upstream-doc/man3/xhtml/glDrawArraysInstanced.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
   3 <!-- saved from url=(0013)about:internet -->
   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>glDrawArraysInstanced</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glDrawArraysInstanced"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glDrawArraysInstanced — draw multiple instances of a range of elements</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">glDrawArraysInstanced</b>(</code></td><td>GLenum  </td><td><var class="pdparam">mode</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">first</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">count</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">primcount</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>
   5                     Specifies what kind of primitives to render. Symbolic constants <code class="constant">GL_POINTS</code>,
   6                     <code class="constant">GL_LINE_STRIP</code>, <code class="constant">GL_LINE_LOOP</code>, <code class="constant">GL_LINES</code>,
   7                     <code class="constant">GL_TRIANGLE_STRIP</code>, <code class="constant">GL_TRIANGLE_FAN</code>, <code class="constant">GL_TRIANGLES</code>
   8                     <code class="constant">GL_LINES_ADJACENCY</code>, <code class="constant">GL_LINE_STRIP_ADJACENCY</code>,
   9                     <code class="constant">GL_TRIANGLES_ADJACENCY</code> and<code class="constant">GL_TRIANGLE_STRIP_ADJACENCY</code>
  10                     are accepted.
  11                 </p></dd><dt><span class="term"><em class="parameter"><code>first</code></em></span></dt><dd><p>
  12                     Specifies the starting index in the enabled arrays.
  13                 </p></dd><dt><span class="term"><em class="parameter"><code>count</code></em></span></dt><dd><p>
  14                     Specifies the number of indices to be rendered.
  15                 </p></dd><dt><span class="term"><em class="parameter"><code>primcount</code></em></span></dt><dd><p>
  16                     Specifies the number of instances of the specified range of indices to be rendered.
  17                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  18             <code class="function">glDrawArraysInstanced</code> behaves identically to <a href="glDrawArrays.xml"><span class="citerefentry"><span class="refentrytitle">glDrawArrays</span></span></a>
  19             except that <em class="parameter"><code>primcount</code></em> instances of the range of elements are executed and the value of the internal counter
  20             <em class="parameter"><code>instanceID</code></em> advances for each iteration. <em class="parameter"><code>instanceID</code></em> is an internal 32-bit integer counter
  21             that may be read by a vertex shader as <code class="constant">gl_InstanceID</code>.
  22         </p><p>
  23             <code class="function">glDrawArraysInstanced</code> has the same effect as:
  24             </p><pre class="programlisting">    if ( mode or count is invalid )
  25         generate appropriate error
  26     else {
  27         for (int i = 0; i &lt; primcount ; i++) {
  28             instanceID = i;
  29             glDrawArrays(mode, first, count);
  30         }
  31         instanceID = 0;
  32     }</pre><p>
  33         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  34             <code class="function">glDrawArraysInstanced</code> is available only if the GL version is 3.1 or greater.
  35         </p><p>
  36             <code class="constant">GL_LINE_STRIP_ADJACENCY</code>,
  37             <code class="constant">GL_LINES_ADJACENCY</code>,
  38             <code class="constant">GL_TRIANGLE_STRIP_ADJACENCY</code> and
  39             <code class="constant">GL_TRIANGLES_ADJACENCY</code>
  40             are available only if the GL version is 3.2 or greater.
  41         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  42             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not one of
  43             the accepted values.
  44         </p><p>
  45             <code class="constant">GL_INVALID_OPERATION</code> is generated if a geometry shader is active and <em class="parameter"><code>mode</code></em>
  46             is incompatible with the input primitive type of the geometry shader in the currently installed program object.
  47         </p><p>
  48             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>count</code></em> or <em class="parameter"><code>primcount</code></em> are negative.
  49         </p><p>
  50             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to an
  51             enabled array and the buffer object's data store is currently mapped.
  52         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  53             <a href="glDrawArrays.xml"><span class="citerefentry"><span class="refentrytitle">glDrawArrays</span></span></a>,
  54             <a href="glDrawElementsInstanced.xml"><span class="citerefentry"><span class="refentrytitle">glDrawElementsInstanced</span></span></a>
  55         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  56             Copyright <span class="trademark"></span>© 2010 Khronos Group.
  57             This material may be distributed subject to the terms and conditions set forth in
  58             the Open Publication License, v 1.0, 8 June 1999.
  59             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  60         </p></div></div></body></html>