[cairo] Frame Buffer and Special Pixel Formats

[Klaus Stehle]

Hallo Cairo,

There is a need to have a simple cairo frame buffer surface,
which can handle all that special pixel formats like
2-byte-RGB16_565, 3-byte-RGB24_888 etc. etc.
because a lot of graphic adapters require such odd formats.

Ok. There is the cairo-image-surface. But I read in the source
code things like this:

     cairoint.h:
     we do not plan on always guaranteeing that cairo will be able
     to draw to these formats.

     cairo-image-surface.c:
     We don't really want to advertise a cairo image surface that
     supports any possible format.


Now the question: What are the real reasons behind those
"we don't want" or "we do not plan" etc.?

The curious thing is that a lot of the programming work is already
done for these formats in the pixman library.

Cheers
Klaus