gluTessVertex.3gl
Digital Equipment Corporation OpenGL man pages

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