Blame |
Last modification |
View Log
| RSS feed
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
"http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
<refentry id="gluTessEndPolygon">
<refmeta>
<refmetainfo>
<copyright>
<year>1991-2006</year>
<holder>Silicon Graphics, Inc.</holder>
</copyright>
</refmetainfo>
<refentrytitle>gluTessEndPolygon</refentrytitle>
<manvolnum>3G</manvolnum>
</refmeta>
<refnamediv>
<refname>gluTessEndPolygon</refname>
<refpurpose>delimit a polygon description</refpurpose>
</refnamediv>
<refsynopsisdiv><title>C Specification</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>gluTessEndPolygon</function></funcdef>
<paramdef>GLUtesselator* <parameter>tess</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<!-- eqn: ignoring delim $$ -->
<refsect1 id="parameters"><title>Parameters</title>
<variablelist>
<varlistentry>
<term><parameter>tess</parameter></term>
<listitem>
<para>
Specifies the tessellation object (created with <citerefentry><refentrytitle>gluNewTess</refentrytitle></citerefentry>).
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id="description"><title>Description</title>
<para>
<citerefentry><refentrytitle>gluTessBeginPolygon</refentrytitle></citerefentry> and <function>gluTessEndPolygon</function> delimit the
definition of a convex, concave, or self-intersecting polygon. Within
each <citerefentry><refentrytitle>gluTessBeginPolygon</refentrytitle></citerefentry>/<function>gluTessEndPolygon</function> pair, there must be
one or more calls to <citerefentry><refentrytitle>gluTessBeginContour</refentrytitle></citerefentry>/<citerefentry><refentrytitle>gluTessEndContour</refentrytitle></citerefentry>.
Within each contour, there are zero or more calls to <citerefentry><refentrytitle>gluTessVertex</refentrytitle></citerefentry>.
The vertices specify a closed contour (the last vertex of each contour
is automatically linked to the first). See the <citerefentry><refentrytitle>gluTessVertex</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>gluTessBeginContour</refentrytitle></citerefentry>, and <citerefentry><refentrytitle>gluTessEndContour</refentrytitle></citerefentry> reference pages for
more details.
</para>
<para>
Once <function>gluTessEndPolygon</function> is called, the polygon is tessellated, and the
resulting triangles are described through callbacks.
See <citerefentry><refentrytitle>gluTessCallback</refentrytitle></citerefentry> for descriptions of the callback functions.
</para>
</refsect1>
<refsect1 id="example"><title>Example</title>
<para>
A quadrilateral with a triangular hole in it can be described like this:
<programlisting>
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);
</programlisting>
In the above example the pointers,
<inlineequation><mml:math><mml:mi mathvariant="italic">v1</mml:mi></mml:math></inlineequation>
through
<inlineequation><mml:math><mml:mi mathvariant="italic">v7</mml:mi></mml:math></inlineequation>,
should point to different
addresses,
since the values stored at these addresses will not be read by
the tesselator until <function>gluTessEndPolygon</function> is called.
</para>
</refsect1>
<refsect1 id="seealso"><title>See Also</title>
<para>
<citerefentry><refentrytitle>gluNewTess</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>gluTessBeginContour</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>gluTessBeginPolygon</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>gluTessCallback</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>gluTessNormal</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>gluTessProperty</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>gluTessVertex</refentrytitle></citerefentry>
</para>
</refsect1>
<refsect1 id="Copyright"><title>Copyright</title>
<para>
Copyright <trademark class="copyright"></trademark> 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
<ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
</para>
</refsect1>
</refentry>