Signature
Parameters
| Variables | Description |
|---|---|
| tess |
Specifies the tessellation object (created with
gluNewTess
).
|
| data |
Specifies a pointer to user polygon data.
|
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.
data
is a pointer to a user-defined data structure. If the appropriate callback(s)
are specified (see
gluTessCallback
), then this pointer is returned to the
callback function(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 functions.
Example
A quadrilateral with a triangular hole in it can be described as follows:
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);
See Also
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/
.
Sample Code References
The following code samples have been found which appear to reference the functions described here. Take care that the code may be old, broken or not even use PyOpenGL.
gluTessBeginPolygon