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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>glGetTexGen</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetTexGen"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetTexGen — return texture coordinate generation parameters</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">glGetTexGendv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">coord</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLdouble *  </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetTexGenfv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">coord</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat *  </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetTexGeniv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">coord</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint *  </td><td><var class="pdparam">params</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>coord</code></em></span></dt><dd><p>
                    Specifies a texture coordinate.
                    Must be
                    <code class="constant">GL_S</code>,
                    <code class="constant">GL_T</code>,
                    <code class="constant">GL_R</code>, or
                    <code class="constant">GL_Q</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
                    Specifies the symbolic name of the value(s) to be returned.
                    Must be either <code class="constant">GL_TEXTURE_GEN_MODE</code>
                    or the name of one of the texture generation plane equations:
                    <code class="constant">GL_OBJECT_PLANE</code> or <code class="constant">GL_EYE_PLANE</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
                    Returns the requested data.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glGetTexGen</code> returns in <em class="parameter"><code>params</code></em> selected parameters of a texture coordinate
            generation function that was specified using <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>.
            <em class="parameter"><code>coord</code></em> names one of the (<span class="emphasis"><em>s</em></span>, <span class="emphasis"><em>t</em></span>, <span class="emphasis"><em>r</em></span>, <span class="emphasis"><em>q</em></span>)
            texture coordinates,
            using the symbolic constant
            <code class="constant">GL_S</code>,
            <code class="constant">GL_T</code>,
            <code class="constant">GL_R</code>, or
            <code class="constant">GL_Q</code>.
        </p><p>
            <em class="parameter"><code>pname</code></em> specifies one of three symbolic names:
        </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_GEN_MODE</code></span></dt><dd><p>
                        <em class="parameter"><code>params</code></em> returns the single-valued texture generation function,
                        a symbolic constant. The initial value is <code class="constant">GL_EYE_LINEAR</code>.
                    </p></dd><dt><span class="term"><code class="constant">GL_OBJECT_PLANE</code></span></dt><dd><p>
                        <em class="parameter"><code>params</code></em> returns the four plane equation coefficients that specify
                        object linear-coordinate generation.
                        Integer values, when requested,
                        are mapped directly from the internal floating-point representation.
                    </p></dd><dt><span class="term"><code class="constant">GL_EYE_PLANE</code></span></dt><dd><p>
                        <em class="parameter"><code>params</code></em> returns the four plane equation coefficients that specify
                        eye linear-coordinate generation.
                        Integer values,
                        when requested,
                        are mapped directly from the internal floating-point representation.
                        The returned values are those maintained in eye coordinates.
                        They are not equal to the values specified using <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>,
                        unless the modelview matrix was identity when <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a> was called.
                    </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            If an error is generated,
            no change is made to the contents of <em class="parameter"><code>params</code></em>.
        </p><p>
            For OpenGL versions 1.3 and greater, or when the <code class="code">ARB_multitexture</code> extension is supported, <code class="function">glGetTexGen</code> returns
            the texture coordinate generation parameters for the active texture unit.
        </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>coord</code></em> or <em class="parameter"><code>pname</code></em> is not an
            accepted value.
        </p><p>
            <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetTexGen</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="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,
            <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</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>
