Updates the handling of perspective quads to calculate the correct,
degenerate-safe projected quad and then derive from that the proper
perspective quad.
In 2D, updated to determine if the optimized outset/inset procedure
is valid, and if not goes through a more robust procedure that is
based on line equation intersections. In particular, the degenerate
inset/outset approach is used when the quad has a zero-length edge,
if insetting/outsetting normally would create a self-intersecting shape,
or if near parallel edge angles would create numerical instabilities.
Performance testing by forcing all rectangle draws through the degenerate
code path suggests that it is about 10% slower than the optimal approach,
at least on my workstation...
Bug: skia:
Change-Id: I2973da8d97949eacebb09a1b27c334d62c1c948e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/194008
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
