diff options
Diffstat (limited to 'Build/source/libs/gd/libgd-src/src/gd_gd.c')
-rw-r--r-- | Build/source/libs/gd/libgd-src/src/gd_gd.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/Build/source/libs/gd/libgd-src/src/gd_gd.c b/Build/source/libs/gd/libgd-src/src/gd_gd.c index 13defa09e42..a1e9ebf343b 100644 --- a/Build/source/libs/gd/libgd-src/src/gd_gd.c +++ b/Build/source/libs/gd/libgd-src/src/gd_gd.c @@ -1,3 +1,40 @@ +/** + * File: GD IO + * + * Read and write GD images. + * + * The GD image format is a proprietary image format of libgd. *It has to be* + * *regarded as being obsolete, and should only be used for development and* + * *testing purposes.* + * + * Structure of a GD image file: + * - file header + * - color header (either truecolor or palette) + * - image data + * + * All numbers are stored in big-endian format. + * + * File header structure: + * signature - 1 word ("\xFF\xFE" for truecolor, "\xFF\xFF" for palette) + * width - 1 word + * height - 1 word + * + * Truecolor image color header: + * truecolor - 1 byte (always "\001") + * transparent - 1 dword (ARGB color) + * + * Palette image color header: + * truecolor - 1 byte (always "\0") + * count - 1 word (the number of used palette colors) + * transparent - 1 dword (ARGB color) + * palette - 256 dwords (RGBA colors) + * + * Image data: + * Sequential pixel data; row-major from top to bottom, left to right: + * - 1 byte per pixel for palette images + * - 1 dword (ARGB) per pixel for truecolor images + */ + #ifdef HAVE_CONFIG_H #include "config.h" #endif |