gluNextContour(3G)	       OpenGL Reference		    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.





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gluNextContour(3G)	       OpenGL Reference		    gluNextContour(3G)



     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     This command is obsolete and is provided for backwards compatibility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


























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