gluTessBeginPolygon and
#gluTessEndPolygon delimit
the definition of a convex, concave or self-intersecting polygon. Within
each
gluTessBeginPolygon/
#gluTessEndPolygon pair,
there must be one or more calls to
#gluTessBeginContour/
#gluTessEndContour. Within
each contour, there are zero or more calls to
#gluTessVertex. The vertices
specify a closed contour (the last vertex of each contour is automatically
linked to the first). See the
#gluTessVertex,
#gluTessBeginContour, and
#gluTessEndContour reference pages for more details.
Optional, throws GLException if not available in profile
data is a reference to a user-defined data structure. If the
appropriate callback(s) are specified (see
#gluTessCallback), then this
reference is returned to the callback method(s). Thus, it is a convenient
way to store per-polygon information.
Once
#gluTessEndPolygon is
called, the polygon is tessellated, and the resulting triangles are
described through callbacks. See
#gluTessCallback for
descriptions of the callback methods.