gluTessVertex.3gl (GLU versions 1.0 and 1.1)

Name

  gluTessVertex	- specify a vertex on a	polygon

C Specification

  void gluTessVertex( GLUtriangulatorObj *tobj,

		      GLdouble v[3],

		      void *data )

Parameters

  tobj	Specifies the tessellation object (created with	gluNewTess).



  v	Specifies the location of the vertex.



  data	Specifies an opaque pointer passed back	to the user with the vertex

	callback (as specified by gluTessCallback).

Description

  gluTessVertex	describes a vertex on a	polygon	that the user is defining.

  Successive gluTessVertex calls describe a closed contour.  For example, if

  the user wants to describe a quadrilateral, then gluTessVertex should	be

  called four times.  gluTessVertex can	only be	called between

  gluBeginPolygon and gluEndPolygon.



  data normally	points to a structure containing the vertex location, as well

  as other per-vertex attributes such as color and normal.  This pointer is

  passed back to the user through the GLU_VERTEX callback after	tessellation

  (see the gluTessCallback reference page).

Example

  A quadrilateral with a triangular hole in it can be described	as follows:



  gluBeginPolygon(tobj);

     gluTessVertex(tobj, v1, v1);

     gluTessVertex(tobj, v2, v2);

     gluTessVertex(tobj, v3, v3);

     gluTessVertex(tobj, v4, v4); 

  gluNextContour(tobj, GLU_INTERIOR);

     gluTessVertex(tobj, v5, v5);

     gluTessVertex(tobj, v6, v6);

     gluTessVertex(tobj, v7, v7); 

  gluEndPolygon(tobj);

See Also

  gluBeginPolygon, gluNewTess, gluNextContour, gluTessCallback