1991-2006
Silicon Graphics, Inc.
gluTessEndPolygon
3G
gluTessEndPolygon
delimit a polygon description
C Specification
void gluTessEndPolygon
GLUtesselator* tess
Parameters
tess
Specifies the tessellation object (created with gluNewTess).
Description
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.
Once gluTessEndPolygon 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:
gluTessBeginPolygon(tobj, NULL);
gluTessBeginContour(tobj);
gluTessVertex(tobj, v1, v1);
gluTessVertex(tobj, v2, v2);
gluTessVertex(tobj, v3, v3);
gluTessVertex(tobj, v4, v4);
gluTessEndContour(tobj);
gluTessBeginContour(tobj);
gluTessVertex(tobj, v5, v5);
gluTessVertex(tobj, v6, v6);
gluTessVertex(tobj, v7, v7);
gluTessEndContour(tobj);
gluTessEndPolygon(tobj);
In the above example the pointers,
v1
through
v7,
should point to different
addresses,
since the values stored at these addresses will not be read by
the tesselator until gluTessEndPolygon is called.
See Also
gluNewTess,
gluTessBeginContour,
gluTessBeginPolygon,
gluTessCallback,
gluTessNormal,
gluTessProperty,
gluTessVertex
Copyright
Copyright 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.