Deathtrack Skyline Map Format
| Format type | Image |
|---|---|
| Hardware | EGA, CGA |
| Colour depth | 4-bit (EGA) |
| Minimum size (pixels) | 1920×25 |
| Maximum size (pixels) | 1920×25 |
| Palette | Shared |
| Plane count | 1 |
| Transparent pixels? | No |
| Hitmap pixels? | No |
| Games |
Despite the name, the ten .MAP files (one per city) are not road maps. Each file holds the horizon skyline that is drawn behind the road during a race. The road itself is described by the .TRK file of the same name.
The whole file is one compression envelope (method 2, LZW); there are no chunk headers.
File format
The decoded data is always 24,026 bytes.
| Data type | Name | Description |
|---|---|---|
| UINT16LE | count | Number of strips N (6) |
| UINT16LE[N] | widths | Strip width in bytes (160 = 320 pixels) |
| UINT16LE[N] | heights | Strip height in pixels (25) |
| BYTE[N][width × height] | strips | Packed 4-bpp pixels, high nibble first, 160 bytes per row; 4,000 bytes per strip |
The six strips are 320×25 each. Placed side by side they form a 1920×25 panorama; the renderer picks the strip from the camera heading (x / 320 mod 6), so the skyline wraps around.
In the original, the heights overwrite the width table in memory after loading (a harmless quirk).
Source code
From re-deathtrack, the open-source browser port:
src/viewer/decode.js–skyline()src/game/flow.js– loader (1000:1208)src/game/render3d.js– strip drawing (2f73:000f)docs/re/resources.md
Credits
This file format was reverse engineered by VorticonCmdr. If you find this information helpful in a project you're working on, please give credit where credit is due. (A link back to this wiki would be nice too!)