Index for Section 3

Alphabetical listing for G

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gluTessBeginPolygon()
NAME
  gluTessBeginPolygon - delimit a polygon description

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

Index for Section 3

Alphabetical listing for G

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