117 lines
5.2 KiB
Markdown
117 lines
5.2 KiB
Markdown
# Dethrace
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[](https://github.com/dethrace-labs/dethrace/actions/workflows/workflow.yml)
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[](https://twitter.com/dethrace_labs)
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[](https://discord.gg/f5StsuP)
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Dethrace is an attempt to learn how the 1997 driving/mayhem game [Carmageddon](https://en.wikipedia.org/wiki/Carmageddon) works behind the scenes and rebuild it to run natively on modern systems.
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## Progress
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(Follow us on Discord or Twitter to get notified of updates!)
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#### Last updated March 2025
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- 94% of functions implemented
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- Latest screenshot:
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<img width="752" alt="Screenshot 2024-05-27 at 8 44 10 AM" src="https://github.com/dethrace-labs/dethrace/assets/1063652/10b3b579-1eb1-4242-8b56-ff062cfff810">
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## Background
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Watcom debug symbols for an earlier internal build [were discovered](http://1amstudios.com/2014/12/02/carma1-symbols-dumped) named `DETHRSC.SYM` on the [Carmageddon Splat Pack](http://carmageddon.wikia.com/wiki/Carmageddon_Splat_Pack) expansion CD release. The symbols unfortunately did not match any known released executable, meaning they were interesting but not immediately usable to reverse engineer the game.
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This is what it looked like from the Watcom debugger - the names of all the methods were present but the code location they were pointing to was junk:
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_CrayzKirk_ from the Carmageddon community picked it up and did a lot of painstaking work manually matching up many functions and data structures in the DOS executable to the debugging symbols.
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We are slowly replacing the original assembly code with equivalent C code, function by function.
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### Is "dethrace" a typo?
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No, well, I don't think so at least. The original files according to the symbol dump were stored in `c:\DETHRACE`, and the symbol file is called `DETHSRC.SYM`. Maybe they removed the "a" to be compatible with [8.3 filenames](https://en.wikipedia.org/wiki/8.3_filename)?
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## Game content
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Dethrace does not ship with any content. You'll need access to the data from the original game. If you don't have an original CD then you can [buy Carmageddon from GoG.com](https://www.gog.com/game/carmageddon_max_pack).
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`dethrace` also supports the various freeware demos:
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- [Original Carmageddon demo](https://rr2000.cwaboard.co.uk/R4/PC/carmdemo.zip)
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- [Splat Pack demo](https://rr2000.cwaboard.co.uk/R4/PC/splatdem.zip)
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- [Splat Pack Xmas demo](https://rr2000.cwaboard.co.uk/R4/PC/Splatpack_christmas_demo.zip)
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## Building
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### Dependencies
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Dethrace has a dependency on SDL2. The easiest way to install SDL is via your favorite package manager.
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OSX:
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```sh
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brew install SDL2
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```
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Linux:
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```sh
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apt-get install libsdl2-dev
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```
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Point Dethrace at the Carmageddon install directory:
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```sh
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export DETHRACE_ROOT_DIR=/path/to/carmageddon
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```
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### Clone
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Dethrace uses [git submodules](https://git-scm.com/book/en/v2/Git-Tools-Submodules), so we must pull them after the inital clone:
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```sh
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git clone https://github.com/dethrace-labs/dethrace
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cd dethrace
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git submodule update --init --recursive
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```
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Dethrace uses [cmake](https://cmake.org/) for generating build files.
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To generate the build files (generally only required once):
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```sh
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mkdir build
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cd build
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cmake ..
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```
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Once cmake has generated the build files for your platform, run the build. For example:
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```sh
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make
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```
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## Running the game
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Firstly, you need a copy of the [Carmageddon game content](https://github.com/dethrace-labs/dethrace?tab=readme-ov-file#game-content). Extract the zip file if necessary.
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Dethrace expects to be placed into the top level Carmageddon folder. You know you have the right folder when you see the original `CARMA.EXE` there. If you are on Windows, you must also place `SDL2.dll` in the same folder.
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<img width="638" alt="Screenshot 2024-09-20 at 12 25 05 PM" src="https://github.com/user-attachments/assets/fda77818-9007-44fa-9d8d-c311396fd435">
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### CD audio
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Dethrace supports the GOG cd audio convention. If there is a `MUSIC` folder in the Carmageddon folder containing files `Track02.ogg`, `Track03.ogg` etc, then Dethrace will use those files in place of the original CD audio functions.
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<img width="571" alt="Screenshot 2024-09-30 at 8 31 59 AM" src="https://github.com/user-attachments/assets/cec72203-9156-4c2a-a15a-328609e65c68">
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## Changelog
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[From the beginning until release](docs/CHANGELOG.md)
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## Credits
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- CrayzKirk (manually matching up functions and data structures in the executable to the debugging symbols)
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- The developer at Stainless Software who left an old debugging .SYM file on the Splat Pack CD ;)
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## Legal
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Dethrace is released to the Public Domain. The documentation and function provided by Dethrace may only be utilized with assets provided by ownership of Carmageddon.
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The source code in this repository is for non-commerical use only. If you use the source code you may not charge others for access to it or any derivative work thereof.
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Dethrace and any of its' maintainers are in no way associated with or endorsed by SCi, Stainless Software or THQ Nordic.
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