Draft: Improve fractional scaling handling of decorations
This MR
- snaps geometries, most importantly their sizes, to the pixel grid
- makes decoration geometry floating point, so that it can render to arbitrary pixel sizes
- fixes decoration rendering for arbitrary pixel sizes, so that there's no gaps between the window and the decoration anymore
For details, see the individual commits. This depends on kdecoration!66 and breeze!470
Draft because this doesn't handle Xwayland windows yet.
Edited by Xaver Hugl