASprite requires a RGBA sprite.");
 
-			parent.DrawSprite(s, a, b, c, d);
+			parent.DrawSprite(s, 0, location, scale, tint, alpha);
 		}
 
-		public void DrawSpriteWithTint(Sprite s, in float3 location, in float3 size, in float3 tint)
+		public void DrawSprite(Sprite s, in float3 a, in float3 b, in float3 c, in float3 d, in float3 tint, float alpha)
 		{
 			if (s.Channel != TextureChannel.RGBA)
 				throw new InvalidOperationException("DrawRGBASprite requires a RGBA sprite.");
 
-			parent.DrawSpriteWithTint(s, location, 0, size, tint);
-		}
-
-		public void DrawSpriteWithTint(Sprite s, in float3 a, in float3 b, in float3 c, in float3 d, in float3 tint)
-		{
-			if (s.Channel != TextureChannel.RGBA)
-				throw new InvalidOperationException("DrawRGBASprite requires a RGBA sprite.");
-
-			parent.DrawSpriteWithTint(s, a, b, c, d, tint);
+			parent.DrawSprite(s, 0, a, b, c, d, tint, alpha);
 		}
 	}
 }

OpenRA.Game/Graphics/SequenceProvider.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -33,10 +33,12 @@ namespace OpenRA.Graphics
 		int[] Frames { get; }
 		Rectangle Bounds { get; }
 		bool IgnoreWorldTint { get; }
+		float Scale { get; }
 
 		Sprite GetSprite(int frame);
 		Sprite GetSprite(int frame, WAngle facing);
 		Sprite GetShadow(int frame, WAngle facing);
+		float GetAlpha(int frame);
 	}
 
 	public interface ISpriteSequenceLoader
@@ -50,7 +52,7 @@ namespace OpenRA.Graphics
 		readonly string tileSet;
 		readonly Lazy<Sequences> sequences;
 		readonly Lazy<SpriteCache> spriteCache;
-		public SpriteCache SpriteCache { get { return spriteCache.Value; } }
+		public SpriteCache SpriteCache => spriteCache.Value;
 
 		readonly Dictionary<string, UnitSequences> sequenceCache = new Dictionary<string, UnitSequences>();
 
@@ -70,15 +72,15 @@ namespace OpenRA.Graphics
 		public ISpriteSequence GetSequence(string unitName, string sequenceName)
 		{
 			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException("Unit `{0}` does not have any sequences defined.".F(unitName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
 
 			if (!unitSeq.Value.TryGetValue(sequenceName, out var seq))
-				throw new InvalidOperationException("Unit `{0}` does not have a sequence named `{1}`".F(unitName, sequenceName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have a sequence named `{sequenceName}`");
 
 			return seq;
 		}
 
-		public IEnumerable<string> Images { get { return sequences.Value.Keys; } }
+		public IEnumerable<string> Images => sequences.Value.Keys;
 
 		public bool HasSequence(string unitName)
 		{
@@ -88,7 +90,7 @@ namespace OpenRA.Graphics
 		public bool HasSequence(string unitName, string sequenceName)
 		{
 			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException("Unit `{0}` does not have any sequences defined.".F(unitName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
 
 			return unitSeq.Value.ContainsKey(sequenceName);
 		}
@@ -96,7 +98,7 @@ namespace OpenRA.Graphics
 		public IEnumerable<string> Sequences(string unitName)
 		{
 			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException("Unit `{0}` does not have any sequences defined.".F(unitName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
 
 			return unitSeq.Value.Keys;
 		}
@@ -123,7 +125,7 @@ namespace OpenRA.Graphics
 				}
 			}
 
-			return new ReadOnlyDictionary<string, UnitSequences>(items);
+			return items;
 		}
 
 		public void Preload()

OpenRA.Game/Graphics/Sheet.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -32,7 +32,7 @@ namespace OpenRA.Graphics
 			return data;
 		}
 
-		public bool Buffered { get { return data != null || texture == null; } }
+		public bool Buffered => data != null || texture == null;
 
 		public Sheet(SheetType type, Size size)
 		{
@@ -79,21 +79,17 @@ namespace OpenRA.Graphics
 
 		public Png AsPng()
 		{
-			var data = GetData();
+			if (Type == SheetType.Indexed)
+				throw new InvalidOperationException("AsPng() cannot be called on Indexed sheets.");
 
-			// Convert BGRA to RGBA
-			for (var i = 0; i < Size.Width * Size.Height; i++)
-			{
-				var temp = data[i * 4];
-				data[i * 4] = data[i * 4 + 2];
-				data[i * 4 + 2] = temp;
-			}
-
-			return new Png(data, Size.Width, Size.Height);
+			return new Png(GetData(), SpriteFrameType.Bgra32, Size.Width, Size.Height);
 		}
 
 		public Png AsPng(TextureChannel channel, IPalette pal)
 		{
+			if (Type != SheetType.Indexed)
+				throw new InvalidOperationException("AsPng(TextureChannel, IPalette) can only be called on Indexed sheets.");
+
 			var d = GetData();
 			var plane = new byte[Size.Width * Size.Height];
 			var dataStride = 4 * Size.Width;
@@ -107,7 +103,7 @@ namespace OpenRA.Graphics
 			for (var i = 0; i < Palette.Size; i++)
 				palColors[i] = pal.GetColor(i);
 
-			return new Png(plane, Size.Width, Size.Height, palColors);
+			return new Png(plane, SpriteFrameType.Indexed8, Size.Width, Size.Height, palColors);
 		}
 
 		public void CreateBuffer()

OpenRA.Game/Graphics/SheetBuilder.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -52,9 +52,16 @@ namespace OpenRA.Graphics
 		{
 			switch (t)
 			{
-				case SpriteFrameType.Indexed: return SheetType.Indexed;
-				case SpriteFrameType.BGRA: return SheetType.BGRA;
-				default: throw new NotImplementedException("Unknown SpriteFrameType {0}".F(t));
+				case SpriteFrameType.Indexed8:
+					return SheetType.Indexed;
+
+				// Util.FastCopyIntoChannel will automatically convert these to BGRA
+				case SpriteFrameType.Bgra32:
+				case SpriteFrameType.Bgr24:
+				case SpriteFrameType.Rgba32:
+				case SpriteFrameType.Rgb24:
+					return SheetType.BGRA;
+				default: throw new NotImplementedException($"Unknown SpriteFrameType {t}");
 			}
 		}
 
@@ -74,16 +81,16 @@ namespace OpenRA.Graphics
 			this.margin = margin;
 		}
 
-		public Sprite Add(ISpriteFrame frame) { return Add(frame.Data, frame.Size, 0, frame.Offset); }
-		public Sprite Add(byte[] src, Size size) { return Add(src, size, 0, float3.Zero); }
-		public Sprite Add(byte[] src, Size size, float zRamp, in float3 spriteOffset)
+		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)
 		{
 			// Don't bother allocating empty sprites
 			if (size.Width == 0 || size.Height == 0)
 				return new Sprite(current, Rectangle.Empty, 0, spriteOffset, channel, BlendMode.Alpha);
 
 			var rect = Allocate(size, zRamp, spriteOffset);
-			Util.FastCopyIntoChannel(rect, src);
+			Util.FastCopyIntoChannel(rect, src, type);
 			current.CommitBufferedData();
 			return rect;
 		}
@@ -96,15 +103,6 @@ namespace OpenRA.Graphics
 			return rect;
 		}
 
-		public Sprite Add(Size size, byte paletteIndex)
-		{
-			var data = new byte[size.Width * size.Height];
-			for (var i = 0; i < data.Length; i++)
-				data[i] = paletteIndex;
-
-			return Add(data, size);
-		}
-
 		TextureChannel? NextChannel(TextureChannel t)
 		{
 			var nextChannel = (int)t + (int)Type;
@@ -149,9 +147,9 @@ namespace OpenRA.Graphics
 			return rect;
 		}
 
-		public Sheet Current { get { return current; } }
-		public TextureChannel CurrentChannel { get { return channel; } }
-		public IEnumerable<Sheet> AllSheets { get { return sheets; } }
+		public Sheet Current => current;
+		public TextureChannel CurrentChannel => channel;
+		public IEnumerable<Sheet> AllSheets => sheets;
 
 		public void Dispose()
 		{

OpenRA.Game/Graphics/Sprite.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -23,7 +23,6 @@ namespace OpenRA.Graphics
 		public readonly float ZRamp;
 		public readonly float3 Size;
 		public readonly float3 Offset;
-		public readonly float3 FractionalOffset;
 		public readonly float Top, Left, Bottom, Right;
 
 		public Sprite(Sheet sheet, Rectangle bounds, TextureChannel channel, float scale = 1)
@@ -38,13 +37,16 @@ namespace OpenRA.Graphics
 			Channel = channel;
 			Size = scale * new float3(bounds.Size.Width, bounds.Size.Height, bounds.Size.Height * zRamp);
 			BlendMode = blendMode;
-			FractionalOffset = Size.Z != 0 ? offset / Size :
-				new float3(offset.X / Size.X, offset.Y / Size.Y, 0);
 
-			Left = (float)Math.Min(bounds.Left, bounds.Right) / sheet.Size.Width;
-			Top = (float)Math.Min(bounds.Top, bounds.Bottom) / sheet.Size.Height;
-			Right = (float)Math.Max(bounds.Left, bounds.Right) / sheet.Size.Width;
-			Bottom = (float)Math.Max(bounds.Top, bounds.Bottom) / sheet.Size.Height;
+			// Some GPUs suffer from precision issues when rendering into non 1:1 framebuffers that result
+			// 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;
 		}
 	}
 

OpenRA.Game/Graphics/SpriteFont.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -10,7 +10,6 @@
 #endregion
 
 using System;
-using System.Linq;
 using OpenRA.Primitives;
 using OpenRA.Support;
 
@@ -21,7 +20,6 @@ namespace OpenRA.Graphics
 		public int TopOffset { get; private set; }
 		readonly int size;
 		readonly SheetBuilder builder;
-		readonly Func<string, float> lineWidth;
 		readonly IFont font;
 		readonly Cache<char, GlyphInfo> glyphs;
 		readonly Cache<(char C, int Radius), Sprite> contrastGlyphs;
@@ -32,7 +30,7 @@ namespace OpenRA.Graphics
 		public SpriteFont(string name, byte[] data, int size, int ascender, float scale, SheetBuilder builder)
 		{
 			if (builder.Type != SheetType.BGRA)
-				throw new ArgumentException("The sheet builder must create BGRA sheets.", "builder");
+				throw new ArgumentException("The sheet builder must create BGRA sheets.", nameof(builder));
 
 			deviceScale = scale;
 			this.size = size;
@@ -43,13 +41,9 @@ namespace OpenRA.Graphics
 			contrastGlyphs = new Cache<(char, int), Sprite>(CreateContrastGlyph);
 			dilationElements = new Cache<int, float[]>(CreateCircularWeightMap);
 
-			// PERF: Cache these delegates for Measure calls.
-			Func<char, float> characterWidth = character => glyphs[character].Advance;
-			lineWidth = line => line.Sum(characterWidth) / deviceScale;
-
 			// Pre-cache small font sizes so glyphs are immediately available when we need them
 			if (size <= 24)
-				using (new PerfTimer("Precache {0} {1}px".F(name, size)))
+				using (new PerfTimer($"Precache {name} {size}px"))
 					for (var n = (char)0x20; n < (char)0x7f; n++)
 						if (glyphs[n] == null)
 							throw new InvalidOperationException();
@@ -89,10 +83,10 @@ namespace OpenRA.Graphics
 				if (g.Sprite != null)
 				{
 					var contrastSprite = contrastGlyphs[(s, screenContrast)];
-					Game.Renderer.RgbaSpriteRenderer.DrawSpriteWithTint(contrastSprite,
+					Game.Renderer.RgbaSpriteRenderer.DrawSprite(contrastSprite,
 						(screen + g.Offset - contrastVector) / deviceScale,
-						contrastSprite.Size / deviceScale,
-						tint);
+						1f / deviceScale,
+						tint, 1f);
 				}
 
 				screen += new int2((int)(g.Advance + 0.5f), 0);
@@ -120,10 +114,10 @@ namespace OpenRA.Graphics
 
 				// Convert screen coordinates back to UI coordinates for drawing
 				if (g.Sprite != null)
-					Game.Renderer.RgbaSpriteRenderer.DrawSpriteWithTint(g.Sprite,
+					Game.Renderer.RgbaSpriteRenderer.DrawSprite(g.Sprite,
 					(screen + g.Offset).ToFloat2() / deviceScale,
-					g.Sprite.Size / deviceScale,
-					tint);
+					1f / deviceScale,
+					tint, 1f);
 
 				screen += new int2((int)(g.Advance + 0.5f), 0);
 			}
@@ -172,12 +166,12 @@ namespace OpenRA.Graphics
 
 					// Offset rotated glyph to align the top-left corner with the screen pixel grid
 					var screenOffset = new float2((int)(ra.X * deviceScale + 0.5f), (int)(ra.Y * deviceScale + 0.5f)) / deviceScale - ra;
-					Game.Renderer.RgbaSpriteRenderer.DrawSpriteWithTint(g.Sprite,
+					Game.Renderer.RgbaSpriteRenderer.DrawSprite(g.Sprite,
 						ra + screenOffset,
 						rb + screenOffset,
 						rc + screenOffset,
 						rd + screenOffset,
-						tint);
+						tint, 1f);
 				}
 
 				p += new float2(g.Advance / deviceScale, 0);
@@ -238,16 +232,26 @@ namespace OpenRA.Graphics
 			if (string.IsNullOrEmpty(text))
 				return new int2(0, size);
 
-			var lines = text.Split('\n');
-			return new int2((int)Math.Ceiling(MaxLineWidth(lines, lineWidth)), lines.Length * size);
+			var lines = text.SplitLines('\n');
+
+			var maxWidth = 0f;
+			var rows = 0;
+			foreach (var line in lines)
+			{
+				rows++;
+				maxWidth = Math.Max(maxWidth, LineWidth(line));
+			}
+
+			return new int2((int)Math.Ceiling(maxWidth), rows * size);
 		}
 
-		static float MaxLineWidth(string[] lines, Func<string, float> lineWidth)
+		float LineWidth(ReadOnlySpan<char> line)
 		{
-			var maxWidth = 0f;
-			foreach (var line in lines)
-				maxWidth = Math.Max(maxWidth, lineWidth(line));
-			return maxWidth;
+			var result = 0f;
+			foreach (var c in line)
+				result += glyphs[c].Advance;
+
+			return result / deviceScale;
 		}
 
 		GlyphInfo CreateGlyph(char c)

OpenRA.Game/Graphics/SpriteLoader.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -18,11 +18,33 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Graphics
 {
-	public enum SpriteFrameType { Indexed, BGRA }
+	/// <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()!
+	/// </summary>
+	public enum SpriteFrameType
+	{
+		// 8 bit index into an external palette
+		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!)
+		Bgra32,
+
+		// Like BGRA, but without an alpha channel
+		Bgr24,
+
+		// 32 bit color in big-endian format, like png
+		Rgba32,
+
+		// Like RGBA, but without an alpha channel
+		Rgb24
+	}
 
 	public interface ISpriteLoader
 	{
-		bool TryParseSprite(Stream s, out ISpriteFrame[] frames, out TypeDictionary metadata);
+		bool TryParseSprite(Stream s, string filename, out ISpriteFrame[] frames, out TypeDictionary metadata);
 	}
 
 	public interface ISpriteFrame
@@ -47,7 +69,7 @@ namespace OpenRA.Graphics
 
 	public class SpriteCache
 	{
-		public readonly Cache<SpriteFrameType, SheetBuilder> SheetBuilders;
+		public readonly Cache<SheetType, SheetBuilder> SheetBuilders;
 		readonly ISpriteLoader[] loaders;
 		readonly IReadOnlyFileSystem fileSystem;
 
@@ -57,7 +79,7 @@ namespace OpenRA.Graphics
 
 		public SpriteCache(IReadOnlyFileSystem fileSystem, ISpriteLoader[] loaders)
 		{
-			SheetBuilders = new Cache<SpriteFrameType, SheetBuilder>(t => new SheetBuilder(SheetBuilder.FrameTypeToSheetType(t)));
+			SheetBuilders = new Cache<SheetType, SheetBuilder>(t => new SheetBuilder(t));
 
 			this.fileSystem = fileSystem;
 			this.loaders = loaders;
@@ -103,7 +125,7 @@ namespace OpenRA.Graphics
 					{
 						if (unloaded[i] != null)
 						{
-							sprite[i] = SheetBuilders[unloaded[i].Type].Add(unloaded[i]);
+							sprite[i] = SheetBuilders[SheetBuilder.FrameTypeToSheetType(unloaded[i].Type)].Add(unloaded[i]);
 							unloaded[i] = null;
 						}
 					}
@@ -142,7 +164,7 @@ namespace OpenRA.Graphics
 			frames = new Cache<string, ISpriteFrame[]>(filename => FrameLoader.GetFrames(fileSystem, filename, loaders, out _));
 		}
 
-		public ISpriteFrame[] this[string filename] { get { return frames[filename]; } }
+		public ISpriteFrame[] this[string filename] => frames[filename];
 	}
 
 	public static class FrameLoader
@@ -151,7 +173,7 @@ namespace OpenRA.Graphics
 		{
 			using (var stream = fileSystem.Open(filename))
 			{
-				var spriteFrames = GetFrames(stream, loaders, out metadata);
+				var spriteFrames = GetFrames(stream, loaders, filename, out metadata);
 				if (spriteFrames == null)
 					throw new InvalidDataException(filename + " is not a valid sprite file!");
 
@@ -159,12 +181,12 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		public static ISpriteFrame[] GetFrames(Stream stream, ISpriteLoader[] loaders, out TypeDictionary metadata)
+		public static ISpriteFrame[] GetFrames(Stream stream, ISpriteLoader[] loaders, string filename, out TypeDictionary metadata)
 		{
 			metadata = null;
 
 			foreach (var loader in loaders)
-				if (loader.TryParseSprite(stream, out var frames, out metadata))
+				if (loader.TryParseSprite(stream, filename, out var frames, out metadata))
 					return frames;
 
 			return null;

OpenRA.Game/Graphics/SpriteRenderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -14,7 +14,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Graphics
 {
-	public struct SpriteRenderable : IRenderable, ITintableRenderable, IFinalizedRenderable
+	public class SpriteRenderable : IPalettedRenderable, IModifyableRenderable, IFinalizedRenderable
 	{
 		public static readonly IEnumerable<IRenderable> None = new IRenderable[0];
 
@@ -25,16 +25,11 @@ namespace OpenRA.Graphics
 		readonly PaletteReference palette;
 		readonly float scale;
 		readonly float3 tint;
+		readonly TintModifiers tintModifiers;
+		readonly float alpha;
 		readonly bool isDecoration;
-		readonly bool ignoreWorldTint;
 
-		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, bool isDecoration)
-			: this(sprite, pos, offset, zOffset, palette, scale, float3.Ones, isDecoration, false) { }
-
-		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, bool isDecoration, bool ignoreWorldTint)
-			: this(sprite, pos, offset, zOffset, palette, scale, float3.Ones, isDecoration, ignoreWorldTint) { }
-
-		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, float3 tint, bool isDecoration, bool ignoreWorldTint)
+		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, float alpha, float3 tint, TintModifiers tintModifiers, bool isDecoration)
 		{
 			this.sprite = sprite;
 			this.pos = pos;
@@ -44,44 +39,61 @@ namespace OpenRA.Graphics
 			this.scale = scale;
 			this.tint = tint;
 			this.isDecoration = isDecoration;
-			this.ignoreWorldTint = ignoreWorldTint;
+			this.tintModifiers = tintModifiers;
+			this.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;
 		}
 
-		public WPos Pos { get { return pos + offset; } }
-		public WVec Offset { get { return offset; } }
-		public PaletteReference Palette { get { return palette; } }
-		public int ZOffset { get { return zOffset; } }
-		public bool IsDecoration { get { return isDecoration; } }
+		public WPos Pos => pos + offset;
+		public WVec Offset => offset;
+		public PaletteReference Palette => palette;
+		public int ZOffset => zOffset;
+		public bool IsDecoration => isDecoration;
 
-		public IRenderable WithPalette(PaletteReference newPalette) { return new SpriteRenderable(sprite, pos, offset, zOffset, newPalette, scale, tint, isDecoration, ignoreWorldTint); }
-		public IRenderable WithZOffset(int newOffset) { return new SpriteRenderable(sprite, pos, offset, newOffset, palette, scale, tint, isDecoration, ignoreWorldTint); }
-		public IRenderable OffsetBy(WVec vec) { return new SpriteRenderable(sprite, pos + vec, offset, zOffset, palette, scale, tint, isDecoration, ignoreWorldTint); }
-		public IRenderable AsDecoration() { return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, tint, true, ignoreWorldTint); }
+		public float Alpha => alpha;
+		public float3 Tint => tint;
+		public TintModifiers TintModifiers => tintModifiers;
 
-		public IRenderable WithTint(in float3 newTint) { return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, newTint, isDecoration, ignoreWorldTint); }
+		public IPalettedRenderable WithPalette(PaletteReference newPalette) { return new SpriteRenderable(sprite, pos, offset, zOffset, newPalette, scale, alpha, tint, tintModifiers, isDecoration); }
+		public IRenderable WithZOffset(int newOffset) { return new SpriteRenderable(sprite, pos, offset, newOffset, palette, scale, alpha, tint, tintModifiers, isDecoration); }
+		public IRenderable OffsetBy(in WVec vec) { return new SpriteRenderable(sprite, pos + vec, offset, zOffset, palette, scale, alpha, tint, tintModifiers, isDecoration); }
+		public IRenderable AsDecoration() { return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, alpha, tint, tintModifiers, true); }
+
+		public IModifyableRenderable WithAlpha(float newAlpha)
+		{
+			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, newAlpha, tint, tintModifiers, isDecoration);
+		}
+
+		public IModifyableRenderable WithTint(in float3 newTint, TintModifiers newTintModifiers)
+		{
+			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, alpha, newTint, newTintModifiers, isDecoration);
+		}
 
 		float3 ScreenPosition(WorldRenderer wr)
 		{
-			var xy = wr.ScreenPxPosition(pos) + wr.ScreenPxOffset(offset) - (0.5f * scale * sprite.Size.XY).ToInt2();
-
-			// HACK: The z offset needs to be applied somewhere, but this probably is the wrong place.
-			return new float3(xy, sprite.Offset.Z + wr.ScreenZPosition(pos, 0) - 0.5f * scale * sprite.Size.Z);
+			var s = 0.5f * scale * sprite.Size;
+			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;
-			if (ignoreWorldTint)
-				wsr.DrawSprite(sprite, ScreenPosition(wr), palette, scale * sprite.Size);
-			else
-			{
-				var t = tint;
-				if (wr.TerrainLighting != null)
-					t *= wr.TerrainLighting.TintAt(pos);
+			var t = alpha * tint;
+			if (wr.TerrainLighting != null && (tintModifiers & TintModifiers.IgnoreWorldTint) == 0)
+				t *= wr.TerrainLighting.TintAt(pos);
 
-				wsr.DrawSpriteWithTint(sprite, ScreenPosition(wr), palette, scale * sprite.Size, t);
-			}
+			// 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)
+				a *= -1;
+
+			wsr.DrawSprite(sprite, palette, ScreenPosition(wr), scale, t, a);
 		}
 
 		public void RenderDebugGeometry(WorldRenderer wr)

OpenRA.Game/Graphics/SpriteRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -10,6 +10,7 @@
 #endregion
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Primitives;
 
@@ -17,8 +18,8 @@ namespace OpenRA.Graphics
 {
 	public class SpriteRenderer : Renderer.IBatchRenderer
 	{
-		const int SheetCount = 7;
-		static readonly string[] SheetIndexToTextureName = Exts.MakeArray(SheetCount, i => "Texture{0}".F(i));
+		public const int SheetCount = 8;
+		static readonly string[] SheetIndexToTextureName = Exts.MakeArray(SheetCount, i => $"Texture{i}");
 
 		readonly Renderer renderer;
 		readonly IShader shader;
@@ -81,119 +82,165 @@ namespace OpenRA.Graphics
 				for (; secondarySheetIndex < ns; secondarySheetIndex++)
 					if (sheets[secondarySheetIndex] == secondarySheet)
 						break;
+
+				// If neither sheet has been mapped both index values will be set to ns.
+				// This is fine if they both reference the same texture, but if they don't
+				// we must increment the secondary sheet index to the next free sampler.
+				if (secondarySheetIndex == sheetIndex && secondarySheet != sheet)
+					secondarySheetIndex++;
 			}
 
 			// Make sure that we have enough free samplers to map both if needed, otherwise flush
-			var needSamplers = (sheetIndex == ns ? 1 : 0) + (secondarySheetIndex == ns ? 1 : 0);
-			if (ns + needSamplers >= sheets.Length)
+			if (Math.Max(sheetIndex, secondarySheetIndex) >= sheets.Length)
 			{
 				Flush();
 				sheetIndex = 0;
-				if (ss != null)
-					secondarySheetIndex = 1;
+				secondarySheetIndex = ss != null && ss.SecondarySheet != sheet ? 1 : 0;
 			}
 
 			if (sheetIndex >= ns)
 			{
 				sheets[sheetIndex] = sheet;
-				ns += 1;
+				ns++;
 			}
 
 			if (secondarySheetIndex >= ns && ss != null)
 			{
 				sheets[secondarySheetIndex] = ss.SecondarySheet;
-				ns += 1;
+				ns++;
 			}
 
 			return new int2(sheetIndex, secondarySheetIndex);
 		}
 
-		internal void DrawSprite(Sprite s, in float3 location, float paletteTextureIndex, in float3 size)
+		float ResolveTextureIndex(Sprite s, PaletteReference pal)
+		{
+			if (pal == null)
+				return 0;
+
+			// PERF: Remove useless palette assignments for RGBA sprites
+			// HACK: This is working around the limitation that palettes are defined on traits rather than on sequences,
+			// and can be removed once this has been fixed
+			if (s.Channel == TextureChannel.RGBA && !pal.HasColorShift)
+				return 0;
+
+			return pal.TextureIndex;
+		}
+
+		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, in float3 scale)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + s.FractionalOffset * size, s, samplers, paletteTextureIndex, nv, size, float3.Ones);
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, float3.Ones, 1f);
 			nv += 6;
 		}
 
-		public void DrawSprite(Sprite s, in float3 location, PaletteReference pal)
-		{
-			DrawSprite(s, location, pal.TextureIndex, s.Size);
-		}
-
-		public void DrawSprite(Sprite s, in float3 location, PaletteReference pal, float3 size)
-		{
-			DrawSprite(s, location, pal.TextureIndex, size);
-		}
-
-		public void DrawSprite(Sprite s, in float3 a, in float3 b, in float3 c, in float3 d)
+		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, float scale)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, a, b, c, d, s, samplers, 0, float3.Ones, nv);
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, float3.Ones, 1f);
 			nv += 6;
 		}
 
-		internal void DrawSpriteWithTint(Sprite s, in float3 location, float paletteTextureIndex, in float3 size, in float3 tint)
+		public void DrawSprite(Sprite s, PaletteReference pal, in float3 location, float scale = 1f)
+		{
+			DrawSprite(s, ResolveTextureIndex(s, pal), location, scale);
+		}
+
+		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, float scale, in float3 tint, float alpha)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + s.FractionalOffset * size, s, samplers, paletteTextureIndex, nv, size, tint);
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, tint, alpha);
 			nv += 6;
 		}
 
-		public void DrawSpriteWithTint(Sprite s, in float3 location, PaletteReference pal, in float3 size, in float3 tint)
+		public void DrawSprite(Sprite s, PaletteReference pal, in float3 location, float scale, in float3 tint, float alpha)
 		{
-			DrawSpriteWithTint(s, location, pal.TextureIndex, size, tint);
+			DrawSprite(s, ResolveTextureIndex(s, pal), location, scale, tint, alpha);
 		}
 
-		public void DrawSpriteWithTint(Sprite s, in float3 a, in float3 b, in float3 c, in float3 d, in float3 tint)
+		internal void DrawSprite(Sprite s, float 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, 0, tint, nv);
+			Util.FastCreateQuad(vertices, a, b, c, d, s, samplers, paletteTextureIndex, tint, alpha, nv);
 			nv += 6;
 		}
 
-		public void DrawVertexBuffer(IVertexBuffer<Vertex> buffer, int start, int length, PrimitiveType type, Sheet sheet, BlendMode blendMode)
+		public void DrawVertexBuffer(IVertexBuffer<Vertex> buffer, int start, int length, PrimitiveType type, IEnumerable<Sheet> sheets, BlendMode blendMode)
 		{
-			shader.SetTexture("Texture0", sheet.GetTexture());
+			var i = 0;
+			foreach (var s in sheets)
+			{
+				if (i >= SheetCount)
+					ThrowSheetOverflow(nameof(sheets));
+
+				if (s != null)
+					shader.SetTexture(SheetIndexToTextureName[i++], s.GetTexture());
+			}
+
 			renderer.Context.SetBlendMode(blendMode);
 			shader.PrepareRender();
 			renderer.DrawBatch(buffer, start, length, type);
 			renderer.Context.SetBlendMode(BlendMode.None);
 		}
 
+		// PERF: methods that throw won't be inlined by the JIT, so extract a static helper for use on hot paths
+		static void ThrowSheetOverflow(string paramName)
+		{
+			throw new ArgumentException($"SpriteRenderer only supports {SheetCount} simultaneous textures", paramName);
+		}
+
 		// For RGBAColorRenderer
-		internal void DrawRGBAVertices(Vertex[] v)
+		internal void DrawRGBAVertices(Vertex[] v, BlendMode blendMode)
 		{
 			renderer.CurrentBatchRenderer = this;
 
-			if (currentBlend != BlendMode.Alpha || nv + v.Length > renderer.TempBufferSize)
+			if (currentBlend != blendMode || nv + v.Length > renderer.TempBufferSize)
 				Flush();
 
-			currentBlend = BlendMode.Alpha;
+			currentBlend = blendMode;
 			Array.Copy(v, 0, vertices, nv, v.Length);
 			nv += v.Length;
 		}
 
-		public void SetPalette(ITexture palette)
+		public void SetPalette(ITexture palette, ITexture colorShifts)
 		{
 			shader.SetTexture("Palette", palette);
+			shader.SetTexture("ColorShifts", colorShifts);
 		}
 
-		public void SetViewportParams(Size screen, float depthScale, float depthOffset, int2 scroll)
+		public void SetViewportParams(Size sheetSize, int downscale, float depthMargin, int2 scroll)
 		{
-			shader.SetVec("Scroll", scroll.X, scroll.Y, scroll.Y);
-			shader.SetVec("r1",
-				2f / screen.Width,
-				2f / screen.Height,
-				-depthScale / screen.Height);
-			shader.SetVec("r2", -1, -1, 1 - depthOffset);
+			// 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.
+			var width = 2f / (downscale * sheetSize.Width);
+			var height = 2f / (downscale * sheetSize.Height);
 
-			// Texture index is sampled as a float, so convert to pixels then scale
-			shader.SetVec("DepthTextureScale", 128 * depthScale / screen.Height);
+			// Depth is more complicated:
+			// * The OpenGL z axis is inverted (negative is closer) relative to OpenRA (positive is closer).
+			// * We want to avoid clipping pixels that are behind the nominal z == y plane at the
+			//   top of the map, or above the nominal z == y plane at the bottom of the map.
+			//   We therefore expand the depth range by an extra margin that is calculated based on
+			//   the maximum expected world height (see Renderer.InitializeDepthBuffer).
+			// * Sprites can specify an additional per-pixel depth offset map, which is applied in the
+			//   fragment shader. The fragment shader operates in OpenGL window coordinates, not NDC,
+			//   with a depth range [0, 1] corresponding to the NDC [-1, 1]. We must therefore multiply the
+			//   sprite channel value [0, 1] by 255 to find the pixel depth offset, then by our depth scale
+			//   to find the equivalent NDC offset, then divide by 2 to find the window coordinate offset.
+			// * If depthMargin == 0 (which indicates per-pixel depth testing is disabled) sprites that
+			//   extend beyond the top of bottom edges of the screen may be pushed outside [-1, 1] and
+			//   culled by the GPU. We avoid this by forcing everything into the z = 0 plane.
+			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);
 		}
 
-		public void SetDepthPreviewEnabled(bool enabled)
+		public void SetDepthPreview(bool enabled, float contrast, float offset)
 		{
 			shader.SetBool("EnableDepthPreview", enabled);
+			shader.SetVec("DepthPreviewParams", contrast, offset);
 		}
 
 		public void SetAntialiasingPixelsPerTexel(float pxPerTx)

OpenRA.Game/Graphics/TargetLineRenderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -15,7 +15,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Graphics
 {
-	public struct TargetLineRenderable : IRenderable, IFinalizedRenderable
+	public class TargetLineRenderable : IRenderable, IFinalizedRenderable
 	{
 		readonly IEnumerable<WPos> waypoints;
 		readonly Color color;
@@ -30,14 +30,19 @@ namespace OpenRA.Graphics
 			this.markerSize = markerSize;
 		}
 
-		public WPos Pos { get { return waypoints.First(); } }
-		public PaletteReference Palette { get { return null; } }
-		public int ZOffset { get { return 0; } }
-		public bool IsDecoration { get { return true; } }
+		public WPos Pos => waypoints.First();
+		public int ZOffset => 0;
+		public bool IsDecoration => true;
 
-		public IRenderable WithPalette(PaletteReference newPalette) { return new TargetLineRenderable(waypoints, color); }
 		public IRenderable WithZOffset(int newOffset) { return new TargetLineRenderable(waypoints, color); }
-		public IRenderable OffsetBy(WVec vec) { return new TargetLineRenderable(waypoints.Select(w => w + vec), color); }
+
+		public IRenderable OffsetBy(in WVec vec)
+		{
+			// Lambdas can't use 'in' variables, so capture a copy for later
+			var offset = vec;
+			return new TargetLineRenderable(waypoints.Select(w => w + offset), color);
+		}
+
 		public IRenderable AsDecoration() { return this; }
 
 		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }

OpenRA.Game/Graphics/TerrainSpriteLayer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -20,9 +20,9 @@ namespace OpenRA.Graphics
 	{
 		static readonly int[] CornerVertexMap = { 0, 1, 2, 2, 3, 0 };
 
-		public readonly Sheet Sheet;
 		public readonly BlendMode BlendMode;
 
+		readonly Sheet[] sheets;
 		readonly Sprite emptySprite;
 
 		readonly IVertexBuffer<Vertex> vertexBuffer;
@@ -35,22 +35,22 @@ namespace OpenRA.Graphics
 		readonly WorldRenderer worldRenderer;
 		readonly Map map;
 
-		readonly PaletteReference palette;
+		readonly PaletteReference[] palettes;
 
-		public TerrainSpriteLayer(World world, WorldRenderer wr, Sheet sheet, BlendMode blendMode, PaletteReference palette, bool restrictToBounds)
+		public TerrainSpriteLayer(World world, WorldRenderer wr, Sprite emptySprite, BlendMode blendMode, bool restrictToBounds)
 		{
 			worldRenderer = wr;
 			this.restrictToBounds = restrictToBounds;
-			Sheet = sheet;
+			this.emptySprite = emptySprite;
+			sheets = new Sheet[SpriteRenderer.SheetCount];
 			BlendMode = blendMode;
-			this.palette = palette;
 
 			map = world.Map;
 			rowStride = 6 * map.MapSize.X;
 
 			vertices = new Vertex[rowStride * map.MapSize.Y];
+			palettes = new PaletteReference[map.MapSize.X * map.MapSize.Y];
 			vertexBuffer = Game.Renderer.Context.CreateVertexBuffer(vertices.Length);
-			emptySprite = new Sprite(sheet, Rectangle.Empty, TextureChannel.Alpha);
 
 			wr.PaletteInvalidated += UpdatePaletteIndices;
 
@@ -63,12 +63,11 @@ namespace OpenRA.Graphics
 
 		void UpdatePaletteIndices()
 		{
-			// Everything in the layer uses the same palette,
-			// so we can fix the indices in one pass
 			for (var i = 0; i < vertices.Length; i++)
 			{
 				var v = vertices[i];
-				vertices[i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, palette.TextureIndex, v.C, v.R, v.G, v.B);
+				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);
 			}
 
 			for (var row = 0; row < map.MapSize.Y; row++)
@@ -77,24 +76,24 @@ namespace OpenRA.Graphics
 
 		public void Clear(CPos cell)
 		{
-			Update(cell, null, true);
+			Update(cell, null, null, 1f, 1f, true);
 		}
 
-		public void Update(CPos cell, ISpriteSequence sequence, int frame)
+		public void Update(CPos cell, ISpriteSequence sequence, PaletteReference palette, int frame)
 		{
-			Update(cell, sequence.GetSprite(frame), sequence.IgnoreWorldTint);
+			Update(cell, sequence.GetSprite(frame), palette, sequence.Scale, sequence.GetAlpha(frame), sequence.IgnoreWorldTint);
 		}
 
-		public void Update(CPos cell, Sprite sprite, bool ignoreTint)
+		public void Update(CPos cell, Sprite sprite, PaletteReference palette, float scale = 1f, float alpha = 1f, bool ignoreTint = false)
 		{
 			var xyz = float3.Zero;
 			if (sprite != null)
 			{
 				var cellOrigin = map.CenterOfCell(cell) - new WVec(0, 0, map.Grid.Ramps[map.Ramp[cell]].CenterHeightOffset);
-				xyz = worldRenderer.Screen3DPosition(cellOrigin) + sprite.Offset - 0.5f * sprite.Size;
+				xyz = worldRenderer.Screen3DPosition(cellOrigin) + scale * (sprite.Offset - 0.5f * sprite.Size);
 			}
 
-			Update(cell.ToMPos(map.Grid.Type), sprite, xyz, ignoreTint);
+			Update(cell.ToMPos(map.Grid.Type), sprite, palette, xyz, scale, alpha, ignoreTint);
 		}
 
 		void UpdateTint(MPos uv)
@@ -102,11 +101,10 @@ namespace OpenRA.Graphics
 			var offset = rowStride * uv.V + 6 * uv.U;
 			if (ignoreTint[offset])
 			{
-				var noTint = float3.Ones;
 				for (var i = 0; i < 6; 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, palette.TextureIndex, v.C, noTint);
+					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);
 				}
 
 				return;
@@ -131,31 +129,61 @@ namespace OpenRA.Graphics
 			for (var i = 0; i < 6; 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, palette.TextureIndex, v.C, weights[CornerVertexMap[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);
 			}
 
 			dirtyRows.Add(uv.V);
 		}
 
-		public void Update(MPos uv, Sprite sprite, in float3 pos, bool ignoreTint)
+		int GetOrAddSheetIndex(Sheet sheet)
 		{
+			if (sheet == null)
+				return 0;
+
+			for (var i = 0; i < sheets.Length; i++)
+			{
+				if (sheets[i] == sheet)
+					return i;
+
+				if (sheets[i] == null)
+				{
+					sheets[i] = sheet;
+					return i;
+				}
+			}
+
+			throw new InvalidDataException("Sheet overflow");
+		}
+
+		public void Update(MPos uv, Sprite sprite, PaletteReference palette, in float3 pos, float scale, float alpha, bool ignoreTint)
+		{
+			int2 samplers;
 			if (sprite != null)
 			{
-				if (sprite.Sheet != Sheet)
-					throw new InvalidDataException("Attempted to add sprite from a different sheet");
-
 				if (sprite.BlendMode != BlendMode)
 					throw new InvalidDataException("Attempted to add sprite with a different blend mode");
+
+				samplers = new int2(GetOrAddSheetIndex(sprite.Sheet), GetOrAddSheetIndex((sprite as SpriteWithSecondaryData)?.SecondarySheet));
+
+				// PERF: Remove useless palette assignments for RGBA sprites
+				// HACK: This is working around the limitation that palettes are defined on traits rather than on sequences,
+				// and can be removed once this has been fixed
+				if (sprite.Channel == TextureChannel.RGBA && !(palette?.HasColorShift ?? false))
+					palette = null;
 			}
 			else
+			{
 				sprite = emptySprite;
+				samplers = int2.Zero;
+			}
 
 			// The vertex buffer does not have geometry for cells outside the map
 			if (!map.Tiles.Contains(uv))
 				return;
 
 			var offset = rowStride * uv.V + 6 * uv.U;
-			Util.FastCreateQuad(vertices, pos, sprite, int2.Zero, palette.TextureIndex, offset, sprite.Size, float3.Ones);
+			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;
 
 			if (worldRenderer.TerrainLighting != null)
 			{
@@ -188,7 +216,7 @@ namespace OpenRA.Graphics
 
 			Game.Renderer.WorldSpriteRenderer.DrawVertexBuffer(
 				vertexBuffer, rowStride * firstRow, rowStride * (lastRow - firstRow),
-				PrimitiveType.TriangleList, Sheet, BlendMode);
+				PrimitiveType.TriangleList, sheets, BlendMode);
 
 			Game.Renderer.Flush();
 		}

OpenRA.Game/Graphics/Theater.cs

@@ -1,197 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright 2007-2020 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 System.IO;
-using System.Linq;
-using OpenRA.Primitives;
-using OpenRA.Support;
-
-namespace OpenRA.Graphics
-{
-	class TheaterTemplate
-	{
-		public readonly Sprite[] Sprites;
-		public readonly int Stride;
-		public readonly int Variants;
-
-		public TheaterTemplate(Sprite[] sprites, int stride, int variants)
-		{
-			Sprites = sprites;
-			Stride = stride;
-			Variants = variants;
-		}
-	}
-
-	public sealed class Theater : IDisposable
-	{
-		readonly Dictionary<ushort, TheaterTemplate> templates = new Dictionary<ushort, TheaterTemplate>();
-		SheetBuilder sheetBuilder;
-		readonly Sprite missingTile;
-		readonly MersenneTwister random;
-		TileSet tileset;
-
-		public Theater(TileSet tileset, Action<uint, string> onMissingImage = null)
-		{
-			this.tileset = tileset;
-			var allocated = false;
-
-			Func<Sheet> allocate = () =>
-			{
-				if (allocated)
-					throw new SheetOverflowException("Terrain sheet overflow. Try increasing the tileset SheetSize parameter.");
-				allocated = true;
-
-				return new Sheet(SheetType.Indexed, new Size(tileset.SheetSize, tileset.SheetSize));
-			};
-
-			random = new MersenneTwister();
-
-			var frameCache = new FrameCache(Game.ModData.DefaultFileSystem, Game.ModData.SpriteLoaders);
-			foreach (var t in tileset.Templates)
-			{
-				var variants = new List<Sprite[]>();
-
-				foreach (var i in t.Value.Images)
-				{
-					ISpriteFrame[] allFrames;
-					if (onMissingImage != null)
-					{
-						try
-						{
-							allFrames = frameCache[i];
-						}
-						catch (FileNotFoundException)
-						{
-							onMissingImage(t.Key, i);
-							continue;
-						}
-					}
-					else
-						allFrames = frameCache[i];
-
-					var frameCount = tileset.EnableDepth ? allFrames.Length / 2 : allFrames.Length;
-					var indices = t.Value.Frames != null ? t.Value.Frames : Exts.MakeArray(t.Value.TilesCount, j => j);
-
-					var start = indices.Min();
-					var end = indices.Max();
-					if (start < 0 || end >= frameCount)
-						throw new YamlException("Template `{0}` uses frames [{1}..{2}] of {3}, but only [0..{4}] actually exist"
-							.F(t.Key, start, end, i, frameCount - 1));
-
-					variants.Add(indices.Select(j =>
-					{
-						var f = allFrames[j];
-						var tile = t.Value.Contains(j) ? t.Value[j] : null;
-
-						// The internal z axis is inverted from expectation (negative is closer)
-						var zOffset = tile != null ? -tile.ZOffset : 0;
-						var zRamp = tile != null ? tile.ZRamp : 1f;
-						var offset = new float3(f.Offset, zOffset);
-						var type = SheetBuilder.FrameTypeToSheetType(f.Type);
-
-						// Defer SheetBuilder creation until we know what type of frames we are loading!
-						// TODO: Support mixed indexed and BGRA frames
-						if (sheetBuilder == null)
-							sheetBuilder = new SheetBuilder(SheetBuilder.FrameTypeToSheetType(f.Type), allocate);
-						else if (type != sheetBuilder.Type)
-							throw new YamlException("Sprite type mismatch. Terrain sprites must all be either Indexed or RGBA.");
-
-						var s = sheetBuilder.Allocate(f.Size, zRamp, offset);
-						Util.FastCopyIntoChannel(s, f.Data);
-
-						if (tileset.EnableDepth)
-						{
-							var ss = sheetBuilder.Allocate(f.Size, zRamp, offset);
-							Util.FastCopyIntoChannel(ss, allFrames[j + frameCount].Data);
-
-							// s and ss are guaranteed to use the same sheet
-							// because of the custom terrain sheet allocation
-							s = new SpriteWithSecondaryData(s, s.Sheet, ss.Bounds, ss.Channel);
-						}
-
-						return s;
-					}).ToArray());
-				}
-
-				var allSprites = variants.SelectMany(s => s);
-
-				// Ignore the offsets baked into R8 sprites
-				if (tileset.IgnoreTileSpriteOffsets)
-					allSprites = allSprites.Select(s => new Sprite(s.Sheet, s.Bounds, s.ZRamp, new float3(float2.Zero, s.Offset.Z), s.Channel, s.BlendMode));
-
-				if (onMissingImage != null && !variants.Any())
-					continue;
-
-				templates.Add(t.Value.Id, new TheaterTemplate(allSprites.ToArray(), variants.First().Count(), t.Value.Images.Length));
-			}
-
-			// 1x1px transparent tile
-			missingTile = sheetBuilder.Add(new byte[sheetBuilder.Type == SheetType.BGRA ? 4 : 1], new Size(1, 1));
-
-			Sheet.ReleaseBuffer();
-		}
-
-		public bool HasTileSprite(TerrainTile r, int? variant = null)
-		{
-			return TileSprite(r, variant) != missingTile;
-		}
-
-		public Sprite TileSprite(TerrainTile r, int? variant = null)
-		{
-			if (!templates.TryGetValue(r.Type, out var template))
-				return missingTile;
-
-			if (r.Index >= template.Stride)
-				return missingTile;
-
-			var start = template.Variants > 1 ? variant.HasValue ? variant.Value : random.Next(template.Variants) : 0;
-			return template.Sprites[start * template.Stride + r.Index];
-		}
-
-		public Rectangle TemplateBounds(TerrainTemplateInfo template, Size tileSize, MapGridType mapGrid)
-		{
-			Rectangle? templateRect = null;
-
-			var i = 0;
-			for (var y = 0; y < template.Size.Y; y++)
-			{
-				for (var x = 0; x < template.Size.X; x++)
-				{
-					var tile = new TerrainTile(template.Id, (byte)(i++));
-					var tileInfo = tileset.GetTileInfo(tile);
-
-					// Empty tile
-					if (tileInfo == null)
-						continue;
-
-					var sprite = TileSprite(tile);
-					var u = mapGrid == MapGridType.Rectangular ? x : (x - y) / 2f;
-					var v = mapGrid == MapGridType.Rectangular ? y : (x + y) / 2f;
-
-					var tl = new float2(u * tileSize.Width, (v - 0.5f * tileInfo.Height) * tileSize.Height) - 0.5f * sprite.Size;
-					var rect = new Rectangle((int)(tl.X + sprite.Offset.X), (int)(tl.Y + sprite.Offset.Y), (int)sprite.Size.X, (int)sprite.Size.Y);
-					templateRect = templateRect.HasValue ? Rectangle.Union(templateRect.Value, rect) : rect;
-				}
-			}
-
-			return templateRect.HasValue ? templateRect.Value : Rectangle.Empty;
-		}
-
-		public Sheet Sheet { get { return sheetBuilder.Current; } }
-
-		public void Dispose()
-		{
-			sheetBuilder.Dispose();
-		}
-	}
-}

OpenRA.Game/Graphics/UISpriteRenderable.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -13,7 +13,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Graphics
 {
-	public struct UISpriteRenderable : IRenderable, IFinalizedRenderable
+	public class UISpriteRenderable : IRenderable, IPalettedRenderable, IFinalizedRenderable
 	{
 		readonly Sprite sprite;
 		readonly WPos effectiveWorldPos;
@@ -21,8 +21,9 @@ namespace OpenRA.Graphics
 		readonly int zOffset;
 		readonly PaletteReference palette;
 		readonly float scale;
+		readonly float alpha;
 
-		public UISpriteRenderable(Sprite sprite, WPos effectiveWorldPos, int2 screenPos, int zOffset, PaletteReference palette, float scale)
+		public UISpriteRenderable(Sprite sprite, WPos effectiveWorldPos, int2 screenPos, int zOffset, PaletteReference palette, float scale = 1f, float alpha = 1f)
 		{
 			this.sprite = sprite;
 			this.effectiveWorldPos = effectiveWorldPos;
@@ -30,25 +31,32 @@ namespace OpenRA.Graphics
 			this.zOffset = zOffset;
 			this.palette = palette;
 			this.scale = scale;
+			this.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;
 		}
 
 		// Does not exist in the world, so a world positions don't make sense
-		public WPos Pos { get { return effectiveWorldPos; } }
-		public WVec Offset { get { return WVec.Zero; } }
-		public bool IsDecoration { get { return true; } }
+		public WPos Pos => effectiveWorldPos;
+		public WVec Offset => WVec.Zero;
+		public bool IsDecoration => true;
 
-		public PaletteReference Palette { get { return palette; } }
-		public int ZOffset { get { return zOffset; } }
+		public PaletteReference Palette => palette;
+		public int ZOffset => zOffset;
 
-		public IRenderable WithPalette(PaletteReference newPalette) { return new UISpriteRenderable(sprite, effectiveWorldPos, screenPos, zOffset, newPalette, scale); }
+		public IPalettedRenderable WithPalette(PaletteReference newPalette) { return new UISpriteRenderable(sprite, effectiveWorldPos, screenPos, zOffset, newPalette, scale, alpha); }
 		public IRenderable WithZOffset(int newOffset) { return this; }
-		public IRenderable OffsetBy(WVec vec) { return this; }
+		public IRenderable OffsetBy(in WVec vec) { return this; }
 		public IRenderable AsDecoration() { return this; }
 
 		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }
 		public void Render(WorldRenderer wr)
 		{
-			Game.Renderer.SpriteRenderer.DrawSprite(sprite, screenPos, palette, scale * sprite.Size);
+			Game.Renderer.SpriteRenderer.DrawSprite(sprite, palette, screenPos, scale, float3.Ones, alpha);
 		}
 
 		public void RenderDebugGeometry(WorldRenderer wr)

OpenRA.Game/Graphics/Util.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -20,29 +20,28 @@ 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, in float3 size, in float3 tint)
+		public static void FastCreateQuad(Vertex[] vertices, in float3 o, Sprite r, int2 samplers, float paletteTextureIndex, int nv, in float3 size, in float3 tint, float alpha)
 		{
 			var b = new float3(o.X + size.X, o.Y, o.Z);
 			var c = new float3(o.X + size.X, o.Y + size.Y, o.Z + size.Z);
 			var d = new float3(o.X, o.Y + size.Y, o.Z + size.Z);
-			FastCreateQuad(vertices, o, b, c, d, r, samplers, paletteTextureIndex, tint, nv);
+			FastCreateQuad(vertices, o, b, c, d, r, samplers, paletteTextureIndex, tint, alpha, nv);
 		}
 
 		public static void FastCreateQuad(Vertex[] vertices,
 			in float3 a, in float3 b, in float3 c, in float3 d,
 			Sprite r, int2 samplers, float paletteTextureIndex,
-			in float3 tint, int nv)
+			in float3 tint, float alpha, int nv)
 		{
 			float sl = 0;
 			float st = 0;
 			float sr = 0;
 			float sb = 0;
 
-			// See shp.vert for documentation on the channel attribute format
+			// See combined.vert for documentation on the channel attribute format
 			var attribC = r.Channel == TextureChannel.RGBA ? 0x02 : ((byte)r.Channel) << 1 | 0x01;
 			attribC |= samplers.X << 6;
-			var ss = r as SpriteWithSecondaryData;
-			if (ss != null)
+			if (r is SpriteWithSecondaryData ss)
 			{
 				sl = ss.SecondaryLeft;
 				st = ss.SecondaryTop;
@@ -54,15 +53,15 @@ namespace OpenRA.Graphics
 			}
 
 			var fAttribC = (float)attribC;
-			vertices[nv] = new Vertex(a, r.Left, r.Top, sl, st, paletteTextureIndex, fAttribC, tint);
-			vertices[nv + 1] = new Vertex(b, r.Right, r.Top, sr, st, paletteTextureIndex, fAttribC, tint);
-			vertices[nv + 2] = new Vertex(c, r.Right, r.Bottom, sr, sb, paletteTextureIndex, fAttribC, tint);
-			vertices[nv + 3] = new Vertex(c, r.Right, r.Bottom, sr, sb, paletteTextureIndex, fAttribC, tint);
-			vertices[nv + 4] = new Vertex(d, r.Left, r.Bottom, sl, sb, paletteTextureIndex, fAttribC, tint);
-			vertices[nv + 5] = new Vertex(a, r.Left, r.Top, sl, st, paletteTextureIndex, fAttribC, tint);
+			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);
 		}
 
-		public static void FastCopyIntoChannel(Sprite dest, byte[] src)
+		public static void FastCopyIntoChannel(Sprite dest, byte[] src, SpriteFrameType srcType)
 		{
 			var destData = dest.Sheet.GetData();
 			var width = dest.Bounds.Width;
@@ -85,12 +84,34 @@ namespace OpenRA.Graphics
 						{
 							for (var i = 0; i < width; i++)
 							{
-								var r = src[k++];
-								var g = src[k++];
-								var b = src[k++];
-								var a = src[k++];
-								var cc = Color.FromArgb(a, r, g, b);
+								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($"Unknown SpriteFrameType {srcType}");
+								}
+
+								var cc = Color.FromArgb(a, r, g, b);
 								data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();
 							}
 						}
@@ -139,16 +160,29 @@ namespace OpenRA.Graphics
 						for (var i = 0; i < width; i++)
 						{
 							Color cc;
-							if (src.Palette == null)
+							switch (src.Type)
 							{
-								var r = src.Data[k++];
-								var g = src.Data[k++];
-								var b = src.Data[k++];
-								var a = src.Data[k++];
-								cc = Color.FromArgb(a, r, g, b);
+								case SpriteFrameType.Indexed8:
+								{
+									cc = src.Palette[src.Data[k++]];
+									break;
+								}
+
+								case SpriteFrameType.Rgba32:
+								case SpriteFrameType.Rgb24:
+								{
+									var r = src.Data[k++];
+									var g = src.Data[k++];
+									var b = src.Data[k++];
+									var a = src.Type == SpriteFrameType.Rgba32 ? src.Data[k++] : (byte)255;
+									cc = Color.FromArgb(a, r, g, b);
+									break;
+								}
+
+								// Pngs don't support BGR[A], so no need to include them here
+								default:
+									throw new InvalidOperationException($"Unknown SpriteFrameType {src.Type}");
 							}
-							else
-								cc = src.Palette[src.Data[k++]];
 
 							data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();
 						}

OpenRA.Game/Graphics/Vertex.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -14,7 +14,7 @@ using System.Runtime.InteropServices;
 namespace OpenRA.Graphics
 {
 	[StructLayout(LayoutKind.Sequential)]
-	public struct Vertex
+	public readonly struct Vertex
 	{
 		// 3d position
 		public readonly float X, Y, Z;
@@ -26,24 +26,24 @@ namespace OpenRA.Graphics
 		public readonly float P, C;
 
 		// Color tint
-		public readonly float R, G, B;
+		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) { }
+			: 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, float p, float c, in float3 tint)
-			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, p, c, tint.X, tint.Y, tint.Z) { }
+		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(float x, float y, float z, float s, float t, float u, float v, float p, float c, in float3 tint)
-			: this(x, y, z, s, t, u, v, p, c, tint.X, tint.Y, tint.Z) { }
+		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, float p, float c, float r, float g, float b)
+		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)
 		{
 			X = x; Y = y; Z = z;
 			S = s; T = t;
 			U = u; V = v;
 			P = p; C = c;
-			R = r; G = g; B = b;
+			R = r; G = g; B = b; A = a;
 		}
 	}
 }

OpenRA.Game/Graphics/Video.cs

@@ -0,0 +1,37 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2021 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 OpenRA.FileSystem;
+using OpenRA.Primitives;
+
+namespace OpenRA.Video
+{
+	public interface IVideo
+	{
+		ushort Frames { get; }
+		byte Framerate { get; }
+		ushort Width { get; }
+		ushort Height { get; }
+		uint[,] FrameData { get; }
+
+		int CurrentFrame { get; }
+		void AdvanceFrame();
+
+		bool HasAudio { get; }
+		byte[] AudioData { get; }
+		int AudioChannels { get; }
+		int SampleBits { get; }
+		int SampleRate { get; }
+
+		void Reset();
+	}
+}

OpenRA.Game/Graphics/VideoLoader.cs

@@ -0,0 +1,32 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2021 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.IO;
+
+namespace OpenRA.Video
+{
+	public interface IVideoLoader
+	{
+		bool TryParseVideo(Stream s, out IVideo video);
+	}
+
+	public static class VideoLoader
+	{
+		public static IVideo GetVideo(Stream stream, IVideoLoader[] loaders)
+		{
+			foreach (var loader in loaders)
+				if (loader.TryParseVideo(stream, out var video))
+					return video;
+
+			return null;
+		}
+	}
+}

OpenRA.Game/Graphics/Viewport.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -51,11 +51,11 @@ namespace OpenRA.Graphics
 		// Viewport geometry (world-px)
 		public int2 CenterLocation { get; private set; }
 
-		public WPos CenterPosition { get { return worldRenderer.ProjectedPosition(CenterLocation); } }
+		public WPos CenterPosition => worldRenderer.ProjectedPosition(CenterLocation);
 
-		public Rectangle Rectangle { get { return new Rectangle(TopLeft, new Size(viewportSize.X, viewportSize.Y)); } }
-		public int2 TopLeft { get { return CenterLocation - viewportSize / 2; } }
-		public int2 BottomRight { get { return CenterLocation + viewportSize / 2; } }
+		public Rectangle Rectangle => new Rectangle(TopLeft, new Size(viewportSize.X, viewportSize.Y));
+		public int2 TopLeft => CenterLocation - viewportSize / 2;
+		public int2 BottomRight => CenterLocation + viewportSize / 2;
 		int2 viewportSize;
 		ProjectedCellRegion cells;
 		bool cellsDirty = true;
@@ -75,10 +75,7 @@ namespace OpenRA.Graphics
 
 		public float Zoom
 		{
-			get
-			{
-				return zoom;
-			}
+			get => zoom;
 
 			private set
 			{
@@ -89,7 +86,7 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		public float MinZoom { get { return minZoom; } }
+		public float MinZoom => minZoom;
 
 		public void AdjustZoom(float dz)
 		{
@@ -253,6 +250,9 @@ namespace OpenRA.Graphics
 			else
 				Zoom = Zoom.Clamp(minZoom, maxZoom);
 
+			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);
 		}

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -21,12 +21,11 @@ namespace OpenRA.Graphics
 	public sealed class WorldRenderer : IDisposable
 	{
 		public static readonly Func<IRenderable, int> RenderableZPositionComparisonKey =
-			r => ZPosition(r.Pos, r.ZOffset);
+			r => r.Pos.Y + r.Pos.Z + r.ZOffset;
 
 		public readonly Size TileSize;
 		public readonly int TileScale;
 		public readonly World World;
-		public readonly Theater Theater;
 		public Viewport Viewport { get; private set; }
 		public readonly ITerrainLighting TerrainLighting;
 
@@ -46,8 +45,6 @@ namespace OpenRA.Graphics
 
 		readonly List<IRenderable> renderablesBuffer = new List<IRenderable>();
 
-		bool lastDepthPreviewEnabled;
-
 		internal WorldRenderer(ModData modData, World world)
 		{
 			World = world;
@@ -68,7 +65,6 @@ namespace OpenRA.Graphics
 
 			palette.Initialize();
 
-			Theater = new Theater(world.Map.Rules.TileSet);
 			TerrainLighting = world.WorldActor.TraitOrDefault<ITerrainLighting>();
 			terrainRenderer = world.WorldActor.TraitOrDefault<IRenderTerrain>();
 
@@ -87,7 +83,13 @@ namespace OpenRA.Graphics
 			return new PaletteReference(name, palette.GetPaletteIndex(name), pal, palette);
 		}
 
-		public PaletteReference Palette(string name) { return palettes.GetOrAdd(name, createPaletteReference); }
+		public PaletteReference Palette(string name)
+		{
+			// 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);
+		}
+
 		public void AddPalette(string name, ImmutablePalette pal, bool allowModifiers = false, bool allowOverwrite = false)
 		{
 			if (allowOverwrite && palette.Contains(name))
@@ -111,6 +113,11 @@ namespace OpenRA.Graphics
 				palettes[name].Palette = pal;
 		}
 
+		public void SetPaletteColorShift(string name, float hueOffset, float satOffset, float minHue, float maxHue)
+		{
+			palette.SetColorShift(name, hueOffset, satOffset, minHue, maxHue);
+		}
+
 		// PERF: Avoid LINQ.
 		void GenerateRenderables()
 		{
@@ -247,11 +254,7 @@ namespace OpenRA.Graphics
 			if (World.WorldActor.Disposed)
 				return;
 
-			if (debugVis.Value != null && lastDepthPreviewEnabled != debugVis.Value.DepthBuffer)
-			{
-				lastDepthPreviewEnabled = debugVis.Value.DepthBuffer;
-				Game.Renderer.WorldSpriteRenderer.SetDepthPreviewEnabled(lastDepthPreviewEnabled);
-			}
+			debugVis.Value?.UpdateDepthBuffer();
 
 			var bounds = Viewport.GetScissorBounds(World.Type != WorldType.Editor);
 			Game.Renderer.EnableScissor(bounds);
@@ -356,7 +359,13 @@ namespace OpenRA.Graphics
 
 		public float3 Screen3DPosition(WPos pos)
 		{
-			var z = ZPosition(pos, 0) * (float)TileSize.Height / TileScale;
+			// The projection from world coordinates to screen coordinates has
+			// a non-obvious relationship between the y and z coordinates:
+			// * A flat surface with constant y (e.g. a vertical wall) in world coordinates
+			//   transforms into a flat surface with constant z (depth) in screen coordinates.
+			// * Increasing the world y coordinate increases screen y and z coordinates equally.
+			// * Increases the world z coordinate decreases screen y but doesn't change screen z.
+			var z = pos.Y * (float)TileSize.Height / TileScale;
 			return new float3((float)TileSize.Width * pos.X / TileScale, (float)TileSize.Height * (pos.Y - pos.Z) / TileScale, z);
 		}
 
@@ -375,7 +384,7 @@ namespace OpenRA.Graphics
 		}
 
 		// For scaling vectors to pixel sizes in the model renderer
-		public float3 ScreenVectorComponents(WVec vec)
+		public float3 ScreenVectorComponents(in WVec vec)
 		{
 			return new float3(
 				(float)TileSize.Width * vec.X / TileScale,
@@ -384,29 +393,19 @@ namespace OpenRA.Graphics
 		}
 
 		// For scaling vectors to pixel sizes in the model renderer
-		public float[] ScreenVector(WVec vec)
+		public float[] ScreenVector(in WVec vec)
 		{
 			var xyz = ScreenVectorComponents(vec);
 			return new[] { xyz.X, xyz.Y, xyz.Z, 1f };
 		}
 
-		public int2 ScreenPxOffset(WVec vec)
+		public int2 ScreenPxOffset(in WVec vec)
 		{
 			// Round to nearest pixel
 			var xyz = ScreenVectorComponents(vec);
 			return new int2((int)Math.Round(xyz.X), (int)Math.Round(xyz.Y));
 		}
 
-		public float ScreenZPosition(WPos pos, int offset)
-		{
-			return ZPosition(pos, offset) * (float)TileSize.Height / TileScale;
-		}
-
-		static int ZPosition(WPos pos, int offset)
-		{
-			return pos.Y + pos.Z + offset;
-		}
-
 		/// <summary>
 		/// Returns a position in the world that is projected to the given screen position.
 		/// There are many possible world positions, and the returned value chooses the value with no elevation.
@@ -425,7 +424,6 @@ namespace OpenRA.Graphics
 			World.Dispose();
 
 			palette.Dispose();
-			Theater.Dispose();
 		}
 	}
 }

OpenRA.Game/HotkeyDefinition.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/HotkeyManager.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -96,14 +96,8 @@ namespace OpenRA
 			return null;
 		}
 
-		public HotkeyReference this[string name]
-		{
-			get
-			{
-				return new HotkeyReference(GetHotkeyReference(name));
-			}
-		}
+		public HotkeyReference this[string name] => new HotkeyReference(GetHotkeyReference(name));
 
-		public IEnumerable<HotkeyDefinition> Definitions { get { return definitions.Values; } }
+		public IEnumerable<HotkeyDefinition> Definitions => definitions.Values;
 	}
 }

OpenRA.Game/HttpExtension.cs

@@ -0,0 +1,63 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2021 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.IO;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace OpenRA
+{
+	public delegate void OnProgress(long total, long totalRead, int progressPercentage);
+
+	public static class HttpExtension
+	{
+		public static async Task ReadAsStreamWithProgress(this HttpResponseMessage response, Stream outputStream, OnProgress onProgress, CancellationToken token)
+		{
+			var total = response.Content.Headers.ContentLength ?? -1;
+			var canReportProgress = total > 0;
+
+#if !MONO
+			using (var contentStream = await response.Content.ReadAsStreamAsync(token))
+#else
+			using (var contentStream = await response.Content.ReadAsStreamAsync())
+#endif
+			{
+				var totalRead = 0L;
+				var buffer = new byte[8192];
+				var hasMoreToRead = true;
+
+				do
+				{
+					var read = await contentStream.ReadAsync(buffer.AsMemory(0, buffer.Length), token);
+					if (read == 0)
+						hasMoreToRead = false;
+					else
+					{
+						await outputStream.WriteAsync(buffer.AsMemory(0, read), token);
+
+						totalRead += read;
+
+						if (canReportProgress)
+						{
+							var progressPercentage = (int)((double)totalRead / total * 100);
+							onProgress?.Invoke(total, totalRead, progressPercentage);
+						}
+					}
+				}
+				while (hasMoreToRead && !token.IsCancellationRequested);
+
+				onProgress?.Invoke(total, totalRead, 100);
+			}
+		}
+	}
+}

OpenRA.Game/IUtilityCommand.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/Input/Hotkey.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -13,7 +13,7 @@ using System;
 
 namespace OpenRA
 {
-	public struct Hotkey : IEquatable<Hotkey>
+	public readonly struct Hotkey : IEquatable<Hotkey>
 	{
 		public static Hotkey Invalid = new Hotkey(Keycode.UNKNOWN, Modifiers.None);
 		public bool IsValid()
@@ -81,11 +81,10 @@ namespace OpenRA
 
 		public override bool Equals(object obj)
 		{
-			var o = obj as Hotkey?;
-			return o != null && o == this;
+			return obj is Hotkey o && (Hotkey?)o == this;
 		}
 
-		public override string ToString() { return "{0} {1}".F(Key, Modifiers.ToString("F")); }
+		public override string ToString() { return $"{Key} {Modifiers.ToString("F")}"; }
 
 		public string DisplayString()
 		{

OpenRA.Game/Input/HotkeyReference.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/Input/IInputHandler.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/Input/InputHandler.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -37,36 +37,24 @@ namespace OpenRA
 
 		public void OnKeyInput(KeyInput input)
 		{
-			Sync.RunUnsynced(Game.Settings.Debug.SyncCheckUnsyncedCode, world, () => Ui.HandleKeyPress(input));
+			Sync.RunUnsynced(world, () => Ui.HandleKeyPress(input));
 		}
 
 		public void OnTextInput(string text)
 		{
-			Sync.RunUnsynced(Game.Settings.Debug.SyncCheckUnsyncedCode, world, () => Ui.HandleTextInput(text));
+			Sync.RunUnsynced(world, () => Ui.HandleTextInput(text));
 		}
 
 		public void OnMouseInput(MouseInput input)
 		{
-			Sync.RunUnsynced(Game.Settings.Debug.SyncCheckUnsyncedCode, world, () => Ui.HandleInput(input));
+			Sync.RunUnsynced(world, () => Ui.HandleInput(input));
 		}
 	}
 
 	public class MouseButtonPreference
 	{
-		public MouseButton Action
-		{
-			get
-			{
-				return Game.Settings.Game.UseClassicMouseStyle ? MouseButton.Left : MouseButton.Right;
-			}
-		}
+		public MouseButton Action => Game.Settings.Game.UseClassicMouseStyle ? MouseButton.Left : MouseButton.Right;
 
-		public MouseButton Cancel
-		{
-			get
-			{
-				return Game.Settings.Game.UseClassicMouseStyle ? MouseButton.Right : MouseButton.Left;
-			}
-		}
+		public MouseButton Cancel => Game.Settings.Game.UseClassicMouseStyle ? MouseButton.Right : MouseButton.Left;
 	}
 }

OpenRA.Game/Input/Keycode.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/InstalledMods.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -16,7 +16,6 @@ using System.IO;
 using System.Linq;
 using OpenRA.FileSystem;
 using OpenRA.Graphics;
-using OpenRA.Primitives;
 
 namespace OpenRA
 {
@@ -75,7 +74,7 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Load mod '{0}': {1}".F(path, e));
+				Log.Write("debug", $"Load mod '{path}': {e}");
 			}
 
 			package?.Dispose();
@@ -99,10 +98,10 @@ namespace OpenRA
 			return ret;
 		}
 
-		public Manifest this[string key] { get { return mods[key]; } }
-		public int Count { get { return mods.Count; } }
-		public ICollection<string> Keys { get { return mods.Keys; } }
-		public ICollection<Manifest> Values { get { return mods.Values; } }
+		public Manifest this[string key] => mods[key];
+		public IEnumerable<string> Keys => mods.Keys;
+		public IEnumerable<Manifest> Values => mods.Values;
+		public int Count => mods.Count;
 		public bool ContainsKey(string key) { return mods.ContainsKey(key); }
 		public IEnumerator<KeyValuePair<string, Manifest>> GetEnumerator() { return mods.GetEnumerator(); }
 		public bool TryGetValue(string key, out Manifest value) { return mods.TryGetValue(key, out value); }

OpenRA.Game/LocalPlayerProfile.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -12,10 +12,10 @@
 using System;
 using System.IO;
 using System.Linq;
-using System.Net;
 using System.Security.Cryptography;
 using System.Text;
 using System.Threading.Tasks;
+using OpenRA.Support;
 
 namespace OpenRA
 {
@@ -24,11 +24,11 @@ namespace OpenRA
 		const int AuthKeySize = 2048;
 		public enum LinkState { Uninitialized, GeneratingKeys, Unlinked, CheckingLink, ConnectionFailed, Linked }
 
-		public LinkState State { get { return innerState; } }
-		public string Fingerprint { get { return innerFingerprint; } }
-		public string PublicKey { get { return innerPublicKey; } }
+		public LinkState State => innerState;
+		public string Fingerprint => innerFingerprint;
+		public string PublicKey => innerPublicKey;
 
-		public PlayerProfile ProfileData { get { return innerData; } }
+		public PlayerProfile ProfileData => innerData;
 
 		volatile LinkState innerState;
 		volatile PlayerProfile innerData;
@@ -76,17 +76,16 @@ namespace OpenRA
 			if (State != LinkState.Unlinked && State != LinkState.Linked && State != LinkState.ConnectionFailed)
 				return;
 
-			Action<DownloadDataCompletedEventArgs> onQueryComplete = i =>
+			Task.Run(async () =>
 			{
 				try
 				{
-					if (i.Error != null)
-					{
-						innerState = LinkState.ConnectionFailed;
-						return;
-					}
+					var client = HttpClientFactory.Create();
 
-					var yaml = MiniYaml.FromString(Encoding.UTF8.GetString(i.Result)).First();
+					var httpResponseMessage = await client.GetAsync(playerDatabase.Profile + Fingerprint);
+					var result = await httpResponseMessage.Content.ReadAsStringAsync();
+
+					var yaml = MiniYaml.FromString(result).First();
 					if (yaml.Key == "Player")
 					{
 						innerData = FieldLoader.Load<PlayerProfile>(yaml.Value);
@@ -110,10 +109,9 @@ namespace OpenRA
 				{
 					onComplete?.Invoke();
 				}
-			};
+			});
 
 			innerState = LinkState.CheckingLink;
-			new Download(playerDatabase.Profile + Fingerprint, _ => { }, onQueryComplete);
 		}
 
 		public void GenerateKeypair()

OpenRA.Game/LogProxy.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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

OpenRA.Game/MPos.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -14,7 +14,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA
 {
-	public struct MPos : IEquatable<MPos>
+	public readonly struct MPos : IEquatable<MPos>
 	{
 		public readonly int U, V;
 
@@ -66,7 +66,7 @@ namespace OpenRA
 	/// <summary>
 	/// Projected map position
 	/// </summary>
-	public struct PPos : IEquatable<PPos>
+	public readonly struct PPos : IEquatable<PPos>
 	{
 		public readonly int U, V;
 

OpenRA.Game/Manifest.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -11,6 +11,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
 using OpenRA.FileSystem;
@@ -20,6 +21,17 @@ namespace OpenRA
 {
 	public interface IGlobalModData { }
 
+	public sealed class TerrainFormat : IGlobalModData
+	{
+		public readonly string Type;
+		public readonly IReadOnlyDictionary<string, MiniYaml> Metadata;
+		public TerrainFormat(MiniYaml yaml)
+		{
+			Type = yaml.Value;
+			Metadata = new ReadOnlyDictionary<string, MiniYaml>(yaml.ToDictionary());
+		}
+	}
+
 	public sealed class SpriteSequenceFormat : IGlobalModData
 	{
 		public readonly string Type;
@@ -48,6 +60,7 @@ namespace OpenRA
 		public string Version;
 		public string Website;
 		public string WebIcon32;
+		public string WindowTitle;
 		public bool Hidden;
 	}
 
@@ -70,13 +83,14 @@ namespace OpenRA
 		public readonly string[] SoundFormats = { };
 		public readonly string[] SpriteFormats = { };
 		public readonly string[] PackageFormats = { };
+		public readonly string[] VideoFormats = { };
 
 		readonly string[] reservedModuleNames =
 		{
 			"Include", "Metadata", "Folders", "MapFolders", "Packages", "Rules",
 			"Sequences", "ModelSequences", "Cursors", "Chrome", "Assemblies", "ChromeLayout", "Weapons",
 			"Voices", "Notifications", "Music", "Translations", "TileSets", "ChromeMetrics", "Missions", "Hotkeys",
-			"ServerTraits", "LoadScreen", "SupportsMapsFrom", "SoundFormats", "SpriteFormats",
+			"ServerTraits", "LoadScreen", "SupportsMapsFrom", "SoundFormats", "SpriteFormats", "VideoFormats",
 			"RequiresMods", "PackageFormats"
 		};
 
@@ -100,7 +114,7 @@ namespace OpenRA
 				var filename = nodes[i].Value.Value;
 				var contents = package.GetStream(filename);
 				if (contents == null)
-					throw new YamlException("{0}: File `{1}` not found.".F(nodes[i].Location, filename));
+					throw new YamlException($"{nodes[i].Location}: File `{filename}` not found.");
 
 				nodes.RemoveAt(i);
 				nodes.InsertRange(i, MiniYaml.FromStream(contents, filename));
@@ -115,7 +129,7 @@ namespace OpenRA
 			MapFolders = YamlDictionary(yaml, "MapFolders");
 
 			if (yaml.TryGetValue("Packages", out var packages))
-				Packages = packages.ToDictionary(x => x.Value).AsReadOnly();
+				Packages = packages.ToDictionary(x => x.Value);
 
 			Rules = YamlList(yaml, "Rules");
 			Sequences = YamlList(yaml, "Sequences");
@@ -155,6 +169,9 @@ namespace OpenRA
 
 			if (yaml.ContainsKey("SpriteFormats"))
 				SpriteFormats = FieldLoader.GetValue<string[]>("SpriteFormats", yaml["SpriteFormats"].Value);
+
+			if (yaml.ContainsKey("VideoFormats"))
+				VideoFormats = FieldLoader.GetValue<string[]>("VideoFormats", yaml["VideoFormats"].Value);
 		}
 
 		public void LoadCustomData(ObjectCreator oc)
@@ -166,7 +183,7 @@ namespace OpenRA
 
 				var t = oc.FindType(kv.Key);
 				if (t == null || !typeof(IGlobalModData).IsAssignableFrom(t))
-					throw new InvalidDataException("`{0}` is not a valid mod manifest entry.".F(kv.Key));
+					throw new InvalidDataException($"`{kv.Key}` is not a valid mod manifest entry.");
 
 				IGlobalModData module;
 				var ctor = t.GetConstructor(new[] { typeof(MiniYaml) });
@@ -199,10 +216,9 @@ namespace OpenRA
 		static IReadOnlyDictionary<string, string> YamlDictionary(Dictionary<string, MiniYaml> yaml, string key)
 		{
 			if (!yaml.ContainsKey(key))
-				return new ReadOnlyDictionary<string, string>();
+				return new Dictionary<string, string>();
 
-			var inner = yaml[key].ToDictionary(my => my.Value);
-			return new ReadOnlyDictionary<string, string>(inner);
+			return yaml[key].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 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -37,7 +37,7 @@ namespace OpenRA
 	public class ActorInitializer : IActorInitializer
 	{
 		public readonly Actor Self;
-		public World World { get { return Self.World; } }
+		public World World => Self.World;
 
 		internal TypeDictionary Dict;
 
@@ -66,7 +66,7 @@ namespace OpenRA
 		{
 			var init = GetOrDefault<T>(info);
 			if (init == null)
-			    throw new InvalidOperationException("TypeDictionary does not contain instance of type `{0}`".F(typeof(T)));
+			    throw new InvalidOperationException($"TypeDictionary does not contain instance of type `{typeof(T)}`");
 
 			return init;
 		}
@@ -150,16 +150,16 @@ namespace OpenRA
 
 		protected ValueActorInit(T value) { this.value = value; }
 
-		public virtual T Value { get { return value; } }
+		public virtual T Value => value;
 
 		public virtual void Initialize(MiniYaml yaml)
 		{
-			Initialize((T)FieldLoader.GetValue("value", typeof(T), yaml.Value));
+			Initialize((T)FieldLoader.GetValue(nameof(value), typeof(T), yaml.Value));
 		}
 
 		public virtual void Initialize(T value)
 		{
-			var field = GetType().GetField("value", BindingFlags.NonPublic | BindingFlags.Instance);
+			var field = GetType().GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance);
 			if (field != null)
 				field.SetValue(this, value);
 		}
@@ -246,14 +246,14 @@ namespace OpenRA
 
 		public void Initialize(MiniYaml yaml)
 		{
-			var field = GetType().GetField("InternalName", BindingFlags.Public | BindingFlags.Instance);
+			var field = GetType().GetField(nameof(InternalName), BindingFlags.Public | BindingFlags.Instance);
 			if (field != null)
 				field.SetValue(this, yaml.Value);
 		}
 
 		public void Initialize(Player player)
 		{
-			var field = GetType().GetField("value", BindingFlags.NonPublic | BindingFlags.Instance);
+			var field = GetType().GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance);
 			if (field != null)
 				field.SetValue(this, player);
 		}

OpenRA.Game/Map/ActorReference.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -27,7 +27,7 @@ namespace OpenRA
 		public string Type;
 		Lazy<TypeDictionary> initDict;
 
-		internal TypeDictionary InitDict { get { return initDict.Value; } }
+		internal TypeDictionary InitDict => initDict.Value;
 
 		public ActorReference(string type)
 			: this(type, new Dictionary<string, MiniYaml>()) { }
@@ -42,7 +42,7 @@ namespace OpenRA
 				{
 					var init = LoadInit(i.Key, i.Value);
 					if (init is ISingleInstanceInit && dict.Contains(init.GetType()))
-						throw new InvalidDataException("Duplicate initializer '{0}'".F(init.GetType().Name));
+						throw new InvalidDataException($"Duplicate initializer '{init.GetType().Name}'");
 
 					dict.Add(init);
 				}
@@ -68,7 +68,7 @@ namespace OpenRA
 			var initInstance = initName.Split(ActorInfo.TraitInstanceSeparator);
 			var type = Game.ModData.ObjectCreator.FindType(initInstance[0] + "Init");
 			if (type == null)
-				throw new InvalidDataException("Unknown initializer type '{0}Init'".F(initInstance[0]));
+				throw new InvalidDataException($"Unknown initializer type '{initInstance[0]}Init'");
 
 			var init = (ActorInit)FormatterServices.GetUninitializedObject(type);
 			if (initInstance.Length > 1)
@@ -76,7 +76,7 @@ namespace OpenRA
 
 			var loader = type.GetMethod("Initialize", new[] { typeof(MiniYaml) });
 			if (loader == null)
-				throw new InvalidDataException("{0}Init does not define a yaml-assignable type.".F(initInstance[0]));
+				throw new InvalidDataException($"{initInstance[0]}Init does not define a yaml-assignable type.");
 
 			loader.Invoke(init, new[] { initYaml });
 			return init;
@@ -119,7 +119,7 @@ namespace OpenRA
 		public void Add(ActorInit init)
 		{
 			if (init is ISingleInstanceInit && InitDict.Contains(init.GetType()))
-				throw new InvalidDataException("Duplicate initializer '{0}'".F(init.GetType().Name));
+				throw new InvalidDataException($"Duplicate initializer '{init.GetType().Name}'");
 
 			InitDict.Add(init);
 		}
@@ -162,7 +162,7 @@ namespace OpenRA
 		{
 			var init = GetOrDefault<T>(info);
 			if (init == null)
-				throw new InvalidOperationException("TypeDictionary does not contain instance of type `{0}`".F(typeof(T)));
+				throw new InvalidOperationException($"TypeDictionary does not contain instance of type `{typeof(T)}`");
 
 			return init;
 		}

OpenRA.Game/Map/CellLayer.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -52,7 +52,15 @@ namespace OpenRA
 		// Resolve an array index from cell coordinates
 		int Index(CPos cell)
 		{
-			return Index(cell.ToMPos(GridType));
+			// PERF: Inline CPos.ToMPos to avoid MPos allocation
+			var x = cell.X;
+			var y = cell.Y;
+			if (GridType == MapGridType.Rectangular)
+				return y * Size.Width + x;
+
+			var u = (x - y) / 2;
+			var v = x + y;
+			return v * Size.Width + u;
 		}
 
 		// Resolve an array index from map coordinates
@@ -64,10 +72,7 @@ namespace OpenRA
 		/// <summary>Gets or sets the <see cref="CellLayer"/> using cell coordinates</summary>
 		public T this[CPos cell]
 		{
-			get
-			{
-				return entries[Index(cell)];
-			}
+			get => entries[Index(cell)];
 
 			set
 			{
@@ -80,10 +85,7 @@ namespace OpenRA
 		/// <summary>Gets or sets the layer contents using raw map coordinates (not CPos!)</summary>
 		public T this[MPos uv]
 		{
-			get
-			{
-				return entries[Index(uv)];
-			}
+			get => entries[Index(uv)];
 
 			set
 			{

OpenRA.Game/Map/CellLayerBase.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -38,7 +38,7 @@ namespace OpenRA
 		public virtual void CopyValuesFrom(CellLayerBase<T> anotherLayer)
 		{
 			if (Size != anotherLayer.Size || GridType != anotherLayer.GridType)
-				throw new ArgumentException("Layers must have a matching size and shape (grid type).", "anotherLayer");
+				throw new ArgumentException("Layers must have a matching size and shape (grid type).", nameof(anotherLayer));
 
 			Array.Copy(anotherLayer.entries, entries, entries.Length);
 		}

OpenRA.Game/Map/CellRegion.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -62,7 +62,7 @@ namespace OpenRA
 		public static CellRegion BoundingRegion(MapGridType shape, IEnumerable<CPos> cells)
 		{
 			if (cells == null || !cells.Any())
-				throw new ArgumentException("cells must not be null or empty.", "cells");
+				throw new ArgumentException("cells must not be null or empty.", nameof(cells));
 
 			var minU = int.MaxValue;
 			var minV = int.MaxValue;
@@ -97,10 +97,7 @@ namespace OpenRA
 			return uv.U >= mapTopLeft.U && uv.U <= mapBottomRight.U && uv.V >= mapTopLeft.V && uv.V <= mapBottomRight.V;
 		}
 
-		public MapCoordsRegion MapCoords
-		{
-			get { return new MapCoordsRegion(mapTopLeft, mapBottomRight); }
-		}
+		public MapCoordsRegion MapCoords => new MapCoordsRegion(mapTopLeft, mapBottomRight);
 
 		public CellRegionEnumerator GetEnumerator()
 		{
@@ -161,8 +158,8 @@ namespace OpenRA
 				v = r.mapTopLeft.V;
 			}
 
-			public CPos Current { get { return current; } }
-			object IEnumerator.Current { get { return Current; } }
+			public CPos Current => current;
+			object IEnumerator.Current => Current;
 			public void Dispose() { }
 		}
 	}

OpenRA.Game/Map/Map.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -17,13 +17,15 @@ using System.Reflection;
 using System.Text;
 using OpenRA.FileFormats;
 using OpenRA.FileSystem;
+using OpenRA.Graphics;
 using OpenRA.Primitives;
 using OpenRA.Support;
 using OpenRA.Traits;
+using OpenRA.Widgets;
 
 namespace OpenRA
 {
-	struct BinaryDataHeader
+	readonly struct BinaryDataHeader
 	{
 		public readonly byte Format;
 		public readonly uint TilesOffset;
@@ -51,7 +53,7 @@ namespace OpenRA
 				ResourcesOffset = s.ReadUInt32();
 			}
 			else
-				throw new InvalidDataException("Unknown binary map format '{0}'".F(Format));
+				throw new InvalidDataException($"Unknown binary map format '{Format}'");
 		}
 	}
 
@@ -98,7 +100,7 @@ namespace OpenRA
 			if (node == null)
 			{
 				if (required)
-					throw new YamlException("Required field `{0}` not found in map.yaml".F(key));
+					throw new YamlException($"Required field `{key}` not found in map.yaml");
 				return;
 			}
 
@@ -163,6 +165,7 @@ namespace OpenRA
 			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"),
@@ -173,7 +176,6 @@ namespace OpenRA
 			new MapField("Voices", "VoiceDefinitions", required: false),
 			new MapField("Music", "MusicDefinitions", required: false),
 			new MapField("Notifications", "NotificationDefinitions", required: false),
-			new MapField("Translations", "TranslationDefinitions", required: false)
 		};
 
 		// Format versions
@@ -189,6 +191,7 @@ namespace OpenRA
 		public Rectangle Bounds;
 		public MapVisibility Visibility = MapVisibility.Lobby;
 		public string[] Categories = { "Conquest" };
+		public string[] Translations;
 
 		public int2 MapSize { get; private set; }
 
@@ -204,7 +207,8 @@ namespace OpenRA
 		public readonly MiniYaml VoiceDefinitions;
 		public readonly MiniYaml MusicDefinitions;
 		public readonly MiniYaml NotificationDefinitions;
-		public readonly MiniYaml TranslationDefinitions;
+
+		public readonly Dictionary<CPos, TerrainTile> ReplacedInvalidTerrainTiles = new Dictionary<CPos, TerrainTile>();
 
 		// Generated data
 		public readonly MapGrid Grid;
@@ -245,6 +249,8 @@ namespace OpenRA
 		CellLayer<List<MPos>> inverseCellProjection;
 		CellLayer<byte> projectedHeight;
 
+		internal Translation Translation;
+
 		public static string ComputeUID(IReadOnlyPackage package)
 		{
 			// UID is calculated by taking an SHA1 of the yaml and binary data
@@ -252,7 +258,7 @@ namespace OpenRA
 			var contents = package.Contents.ToList();
 			foreach (var required in requiredFiles)
 				if (!contents.Contains(required))
-					throw new FileNotFoundException("Required file {0} not present in this map".F(required));
+					throw new FileNotFoundException($"Required file {required} not present in this map");
 
 			var streams = new List<Stream>();
 			try
@@ -282,18 +288,17 @@ namespace OpenRA
 		/// Initializes a new map created by the editor or importer.
 		/// The map will not receive a valid UID until after it has been saved and reloaded.
 		/// </summary>
-		public Map(ModData modData, TileSet tileset, int width, int height)
+		public Map(ModData modData, ITerrainInfo terrainInfo, int width, int height)
 		{
 			this.modData = modData;
 			var size = new Size(width, height);
 			Grid = modData.Manifest.Get<MapGrid>();
-			var tileRef = new TerrainTile(tileset.Templates.First().Key, 0);
 
 			Title = "Name your map here";
 			Author = "Your name here";
 
 			MapSize = new int2(size);
-			Tileset = tileset.Id;
+			Tileset = terrainInfo.Id;
 
 			// Empty rules that can be added to by the importers.
 			// Will be dropped on save if nothing is added to it
@@ -310,7 +315,7 @@ namespace OpenRA
 				Tiles.CellEntryChanged += UpdateRamp;
 			}
 
-			Tiles.Clear(tileRef);
+			Tiles.Clear(terrainInfo.DefaultTerrainTile);
 
 			PostInit();
 		}
@@ -321,19 +326,16 @@ namespace OpenRA
 			Package = package;
 
 			if (!Package.Contains("map.yaml") || !Package.Contains("map.bin"))
-				throw new InvalidDataException("Not a valid map\n File: {0}".F(package.Name));
+				throw new InvalidDataException($"Not a valid map\n File: {package.Name}");
 
 			var yaml = new MiniYaml(null, MiniYaml.FromStream(Package.GetStream("map.yaml"), package.Name));
 			foreach (var field in YamlFields)
 				field.Deserialize(this, yaml.Nodes);
 
 			if (MapFormat != SupportedMapFormat)
-				throw new InvalidDataException("Map format {0} is not supported.\n File: {1}".F(MapFormat, package.Name));
+				throw new InvalidDataException($"Map format {MapFormat} is not supported.\n File: {package.Name}");
 
 			PlayerDefinitions = MiniYaml.NodesOrEmpty(yaml, "Players");
-			if (PlayerDefinitions.Count > 64)
-				throw new InvalidDataException("Maps must not define more than 64 players.\n File: {0}".F(package.Name));
-
 			ActorDefinitions = MiniYaml.NodesOrEmpty(yaml, "Actors");
 
 			Grid = modData.Manifest.Get<MapGrid>();
@@ -418,6 +420,8 @@ namespace OpenRA
 
 			Rules.Sequences.Preload();
 
+			Translation = new Translation(Game.Settings.Player.Language, Translations, this);
+
 			var tl = new MPos(0, 0).ToCPos(this);
 			var br = new MPos(MapSize.X - 1, MapSize.Y - 1).ToCPos(this);
 			AllCells = new CellRegion(Grid.Type, tl, br);
@@ -430,12 +434,18 @@ namespace OpenRA
 			foreach (var uv in AllCells.MapCoords)
 				CustomTerrain[uv] = byte.MaxValue;
 
-			// Cache initial ramp state
-			var tileset = Rules.TileSet;
-			foreach (var uv in AllCells)
+			// Replace invalid tiles and cache ramp state
+			var terrainInfo = Rules.TerrainInfo;
+			foreach (var uv in AllCells.MapCoords)
 			{
-				var tile = tileset.GetTileInfo(Tiles[uv]);
-				Ramp[uv] = tile != null ? tile.RampType : (byte)0;
+				if (!terrainInfo.TryGetTerrainInfo(Tiles[uv], out var info))
+				{
+					ReplacedInvalidTerrainTiles[uv.ToCPos(this)] = Tiles[uv];
+					Tiles[uv] = terrainInfo.DefaultTerrainTile;
+					info = terrainInfo.GetTerrainInfo(terrainInfo.DefaultTerrainTile);
+				}
+
+				Ramp[uv] = info.RampType;
 			}
 
 			AllEdgeCells = UpdateEdgeCells();
@@ -443,8 +453,7 @@ namespace OpenRA
 
 		void UpdateRamp(CPos cell)
 		{
-			var tile = Rules.TileSet.GetTileInfo(Tiles[cell]);
-			Ramp[cell] = tile != null ? tile.RampType : (byte)0;
+			Ramp[cell] = Rules.TerrainInfo.GetTerrainInfo(Tiles[cell]).RampType;
 		}
 
 		void InitializeCellProjection()
@@ -531,8 +540,7 @@ namespace OpenRA
 					// The original games treat the top of cliffs the same way as the bottom
 					// This information isn't stored in the map data, so query the offset from the tileset
 					var temp = inverse.MaxBy(uv => uv.V);
-					var terrain = Tiles[temp];
-					return (byte)(Height[temp] - Rules.TileSet.Templates[terrain.Type][terrain.Index].Height);
+					return (byte)(Height[temp] - Rules.TerrainInfo.GetTerrainInfo(Tiles[temp]).Height);
 				}
 
 				// Try the next cell down if this is a cliff face
@@ -667,35 +675,23 @@ namespace OpenRA
 
 		public (Color Left, Color Right) GetTerrainColorPair(MPos uv)
 		{
-			Color left, right;
-			var tileset = Rules.TileSet;
-			var type = tileset.GetTileInfo(Tiles[uv]);
-			if (type != null)
-			{
-				if (type.MinColor != type.MaxColor)
-				{
-					left = Exts.ColorLerp(Game.CosmeticRandom.NextFloat(), type.MinColor, type.MaxColor);
-					right = Exts.ColorLerp(Game.CosmeticRandom.NextFloat(), type.MinColor, type.MaxColor);
-				}
-				else
-					left = right = type.MinColor;
+			var terrainInfo = Rules.TerrainInfo;
+			var type = terrainInfo.GetTerrainInfo(Tiles[uv]);
+			var left = type.GetColor(Game.CosmeticRandom);
+			var right = type.GetColor(Game.CosmeticRandom);
 
-				if (tileset.MinHeightColorBrightness != 1.0f || tileset.MaxHeightColorBrightness != 1.0f)
-				{
-					var scale = float2.Lerp(tileset.MinHeightColorBrightness, tileset.MaxHeightColorBrightness, Height[uv] * 1f / Grid.MaximumTerrainHeight);
-					left = Color.FromArgb((int)(scale * left.R).Clamp(0, 255), (int)(scale * left.G).Clamp(0, 255), (int)(scale * left.B).Clamp(0, 255));
-					right = Color.FromArgb((int)(scale * right.R).Clamp(0, 255), (int)(scale * right.G).Clamp(0, 255), (int)(scale * right.B).Clamp(0, 255));
-				}
+			if (terrainInfo.MinHeightColorBrightness != 1.0f || terrainInfo.MaxHeightColorBrightness != 1.0f)
+			{
+				var scale = float2.Lerp(terrainInfo.MinHeightColorBrightness, terrainInfo.MaxHeightColorBrightness, Height[uv] * 1f / Grid.MaximumTerrainHeight);
+				left = Color.FromArgb((int)(scale * left.R).Clamp(0, 255), (int)(scale * left.G).Clamp(0, 255), (int)(scale * left.B).Clamp(0, 255));
+				right = Color.FromArgb((int)(scale * right.R).Clamp(0, 255), (int)(scale * right.G).Clamp(0, 255), (int)(scale * right.B).Clamp(0, 255));
 			}
-			else
-				left = right = Color.Black;
 
 			return (left, right);
 		}
 
 		public byte[] SavePreview()
 		{
-			var tileset = Rules.TileSet;
 			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)>();
@@ -710,95 +706,120 @@ namespace OpenRA
 			}
 
 			// ResourceLayer is on world actor, which isn't caught above, so an extra check for it.
-			var worldActorInfo = Rules.Actors["world"];
+			var worldActorInfo = Rules.Actors[SystemActors.World];
 			var worldimpsis = worldActorInfo.TraitInfos<IMapPreviewSignatureInfo>();
 			foreach (var worldimpsi in worldimpsis)
 				worldimpsi.PopulateMapPreviewSignatureCells(this, worldActorInfo, null, positions);
 
-			using (var stream = new MemoryStream())
+			var isRectangularIsometric = Grid.Type == MapGridType.RectangularIsometric;
+
+			var top = int.MaxValue;
+			var bottom = int.MinValue;
+
+			if (Grid.MaximumTerrainHeight > 0)
 			{
-				var isRectangularIsometric = Grid.Type == MapGridType.RectangularIsometric;
-
-				// Fudge the heightmap offset by adding as much extra as we need / can.
-				// This tries to correct for our incorrect assumption that MPos == PPos
-				var heightOffset = Math.Min(Grid.MaximumTerrainHeight, MapSize.Y - Bounds.Bottom);
-				var width = Bounds.Width;
-				var height = Bounds.Height + heightOffset;
-
-				var bitmapWidth = width;
-				if (isRectangularIsometric)
-					bitmapWidth = 2 * bitmapWidth - 1;
-
-				var stride = bitmapWidth * 4;
-				var pxStride = 4;
-				var minimapData = new byte[stride * height];
-				(Color Left, Color Right) terrainColor = default((Color, Color));
-
-				for (var y = 0; y < height; y++)
+				// 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++)
 				{
-					for (var x = 0; x < width; x++)
+					var allTop = Unproject(new PPos(x, Bounds.Top));
+					var allBottom = Unproject(new PPos(x, Bounds.Bottom));
+					if (allTop.Any())
+						top = Math.Min(top, allTop.MinBy(uv => uv.V).V);
+
+					if (allBottom.Any())
+						bottom = Math.Max(bottom, allBottom.MaxBy(uv => uv.V).V);
+				}
+			}
+			else
+			{
+				// If the mod uses flat maps, MPos == PPos and we can take the bounds rect directly
+				top = Bounds.Top;
+				bottom = Bounds.Bottom;
+			}
+
+			var width = Bounds.Width;
+			var height = bottom - top;
+
+			var bitmapWidth = width;
+			if (isRectangularIsometric)
+				bitmapWidth = 2 * bitmapWidth - 1;
+
+			var stride = bitmapWidth * 4;
+			var pxStride = 4;
+			var minimapData = new byte[stride * height];
+			(Color Left, Color Right) terrainColor = default;
+
+			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;
+					if (actorColor.A == 0)
+						terrainColor = GetTerrainColorPair(uv);
+
+					if (isRectangularIsometric)
 					{
-						var uv = new MPos(x + Bounds.Left, y + Bounds.Top);
-
-						// FirstOrDefault will return a (MPos.Zero, Color.Transparent) if positions is empty
-						var actorColor = positions.FirstOrDefault(ap => ap.Position == uv).Color;
-						if (actorColor.A == 0)
-							terrainColor = GetTerrainColorPair(uv);
-
-						if (isRectangularIsometric)
+						// Odd rows are shifted right by 1px
+						var dx = uv.V & 1;
+						var xOffset = pxStride * (2 * x + dx);
+						if (x + dx > 0)
 						{
-							// Odd rows are shifted right by 1px
-							var dx = uv.V & 1;
-							var xOffset = pxStride * (2 * x + dx);
-							if (x + dx > 0)
-							{
-								var z = y * stride + xOffset - pxStride;
-								var c = actorColor.A == 0 ? terrainColor.Left : actorColor;
-								minimapData[z++] = c.R;
-								minimapData[z++] = c.G;
-								minimapData[z++] = c.B;
-								minimapData[z] = c.A;
-							}
-
-							if (xOffset < stride)
-							{
-								var z = y * stride + xOffset;
-								var c = actorColor.A == 0 ? terrainColor.Right : actorColor;
-								minimapData[z++] = c.R;
-								minimapData[z++] = c.G;
-								minimapData[z++] = c.B;
-								minimapData[z] = c.A;
-							}
-						}
-						else
-						{
-							var z = y * stride + pxStride * x;
+							var z = y * stride + xOffset - pxStride;
 							var c = actorColor.A == 0 ? terrainColor.Left : actorColor;
 							minimapData[z++] = c.R;
 							minimapData[z++] = c.G;
 							minimapData[z++] = c.B;
 							minimapData[z] = c.A;
 						}
+
+						if (xOffset < stride)
+						{
+							var z = y * stride + xOffset;
+							var c = actorColor.A == 0 ? terrainColor.Right : actorColor;
+							minimapData[z++] = c.R;
+							minimapData[z++] = c.G;
+							minimapData[z++] = c.B;
+							minimapData[z] = c.A;
+						}
+					}
+					else
+					{
+						var z = y * stride + pxStride * x;
+						var c = actorColor.A == 0 ? terrainColor.Left : actorColor;
+						minimapData[z++] = c.R;
+						minimapData[z++] = c.G;
+						minimapData[z++] = c.B;
+						minimapData[z] = c.A;
 					}
 				}
-
-				var png = new Png(minimapData, bitmapWidth, height);
-				return png.Save();
 			}
+
+			var png = new Png(minimapData, SpriteFrameType.Rgba32, bitmapWidth, height);
+			return png.Save();
 		}
 
 		public bool Contains(CPos cell)
 		{
-			// .ToMPos() returns the same result if the X and Y coordinates
-			// are switched. X < Y is invalid in the RectangularIsometric coordinate system,
-			// so we pre-filter these to avoid returning the wrong result
-			if (Grid.Type == MapGridType.RectangularIsometric && cell.X < cell.Y)
-				return false;
-
-			// If the mod uses flat & rectangular maps, ToMPos and Contains(MPos) create unnecessary cost.
-			// Just check if CPos is within map bounds.
-			if (Grid.MaximumTerrainHeight == 0 && Grid.Type == MapGridType.Rectangular)
-				return Bounds.Contains(cell.X, cell.Y);
+			if (Grid.Type == MapGridType.RectangularIsometric)
+			{
+				// .ToMPos() returns the same result if the X and Y coordinates
+				// are switched. X < Y is invalid in the RectangularIsometric coordinate system,
+				// so we pre-filter these to avoid returning the wrong result
+				if (cell.X < cell.Y)
+					return false;
+			}
+			else
+			{
+				// If the mod uses flat & rectangular maps, ToMPos and Contains(MPos) create unnecessary cost.
+				// Just check if CPos is within map bounds.
+				if (Grid.MaximumTerrainHeight == 0)
+					return Bounds.Contains(cell.X, cell.Y);
+			}
 
 			return Contains(cell.ToMPos(this));
 		}
@@ -896,6 +917,14 @@ namespace OpenRA
 			return new WDist(offset.Z);
 		}
 
+		public WRot TerrainOrientation(CPos cell)
+		{
+			if (!Ramp.Contains(cell))
+				return WRot.None;
+
+			return Grid.Ramps[Ramp[cell]].Orientation;
+		}
+
 		public WVec Offset(CVec delta, int dz)
 		{
 			if (Grid.Type == MapGridType.Rectangular)
@@ -907,15 +936,9 @@ namespace OpenRA
 		/// <summary>
 		/// The size of the map Height step in world units
 		/// </summary>
-		public WDist CellHeightStep
-		{
-			get
-			{
-				// RectangularIsometric defines 1024 units along the diagonal axis,
-				// giving a half-tile height step of sqrt(2) * 512
-				return new WDist(Grid.Type == MapGridType.RectangularIsometric ? 724 : 512);
-			}
-		}
+		/// 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 CPos CellContaining(WPos pos)
 		{
@@ -1025,33 +1048,6 @@ namespace OpenRA
 			ProjectedCells = new ProjectedCellRegion(this, tl, br).ToArray();
 		}
 
-		public void FixOpenAreas()
-		{
-			var r = new Random();
-			var tileset = Rules.TileSet;
-
-			for (var j = Bounds.Top; j < Bounds.Bottom; j++)
-			{
-				for (var i = Bounds.Left; i < Bounds.Right; i++)
-				{
-					var type = Tiles[new MPos(i, j)].Type;
-					var index = Tiles[new MPos(i, j)].Index;
-					if (!tileset.Templates.ContainsKey(type))
-					{
-						Console.WriteLine("Unknown Tile ID {0}".F(type));
-						continue;
-					}
-
-					var template = tileset.Templates[type];
-					if (!template.PickAny)
-						continue;
-
-					index = (byte)r.Next(0, template.TilesCount);
-					Tiles[new MPos(i, j)] = new TerrainTile(type, index);
-				}
-			}
-		}
-
 		public byte GetTerrainIndex(CPos cell)
 		{
 			const short InvalidCachedTerrainIndex = -1;
@@ -1075,8 +1071,7 @@ namespace OpenRA
 			if (terrainIndex == InvalidCachedTerrainIndex)
 			{
 				var custom = CustomTerrain[uv];
-				terrainIndex = cachedTerrainIndexes[uv] =
-					custom != byte.MaxValue ? custom : Rules.TileSet.GetTerrainIndex(Tiles[uv]);
+				terrainIndex = cachedTerrainIndexes[uv] = custom != byte.MaxValue ? custom : Rules.TerrainInfo.GetTerrainInfo(Tiles[uv]).TerrainType;
 			}
 
 			return (byte)terrainIndex;
@@ -1084,7 +1079,7 @@ namespace OpenRA
 
 		public TerrainTypeInfo GetTerrainInfo(CPos cell)
 		{
-			return Rules.TileSet[GetTerrainIndex(cell)];
+			return Rules.TerrainInfo.TerrainTypes[GetTerrainIndex(cell)];
 		}
 
 		public CPos Clamp(CPos cell)
@@ -1264,7 +1259,7 @@ namespace OpenRA
 			return AllEdgeCells.Random(rand);
 		}
 
-		public WDist DistanceToEdge(WPos pos, WVec dir)
+		public WDist DistanceToEdge(WPos pos, in WVec dir)
 		{
 			var projectedPos = pos - new WVec(0, pos.Z, pos.Z);
 			var x = dir.X == 0 ? int.MaxValue : ((dir.X < 0 ? ProjectedTopLeft.X : ProjectedBottomRight.X) - projectedPos.X) / dir.X;
@@ -1279,11 +1274,11 @@ namespace OpenRA
 		public IEnumerable<CPos> FindTilesInAnnulus(CPos center, int minRange, int maxRange, bool allowOutsideBounds = false)
 		{
 			if (maxRange < minRange)
-				throw new ArgumentOutOfRangeException("maxRange", "Maximum range is less than the minimum range.");
+				throw new ArgumentOutOfRangeException(nameof(maxRange), "Maximum range is less than the minimum range.");
 
 			if (maxRange >= Grid.TilesByDistance.Length)
-				throw new ArgumentOutOfRangeException("maxRange",
-					"The requested range ({0}) cannot exceed the value of MaximumTileSearchRange ({1})".F(maxRange, Grid.MaximumTileSearchRange));
+				throw new ArgumentOutOfRangeException(nameof(maxRange),
+					$"The requested range ({maxRange}) cannot exceed the value of MaximumTileSearchRange ({Grid.MaximumTileSearchRange})");
 
 			for (var i = minRange; i <= maxRange; i++)
 			{
@@ -1346,5 +1341,13 @@ namespace OpenRA
 
 			return false;
 		}
+
+		public string Translate(string key, IDictionary<string, object> args = null, string attribute = null)
+		{
+			if (Translation.GetFormattedMessage(key, args, attribute) == key)
+				return Ui.Translate(key, args, attribute);
+
+			return Translation.GetFormattedMessage(key, args, attribute);
+		}
 	}
 }

OpenRA.Game/Map/MapCache.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -14,9 +14,8 @@ using System.Collections;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Net;
-using System.Text;
 using System.Threading;
+using System.Threading.Tasks;
 using OpenRA.FileSystem;
 using OpenRA.Graphics;
 using OpenRA.Primitives;
@@ -27,7 +26,7 @@ namespace OpenRA
 	public sealed class MapCache : IEnumerable<MapPreview>, IDisposable
 	{
 		public static readonly MapPreview UnknownMap = new MapPreview(null, null, MapGridType.Rectangular, null);
-		public readonly IReadOnlyDictionary<IReadOnlyPackage, MapClassification> MapLocations;
+		public IReadOnlyDictionary<IReadOnlyPackage, MapClassification> MapLocations => mapLocations;
 		readonly Dictionary<IReadOnlyPackage, MapClassification> mapLocations = new Dictionary<IReadOnlyPackage, MapClassification>();
 
 		readonly Cache<string, MapPreview> previews;
@@ -47,8 +46,6 @@ namespace OpenRA
 			var gridType = Exts.Lazy(() => modData.Manifest.Get<MapGrid>().Type);
 			previews = new Cache<string, MapPreview>(uid => new MapPreview(modData, uid, gridType.Value, this));
 			sheetBuilder = new SheetBuilder(SheetType.BGRA);
-
-			MapLocations = new ReadOnlyDictionary<IReadOnlyPackage, MapClassification>(mapLocations);
 		}
 
 		public void LoadMaps()
@@ -149,8 +146,7 @@ namespace OpenRA
 				{
 					foreach (var map in package.Contents)
 					{
-						var mapPackage = package.OpenPackage(map, modData.ModFiles) as IReadWritePackage;
-						if (mapPackage != null)
+						if (package.OpenPackage(map, modData.ModFiles) is IReadWritePackage mapPackage)
 							yield return mapPackage;
 					}
 				}
@@ -163,55 +159,57 @@ namespace OpenRA
 				yield return new Map(modData, mapPackage);
 		}
 
-		public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids, Action<MapPreview> mapDetailsReceived = null, Action queryFailed = null)
+		public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids, Action<MapPreview> mapDetailsReceived = null, Action<MapPreview> mapQueryFailed = null)
 		{
-			var maps = uids.Distinct()
+			var queryUids = uids.Distinct()
+				.Where(uid => uid != null)
 				.Select(uid => previews[uid])
 				.Where(p => p.Status == MapStatus.Unavailable)
-				.ToDictionary(p => p.Uid, p => p);
+				.Select(p => p.Uid)
+				.ToList();
 
-			if (!maps.Any())
-				return;
+			foreach (var uid in queryUids)
+				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null);
 
-			foreach (var p in maps.Values)
-				p.UpdateRemoteSearch(MapStatus.Searching, null);
-
-			var url = repositoryUrl + "hash/" + string.Join(",", maps.Keys) + "/yaml";
-
-			Action<DownloadDataCompletedEventArgs> onInfoComplete = i =>
+			Task.Run(async () =>
 			{
-				if (i.Error != null)
+				var client = HttpClientFactory.Create();
+
+				// Limit each query to 50 maps at a time to avoid request size limits
+				for (var i = 0; i < queryUids.Count; i += 50)
 				{
-					Log.Write("debug", "Remote map query failed with error: {0}", Download.FormatErrorMessage(i.Error));
-					Log.Write("debug", "URL was: {0}", url);
-					foreach (var p in maps.Values)
-						p.UpdateRemoteSearch(MapStatus.Unavailable, null);
+					var batchUids = queryUids.Skip(i).Take(50).ToList();
+					var url = repositoryUrl + "hash/" + string.Join(",", batchUids) + "/yaml";
+					try
+					{
+						var httpResponseMessage = await client.GetAsync(url);
+						var result = await httpResponseMessage.Content.ReadAsStringAsync();
 
-					queryFailed?.Invoke();
+						var yaml = MiniYaml.FromString(result);
+						foreach (var kv in yaml)
+							previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, mapDetailsReceived);
 
-					return;
+						foreach (var uid in batchUids)
+						{
+							var p = previews[uid];
+							if (p.Status != MapStatus.DownloadAvailable)
+								p.UpdateRemoteSearch(MapStatus.Unavailable, null);
+						}
+					}
+					catch (Exception e)
+					{
+						Log.Write("debug", "Remote map query failed with error: {0}", e);
+						Log.Write("debug", "URL was: {0}", url);
+
+						foreach (var uid in batchUids)
+						{
+							var p = previews[uid];
+							p.UpdateRemoteSearch(MapStatus.Unavailable, null);
+							mapQueryFailed?.Invoke(p);
+						}
+					}
 				}
-
-				var data = Encoding.UTF8.GetString(i.Result);
-				try
-				{
-					var yaml = MiniYaml.FromString(data);
-					foreach (var kv in yaml)
-						maps[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, mapDetailsReceived);
-
-					foreach (var map in maps)
-						if (map.Value.Status != MapStatus.DownloadAvailable)
-							map.Value.UpdateRemoteSearch(MapStatus.Unavailable, null);
-				}
-				catch (Exception e)
-				{
-					Log.Write("debug", "Can't parse remote map search data:\n{0}", data);
-					Log.Write("debug", "Exception: {0}", e);
-					queryFailed?.Invoke();
-				}
-			};
-
-			new Download(url, _ => { }, onInfoComplete);
+			});
 		}
 
 		void LoadAsyncInternal()
@@ -334,10 +332,7 @@ namespace OpenRA
 			return initialUid;
 		}
 
-		public MapPreview this[string key]
-		{
-			get { return previews[key]; }
-		}
+		public MapPreview this[string key] => previews[key];
 
 		public IEnumerator<MapPreview> GetEnumerator()
 		{

OpenRA.Game/Map/MapCoordsRegion.cs

@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2021 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
@@ -14,7 +14,7 @@ using System.Collections.Generic;
 
 namespace OpenRA
 {
-	public struct MapCoordsRegion : IEnumerable<MPos>
+	public readonly struct MapCoordsRegion : IEnumerable<MPos>
 	{
 		public struct MapCoordsEnumerator : IEnumerator<MPos>
 		{
@@ -53,8 +53,8 @@ namespace OpenRA
 				current = new MPos(r.topLeft.U - 1, r.topLeft.V);
 			}
 
-			public MPos Current { get { return current; } }
-			object IEnumerator.Current { get { return Current; } }
+			public MPos Current => current;
+			object IEnumerator.Current => Current;
 			public void Dispose() { }
 		}
 
@@ -82,7 +82,7 @@ namespace OpenRA
 			return GetEnumerator();
 		}
 
-		public MPos TopLeft { get { return topLeft; } }
-		public MPos BottomRight { get { return bottomRight; } }
+		public MPos TopLeft => topLeft;
+		public MPos BottomRight => bottomRight;
 	}
 }