Duke Nukem II Palette Formats
There are two different palette formats used by Duke Nukem II.
16-Color Palette
| Format type | Palette |
|---|---|
| Hardware | VGA |
| Colour depth | 18-bit |
| Number of colours | 16 |
| Games |
The 16-color palette is the most common palette format. It can be found in:
- 16-color images
- individual palette files (*.PAL)
- the game's main executable (at offset 0x1B038 in the decompressed registered version executable)
The palette stores each entry's red, green and blue value (in that order) each as one byte value, resulting in a total size of 48 bytes. However, the color values are not standard 6-bit VGA values - they range from 0 to 68 inclusive! The following table lists all the palette values and the corresponding 8-bit values.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 36 | 40 | 44 | 48 | 52 | 56 |
| 16 | 60 | 60 | 65 | 69 | 73 | 77 | 81 | 85 | 89 | 93 | 97 | 101 | 105 | 109 | 113 | 117 |
| 32 | 121 | 121 | 125 | 130 | 134 | 138 | 142 | 146 | 150 | 154 | 158 | 162 | 166 | 170 | 174 | 178 |
| 48 | 182 | 182 | 186 | 190 | 195 | 199 | 203 | 207 | 211 | 215 | 219 | 223 | 227 | 231 | 235 | 239 |
| 64 | 243 | 243 | 247 | 251 | 255 |
It is possible to use palette values greater than 68, but that will result in color errors during fade-in and fade-out.
Despite the 0-68 range, the hardware palette can only store 64 different color values. To convert the palette values to standard 6-bit VGA values, you can use this formula:
val6 = Max(0, (val-1) - (val-1)/16)
A more efficient version might be:
IF val = 0 val6 = 0 ELSE val6 = val-1 val6 = val6 - val6/16 ENDIF
See VGA Palette for details on converting between 6-bit and 8-bit values.
256-Color Palette
| Format type | Palette |
|---|---|
| Hardware | VGA |
| Colour depth | 18-bit |
| Number of colours | 256 |
| Games |
"Real" VGA palettes are stored in:
- NUKEM2.F* (see Duke Nukem II Animation Format)
- LCR.MNI
These are 768-byte files in classic (6-bit) VGA Palette format.
Credits
This file format was reverse engineered by K1n9_Duk3. 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!)