Fixes https://gitlab.com/kicad/code/kicad/-/issues/8522
Conservative makes SMAA usable in Eeschema through weaker AA.
Aggressive reduces some artifacts compared to the High preset.
Restores the unused Ultra preset in the shader source to its original state.
Avoid fractional pixel offsets by forcing integer division of m_screenSize.
Shift rounded lookAtPoint onto OpenGL pixel center to ensure consistent rounding to int.
The pixel 0..1 @ 1x needs to fill the area 0..2 @ 2x so its center moves by 0.5 * (pixel size @ 1x).
Both Cairo and OpenGL had issues (different, though) with circles that are
thicker in line width than they have radius. This corrects the OpenGL
implementation (radius is calculated to the outer edge) as well as Cairo
(line width needs to be clamped to twice the radius)
Fixes: lp:1822765
* https://bugs.launchpad.net/kicad/+bug/1822765
And filled but we don't use those yet. No pixel-alignment needed for
stroked semi-circles (I think) as we set the pixel width to be 1
regardless of the zoom level.
Fixes: lp:1816263
* https://bugs.launchpad.net/kicad/+bug/1816263
gal: pixel alignment for Cairo.
gal: pixel alignment for OpenGL
Cleanup of pixel alignment patches
gal/opengl: more pixel alignment patches:
- works on Retina displays now
- pixel alignment for circles
- correct 1-pixel strokes
- fixed unfinished 1-pixel line ends
GAL: Restore antialiasing options in Cairo
GAL: Fix arc drawing
Removes DrawArcSegment, which drew arcs whose edge was optionally
stroked (a feature that we did not use). Fixes Cairo arc drawing issue
where arcs were not visible in pcbnew.
gal: further cleanup
gal: removed unused shader parameter
