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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" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glGetUniformIndices - 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="glGetUniformIndices"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetUniformIndices — retrieve the index of a named uniform block</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">glGetUniformIndices</b>(</code></td><td>GLuint  </td><td><var class="pdparam">program</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">uniformCount</var>, </td></tr><tr><td> </td><td>const GLchar ** </td><td><var class="pdparam">uniformNames</var>, </td></tr><tr><td> </td><td>GLuint * </td><td><var class="pdparam">uniformIndices</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>program</code></em></span></dt><dd><p>
                    Specifies the name of a program containing uniforms whose indices to query.
                </p></dd><dt><span class="term"><em class="parameter"><code>uniformCount</code></em></span></dt><dd><p>
                    Specifies the number of uniforms whose indices to query.
                </p></dd><dt><span class="term"><em class="parameter"><code>uniformNames</code></em></span></dt><dd><p>
                    Specifies the address of an array of pointers to buffers containing the names of the queried uniforms.
                </p></dd><dt><span class="term"><em class="parameter"><code>uniformIndices</code></em></span></dt><dd><p>
                    Specifies the address of an array that will receive the indices of the uniforms.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glGetUniformIndices</code> retrieves the indices of a number of uniforms within <em class="parameter"><code>program</code></em>.
        </p><p>
            <em class="parameter"><code>program</code></em> must be the name of a program object for which the command
            <a href="glLinkProgram.xml"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a> must have been called in the past, although it is not required that
            <a href="glLinkProgram.xml"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a> must have succeeded. The link could have failed because the number
            of active uniforms exceeded the limit.
        </p><p>
            <em class="parameter"><code>uniformCount</code></em> indicates both the number of elements in the array of names <em class="parameter"><code>uniformNames</code></em> and the
            number of indices that may be written to <em class="parameter"><code>uniformIndices</code></em>.
        </p><p>
            <em class="parameter"><code>uniformNames</code></em> contains a list of <em class="parameter"><code>uniformCount</code></em> name strings identifying the uniform names to be
            queried for indices. For each name string in <em class="parameter"><code>uniformNames</code></em>, the index assigned to the active uniform of that name will
            be written to the corresponding element of <em class="parameter"><code>uniformIndices</code></em>. If a string in <em class="parameter"><code>uniformNames</code></em> is not
            the name of an active uniform, the special value <code class="constant">GL_INVALID_INDEX</code> will be written to the corresponding element of
            <em class="parameter"><code>uniformIndices</code></em>.
        </p><p>
            If an error occurs, nothing is written to <em class="parameter"><code>uniformIndices</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_OPERATION</code> is generated if <em class="parameter"><code>program</code></em> is not the name of a program object for which
            <a href="glLinkProgram.xml"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a> has been called in the past.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            <code class="function">glGetUniformIndices</code> is available only if the GL version is 3.1 or greater.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a href="glGetActiveUniform.xml"><span class="citerefentry"><span class="refentrytitle">glGetActiveUniform</span></span></a>,
            <a href="glGetActiveUniformName.xml"><span class="citerefentry"><span class="refentrytitle">glGetActiveUniformName</span></span></a>,
            <a href="glLinkProgram.xml"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</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>© 2010 Khronos Group. 
            This material may be distributed subject to the terms and conditions set forth in 
            the Open Publication License, v 1.0, 8 June 1999.
            <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
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