gluTessBeginPolygon

GLUTESSBEGINPOLYGON(3G)				      GLUTESSBEGINPOLYGON(3G)



NAME
       gluTessBeginPolygon - delimit a polygon description


C SPECIFICATION
       void gluTessBeginPolygon( GLUtesselator* tess,
				 GLvoid* data )


PARAMETERS
       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 fol-
       lows:

       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
       gluNewTess(3G),	    gluTessBeginContour(3G),	   gluTessVertex(3G),
       gluTessCallback(3G),	 gluTessProperty(3G),	   gluTessNormal(3G),
       gluTessEndPolygon(3G)



						      GLUTESSBEGINPOLYGON(3G)