RAW is an image format introduced with the Dark Forces Remaster. It is the format for high resolution textures. RAW textures are true colour; they do not reference the original palettes.
RAW textures will be loaded in place of a classic texture if they have the same name (eg. hello.BM, hello.RAW). They must be exactly double the dimensions of the BM they are replacing. For example, a 64x128 BM must be replaced by a 128x256 RAW.
File format
RAW files are headerless and uncompressed. Image width and height are obtained from the corresponding BM.
A RAW contains nothing more than an array of pixels. The number of pixels will be BM width x BM height x 4. Pixels are arranged by rows (note this is different from BMs where pixels are arranged in columns).
Each pixel is a 4 byte struct:
Pixel {
Red
Blue
Green
Alpha
}
Each value can be between 0 and 0xFF.
The way the Alpha channel is handled by the game is as follows:
0 |
The pixel will be transparent on an adjoining-mid texture, otherwise it will be full-bright. |
Any value from 0x1 to 0xFE |
The pixel will be full-bright (fully lit in all light levels and produce bloom) |
0xFF |
An ordinary pixel. |
Multiple images
Where a RAW is replacing a multi BM (most commonly, a switch), each subsequent image simply follows immediately after the previous one.