upstream-man-pages/man2/xhtml/glGetQueryiv.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>glGetQueryiv</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetQueryiv"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetQueryiv — return parameters of a query object target</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">glGetQueryiv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint *  </td><td><var class="pdparam">params</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 a query object target.
   5                     Must be <code class="constant">GL_SAMPLES_PASSED</code>.
   6                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
   7                     Specifies the symbolic name of a query object target parameter.
   8                     Accepted values are <code class="constant">GL_CURRENT_QUERY</code> or <code class="constant">GL_QUERY_COUNTER_BITS</code>.
   9                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  10                     Returns the requested data.
  11                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  12             <code class="function">glGetQueryiv</code> returns in <em class="parameter"><code>params</code></em> a selected parameter of the query object target
  13             specified by <em class="parameter"><code>target</code></em>.
  14         </p><p>
  15             <em class="parameter"><code>pname</code></em> names a specific query object target parameter.  When <em class="parameter"><code>target</code></em> is
  16             <code class="constant">GL_SAMPLES_PASSED</code>, <em class="parameter"><code>pname</code></em> can be as follows:
  17         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_CURRENT_QUERY</code></span></dt><dd><p>
  18                         <em class="parameter"><code>params</code></em> returns the name of the currently active occlusion query object.
  19                         If no occlusion query is active, 0 is returned.  The initial value is 0.
  20                     </p></dd><dt><span class="term"><code class="constant">GL_QUERY_COUNTER_BITS</code></span></dt><dd><p>
  21                         <em class="parameter"><code>params</code></em> returns the number of bits in the query counter used to accumulate passing samples.
  22                         If the number of bits returned is 0, the implementation does not support a query counter, and the results
  23                         obtained from <a class="citerefentry" href="glGetQueryObject.xml"><span class="citerefentry"><span class="refentrytitle">glGetQueryObject</span></span></a> are useless.
  24                     </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  25             If an error is generated,
  26             no change is made to the contents of <em class="parameter"><code>params</code></em>.
  27         </p><p>
  28             <code class="function">glGetQueryiv</code> is available only if the GL version is 1.5 or greater.
  29         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  30             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> or <em class="parameter"><code>pname</code></em> is not an
  31             accepted value.
  32         </p><p>
  33             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetQueryiv</code>
  34             is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
  35             and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
  36         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  37             <a class="citerefentry" href="glGetQueryObject.xml"><span class="citerefentry"><span class="refentrytitle">glGetQueryObject</span></span></a>,
  38             <a class="citerefentry" href="glIsQuery.xml"><span class="citerefentry"><span class="refentrytitle">glIsQuery</span></span></a>
  39         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  40             Copyright <span class="trademark"></span>© 2005 Addison-Wesley.
  41             This material may be distributed subject to the terms and conditions set forth in
  42             the Open Publication License, v 1.0, 8 June 1999.
  43             <a class="ulink" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  44         </p></div></div></body></html>