[cairo] 24-bits pixels in Cairo and libpixman

[Jordi Mas]

Hello,

Cairo and libpixman encode 24-bit pixels as 32-bits ones. See for
example _cairo_format_bpp in Cairo or pixman_format_create at libpixman.

Is there any special reason for this? I think that if you select 24-bit
pixels you will expect 3 bytes instead of 4.

Thanks,

Jordi,