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<?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>glGetClipPlane</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetClipPlane"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetClipPlane — return the coefficients of the specified clipping plane</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">glGetClipPlane</b>(</code></td><td>GLenum  </td><td><var class="pdparam">plane</var>, </td></tr><tr><td> </td><td>GLdouble *  </td><td><var class="pdparam">equation</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>plane</code></em></span></dt><dd><p>
                    Specifies a clipping plane.
                    The number of clipping planes depends on the implementation,
                    but at least six clipping planes are supported.
                    They are identified by symbolic names of the form <code class="constant">GL_CLIP_PLANE</code>
                    <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
                    where i ranges from 0 to the value of <code class="constant">GL_MAX_CLIP_PLANES</code> - 1.
                </p></dd><dt><span class="term"><em class="parameter"><code>equation</code></em></span></dt><dd><p>
                    Returns four double-precision values that are the coefficients of the plane equation of <em class="parameter"><code>plane</code></em> in eye coordinates.
                    The initial value is (0, 0, 0, 0).
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glGetClipPlane</code> returns in <em class="parameter"><code>equation</code></em> the four coefficients of the plane equation
            for <em class="parameter"><code>plane</code></em>.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            It is always the case that <code class="constant">GL_CLIP_PLANE</code>
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
            = <code class="constant">GL_CLIP_PLANE0</code> + 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>.
        </p><p>
            If an error is generated,
            no change is made to the contents of <em class="parameter"><code>equation</code></em>.
        </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>plane</code></em> is not an accepted value.
        </p><p>
            <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetClipPlane</code>
            is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
            and the corresponding execution of <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="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="glClipPlane.xml"><span class="citerefentry"><span class="refentrytitle">glClipPlane</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>
