[cairo] ARGB, BGRA, RGBA mess

[Bill Spitzak]

> So, using this system, how would you describe the memory layout of a
> 16bpp framebuffer that uses 5 bits for red, 6 for green and 5 for blue?
> Say on a graphics card that reads words as little-endian. (I'm not sure,
> but I think this is the most common arrangement for all PCs running in
> 16bpp.)

That is RGB565 or something like that. A symbol that implies that the 
memory is 16-bit words that have r,g,b encoded inside them. It is as 
different from RGB as HSV or YUV is and should be treated that way.

RGB implies that r,g,b are stored in entries of at least 8 bits each.