andy
bd417b3307
The build embeds assets/ and nothing reads the disk images any more. desktop.ini only labelled the images in Windows Explorer, so it goes too. skids extract --data <adfs> can still regenerate assets/ from a copy.
130 lines
5.2 KiB
Markdown
130 lines
5.2 KiB
Markdown
# Skids: a Super Skidmarks revival
|
||
|
||
A cross-platform (Windows, macOS, Linux) engine written in Rust that plays
|
||
*Super Skidmarks* (Acid Software, 1995) on the original Amiga data.
|
||
|
||
The game's data was converted from the original ADF disk images (disks 2–6
|
||
of the six-disk set) into editable files in [`assets/`](assets/README.md).
|
||
The images themselves are no longer kept in this repository.
|
||
|
||
- **Each track:** a 16-colour PNG (the PNG's palette is the track's
|
||
palette), plus a text file with the lap gates and height map.
|
||
- **Each car:** a PNG sprite sheet, plus a text file with its name and
|
||
handling.
|
||
|
||
Edit them with any image editor or text editor. The build embeds the
|
||
`assets/` folder, so the finished program is a single self-contained file.
|
||
|
||
The engine can still read the original disks directly: ADF images, the LHA
|
||
archives on them, and their CrunchMania-packed files.
|
||
`skids extract --data <adfs>` regenerates `assets/` from them.
|
||
|
||
Because the binary and `assets/` carry the original game data, anyone you
|
||
give either to also gets the game data.
|
||
|
||
## What works
|
||
|
||
- All 24 tracks across the four track files. Each has its isometric height
|
||
map and lap gates.
|
||
- All 8 vehicles (Mini, Beetle, Porsche, Formula 1, Midget, Truck, Police,
|
||
Cow), with 32 headings and 25 body-tilt frames for hills.
|
||
- 1 or 2 players (split screen) plus up to 7 computer drivers.
|
||
- Power-slide handling, slopes, car-to-car bumping, and skid marks burnt
|
||
into the track.
|
||
- Lap and position tracking, lap times, and a results table.
|
||
- Procedural engine, tyre and crash sound.
|
||
|
||
## What's reconstructed
|
||
|
||
Disk 1 of the six-disk set is missing from this archive. It held the
|
||
executable, palettes, sound and music. As a result:
|
||
|
||
- **Handling, AI and race rules** are new code written to feel like the
|
||
original, not a translation of the original 68000 code.
|
||
- **Colours** come from a reconstructed palette, built around how the
|
||
tracks use their 16 colour indices. If you have the real palettes, put
|
||
them in a `palettes/` folder next to the disks as `.pal` files (16 lines
|
||
of `RRGGBB`):
|
||
- `track1-3.pal` for one track
|
||
- `track1.pal` for all six tracks in a file
|
||
- `default.pal` for everything
|
||
- **Sound** is synthesised.
|
||
|
||
If you find disk 1, drop it in with the others. Anything it contains under
|
||
`track/` or `vehicles/` is picked up automatically. The format notes in
|
||
[docs/FORMATS.md](docs/FORMATS.md) cover everything reverse engineered so
|
||
far.
|
||
|
||
## Running
|
||
|
||
```sh
|
||
cargo run --release
|
||
```
|
||
|
||
The built executable (`target/release/skids`, or `skids.exe` on Windows)
|
||
runs on its own from anywhere.
|
||
|
||
`--data DIR` adds to or overrides the built-in data. `DIR` can be an
|
||
assets folder, which lets you try edits without rebuilding:
|
||
`skids --data assets`. It can also be the original ADF images or LHA
|
||
archives. Without `--data`, a folder like that in the current directory or
|
||
next to the executable is picked up automatically. When a track or car
|
||
exists both as an asset and on disk, the asset wins.
|
||
|
||
| Action | Player 1 | Player 2 |
|
||
|-------------|---------------------------------------|----------|
|
||
| Accelerate | ↑ (or W in one-player games) | W |
|
||
| Brake / reverse | ↓ (or S) | S |
|
||
| Steer | ← → (or A D) | A D |
|
||
| Pause | P | |
|
||
| Leave race | Esc | |
|
||
|
||
Options: `--scale 1|2|4` (window size), `--mute`.
|
||
|
||
### Tools
|
||
|
||
```sh
|
||
skids info --data DIR # list tracks and vehicles found
|
||
skids extract --data ADFS [--out assets] # convert original disks into editable assets
|
||
skids bench --data DIR --seconds 120 # race CPU cars on every track: laps and time on road
|
||
skids trace --data DIR --track 11 --out t.png # plot CPU racing lines
|
||
skids render --data DIR --track 3 --out shot.png # headless screenshot
|
||
```
|
||
|
||
## Building
|
||
|
||
You need a stable Rust toolchain.
|
||
|
||
- **Linux:** install the ALSA and X11 development packages, e.g.
|
||
`sudo apt install libasound2-dev libx11-dev libxkbcommon-dev`. To build
|
||
without sound (no ALSA needed), use
|
||
`cargo build --release --no-default-features --features embed`.
|
||
- **macOS / Windows:** `cargo build --release` works as is.
|
||
|
||
The build embeds `assets/`. To use a different folder, set
|
||
`SKIDS_ASSETS_DIR=/path/to/assets`. To build without embedding, so the game
|
||
needs `--data` at run time, use `--no-default-features --features audio`.
|
||
The ADF images aren't needed to build.
|
||
|
||
GitHub Actions builds all three platforms on every push
|
||
(`.github/workflows/build.yml`).
|
||
|
||
## Layout
|
||
|
||
```
|
||
assets/ the game data as editable PNG and text files
|
||
build.rs embeds assets/ into the executable
|
||
src/formats/ ADF (OFS/FFS), LHA and CrunchMania readers
|
||
src/data/ track, vehicle and palette decoding; locating the game files
|
||
src/game/ physics, AI and race rules
|
||
src/render/ software renderer at 320×256 (PAL low-res) and a bitmap font
|
||
src/audio.rs synthesised sound (cpal)
|
||
src/app.rs menus, race screens and results
|
||
```
|
||
|
||
## Credits
|
||
|
||
*Super Skidmarks* is by Acid Software. This project is an unofficial
|
||
revival for preservation. The CrunchMania bitstream layout follows Teemu
|
||
Suutari's [ancient](https://github.com/temisu/ancient) (BSD-2-Clause).
|