[cairo] How to load a BMP/JPG/TGA to a Surface?

[Bill Spitzak]

Actually Cairo's image format is ARGB32, meaning each 32-bit word has 
the bits arranged so that A is the high-order 8 bits and B in the lowest 
8 bits. On a little-endian machine the bytes are then arranged in BGRA 
order, but on a big-endian machine they would be ARGB.

I think DevIL will need to be changed. ARGB32 is used extensively and is 
often the only or most-accelerated option on graphics hardware, due to 
it being the format used by the Windows API.

Adrian Lopez wrote:

> I load images into memory using DevIL [1] and copy them from memory onto 
> a Cairo image surface, translating from DevIL's IL_RGBA format to 
> Cairo's CAIRO_FORMAT_ARGB32 [2]. Cairo has no built-in support for most 
> image formats, so your only options are to use a third party library 
> like DevIL or write your own image loading routines.
> 
> [1] http://openil.sourceforge.net/
> [2] Something to look out for if you decide to do this: While the order 
> of pixel components in Cairo's image format is affected by endianness, 
> the order of components in DevIL is not. Thus, on x86 systems it turns 
> out that while DevIL's format looks like (R, G, B, A), Cairo's format 
> actually looks like (B, G, R, A).