upstream-doc/man2/xhtml/glGetBufferSubData.xml

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   3 <?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>glGetBufferSubData</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetBufferSubData"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetBufferSubData — returns a subset of a buffer object's data store</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">glGetBufferSubData</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLintptr  </td><td><var class="pdparam">offset</var>, </td></tr><tr><td> </td><td>GLsizeiptr  </td><td><var class="pdparam">size</var>, </td></tr><tr><td> </td><td>GLvoid *  </td><td><var class="pdparam">data</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>target</code></em></span></dt><dd><p>
   4                     Specifies the target buffer object.
   5                     The symbolic constant must be <code class="constant">GL_ARRAY_BUFFER</code>,
   6                     <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>,
   7                     <code class="constant">GL_PIXEL_PACK_BUFFER</code>, or
   8                     <code class="constant">GL_PIXEL_UNPACK_BUFFER</code>.
   9                 </p></dd><dt><span class="term"><em class="parameter"><code>offset</code></em></span></dt><dd><p>
  10                     Specifies the offset into the buffer object's data store from which data will be returned,
  11                     measured in bytes.
  12                 </p></dd><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p>
  13                     Specifies the size in bytes of the data store region being returned.
  14                 </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
  15                     Specifies a pointer to the location where buffer object data is returned.
  16                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  17             <code class="function">glGetBufferSubData</code> returns some or all of the data from the buffer object currently
  18             bound to <em class="parameter"><code>target</code></em>. Data starting at byte offset <em class="parameter"><code>offset</code></em> and
  19             extending for <em class="parameter"><code>size</code></em> bytes is copied from the data store to the memory pointed to by
  20             <em class="parameter"><code>data</code></em>. An error is thrown if the buffer object is currently mapped, or if
  21             <em class="parameter"><code>offset</code></em> and <em class="parameter"><code>size</code></em> together define a range beyond the bounds
  22             of the buffer object's data store.
  23         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  24             If an error is generated,
  25             no change is made to the contents of <em class="parameter"><code>data</code></em>.
  26         </p><p>
  27             <code class="function">glGetBufferSubData</code> is available only if the GL version is 1.5 or greater.
  28         </p><p>
  29             Targets <code class="constant">GL_PIXEL_PACK_BUFFER</code> and <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> are available
  30             only if the GL version is 2.1 or greater.
  31         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  32             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> is not
  33             <code class="constant">GL_ARRAY_BUFFER</code>, <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>,
  34             <code class="constant">GL_PIXEL_PACK_BUFFER</code>, or <code class="constant">GL_PIXEL_UNPACK_BUFFER</code>.
  35         </p><p>
  36             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>offset</code></em> or
  37             <em class="parameter"><code>size</code></em> is negative, or if together they define a region of memory
  38             that extends beyond the buffer object's allocated data store.
  39         </p><p>
  40             <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>.
  41         </p><p>
  42             <code class="constant">GL_INVALID_OPERATION</code> is generated if the buffer object being queried is mapped.
  43         </p><p>
  44             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetBufferSubData</code>
  45             is executed between the execution of
  46             <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding execution of
  47             <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
  48         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  49             <a class="citerefentry" href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>,
  50             <a class="citerefentry" href="glBufferData.xml"><span class="citerefentry"><span class="refentrytitle">glBufferData</span></span></a>,
  51             <a class="citerefentry" href="glBufferSubData.xml"><span class="citerefentry"><span class="refentrytitle">glBufferSubData</span></span></a>,
  52             <a class="citerefentry" href="glMapBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glMapBuffer</span></span></a>,
  53             <a class="citerefentry" href="glUnmapBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glUnmapBuffer</span></span></a>
  54         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  55             Copyright <span class="trademark"></span>© 2005 Addison-Wesley.
  56             This material may be distributed subject to the terms and conditions set forth in
  57             the Open Publication License, v 1.0, 8 June 1999.
  58             <a class="ulink" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  59         </p></div></div></body></html>