This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles.

For more information about the manual page format, see the manual page for manpages(5).

GLUTESSBEGINPOLYGON(3G)                                                              GLUTESSBEGINPOLYGON(3G)



NAME
       gluTessBeginPolygon - delimit a polygon description


C SPECIFICATION
       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-inter-secting self-intersecting
       secting 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  automati-cally automatically
       cally  linked to the first). See the gluTessVertex, gluTessBeginContour, and gluTessEndContour refer-ence reference
       ence 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(3G),  gluTessBeginContour(3G),  gluTessVertex(3G),  gluTessCallback(3G),  gluTessProperty(3G),  gluTessNormal(3G),
       gluTessEndPolygon(3G)




                                                                                     GLUTESSBEGINPOLYGON(3G)