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glunextcontour(3g) [osx man page]

GLUNEXTCONTOUR(3G)														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  exte-
			 rior  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  con-
       tours will be changed to GLU_UNKNOWN).

       Note that there is no real difference between the GLU_CCW and GLU_CW contour types.

       Before  the  first  contour  is	described, gluNextContour can be called 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       This command is obsolete and is provided for backward compatibility only.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

																GLUNEXTCONTOUR(3G)

Check Out this Related Man Page

GLUTESSENDPOLYGON(3G)													     GLUTESSENDPOLYGON(3G)

NAME

       gluTessEndPolygon - delimit a polygon description

C SPECIFICATION

       void gluTessEndPolygon( GLUtesselator* tess )

PARAMETERS

       tess  Specifies the tessellation object (created with gluNewTess).

DESCRIPTION

       gluTessBeginPolygon  and  gluTessEndPolygon  delimit  the  definition  of  a  convex,  concave  or  self-intersecting  polygon. Within each
       gluTessBeginPolygon/gluTessEndPolygon pair, there must be one or more calls to gluTessBeginContour/gluTessEndContour.  Within each contour,
       there  are  zero  or  more  calls to gluTessVertex. The vertices specify a closed contour (the last vertex of each contour is automatically
       linked to the first). See the gluTessVertex, gluTessBeginContour and gluTessEndContour reference pages for more details.

       Once gluTessEndPolygon is called, the  polygon  is  tessellated,  and  the  resulting  triangles  are  described  through  callbacks.   See
       gluTessCallback for descriptions of the callback functions.

EXAMPLE

       A quadrilateral with a triangular hole in it can be described like this:

       gluTessBeginPolygon(tobj, NULL);
	gluTessBeginContour(tobj);
	  gluTessVertex(tobj, v1, v1);
	  gluTessVertex(tobj, v2, v2);
	  gluTessVertex(tobj, v3, v3);
	  gluTessVertex(tobj, v4, v4);
	gluTessEndContour(tobj);
	gluTessBeginContour(tobj);
	  gluTessVertex(tobj, v5, v5);
	  gluTessVertex(tobj, v6, v6);
	  gluTessVertex(tobj, v7, v7);
	gluTessEndContour(tobj); gluTessEndPolygon(tobj);
       In  the above example the pointers, v1 through v7, should point to different addresses, since the values stored at these addresses will not
       be read by the tesselator until gluTessEndPolygon is called.

SEE ALSO

       gluNewTess(3G),	  gluTessBeginContour(3G),     gluTessVertex(3G),     gluTessCallback(3G),     gluTessProperty(3G),	gluTessNormal(3G),
       gluTessBeginPolygon(3G)

															     GLUTESSENDPOLYGON(3G)
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