1GLUTESSBEGINPOLYGON(3G)          OpenGL Manual         GLUTESSBEGINPOLYGON(3G)
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NAME

6       gluTessBeginPolygon - delimit a polygon description
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C SPECIFICATION

9       void gluTessBeginPolygon(GLUtesselator* tess, GLvoid* data);
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PARAMETERS

12       tess
13           Specifies the tessellation object (created with gluNewTess()).
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15       data
16           Specifies a pointer to user polygon data.
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DESCRIPTION

19       gluTessBeginPolygon and gluTessEndPolygon() delimit the definition of a
20       convex, concave or self-intersecting polygon. Within each
21       gluTessBeginPolygon/gluTessEndPolygon() pair, there must be one or more
22       calls to gluTessBeginContour()/gluTessEndContour(). Within each
23       contour, there are zero or more calls to gluTessVertex(). The vertices
24       specify a closed contour (the last vertex of each contour is
25       automatically linked to the first). See the gluTessVertex(),
26       gluTessBeginContour(), and gluTessEndContour() reference pages for more
27       details.
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29       data is a pointer to a user-defined data structure. If the appropriate
30       callback(s) are specified (see gluTessCallback()), then this pointer is
31       returned to the callback function(s). Thus, it is a convenient way to
32       store per-polygon information.
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34       Once gluTessEndPolygon() is called, the polygon is tessellated, and the
35       resulting triangles are described through callbacks. See
36       gluTessCallback() for descriptions of the callback functions.
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EXAMPLE

39       A quadrilateral with a triangular hole in it can be described as
40       follows:
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42           gluTessBeginPolygon(tobj, NULL);
43              gluTessBeginContour(tobj);
44                 gluTessVertex(tobj, v1, v1);
45                 gluTessVertex(tobj, v2, v2);
46                 gluTessVertex(tobj, v3, v3);
47                 gluTessVertex(tobj, v4, v4);
48              gluTessEndContour(tobj);
49              gluTessBeginContour(tobj);
50                 gluTessVertex(tobj, v5, v5);
51                 gluTessVertex(tobj, v6, v6);
52                 gluTessVertex(tobj, v7, v7);
53              gluTessEndContour(tobj);
54           gluTessEndPolygon(tobj);
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SEE ALSO

58       gluNewTess(), gluTessBeginContour(), gluTessCallback(),
59       gluTessEndPolygon(), gluTessNormal(), gluTessProperty(),
60       gluTessVertex()
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63       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
64       under the SGI Free Software B License. For details, see
65       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

68       opengl.org
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72opengl.org                        07/13/2018           GLUTESSBEGINPOLYGON(3G)
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