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+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
+<!-- saved from url=(0013)about:internet -->
+<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glFrontFace - OpenGL 4 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glFrontFace"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glFrontFace — define front- and back-facing polygons</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><p><code class="funcdef">void <b class="fsfunc">glFrontFace</b>(</code>GLenum <var class="pdparam">mode</var><code>)</code>;</p></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>mode</code></em></span></dt><dd><p>
+ Specifies the orientation of front-facing polygons.
+ <code class="constant">GL_CW</code> and <code class="constant">GL_CCW</code> are accepted.
+ The initial value is <code class="constant">GL_CCW</code>.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ In a scene composed entirely of opaque closed surfaces,
+ back-facing polygons are never visible.
+ Eliminating these invisible polygons has the obvious benefit
+ of speeding up the rendering of the image.
+ To enable and disable elimination of back-facing polygons, call <a href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a>
+ and <a href="glDisable.xml"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> with argument <code class="constant">GL_CULL_FACE</code>.
+ </p><p>
+ The projection of a polygon to window coordinates is said to have
+ clockwise winding if an imaginary object following the path
+ from its first vertex,
+ its second vertex,
+ and so on,
+ to its last vertex,
+ and finally back to its first vertex,
+ moves in a clockwise direction about the interior of the polygon.
+ The polygon's winding is said to be counterclockwise if the imaginary
+ object following the same path moves in a counterclockwise direction
+ about the interior of the polygon.
+ <code class="function">glFrontFace</code> specifies whether polygons with clockwise winding in window coordinates,
+ or counterclockwise winding in window coordinates,
+ are taken to be front-facing.
+ Passing <code class="constant">GL_CCW</code> to <em class="parameter"><code>mode</code></em> selects counterclockwise polygons as
+ front-facing;
+ <code class="constant">GL_CW</code> selects clockwise polygons as front-facing.
+ By default, counterclockwise polygons are taken to be front-facing.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
+ <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not an accepted value.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
+ <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_FRONT_FACE</code>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a href="glCullFace.xml"><span class="citerefentry"><span class="refentrytitle">glCullFace</span></span></a>,
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
+ Copyright <span class="trademark"></span>© 1991-2006
+ Silicon Graphics, Inc. This document is licensed under the SGI
+ Free Software B License. For details, see
+ <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
+ </p></div></div></body></html>
HCoop / clinton / guile-figl.git / blobdiff