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Text File  |  2002-10-03  |  5.9 KB  |  133 lines
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  4. ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn((((3333GGGG))))       OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee       ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn((((3333GGGG))))
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  8. NNNNAAAAMMMMEEEE
  9.      ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn - delimit a polygon description
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  12. FFFFOOOORRRRTTTTRRRRAAAANNNN SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      SUBROUTINE ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn( CHARACTER*8 _t_e_s_s,
  14.                                       CHARACTER*8 _d_a_t_a )
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  17. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  18.      _t_e_s_s  Specifies the tessellation object (created with ffffgggglllluuuuNNNNeeeewwwwTTTTeeeessssssss).
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  20.      _d_a_t_a  Specifies a pointer to user polygon data.
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  22. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  23.      ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn and ffffgggglllluuuuTTTTeeeessssssssEEEEnnnnddddPPPPoooollllyyyyggggoooonnnn delimit the definition of a
  24.      convex, concave or self-intersecting polygon. Within each
  25.      ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn/ffffgggglllluuuuTTTTeeeessssssssEEEEnnnnddddPPPPoooollllyyyyggggoooonnnn pair, there must be one or more
  26.      calls to ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnCCCCoooonnnnttttoooouuuurrrr/ffffgggglllluuuuTTTTeeeessssssssEEEEnnnnddddCCCCoooonnnnttttoooouuuurrrr. Within each contour,
  27.      there are zero or more calls to ffffgggglllluuuuTTTTeeeessssssssVVVVeeeerrrrtttteeeexxxx. The vertices specify a
  28.      closed contour (the last vertex of each contour is automatically linked
  29.      to the first). See the ffffgggglllluuuuTTTTeeeessssssssVVVVeeeerrrrtttteeeexxxx, ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnCCCCoooonnnnttttoooouuuurrrr, and
  30.      ffffgggglllluuuuTTTTeeeessssssssEEEEnnnnddddCCCCoooonnnnttttoooouuuurrrr reference pages for more details.
  31.  
  32.      _d_a_t_a is a pointer to a user-defined data structure. If the appropriate
  33.      callback(s) are specified (see ffffgggglllluuuuTTTTeeeessssssssCCCCaaaallllllllbbbbaaaacccckkkk), then this pointer is
  34.      returned to the callback function(s). Thus, it is a convenient way to
  35.      store per-polygon information.
  36.  
  37.      Once ffffgggglllluuuuTTTTeeeessssssssEEEEnnnnddddPPPPoooollllyyyyggggoooonnnn is called, the polygon is tessellated, and the
  38.      resulting triangles are described through callbacks.  See
  39.      ffffgggglllluuuuTTTTeeeessssssssCCCCaaaallllllllbbbbaaaacccckkkk for descriptions of the callback functions.
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  41. EEEEXXXXAAAAMMMMPPPPLLLLEEEE
  42.      A quadrilateral with a triangular hole in it can be described as follows:
  43.  
  44.  
  45.           gluTessBeginPolygon(tobj, NULL);
  46.            gluTessBeginContour(tobj);
  47.              gluTessVertex(tobj, v1, v1);
  48.              gluTessVertex(tobj, v2, v2);
  49.              gluTessVertex(tobj, v3, v3);
  50.              gluTessVertex(tobj, v4, v4);
  51.            gluTessEndContour(tobj);
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn((((3333GGGG))))       OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee       ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnPPPPoooollllyyyyggggoooonnnn((((3333GGGG))))
  71.  
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  74.            gluTessBeginContour(tobj);
  75.              gluTessVertex(tobj, v5, v5);
  76.              gluTessVertex(tobj, v6, v6);
  77.              gluTessVertex(tobj, v7, v7);
  78.            gluTessEndContour(tobj);
  79.           gluTessEndPolygon(tobj);
  80.  
  81.  
  82.  
  83. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  84.      ffffgggglllluuuuNNNNeeeewwwwTTTTeeeessssssss, ffffgggglllluuuuTTTTeeeessssssssBBBBeeeeggggiiiinnnnCCCCoooonnnnttttoooouuuurrrr, ffffgggglllluuuuTTTTeeeessssssssVVVVeeeerrrrtttteeeexxxx, ffffgggglllluuuuTTTTeeeessssssssCCCCaaaallllllllbbbbaaaacccckkkk,
  85.      ffffgggglllluuuuTTTTeeeessssssssPPPPrrrrooooppppeeeerrrrttttyyyy, ffffgggglllluuuuTTTTeeeessssssssNNNNoooorrrrmmmmaaaallll, ffffgggglllluuuuTTTTeeeessssssssEEEEnnnnddddPPPPoooollllyyyyggggoooonnnn
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  129.                                                                         PPPPaaaaggggeeee 2222
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