[cairo] Interfacing with gdk_rgb_draw_image

[Ashwin Bharambe]

Hi all,

I have just begun playing with cairo and I have two elementary
questions: cairo_set_target_image() allows specifying a
CAIRO_FORMAT_RGB24 or CAIRO_FORMAT_ARGB32. Both of these use a 32-bit
pixel value (the first one leaves the alpha bits unused). However,
gdk_rgb_draw_image() requires a 24-bit packed pixel representation.
Will I have to do the conversion manually? Or is there any way cairo
can render to a 24-bit packed pixel representation?

Also I assume that even if I use RGB24, the pixels for the cairo
current context will be calculated taking transparency into account,
just that no separate alpha channel values will be stored for later
use. Am I right on this?

Thanks,
Ashwin