'\"! eqn | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 6 March 1997
.ds Re Release 1.2.0
.ds Dp Mar 17 18:18
.ds Dm  Mar  6 19:5
.ds Xs 34325 4 beginpolygon.gl
.TH GLUBEGINPOLYGON
.SH NAME
.B "gluBeginPolygon, gluEndPolygon
\- delimit a polygon description

.SH C SPECIFICATION
void \f3gluBeginPolygon\fP(
GLUtesselator* \fItess\fP )
.nf
.fi

void \f3gluEndPolygon\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
\f3gluBeginPolygon\fP and \f3gluEndPolygon\fP delimit the definition of a
nonconvex polygon.
To define such a polygon, first call \f3gluBeginPolygon\fP.
Then define the contours of the polygon
by calling 
\f3gluTessVertex\fP for each vertex
and \f3gluNextContour\fP to start each new contour.
Finally, call \f3gluEndPolygon\fP
to signal the end of the definition.
See the \f3gluTessVertex\fP and 
\f3gluNextContour\fP reference pages for more details.
.P
Once \f3gluEndPolygon\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 NOTES
This command is obsolete and is provided for backward compatibility
only. Calls to \f3gluBeginPolygon\fP are mapped to 
\f3gluTessBeginPolygon\fP
followed by 
\f3gluTessBeginContour\fP. Calls to \f3gluEndPolygon\fP are mapped
to \f3gluTessEndContour\fP followed by \f3gluTessEndPolygon\fP.
.SH EXAMPLE
A quadrilateral with a triangular hole in it can be described like this:
.sp
.Ex
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);
.Ee
.SH SEE ALSO
\f3gluNewTess\fP, \f3gluNextContour\fP, \f3gluTessCallback\fP, \f3gluTessVertex\fP,
\f3gluTessBeginPolygon\fP, \f3gluTessBeginContour\fP