<div class="refentry" lang="en" xml:lang="en"><a id="glBlendColor"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBlendColor — set the blend color</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table><tr><td><code class="funcdef">void <b class="fsfunc">glBlendColor</b>(</code></td><td>GLclampf  </td><td><var class="pdparam">red</var>, </td></tr><tr><td> </td><td>GLclampf  </td><td><var class="pdparam">green</var>, </td></tr><tr><td> </td><td>GLclampf  </td><td><var class="pdparam">blue</var>, </td></tr><tr><td> </td><td>GLclampf  </td><td><var class="pdparam">alpha</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>red</code></em>, </span><span class="term"><em class="parameter"><code>green</code></em>, </span><span class="term"><em class="parameter"><code>blue</code></em>, </span><span class="term"><em class="parameter"><code>alpha</code></em></span></dt><dd><p>

specify the components of <code class="constant">GL_BLEND_COLOR</code>

</p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>

The <code class="constant">GL_BLEND_COLOR</code> may be used to calculate the source and destination

blending factors. The color components are clamped to the range

<math overflow="scroll">

<mfenced open="[" close="]">

<mn>0</mn>

<mn>1</mn>

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before being stored. See <a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> for a complete description of the

blending operations.

Initially the <code class="constant">GL_BLEND_COLOR</code> is set to (0, 0, 0, 0).

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>

<code class="function">glBlendColor</code> is part of the <code class="code">ARB_imaging</code> subset. <code class="function">glBlendColor</code> is present only

if <code class="code">ARB_imaging</code> is returned when <a class="citerefentry" href="glGetString"><span class="citerefentry"><span class="refentrytitle">glGetString</span></span></a> is called with

<code class="constant">GL_EXTENSIONS</code> as its argument.

</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 <code class="function">glBlendColor</code> is executed

between the execution of <a class="citerefentry" href="glBegin"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding

execution of <a class="citerefentry" href="glEnd"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.

</p><p>

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>

<a class="citerefentry" href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with an argument of <code class="constant">GL_BLEND_COLOR</code>

</p></div>

{$pipelinestall}{$examples}

<div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>

<a class="citerefentry" href="glBlendEquation"><span class="citerefentry"><span class="refentrytitle">glBlendEquation</span></span></a>,

<a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a>,

<a class="citerefentry" href="glGetString"><span class="citerefentry"><span class="refentrytitle">glGetString</span></span></a>

</p></div><div class="refsect1" lang="en" xml:lang="en"><div id="Copyright"><h2>Copyright</h2><p>

Copyright © 1991-2006

Silicon Graphics, Inc. This document is licensed under the SGI

Free Software B License. For details, see

<a class="ulink" href="https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/" target="_top">https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/</a>.

</p></div></div></div>