gluNextContour(3G)

NAME
     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 multiple 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 contour 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 counterclockwise) as the first contour, and
                    interior if they are not.

                    If one contour is of type GLU_CCW or GLU_CW, then all
                    contours must be of the same type (if they are not, then
                    all GLU_CCW and GLU_CW contours will be changed to
                    GLU_UNKNOWN).

                    Note that there is no real difference between the GLU_CCW
                    and GLU_CW contour types.
     gluNextContour can be called before the first contour is described to
     define the type of the first contour.  If gluNextContour is not called
     before the first contour, then the first contour is marked GLU_EXTERIOR.

     This command is obsolete and is provided for backwards compatibility
     only. Calls to gluNextContour are mapped to gluTessEndContour followed by
     gluTessBeginContour.


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