upstream-man-pages/man4/xhtml/glBufferSubData.xml

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   4 <?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>glBufferSubData - 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="glBufferSubData"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBufferSubData — updates 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">glBufferSubData</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>const 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>
   5                     Specifies the target buffer object.
   6                     The symbolic constant must be
   7                     <code class="constant">GL_ARRAY_BUFFER</code>,
   8                     <code class="constant">GL_ATOMIC_COUNTER_BUFFER</code>,
   9                     <code class="constant">GL_COPY_READ_BUFFER</code>,
  10                     <code class="constant">GL_COPY_WRITE_BUFFER</code>,
  11                     <code class="constant">GL_DRAW_INDIRECT_BUFFER</code>,
  12                     <code class="constant">GL_DISPATCH_INDIRECT_BUFFER</code>,
  13                     <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>,
  14                     <code class="constant">GL_PIXEL_PACK_BUFFER</code>,
  15                     <code class="constant">GL_PIXEL_UNPACK_BUFFER</code>,
  16                     <code class="constant">GL_SHADER_STORAGE_BUFFER</code>,
  17                     <code class="constant">GL_TEXTURE_BUFFER</code>,
  18                     <code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER</code>, or
  19                     <code class="constant">GL_UNIFORM_BUFFER</code>.
  20                 </p></dd><dt><span class="term"><em class="parameter"><code>offset</code></em></span></dt><dd><p>
  21                     Specifies the offset into the buffer object's data store where data replacement will begin,
  22                     measured in bytes.
  23                 </p></dd><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p>
  24                     Specifies the size in bytes of the data store region being replaced.
  25                 </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
  26                     Specifies a pointer to the new data that will be copied into the data store.
  27                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  28             <code class="function">glBufferSubData</code> redefines some or all of the data store for the buffer object currently
  29             bound to <em class="parameter"><code>target</code></em>. Data starting at byte offset <em class="parameter"><code>offset</code></em> and
  30             extending for <em class="parameter"><code>size</code></em> bytes is copied to the data store from the memory pointed to by
  31             <em class="parameter"><code>data</code></em>.  An error is thrown if <em class="parameter"><code>offset</code></em> and <em class="parameter"><code>size</code></em>
  32             together define a range beyond the bounds of the buffer object's data store.
  33         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  34             When replacing the entire data store, consider using <code class="function">glBufferSubData</code> rather
  35             than completely recreating the data store with <code class="function">glBufferData</code>.  This avoids the cost of
  36             reallocating the data store.
  37         </p><p>
  38             Consider using multiple buffer objects to avoid stalling the rendering pipeline during data store updates.
  39             If any rendering in the pipeline makes reference to data in the buffer object being updated by
  40             <code class="function">glBufferSubData</code>, especially from the specific region being updated, that rendering must
  41             drain from the pipeline before the data store can be updated.
  42         </p><p>
  43             Clients must align data elements consistent with the requirements of the client
  44             platform, with an additional base-level requirement that an offset within a buffer to
  45             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
  46             multiple of <mml:mi mathvariant="italic">N</mml:mi></mml:math>.
  47         </p><p>
  48             The <code class="constant">GL_ATOMIC_COUNTER_BUFFER</code> target is available only if the GL version
  49             is 4.2 or greater.
  50         </p><p>
  51             The <code class="constant">GL_DISPATCH_INDIRECT_BUFFER</code> and <code class="constant">GL_SHADER_STORAGE_BUFFER</code> targets are available only if the GL version
  52             is 4.3 or greater.
  53         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  54             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> is not
  55             one of the accepted buffer targets.
  56         </p><p>
  57             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>offset</code></em> or
  58             <em class="parameter"><code>size</code></em> is negative, or if together they define a region of memory
  59             that extends beyond the buffer object's allocated data store.
  60         </p><p>
  61             <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>.
  62         </p><p>
  63             <code class="constant">GL_INVALID_OPERATION</code> is generated if the buffer object being updated is mapped.
  64         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
  65             <a href="glGetBufferSubData.xml"><span class="citerefentry"><span class="refentrytitle">glGetBufferSubData</span></span></a>
  66         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  67             <a href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>,
  68             <a href="glBufferData.xml"><span class="citerefentry"><span class="refentrytitle">glBufferData</span></span></a>,
  69             <a href="glMapBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glMapBuffer</span></span></a>,
  70             <a href="glUnmapBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glUnmapBuffer</span></span></a>
  71         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  72             Copyright <span class="trademark"></span>© 2005 Addison-Wesley.
  73             This material may be distributed subject to the terms and conditions set forth in
  74             the Open Publication License, v 1.0, 8 June 1999.
  75             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  76         </p></div></div></body></html>