<!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" /><title>glEdgeFlag</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glEdgeFlag"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glEdgeFlag — flag edges as either boundary or nonboundary</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glEdgeFlag</b>(</code></td><td>GLboolean  </td><td><var class="pdparam">flag</var><code>)</code>;</td></tr></table></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>flag</code></em></span></dt><dd><p>
                    Specifies the current edge flag value,
                    either <code class="constant">GL_TRUE</code> or <code class="constant">GL_FALSE</code>. The initial value is <code class="constant">GL_TRUE</code>.
                </p></dd></dl></div></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glEdgeFlagv</b>(</code></td><td>const GLboolean *  </td><td><var class="pdparam">flag</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters2"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>flag</code></em></span></dt><dd><p>
                    Specifies a pointer to an array that contains a single boolean element,
                    which replaces the current edge flag value.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            Each vertex of a polygon,
            separate triangle,
            or separate quadrilateral specified between a <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>/<a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a> pair
            is marked as the start of either a boundary or nonboundary edge.
            If the current edge flag is true when the vertex is specified,
            the vertex is marked as the start of a boundary edge.
            Otherwise, the vertex is marked as the start of a nonboundary edge.
            <code class="function">glEdgeFlag</code> sets the edge flag bit to <code class="constant">GL_TRUE</code> if <em class="parameter"><code>flag</code></em> is <code class="constant">GL_TRUE</code>
            and to <code class="constant">GL_FALSE</code> otherwise.
        </p><p>
            The vertices of connected triangles and connected quadrilaterals are always
            marked as boundary,
            regardless of the value of the edge flag.
        </p><p>
            Boundary and nonboundary edge flags on vertices are significant only if
            <code class="constant">GL_POLYGON_MODE</code> is set to <code class="constant">GL_POINT</code> or <code class="constant">GL_LINE</code>.
            See <a class="citerefentry" href="glPolygonMode.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonMode</span></span></a>.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            The current edge flag can be updated at any time.
            In particular,
            <code class="function">glEdgeFlag</code> can be called between a call to <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding
            call to <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
            <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_EDGE_FLAG</code>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>,
            <code class="function">glEdgeFlagPointer</code>,
            <a class="citerefentry" href="glPolygonMode.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonMode</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 class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>
