hkmoddandClaude Opus 5.5
7c19ec27ea
The texture cache dropped a texture once it had gone 1800 frames without being drawn, and checked every 600 frames: half a minute and ten seconds at 60 frames a second. At 360 frames a second it is five seconds, so looking away from part of a level for five seconds dropped its textures, and turning back converted and uploaded them again; the faster the display, the more often. On b30 at 357 frames a second, 105 textures were dropped in 38 seconds of play. The cache now sweeps every 10 seconds of time (SDL_GetTicks, which the Android guest and the web have too) and drops the textures not drawn since the sweep three sweeps before: 30 to 40 seconds after they were last drawn, which is what it did at 60 frames a second. The frame counter still orders the palette variants. Checked with a harness test (tools/harness/tests/test_texture_idle.py) that runs xgpu_texture_cache_begin_frame from the sources against a fake clock: a texture last drawn 1 or 25 seconds in is dropped 30 to 40 seconds later at 360 frames a second, and at 60 as before; on main the 360 cases fail (dropped after 5.7 and 6.7 seconds) and the 60 one passes. Four negative controls. Not measured: the time saved, which is small on an RTX 4080 (each upload took 1.6 ms or less) and larger where conversion and uploads cost more. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Halo: Combat Evolved for Linux, Windows, Android and the web
This project is a port of the Halo: Combat Evolved decompilation to Linux,
Windows, Android and web browsers. The decompilation is of the Xbox build 2342
(cachebeta.exe, SHA-256
4cc87b45f721270392a96f1674ed2b5cd4a7bb4355faeab4531d1cf1884d9520).
The port starts from the decompilation of bnunu/halo-1. That project is a fork of punpckhdq/halo.
Download
GitHub Actions builds the game for each commit. These links download the builds of the latest release:
| Platform | Release | Debug |
|---|---|---|
| Linux | halo-linux-release.zip | halo-linux-debug.zip |
| Windows | halo-windows-release.zip | halo-windows-debug.zip |
| Android | halo-android-release.zip | halo-android-debug.zip |
| Web | halocombatevolved.com (or halo-web-release.zip for your own server) | halo-web-debug.zip |
Use the release build to play. The debug build stops at the first failed assertion and writes it to the log. Use the debug build to find and report problems.
The game updates itself. At start-up it looks for a newer release, and asks if you want to install it. Refer to "Updates" in port/linux/README.md. The web site offers each new build when it is out.
Each build of the main branch that passes on all four platforms is a new
release, and the web site then plays it. The Releases
page keeps the last five releases. If the latest build has a problem, get
an older build from that page.
Game data
The port does not include the game data. Download an Xbox disc image
(.xiso or .iso) of Halo: Combat Evolved. All versions of the game
operate. The maps of the European (PAL) version were made for a slower
console. The port changes them to play as the North American (NTSC) maps do,
so players of the two versions can play together.
- Start the game.
- At the first start, the game asks for the disc image. Select it.
- The game extracts the
maps/folder. Then the game starts.
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. On
the web, the page copies maps/ out of the disc image into the browser's
storage for the site; nothing is uploaded. Refer to
port/web/README.md.
Platforms
Each platform has its own instructions:
| Platform | Instructions |
|---|---|
| Linux (32-bit x86 executable, OpenGL 4.5, SDL3) | port/linux/README.md |
| Windows (32-bit x86 executable, OpenGL 4.5, SDL3) | port/windows/README.md |
| Android (arm64 app, OpenGL ES 3, SDL3) | port/android/README.md |
| Web (WebAssembly, WebGL 2, SDL3; desktop Chrome, Edge and Firefox) | port/web/README.md |
The Linux README also gives the controls, the settings and the multiplayer functions. These are almost the same on all platforms.
Multiplayer
The game can play system link games on a local network and on the internet:
- A system link game can have up to 128 players on up to 128 machines.
- Linux, Windows and Android machines and browsers can play in the same game. On a local network, the native builds play system link; browsers play each other in rooms, over WebRTC (port/web/README.md).
- An invite link, or the server browser, lets a machine join a game on the internet, browsers too: a native build takes a browser's WebRTC (port/linux/README.md, "Browsers"). No server of this project is necessary.
- The netcode is new. Each machine moves its own player at once, and the host makes the decisions for the game. Refer to port/linux/NETCODE.md.
Build the game
You do not need the Xbox SDK. The port supplies the SDK declarations that the game uses. Refer to port/include/xdk.
To build the game:
- Install Python and ninja.
- Install the tools for your platform. Refer to the README for the platform.
- In the root folder of the repository, enter
python configure.py. - Enter
ninjawith the target for the platform:
| Target | Result |
|---|---|
ninja linux |
build/linux/halo |
ninja windows (on Windows) |
build/windows/halo.exe and SDL3.dll |
ninja android_apk |
port/android/app/build/outputs/apk/debug/app-debug.apk |
ninja web |
build/web/site/, the web site (python tools/web_serve.py serves it) |
If you enter ninja without a target, ninja builds the game for the
computer that you use.
tools/ci_build.py makes the same builds as GitHub Actions. For example,
enter python tools/ci_build.py linux release.
Build options
Give these options to configure.py:
| Option | Result |
|---|---|
| (none) | A debug build. A failed assertion stops the game. |
--release |
A release build. The game does not examine assertions, as in the retail game. |
--portable |
The Linux and Windows builds operate on all x86-64 processors. The Linux build also operates on older distributions and on SteamOS: refer to "Portable build" in port/linux/README.md. Use this option for builds that you give to other persons. |
--lto=thin, --lto=off |
Less link-time optimization. The link is faster. |
--pgo=off |
No profile-guided optimization. |
--pgo=train |
Records a new optimization profile. Refer to "Optimization profiles". |
--profile |
A profiling build. It records CPU times. Refer to "Profiling builds". |
--web-emcc PATH |
The Emscripten emcc for ninja web (else the one on the PATH, or ~/emsdk's). |
Without --portable, the Linux and Windows builds use all the instructions
of the processor that builds them (-march=native). Such a build does not
always start on a different computer.
Optimization profiles
The builds use profiles of the game to optimize the code:
pgo/halo_linux.profdatafor Linux and Android.pgo/halo_windows.profdatafor Windows.
The profiles need clang 22 or later. With an older clang, the builds do not use the profiles.
To record a new profile:
- Delete the profile.
- Enter
python configure.py --pgo=train. - Enter
ninja linuxorninja windows.
The build then plays the main menu and the first minute of each campaign
level. This procedure continues for approximately 15 minutes. The game
data must be in assets/.
Profiling builds
A profiling build records where the game spends its time.
- Enter
python configure.py --profile, then build as usual. - Start a recording. Enter
profile_recordin the console (or the telnet console), or setdebug.profile_record = trueinconfig.toml. To record each game of a session, also setdebug.profile_record_when = "game". - Stop the recording. Enter
profile_stop, load another map, or quit.
The game writes numbered .part<n>.json files under profiles/ in its data root
and logs their paths. Parts are retained after the recording stops. Logs go to
standard error; a Windows release build without standard error writes them to
halo.log next to halo.exe.
tools/net_report.py is a helper for developers. Enter
python tools/net_report.py <recording.part1.json> to read a recording
as tables. The command also writes <recording>.summary.txt, a short text
file.
| Command | Result |
|---|---|
profile_record [seconds] |
Starts a recording. With a number of seconds, the recording stops after that time. |
profile_stop |
Stops the recording. |
debug.profile_memory sets the memory of a recording in MB (default 256,
from 4 to 1024). A recording has no length limit:
the game writes a part each time the memory is full. Refer to "Settings" in
port/linux/README.md.
On Android, the files are in /sdcard/Android/data/com.halo.decomp/files/profiles/.
Enter adb pull to copy the recording parts to a computer.
A profiling build plays with normal builds. It does not use
--pgo=train.