[Plib-users] Tessellation Example

[Peijing <est...@si...>]

Hi,
I'm new to plib and I need to create a rectangular polygon with a =
triangular hole like this:
_______
|           | =20
|__/\___|

but I do not know how to do this with plibs. I've got some examples from =
the opengl redbook and I'm looking for a plib equivalent of it.=20
Could someone enlighten me regarding how to go about doing this or any =
online references I can refer to?

The opengl code is such:
 GLUtesselator *tobj;
 =20
  GLdouble rect[4][3] =3D {50.0, 50.0, 0.0,
                          200.0, 50.0, 0.0,
                          200.0, 200.0, 0.0,
                          50.0, 200.0, 0.0};
   GLdouble tri[3][3] =3D {75.0, 75.0, 0.0,
                         125.0, 175.0, 0.0,
                         175.0, 75.0, 0.0};
 =20
   glClearColor(0.0, 0.0, 0.0, 0.0);

   startList =3D glGenLists(2);

   tobj =3D gluNewTess();
   gluTessCallback(tobj, GLU_TESS_VERTEX,=20
                   glVertex3dv);
   gluTessCallback(tobj, GLU_TESS_BEGIN,=20
                   beginCallback);
   gluTessCallback(tobj, GLU_TESS_END,=20
                   endCallback);
   gluTessCallback(tobj, GLU_TESS_ERROR,=20
                   errorCallback);

   /*  rectangle with triangular hole inside  */
   glNewList(startList, GL_COMPILE);
   glShadeModel(GL_FLAT);   =20
   gluTessBeginPolygon(tobj, NULL);
      gluTessBeginContour(tobj);
         gluTessVertex(tobj, rect[0], rect[0]);
         gluTessVertex(tobj, rect[1], rect[1]);
         gluTessVertex(tobj, rect[2], rect[2]);
         gluTessVertex(tobj, rect[3], rect[3]);
      gluTessEndContour(tobj);
      gluTessBeginContour(tobj);
         gluTessVertex(tobj, tri[0], tri[0]);
         gluTessVertex(tobj, tri[1], tri[1]);
         gluTessVertex(tobj, tri[2], tri[2]);
      gluTessEndContour(tobj);
   gluTessEndPolygon(tobj);
   glEndList();
   gluDeleteTess(tobj);

Any help is appreciated.=20

Thanks,
EL