xenocara/doc/gl-docs/GLU/tessendpolygon.3gl
2006-11-29 17:01:51 +00:00

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'\" e
'\"! eqn | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 6 March 1997
.ds Re Release 1.2.0
.ds Dp May 02 11:53
.ds Dm 37 tessendpo
.ds Xs 16616 4 tessendpolygon.gl
.TH GLUTESSENDPOLYGON 3G
.SH NAME
.B "gluTessEndPolygon
\- delimit a polygon description
.SH C SPECIFICATION
void \f3gluTessEndPolygon\fP(
GLUtesselator* \fItess\fP )
.nf
.fi
.EQ
delim $$
.EN
.SH PARAMETERS
.TP \w'\f2tess\fP\ \ 'u
\f2tess\fP
Specifies the tessellation object (created with \%\f3gluNewTess\fP).
.SH DESCRIPTION
\%\f3gluTessBeginPolygon\fP and \%\f3gluTessEndPolygon\fP delimit the definition of a
convex, concave or self-intersecting polygon. Within each \%\f3gluTessBeginPolygon\fP/\%\f3gluTessEndPolygon\fP
pair, there must be one or more calls to \%\f3gluTessBeginContour\fP/\%\f3gluTessEndContour\fP.
Within each contour, there are zero or more calls to \%\f3gluTessVertex\fP. The vertices
specify a closed contour (the last vertex of each contour is automatically linked
to the first). See the \%\f3gluTessVertex\fP, \%\f3gluTessBeginContour\fP and
\%\f3gluTessEndContour\fP reference pages for more details.
.P
Once \%\f3gluTessEndPolygon\fP is called, the polygon is tessellated, and the
resulting triangles are described through callbacks.
See \%\f3gluTessCallback\fP for descriptions of the callback functions.
.SH EXAMPLE
A quadrilateral with a triangular hole in it can be described like this:
.sp
.Ex
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);
.Ee
.bp
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 \%\f3gluTessEndPolygon\fP is called.
.SH SEE ALSO
\%\f3gluNewTess(3G)\fP, \%\f3gluTessBeginContour(3G)\fP, \%\f3gluTessVertex(3G)\fP,
\%\f3gluTessCallback(3G)\fP,
\%\f3gluTessProperty(3G)\fP, \%\f3gluTessNormal(3G)\fP,
\%\f3gluTessBeginPolygon(3G)\fP