<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd"><!-- saved from url=(0013)about:internet -->
<?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>glBufferData</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1" /></head><body><div class="refentry"><a id="glBufferData"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBufferData — creates and initializes a buffer object's data store.</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glBufferData</strong>(</code></td><td>GLenum <var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLsizeiptr <var class="pdparam">size</var>, </td></tr><tr><td> </td><td>const GLvoid * <var class="pdparam">data</var>, </td></tr><tr><td> </td><td>GLenum <var class="pdparam">usage</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term">
                    <em class="parameter"><code>target</code></em>
                </span></dt><dd><p>
                    Specifies the target buffer object. The symbolic constant must be
                    <code class="constant">GL_ARRAY_BUFFER</code>
                    or <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>.
                    </p></dd><dt><span class="term">
                    <em class="parameter"><code>size</code></em>
                </span></dt><dd><p>Specifies the size in bytes of the buffer object's new data store.</p></dd><dt><span class="term">
                    <em class="parameter"><code>data</code></em>
                </span></dt><dd><p>Specifies a pointer to data that will be copied into the data store for
                    initialization, or <code class="constant">NULL</code> if no data is to be copied.</p></dd><dt><span class="term">
                    <em class="parameter"><code>usage</code></em>
                </span></dt><dd><p>
                    Specifies the expected usage pattern of the data store. The symbolic constant
                    must be
                    <code class="constant">GL_STATIC_DRAW</code> or
                    <code class="constant">GL_DYNAMIC_DRAW</code>.
                    </p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glBufferData</code> creates a new data store for the buffer object currently bound to
            <em class="parameter"><code>target</code></em>. Any pre-existing data store is deleted. The new data store is created with the
            specified <em class="parameter"><code>size</code></em> in bytes and <em class="parameter"><code>usage</code></em>. If <em class="parameter"><code>data</code></em>
            is not <code class="constant">NULL</code>, the data store is initialized with data from this pointer.
        </p><p>
            <em class="parameter"><code>usage</code></em> is a hint to the GL implementation as to how a buffer object's data store will be 
            accessed. This enables the GL implementation to make more intelligent decisions that may significantly 
            impact buffer object performance. It does not, however, constrain the actual usage of the data store.
        </p><p>
        <em class="parameter"><code>usage</code></em> may be one of these:
        </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="constant">GL_STATIC_DRAW</code></span></dt><dd><p>
                    The data store contents will be modified once
                    and used many times as the source for GL drawing commands.
                    </p></dd><dt><span class="term"><code class="constant">GL_DYNAMIC_DRAW</code></span></dt><dd><p>
                    The data store contents will be modified repeatedly
                    and used many times as the source for GL drawing commands.
                    </p></dd></dl></div><p>
        </p></div><div class="refsect1"><a id="notes"></a><h2>Notes</h2><p>
            If <em class="parameter"><code>data</code></em> is <code class="constant">NULL</code>, a data store of the specified size is still created,
            but its contents remain uninitialized and thus undefined.
        </p><p>
            Clients must align data elements consistent with the requirements of the client
            platform, with an additional base-level requirement that an offset within a buffer to
            a datum comprising <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi> bytes be a 
            multiple of <mml:mi mathvariant="italic">N</mml:mi></mml:math>.
        </p></div><div class="refsect1"><a id="errors"></a><h2>Errors</h2><p>
            <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> is not 
            <code class="constant">GL_ARRAY_BUFFER</code> or <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>.
        </p><p>
            <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>usage</code></em> is not 
            <code class="constant">GL_STATIC_DRAW</code> or
            <code class="constant">GL_DYNAMIC_DRAW</code>.
        </p><p>
            <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>size</code></em> is negative.
        </p><p>
            <code class="constant">GL_INVALID_OPERATION</code> is generated if the reserved buffer object name 0 is bound to <em class="parameter"><code>target</code></em>.
        </p><p>
            <code class="constant">GL_OUT_OF_MEMORY</code> is generated if the GL is unable to create a data store with the specified <em class="parameter"><code>size</code></em>.
        </p></div><div class="refsect1"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
            <a class="citerefentry" href="glGetBufferParameteriv.xml"><span class="citerefentry"><span class="refentrytitle">glGetBufferParameteriv</span></span></a> with argument <code class="constant">GL_BUFFER_SIZE</code> or <code class="constant">GL_BUFFER_USAGE</code>
        </p></div><div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>
        <a class="citerefentry" href="glBufferSubData.xml"><span class="citerefentry"><span class="refentrytitle">glBufferSubData</span></span></a>,
        <a class="citerefentry" href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>
        </p></div><div class="refsect1"><a id="copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 2003-2004
            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>