upstream-doc/man2/xhtml/glGetQueryObject.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>glGetQueryObject</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetQueryObject"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetQueryObject — return parameters of a query object</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">glGetQueryObjectiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">id</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 class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetQueryObjectuiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">id</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLuint *  </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>id</code></em></span></dt><dd><p>
   4                     Specifies the name of a query object.
   5                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
   6                     Specifies the symbolic name of a query object parameter.
   7                     Accepted values are <code class="constant">GL_QUERY_RESULT</code> or <code class="constant">GL_QUERY_RESULT_AVAILABLE</code>.
   8                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
   9                     Returns the requested data.
  10                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  11             <code class="function">glGetQueryObject</code> returns in <em class="parameter"><code>params</code></em> a selected parameter of the query object
  12             specified by <em class="parameter"><code>id</code></em>.
  13         </p><p>
  14             <em class="parameter"><code>pname</code></em> names a specific query object parameter.  <em class="parameter"><code>pname</code></em> can be as follows:
  15         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_QUERY_RESULT</code></span></dt><dd><p>
  16                         <em class="parameter"><code>params</code></em> returns the value of the query object's passed samples counter.
  17                         The initial value is 0.
  18                     </p></dd><dt><span class="term"><code class="constant">GL_QUERY_RESULT_AVAILABLE</code></span></dt><dd><p>
  19                         <em class="parameter"><code>params</code></em> returns whether the passed samples counter is immediately available.
  20                         If a delay would occur waiting for the query result, <code class="constant">GL_FALSE</code> is returned.
  21                         Otherwise, <code class="constant">GL_TRUE</code> is returned, which also indicates that the results of all
  22                         previous queries are available as well.
  23                     </p></dd></dl></div></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>params</code></em>.
  26         </p><p>
  27             <code class="function">glGetQueryObject</code> implicitly flushes the GL pipeline so that any incomplete rendering
  28             delimited by the occlusion query completes in finite time.
  29         </p><p>
  30             If multiple queries are issued using the same query object <em class="parameter"><code>id</code></em> before calling
  31             <code class="function">glGetQueryObject</code>, the results of the most recent query will be returned.  In this case,
  32             when issuing a new query, the results of the previous query are discarded.
  33         </p><p>
  34             <code class="function">glGetQueryObject</code> is available only if the GL version is 1.5 or greater.
  35         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  36             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>pname</code></em> is not an accepted value.
  37         </p><p>
  38             <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>id</code></em> is not the name of a query object.
  39         </p><p>
  40             <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>id</code></em> is the name of a currently active
  41             query object.
  42         </p><p>
  43             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetQueryObject</code>
  44             is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
  45             and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
  46         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  47             <a class="citerefentry" href="glBeginQuery.xml"><span class="citerefentry"><span class="refentrytitle">glBeginQuery</span></span></a>,
  48             <a class="citerefentry" href="glEndQuery.xml"><span class="citerefentry"><span class="refentrytitle">glEndQuery</span></span></a>,
  49             <a class="citerefentry" href="glGetQueryiv.xml"><span class="citerefentry"><span class="refentrytitle">glGetQueryiv</span></span></a>,
  50             <a class="citerefentry" href="glIsQuery.xml"><span class="citerefentry"><span class="refentrytitle">glIsQuery</span></span></a>
  51         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  52             Copyright <span class="trademark"></span>© 2005 Addison-Wesley.
  53             This material may be distributed subject to the terms and conditions set forth in
  54             the Open Publication License, v 1.0, 8 June 1999.
  55             <a class="ulink" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  56         </p></div></div></body></html>