gluNextContour()                                 gluNextContour()

NAME    [Toc]    [Back]

       gluNextContour - mark the beginning of another contour

SYNOPSIS    [Toc]    [Back]

       void gluNextContour(
               GLUtesselator* tess,
               GLenum type );

PARAMETERS    [Toc]    [Back]

       Specifies  the  tessellation object (created with gluNewTess()).
  Specifies the type of the contour being  defined.
       Valid  values are GLU_EXTERIOR, GLU_INTERIOR, GLU_UNKNOWN,
       GLU_CCW, and GLU_CW.

DESCRIPTION    [Toc]    [Back]

       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: An exterior contour defines  an
       exterior  boundary  of  the  polygon.  An interior contour
       defines an interior boundary of the  polygon  (such  as  a
       hole).   An  unknown contour is analyzed by the library to
       determine if  it  is  interior  or  exterior.   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.

       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       This command is obsolete and is provided for backward compatibility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    [Toc]    [Back]

       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    [Toc]    [Back]

       gluBeginPolygon(3),   gluNewTess(3),   gluTessCallback(3),
       gluTessVertex(3), gluTessBeginContour(3)



                                                 gluNextContour()