From Dark Omen Wiki

Revision as of 16:20, 19 July 2008

Overall Structure

The overall structure of a sprite file looks a like this (in this order):

SPRITE FILE HEADER (32 bytes)
FRAME HEADERS x Number of frames (32 bytes each)
PALETTE ENTRIES x Number of colors in palette (4 bytes each)
FRAME DATA x Number of frames (size varies)

For a description of each part, see below.

File Header

The file header consists of the first 32 bytes of the file

struct SpriteFileHeader
{
    char ID[4];            // = 'WHDO'
    int  filesize;         // = the size of the file in bytes
    int  version?;         // = 32
    int  frameDataOffset   // = file offset to beginning of the frame data
    int  paletteDataOffset // = file offset to beginning of the palette data
    int  paletteEntryCount // = the total number of palette entries (*)
    int  paletteCount      // = how many unique palettes exist in this sprite
    int  frameCount        // = the number of frames of animation in this sprite   
}

(* This is the total number of colours stored in the file, each of which belongs only to one palette. e.g. there may be 300 colours stored in the file, spread throughout 5 different palettes; the paletteEntryCount is 300, the paletteCount is 5 )