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<STRONG>NAME</STRONG>
<STRONG>gluNextContour</STRONG> - mark the beginning of another contour
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>gluNextContour</STRONG>( GLUtesselator* <EM>tess</EM>,
GLenum <EM>type</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>tess</EM> Specifies the tessellation object (created with
<STRONG>gluNewTess</STRONG>).
<EM>type</EM> Specifies the type of the contour being defined. Valid
values are <STRONG>GLU_EXTERIOR</STRONG>, <STRONG>GLU_INTERIOR</STRONG>, <STRONG>GLU_UNKNOWN</STRONG>,
<STRONG>GLU_CCW</STRONG>, and <STRONG>GLU_CW</STRONG>.
<STRONG>DESCRIPTION</STRONG>
<STRONG>gluNextContour</STRONG> is used in describing polygons with multiple
contours. After the first contour has been described through
a series of <STRONG>gluTessVertex</STRONG> calls, a <STRONG>gluNextContour</STRONG> call
indicates that the previous contour is complete and that the
next contour is about to begin. Another series of
<STRONG>gluTessVertex</STRONG> calls is then used to describe the new
contour. This process can be repeated until all contours
have been described.
<EM>type</EM> defines what type of contour follows. The legal
contour types are as follows:
<STRONG>GLU_EXTERIOR</STRONG> An exterior contour defines an exterior
boundary of the polygon.
<STRONG>GLU_INTERIOR</STRONG> An interior contour defines an interior
boundary of the polygon (such as a hole).
<STRONG>GLU_UNKNOWN</STRONG> An unknown contour is analyzed by the
library to determine if it is interior or
exterior.
<STRONG>GLU_CCW</STRONG>,
<STRONG>GLU_CW</STRONG> The first <STRONG>GLU_CCW</STRONG> or <STRONG>GLU_CW</STRONG> 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 <STRONG>GLU_CCW</STRONG> or <STRONG>GLU_CW</STRONG>, then all
contours must be of the same type (if they are not, then all
<STRONG>GLU_CCW</STRONG> and <STRONG>GLU_CW</STRONG> contours will be changed to <STRONG>GLU_UNKNOWN</STRONG>).
Note that there is no real difference between the <STRONG>GLU_CCW</STRONG>
and <STRONG>GLU_CW</STRONG> contour types.
Before the first contour is described, <STRONG>gluNextContour</STRONG> can be
called to define the type of the first contour. If
<STRONG>gluNextContour</STRONG> is not called before the first contour, then
the first contour is marked <STRONG>GLU_EXTERIOR</STRONG>.
This command is obsolete and is provided for backward
compatibility only. Calls to <STRONG>gluNextContour</STRONG> are mapped to
<STRONG>gluTessEndContour</STRONG> followed by <STRONG>gluTessBeginContour</STRONG>.
<STRONG>EXAMPLE</STRONG>
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);
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>gluBeginPolygon</STRONG>, <STRONG>gluNewTess</STRONG>, <STRONG>gluTessCallback</STRONG>, <STRONG>gluTessVertex</STRONG>,
<STRONG>gluTessBeginContour</STRONG>
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