When removing steiner points, there is the possibility that the test
point is also removed. In this case, it is no longer a member of the
linked list and will break the output.
The test for re-fracturing a broken polygon can also result in multiple
polygons, rather than only 0 or 1. Skipping the extra polygons will
result in a limited tesselation.
Fixes: lp:1812393
* https://bugs.launchpad.net/kicad/+bug/1812393
The fracture() call may result in zero polygons remaining, which will
cause failure in our tesselation routine, so we need to check whether
this is a valid POLYGON before re-tesselating.
Tesselation can fail for a number of reasons. When this happens, we set
the triangulationValid flag to false to prevent using the broken
triangulation. This will fall back to the slow OpenGL triangulation
when DrawPolygon is called.
Use TesselatePolygon() to draw polygons in Gerbview instead of GLU tesselation, much slower.
Add helper methods in GAL to know if the current GAL engine is Cairo, OpenGL or something else,
useful to optimize drawing code.
Commit 73c229714 was a bit of a sledgehammer for the associated problem
of degenerate points. This commit replaces that one by only performing
additional simplification of the zone polygons on those polygons that
fail our initial triangulation attempt.
Replaces Poly2Tri with updated code to process polygons faster and more
robustly. Notably, we can now handle overlapping holes in the polygons,
allowing us to cache the triangulation of complex boards
Seth Hillbrand
jean-pierre charras