[Cairo] Image functions

[Alexandre Pigolkine]

Hello,

I use cairo_show_surface function to display an in-memory bitmap 
on a Drawable. But I noticed that it sends coordinates of the current
position on the destination surface as src_x, src_y parameters
to the _cairo_surface_composite function. So IMHO the function is not
really suitable to copy complete bitmap to an arbitrary position on a
Drawable.

Is there a way to specify an origin on the source surface or shall I use
a different function ?

Alexandre Pigolkine