gluTessVertex(3G)	       OpenGL Reference		     gluTessVertex(3G)



NAME
     gluTessVertex - specify a vertex on a polygon


C SPECIFICATION
     void gluTessVertex( GLUtesselator*	tess,
			 GLdouble *location,
			 GLvoid* data )


PARAMETERS
     tess      Specifies the tessellation object (created with gluNewTess).

     location  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
     gluTessBeginContour and gluTessEndContour.

     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_TESS_VERTEX or
     GLU_TESS_VERTEX_DATA callback after tessellation (see the gluTessCallback
     reference page).



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);




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gluTessVertex(3G)	       OpenGL Reference		     gluTessVertex(3G)



NOTES
     The pointers specified by	location and data are not dereferenced until
     gluTessEndPolygon is executed.  In	the above example v1 must point	to a
     different location	from v2, etc.


SEE ALSO
     gluTessBeginPolygon, gluNewTess, gluTessBeginContour, gluTessCallback,
     gluTessProperty, gluTessNormal, gluTessEndPolygon














































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