Add Halo 1 MCC custom map (version 13) support

.gitattributes

@@ -2,3 +2,6 @@
 # Windows checkout (core.autocrlf): a CRLF shebang line does not start.
 *.sh text eol=lf
 port/android/gradlew text eol=lf
+
+# Preserve the pinned upstream decoder byte-for-byte, including its whitespace.
+port/third_party/bcdec/bcdec.h -text -whitespace

.github/workflows/mcc.yml

@@ -0,0 +1,81 @@
+name: MCC map validation
+
+# Asset-free checks only. Real map files remain outside the repository and
+# require explicit MCC_TEST_MAP/HALO_CUSTOM_EDITION_MAPS locally.
+on:
+  push:
+    paths:
+      - "port/linux/game/**"
+      - "port/linux/src/**"
+      - "port/tools/**"
+      - "port/third_party/bcdec/**"
+      - "source/**"
+      - "tools/test_mcc_*.py"
+      - "tools/mcc_native_smoke.py"
+      - "tools/test_cache_file_formats.py"
+      - "tools/harness/**"
+      - ".github/workflows/mcc.yml"
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: mcc-validation-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  reader-and-validator:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install native test dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang lld gcc-multilib python3-pytest
+      - name: Check MCC parsing, validation, codecs and existing CE parsing
+        run: >-
+          python3 -m pytest -q
+          tools/test_mcc_cache_format.py
+          tools/test_mcc_tag_validation.py
+          tools/test_mcc_media.py
+          tools/test_mcc_resources.py
+          tools/test_mcc_bitmap_flags.py
+          tools/test_mcc_shader_channels.py
+          tools/test_mcc_hud.py
+          tools/test_mcc_vorbis.py
+          tools/test_mcc_texture_bridge.py
+          tools/test_mcc_maps.py
+          tools/test_mcc_menu.py
+          tools/test_mcc_pause.py
+          tools/test_mcc_pause_runtime.py
+          tools/test_mcc_ui.py
+          tools/test_mcc_ui_teams.py
+          tools/test_mcc_ui_network.py
+          tools/test_mcc_lifecycle.py
+          tools/test_mcc_native_smoke.py
+          tools/test_mcc_recordings.py
+          tools/test_mcc_saved_games.py
+          tools/test_mcc_network.py
+          tools/test_mcc_checkpoint.py
+          tools/test_mcc_grenades.py
+          tools/test_cache_file_formats.py
+
+  windows-adapters:
+    runs-on: windows-2025
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Python test runner
+        run: python -m pip install pytest
+      - name: Check native x86 MCC adapters and legacy isolation
+        shell: cmd
+        run: |
+          for /f "usebackq tokens=*" %%i in (`"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" -latest -products * -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -property installationPath`) do set "MCC_VS_INSTALL=%%i"
+          if not defined MCC_VS_INSTALL exit /b 1
+          call "%MCC_VS_INSTALL%\Common7\Tools\VsDevCmd.bat" -host_arch=x64 -arch=x86
+          if errorlevel 1 exit /b 1
+          clang --version
+          python -m pytest -q tools/test_mcc_recordings.py tools/test_mcc_native_smoke.py tools/test_mcc_cache_format.py tools/test_mcc_tag_validation.py tools/test_mcc_media.py tools/test_mcc_resources.py tools/test_mcc_bitmap_flags.py tools/test_mcc_shader_channels.py tools/test_mcc_hud.py tools/test_mcc_vorbis.py tools/test_mcc_texture_bridge.py tools/test_mcc_geometry.py tools/test_mcc_scripts.py tools/test_mcc_campaign.py tools/test_mcc_parameters.py tools/test_mcc_syntax.py tools/test_mcc_maps.py tools/test_mcc_menu.py tools/test_mcc_pause.py tools/test_mcc_pause_runtime.py tools/test_mcc_ui.py tools/test_mcc_ui_network.py tools/test_mcc_ui_teams.py tools/test_mcc_lifecycle.py tools/test_mcc_saved_games.py tools/test_mcc_network.py tools/test_mcc_checkpoint.py tools/test_mcc_grenades.py tools/test_cache_file_formats.py

.gitignore

@@ -30,3 +30,6 @@ original/
 
 # CI build outputs (tools/ci_build.py)
 dist/
+
+# User-supplied Halo 1 MCC maps and resources
+mcc_maps/

README.md

@@ -48,6 +48,13 @@ so players of the two versions can play together.
 2. At the first start, the game asks for the disc image. Select it.
 3. The game extracts the `maps/` folder. Then the game starts.
 
+Halo 1 MCC custom maps use a separate `mcc_maps/` directory and the
+**MCC SINGLEPLAYER** and **MCC MULTIPLAYER** map categories. The experimental
+adapter supports modern version-13 maps with embedded resources or matching
+MCC `sounds.map` and `bitmaps.map` files in `mcc_maps`. It does not use
+Custom Edition's resource files. See [MCC map support](docs/mcc_maps.md)
+for supported features, installation and compatibility limits.
+
 On Linux and Windows, the game puts `maps/` next to the executable. On
 Android, copy the disc image to the phone first. The app puts `maps/` in its
 data folder. Refer to [port/android/README.md](port/android/README.md).