[Xcb] Transparent Blt?

[Matthew Allen]

I have some 32-bit bitmaps (RGBA) that I want to blt to the screen... currently they show up fine (I've got the component order right) but the alpha channel is being ignored. Is there a way of blt'ing them and having the alpha channel used to composite the bitmap onto the screen?

The current code is using xcb_put_image, either to do the whole bitmap, or slice it up into scanlines if I only want to blt part of the source bitmap (gee it would be nice to have a way of blting a sub-image in one go).

Or should I be fetching the pixels under the destination area from the server first, comp'ing them myself and THEN blt'ing the result? (Sounds slow/lame over TCP etc)

Regards
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Matthew Allen