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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>glDrawBuffer</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glDrawBuffer"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glDrawBuffer — specify which color buffers are to be drawn into</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">glDrawBuffer</b>(</code></td><td>GLenum </td><td><var class="pdparam">mode</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>mode</code></em></span></dt><dd><p>
+ Specifies up to four color buffers to be drawn into.
+ Symbolic constants
+ <code class="constant">GL_NONE</code>,
+ <code class="constant">GL_FRONT_LEFT</code>,
+ <code class="constant">GL_FRONT_RIGHT</code>,
+ <code class="constant">GL_BACK_LEFT</code>,
+ <code class="constant">GL_BACK_RIGHT</code>,
+ <code class="constant">GL_FRONT</code>,
+ <code class="constant">GL_BACK</code>,
+ <code class="constant">GL_LEFT</code>,
+ <code class="constant">GL_RIGHT</code>,
+ <code class="constant">GL_FRONT_AND_BACK</code>, and
+ <code class="constant">GL_AUX</code><span class="emphasis"><em>i</em></span>,
+ where <span class="emphasis"><em>i</em></span> is between 0 and the value of <code class="constant">GL_AUX_BUFFERS</code> minus 1,
+ are accepted. (<code class="constant">GL_AUX_BUFFERS</code> is not the upper limit; use <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
+ to query the number of available aux buffers.)
+ The initial value is <code class="constant">GL_FRONT</code> for single-buffered contexts,
+ and <code class="constant">GL_BACK</code> for double-buffered contexts.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ When colors are written to the frame buffer,
+ they are written into the color buffers specified by <code class="function">glDrawBuffer</code>.
+ The specifications are as follows:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_NONE</code></span></dt><dd><p>
+ No color buffers are written.
+ </p></dd><dt><span class="term"><code class="constant">GL_FRONT_LEFT</code></span></dt><dd><p>
+ Only the front left color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_FRONT_RIGHT</code></span></dt><dd><p>
+ Only the front right color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_BACK_LEFT</code></span></dt><dd><p>
+ Only the back left color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_BACK_RIGHT</code></span></dt><dd><p>
+ Only the back right color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_FRONT</code></span></dt><dd><p>
+ Only the front left and front right color buffers are written.
+ If there is no front right color buffer,
+ only the front left color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_BACK</code></span></dt><dd><p>
+ Only the back left and back right color buffers are written.
+ If there is no back right color buffer,
+ only the back left color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_LEFT</code></span></dt><dd><p>
+ Only the front left and back left color buffers are written.
+ If there is no back left color buffer,
+ only the front left color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_RIGHT</code></span></dt><dd><p>
+ Only the front right and back right color buffers are written.
+ If there is no back right color buffer,
+ only the front right color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_FRONT_AND_BACK</code></span></dt><dd><p>
+ All the front and back color buffers
+ (front left, front right, back left, back right)
+ are written.
+ If there are no back color buffers,
+ only the front left and front right color buffers are written.
+ If there are no right color buffers,
+ only the front left and back left color buffers are written.
+ If there are no right or back color buffers,
+ only the front left color buffer is written.
+ </p></dd><dt><span class="term"><code class="constant">GL_AUX</code><span class="emphasis"><em>i</em></span></span></dt><dd><p>
+ Only auxiliary color buffer <span class="emphasis"><em>i</em></span> is written.
+ </p></dd></dl></div><p>
+ If more than one color buffer is selected for drawing,
+ then blending or logical operations are computed and applied independently
+ for each color buffer and can produce different results in each buffer.
+ </p><p>
+ Monoscopic contexts include only
+ <span class="emphasis"><em>left</em></span>
+ buffers, and stereoscopic contexts include both
+ <span class="emphasis"><em>left</em></span>
+ and
+ <span class="emphasis"><em>right</em></span>
+ buffers.
+ Likewise, single-buffered contexts include only
+ <span class="emphasis"><em>front</em></span>
+ buffers, and double-buffered contexts include both
+ <span class="emphasis"><em>front</em></span>
+ and
+ <span class="emphasis"><em>back</em></span>
+ buffers.
+ The context is selected at GL initialization.
+ </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_AUX</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_AUX0</code> +
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>.
+ </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>mode</code></em> is not an accepted value.
+ </p><p>
+ <code class="constant">GL_INVALID_OPERATION</code> is generated if none of the buffers indicated
+ by <em class="parameter"><code>mode</code></em> exists.
+ </p><p>
+ <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glDrawBuffer</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="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_DRAW_BUFFER</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_AUX_BUFFERS</code>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a class="citerefentry" href="glBlendFunc.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a>,
+ <a class="citerefentry" href="glColorMask.xml"><span class="citerefentry"><span class="refentrytitle">glColorMask</span></span></a>,
+ <a class="citerefentry" href="glIndexMask.xml"><span class="citerefentry"><span class="refentrytitle">glIndexMask</span></span></a>,
+ <a class="citerefentry" href="glLogicOp.xml"><span class="citerefentry"><span class="refentrytitle">glLogicOp</span></span></a>,
+ <a class="citerefentry" href="glReadBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glReadBuffer</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>
HCoop / clinton / guile-figl.git / blobdiff