Hello,
I am currently playing with the tesselator and I appear to be getting results I do not expect.
If I place the following contours into the tesselator:
{ (1,1), (1,-1), (-1,-1), (-1,1) } // CW square
{ (2,2), (-2,2), (-2,-2), (2,-2) } // CCW square
{ (3,3), (-3,3), (-3,-3), (3,-3) } // CCW square
{ (4,4), (4,-4), (-4,-4), (-4,4) } // CW square
With a winding rule of GLU_TESS_WINDING_POSITIVE and the tesselator set for boundary only, I get back:
{ (-4,-4), (-4,4), (4,4), (4,-4) } // CW square
{ (-3,3), (-3,-3), (3,-3), (3,3) } // CCW square
Which is puzzling, as my understanding of the documentation leads me to believe I should get something similar to:
{ (1,1), (1,-1), (-1,-1), (-1,1) } // CW square
{ (2,2), (-2,2), (-2,-2), (2,-2) } // CCW square
I am unsure if this a problem with my reading of the documentation (most likely) or an issue with the tesselator.
Essentially, I am trying to get “negative†polygons to just disappear (except where the overlap a positive polygon) leaving the positive polygons (minus any bits of negative polygon).
Does anyone have any ideas what may be the issue?