New unaligned-offscreen test failing in GTK 4.6.3 on Debian
While trying to update Debian's GTK 4 to 4.6.3, I encountered a test failure in the newly-added unaligned-offscreen test. This might be caused by a dependency not having been updated yet, or it might be a GTK issue.
Reference:
Cairo, X11:
GL, X11:
Enlarged to 8x with no interpolation to make the differences more obvious:
Reference:
Cairo, X11:
GL, X11:
What you can't see so easily from those is that the Cairo and GL renderings are actually 101px wide: the Cairo rendering has an additional column of transparent pixels on the right, and the GL rendering has 2 columns of transparent pixels.
It looks as though the reference rendering is actually more blurry than my Cairo rendering, so perhaps my Cairo rendering is (somehow) doing a better job of solving #3833 (closed) than the reference? But the extra column of transparent pixels seems like a bug.
However, my GL rendering is clearly misaligned: it looks as though it has been split into two, with the right half moved 1px to the left when compared with my Cairo rendering.
Some dependency versions:
- Debian unstable (rolling release) as of 2022-05-04
- Cairo 1.16.0
- Fontconfig 2.13.1
- Harfbuzz 2.7.4
- Pango 1.50.6, pango!608 (merged) applied as a patch
- Mesa 22.0.2 on Intel KBL GT2 (UHD Graphics 620),
iris
driver (but this test also failed in a qemu VM) - Cantarell font 0.303