Hi, There isn't really any guide. What I'd suggest is grepping the source code for "sRGB" and then adding support for your new PIXMAN_r8g8b8_sRGB format in all those places. Aside from adding the format to the header file, the main work would be implementing the accessor functions in pixman-access.c.
Thanks, Søren On Fri, Mar 5, 2021 at 11:00 AM Claude Heiland-Allen <[email protected]> wrote: > > Hi Søren, > > On 04/03/2021 19:55, Søren Sandmann wrote: > > You are right that pixman doesn't have support for sRGB formats > > without an alpha channel. It would make sense to add such support (and > > it should be straightforward to do so). > Is there a guide for this kind of work? For example a patch series > wherein a similar format was added? I could try to implement it, but > I'm not familiar with pixman code. > > You might consider biting the bullet and just use an alpha channel. > > Usually a8r8g8b8 images are faster to work with than r8g8b8 anyway > > since they are aligned at 32 bits and tend to have more optimized fast > > paths available for them. > That is something to think about longer term for my project, but for the > short term the only thing I'd need an alpha channel for would be this > sRGB gamma-correct downscaling. I'd rather spend my development time to > try to contribute sRGB-without-alpha to pixman as I'm sure others would > find it useful too. > > > Claude > -- > https://mathr.co.uk > > _______________________________________________ > Pixman mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/pixman _______________________________________________ Pixman mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/pixman
