NAME fgluTessBeginPolygon - delimit a polygon description FORTRAN SPECIFICATION SUBROUTINE fgluTessBeginPolygon( CHARACTER*8 tess, CHARACTER*8 data ) PARAMETERS tess Specifies the tessellation object (created with fgluNewTess). data Specifies a pointer to user polygon data. DESCRIPTION fgluTessBeginPolygon and fgluTessEndPolygon delimit the definition of a convex, concave or self-intersecting polygon. Within each fgluTessBeginPolygon/fgluTessEndPolygon pair, there must be one or more calls to fgluTessBeginContour/fgluTessEndContour. Within each contour, there are zero or more calls to fgluTessVertex. The vertices specify a closed contour (the last vertex of each contour is automatically linked to the first). See the fgluTessVertex, fgluTessBeginContour, and fgluTessEndContour reference pages for more details. data is a pointer to a user-defined data structure. If the appropriate callback(s) are specified (see fgluTessCallback), then this pointer is returned to the callback function(s). Thus, it is a convenient way to store per-polygon information. Once fgluTessEndPolygon is called, the polygon is tessellated, and the resulting triangles are described through callbacks. See fgluTessCallback 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 fgluNewTess, fgluTessBeginContour, fgluTessVertex, fgluTessCallback, fgluTessProperty, fgluTessNormal, fgluTessEndPolygon