FillPolyTest
Test
Screen '
FillPoly' for speed and correctness.
Screen '
FillPoly' renders both convex and concave polygons, but treats
them differently; Convex polygons it renders quickly using GL_POLYGON.
Concave polygons it renders slowly using GLU tesselators.
FillPolyTest draws a "Butterfly" concave polygon to test if
FillPolly
correctly detects and renders concave polygons. If
FillPoly failed to
detect concavity, it would use GL_POLYGON, which renders concave polygons
incorrectly.
Psychtoolbox/PsychTests/FillPolyTest.m