[cairo] Frame Buffer and Special Pixel Formats

[Owen Taylor]

On Mon, 2006-12-04 at 08:31 -0800, Carl Worth wrote:
> On Mon, 4 Dec 2006 09:58:48 +0100 (CET), Klaus Stehle wrote:
> > > My understanding is that we don't want to clutter the image-backend API.
> 
> It's not just a question of avoiding API clutter. I think a bigger
> issue is the desire to have an optimized software rendering
> implementation. With the very small number of image formats that cairo
> provides, (as well as the rich set of operators), there's already
> fairly large combinatorial explosion going on inside the rendering
> code.
> 
> So it doesn't make sense to add new image formats unless we're also
> committed to implementing as much optimization in the rendering for
> those as we plan to implement for all other image formats.

While this makes sense in general (for 24bpp formats, say), for things
that are actually common frame buffer formats like rgb565, it makes
less sense, since we are actually basically sharing the code used
in the X server... we already have optimized rgb565 code.

					- Owen