gluNextContour - mark the beginning of another contour



C SPECIFICATION

       void gluNextContour( GLUtesselator* tess,
                            GLenum type )



PARAMETERS

       tess  Specifies  the  tessellation  object  (created  with
             gluNewTess).

       type  Specifies the type of  the  contour  being  defined.
             Valid   values   are   GLU_EXTERIOR,   GLU_INTERIOR,
             GLU_UNKNOWN, GLU_CCW, and GLU_CW.


DESCRIPTION

       gluNextContour is used in describing polygons with  multi-
       ple  contours.  After the first contour has been described
       through a series of gluTessVertex calls, a  gluNextContour
       call  indicates  that the previous contour is complete and
       that the next contour is about to begin.   Another  series
       of  gluTessVertex  calls  is then used to describe the new
       contour. This process can be repeated until  all  contours
       have been described.

       type defines what type of contour follows.  The legal con-
       tour types are as follows:

       GLU_EXTERIOR      An exterior contour defines an  exterior
                         boundary of the polygon.

       GLU_INTERIOR      An  interior contour defines an interior
                         boundary  of  the  polygon  (such  as  a
                         hole).

       GLU_UNKNOWN       An  unknown  contour  is analyzed by the
                         library to determine if it  is  interior
                         or exterior.

       GLU_CCW,

       GLU_CW            The  first  GLU_CCW  or  GLU_CW  contour
                         defined is considered  to  be  exterior.
                         All  other contours are considered to be
                         exterior if they  are  oriented  in  the
                         same  direction  (clockwise  or counter-
                         clockwise) as  the  first  contour,  and
                         interior if they are not.

       If one contour is of type GLU_CCW or GLU_CW, then all con-
       tours must be of the same type (if they are not, then  all


EXAMPLE

       A quadrilateral with  a  triangular  hole  in  it  can  be
       described as follows:

       gluBeginPolygon(tobj);
          gluTessVertex(tobj, v1, v1);
          gluTessVertex(tobj, v2, v2);
          gluTessVertex(tobj, v3, v3);
          gluTessVertex(tobj,   v4,   v4);   gluNextContour(tobj,
       GLU_INTERIOR);
          gluTessVertex(tobj, v5, v5);
          gluTessVertex(tobj, v6, v6);
          gluTessVertex(tobj, v7, v7); gluEndPolygon(tobj);


SEE ALSO

       gluBeginPolygon,       gluNewTess,        gluTessCallback,
       gluTessVertex, gluTessBeginContour




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