GLUTESSENDPOLYGON

Section: Misc. Reference Manual Pages (3G)
Index Return to Main Contents
 

NAME

gluTessEndPolygon - delimit a polygon description

 

C SPECIFICATION

void gluTessEndPolygon( GLUtesselator* tess ) 





delim $$

 

PARAMETERS





tess

Specifies the tessellation object (created with gluNewTess).


 

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.

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 like this:



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);


In the above example the pointers, $v1$ through $v7$, 
should point to different
addresses, 
since the values stored at these addresses will not be read by
the tesselator until gluTessEndPolygon is called.
 

SEE ALSO


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