DESCRIPTION
gluBeginPolygon and
gluEndPolygon delimit the definition of a nonconvex polygon. To define such a polygon, first call
gluBeginPolygon. Then define the contours of the polygon by calling
gluTessVertex for each vertex and
gluNextContour to start each new contour. Finally, call
gluEndPolygon to signal the end of the definition. See the
gluTessVertex and
gluNextContour reference pages for more details.
Once gluEndPolygon is called, the polygon is tessellated, and the resulting triangles are described through callbacks. See gluTessCallback for descriptions of the callback functions.
EXAMPLE
A quadrilateral with a triangular hole in it can be described like this:
gluBeginPolygon(tobj);
gluTessVertex(tobj, v1, v1);
gluTessVertex(tobj, v2, v2);
gluTessVertex(tobj, v3, v3);
gluTessVertex(tobj, v4, v4); gluNextContour(tobj, GLU_INTERIOR);
gluTessVertex(tobj, v5, v5);
gluTessVertex(tobj, v6, v6);
gluTessVertex(tobj, v7, v7); gluEndPolygon(tobj);