Make output layers take GraphicsBuffer
This has a series of advantages. For example:
- direct scanout will not be locked to wayland surfaces
- qtquick effects can potentially (depending on things such as used color space, buffer transform) skip intermediate blit and be presented directly on the screen
- provide more options how software output layers can be handled by giving the Compositor more control over swapchains
API-wise, it's a lot cleaner design as well, i.e. specify the buffer, the target rectangle, the source rectangle, and try to present that on the screen.
Edited by Vlad Zahorodnii