This removes a whole lot of code from `pathfinder_path_utils`. Hopefully
the remaining code can go upstream.
These changes regress quality of stroke widths for cubic curves, because
they move fill-to-stroke conversion before cubic-to-quadratic
conversion. To fix that, we will need to recursively subdivide when
doing fill-to-stroke conversion.
enable early Z for SVG.
Additionally, this switches the B-quad patches for XCAA to be convex
hulls instead of bounding boxes, reducing fragment shader load.
This is a large speedup for the Ghostscript tiger demo: 5x or more.
Closes#33.
I'm not too happy with this, as I discovered a segfault in FreeType that doesn't give me confidence
in this as a solution for the long term. Additionally, this exposes the problems in the partitioner
with lack of winding fill rule, proper handling of self-intersections, and splitting of paths at
their extrema. (I believe these problems should be fairly straightforward to handle, but we just
don't handle them yet.)
Patrick Walton