Added color format documentation.

This commit is contained in:
Armin Novak 2016-10-06 10:21:00 +02:00
parent 376dc216e6
commit 0e2b5184c2

View File

@ -45,8 +45,24 @@
#define FREERDP_PIXEL_FORMAT_FLIP_MASKED(_format) (_format & 0x3FFFFFFF)
/** Design considerations
*
* The format naming scheme is based on byte position in memory.
* RGBA for example names a byte array with red on positon 0, green on 1 etc.
*
* To read and write the appropriate format from / to memory use ReadColor and
* WriteColor.
*
* The single pixel manipulation functions use an intermediate integer representation
* that must not be interpreted outside the functions as it is platform dependent.
*
* _VF denotes vertically flipped bitmaps.
* X for alpha channel denotes unused (but existing) alpha channel data.
*/
/* 32bpp formats */
#define PIXEL_FORMAT_A8R8G8B8_F(_flip) FREERDP_PIXEL_FORMAT(_flip, 32, FREERDP_PIXEL_FORMAT_TYPE_ARGB, 8, 8, 8, 8)
#define PIXEL_FORMAT_ARGB32 PIXEL_FORMAT_A8R8G8B8_F(0)
#define PIXEL_FORMAT_ARGB32_VF PIXEL_FORMAT_A8R8G8B8_F(1)