andy
9d82d99c15
- LHA -lh5/-lh6/-lh7 decoding with CRC checks (disk 1 is mostly lh5) - Real track palettes and set names, read from each track file's header - Camaro, plus the caravan as a towable trailer (Caravans option) - Drivers' names, menu pictures and the original .set values per car - Original sound effects (IFF 8SVX) through a new sample mixer: engine pitched with revs, tyre screech, crashes, backfire, horn, start beeps - The original tune (OctaMED MMD1) through a new player; loudness tracks OpenMPT's render through the whole song. Music option in the menu - Title picture (IFF ILBM) at the top of the menu - skids unpack and skids music commands - Gate crossings now judged on each car's whole movement per frame, including collision knocks; stalled computer cars are put back on the line after 8 seconds The executable's game logic (handling, AI) is still not decoded.
137 lines
4.9 KiB
Markdown
137 lines
4.9 KiB
Markdown
# Game assets
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Everything the game uses is stored here as editable files. The build embeds
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this folder into the executable. To pick up changes:
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- **Rebuild:** `cargo run --release`.
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- **Or skip the rebuild:** run with `--data assets`. Files given with
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`--data` override the built-in copy.
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These files were converted from the original Amiga disks with
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`skids extract --data <folder with the ADFs>`. That conversion is lossless,
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and running it again overwrites your edits.
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## Tracks: `tracks/<name>/`
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### `track.png`
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The track picture: 1024 × 512, a 16-colour indexed (palette) image.
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- **Palette:** the PNG's palette is the track's palette. Change a palette
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entry to recolour every pixel that uses it.
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- **Road vs scenery:** colours 8–15 are road (full grip, full speed).
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Colours 0–7 are scenery (less grip, slower).
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- **Painting a new route:** paint it with the upper eight colours and
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update the gates to match.
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- **Saving:** keep the image indexed if your editor allows it. If it saves
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as full-colour RGB instead, each pixel is matched to the nearest default
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colour, which loses your palette.
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### `track.txt`
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Plain text; lines starting with `#` are comments.
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- **`gate x1 y1 x2 y2`:** lap gates in race order.
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- Gate 0 is the start/finish line, and the grid forms up behind it.
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- Cars must cross every gate, in order, to complete a lap. Computer
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drivers steer from one gate to the next.
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- Coordinates are on the isometric ground plane. To find where a point
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sits in the picture:
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`picture x = wx - wy + 512`, `picture y = (wx + wy) × 31/64 − 252`.
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- `skids trace --data assets --track N --out t.png` draws the gates
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(gate 0 in yellow) and the computer cars' paths over the picture.
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- **`height`:** 64 rows of 64 numbers giving ground height × 256. Each
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number covers a 16 × 8 pixel cell of the picture. Slopes push cars
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downhill and tilt the car sprites.
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- **`set`:** the name of the set of tracks this one belongs to, shown under
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the menu thumbnail.
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- **`start`, `flags`:** values from the original data that the game
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doesn't use.
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To add a track, make a new folder with both files. Tracks are listed in
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name order.
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## Vehicles: `vehicles/<id>.png` and `<id>.txt`
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### `<id>.png`
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A 2048 × 800 sprite sheet: 32 headings across by 25 tilts down, each cell
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64 × 32.
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- **Colours:** use only palette indices 0–3:
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- 0 transparent
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- 1 tyres / shadow
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- 2 trim
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- 3 bodywork
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The colours in the file are only a preview; each player's car is
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recoloured at run time.
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- **Headings:** column 12 faces right, and columns advance clockwise in
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11.25° steps.
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- **Tilts:** row = roll × 5 + pitch (each 0–4), so row 12 is the car on
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flat ground.
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### `<id>-menu.png` (optional)
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The car's 64 × 32 picture from the original select screen, in the same
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four colours as the sprite sheet.
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### `<id>.txt`
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The display name, driver and handling:
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| Setting | Meaning |
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|-----------|---------|
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| `name` | name shown in the menu |
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| `driver` | driver's name, shown next to it |
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| `trailer` | `yes` for something towed behind cars (the caravan) rather than driven |
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| `original`| the 16 values from the original `.set` file, kept for reference; the game doesn't use them yet |
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| `top` | top speed on tarmac |
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| `accel` | acceleration |
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| `brake` | braking |
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| `grip` | sideways grip; higher means less sliding |
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| `turn` | steering rate |
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| `mass` | weight in collisions |
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| `offroad` | speed and grip multiplier on scenery |
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The handling values are a reconstruction, so tune them freely. To add a
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car, add a new `<id>.png` / `<id>.txt` pair.
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## Sounds: `sounds/*.wav`
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8-bit mono WAV files at the original Amiga sample rates. A loop point,
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stored in the WAV's `smpl` chunk, makes a sound repeat from there; most
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sample editors keep it. The game uses these names:
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| Sound | Use |
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|-------|-----|
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| `motor3` | engine, pitched up and down with revs (falls back to `motor`, then `engine`) |
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| `screech2` | tyres sliding (falls back to `screech3`, then `screech`) |
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| `crash1`, `crash2`, `crash3` | collisions, picked at random |
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| `backfire` | lifting off at high revs |
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| `horn` | Right Shift (player 1) or Left Shift (player 2) |
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| `beep`, `beep2` | countdown, then lights out |
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Missing sounds fall back to synthesised ones. Any other WAV files are kept
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but not used.
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## Music: `music/*.med`
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The tune, an OctaMED module. Edit it in a tracker that reads MED files,
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such as OpenMPT. The game's player supports plain sample instruments (no
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synth sounds) and the commands listed in `docs/FORMATS.md`. Preview it
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with `skids music --data assets --out tune.wav`. If there are several
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files, the first in name order plays.
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## Pictures: `gfx/*.png`
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Indexed PNGs. `skidtoon.png` is the title picture at the top of the menu,
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shown at half size. The others aren't used.
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## Palettes: `palettes/*.pal` (optional)
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16 lines of `RRGGBB`. Each file overrides the PNG palettes:
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- `track1-3.pal`: one track
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- `track1.pal`: every TRACK1 track
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- `default.pal`: all tracks
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