HCoop / clinton / guile-figl.git / blame
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| 7faf1d71 AW |
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>glBeginConditionalRender</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /></head><body><div class="refentry" title="glBeginConditionalRender"><a id="glBeginConditionalRender"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBeginConditionalRender — start conditional rendering</p></div><div class="refsynopsisdiv" title="C Specification"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void <b class="fsfunc">glBeginConditionalRender</b>(</code></td><td>GLuint <var class="pdparam">id</var>, </td></tr><tr><td> </td><td>GLenum <var class="pdparam">mode</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Parameters"><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> | |
| 5 | Specifies the name of an occlusion query object whose results are used to determine if the rendering commands are discarded. | |
| 6 | </p></dd><dt><span class="term"><em class="parameter"><code>mode</code></em></span></dt><dd><p> | |
| 7 | Specifies how <code class="function">glBeginConditionalRender</code> interprets the results of the occlusion query. | |
| 8 | </p></dd></dl></div></div><div class="refsynopsisdiv" title="C Specification"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void <b class="fsfunc">glEndConditionalRender</b>(</code></td><td><var class="pdparam">void</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Description"><a id="description"></a><h2>Description</h2><p> | |
| 9 | Conditional rendering is started using <code class="function">glBeginConditionalRender</code> and ended using <code class="function">glEndConditionalRender</code>. | |
| 10 | During conditional rendering, all vertex array commands, as well as <a class="citerefentry" href="glClear.xml"><span class="citerefentry"><span class="refentrytitle">glClear</span></span></a> and | |
| 11 | <a class="citerefentry" href="glClearBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glClearBuffer</span></span></a> have no effect if the (<code class="constant">GL_SAMPLES_PASSED</code>) result | |
| 12 | of the query object <em class="parameter"><code>id</code></em> is zero, or if the (<code class="constant">GL_ANY_SAMPLES_PASSED</code>) result is <code class="constant">GL_FALSE</code>. | |
| 13 | The results of commands setting the current vertex state, such as <a class="citerefentry" href="glVertexAttrib.xml"><span class="citerefentry"><span class="refentrytitle">glVertexAttrib</span></span></a> are | |
| 14 | undefined. If the (<code class="constant">GL_SAMPLES_PASSED</code>) result is non-zero or if the (<code class="constant">GL_ANY_SAMPLES_PASSED</code>) result is | |
| 15 | <code class="constant">GL_TRUE</code>, such commands are not discarded. The <em class="parameter"><code>id</code></em> parameter to <code class="function">glBeginConditionalRender</code> | |
| 16 | must be the name of a query object previously returned from a call to <a class="citerefentry" href="glGenQueries.xml"><span class="citerefentry"><span class="refentrytitle">glGenQueries</span></span></a>. | |
| 17 | <em class="parameter"><code>mode</code></em> specifies how the results of the query object are to be interpreted. If <em class="parameter"><code>mode</code></em> is | |
| 18 | <code class="constant">GL_QUERY_WAIT</code>, the GL waits for the results of the query to be available and then uses the results to determine if subsequent | |
| 19 | rendering commands are discarded. If <em class="parameter"><code>mode</code></em> is <code class="constant">GL_QUERY_NO_WAIT</code>, the GL may choose to unconditionally | |
| 20 | execute the subsequent rendering commands without waiting for the query to complete. | |
| 21 | </p><p> | |
| 22 | If <em class="parameter"><code>mode</code></em> is <code class="constant">GL_QUERY_BY_REGION_WAIT</code>, the GL will also wait for occlusion query results and discard | |
| 23 | rendering commands if the result of the occlusion query is zero. If the query result is non-zero, subsequent rendering commands are executed, | |
| 24 | but the GL may discard the results of the commands for any region of the framebuffer that did not contribute to the sample count in the specified | |
| 25 | occlusion query. Any such discarding is done in an implementation-dependent manner, but the rendering command results may not be discarded for | |
| 26 | any samples that contributed to the occlusion query sample count. If <em class="parameter"><code>mode</code></em> is <code class="constant">GL_QUERY_BY_REGION_NO_WAIT</code>, | |
| 27 | the GL operates as in <code class="constant">GL_QUERY_BY_REGION_WAIT</code>, but may choose to unconditionally execute the subsequent rendering commands | |
| 28 | without waiting for the query to complete. | |
| 29 | </p></div><div class="refsect1" title="Notes"><a id="notes"></a><h2>Notes</h2><p> | |
| 30 | <code class="function">glBeginConditionalRender</code> and <code class="function">glEndConditionalRender</code> are available only if the GL version is 3.0 or greater. | |
| 31 | </p><p> | |
| 32 | The <code class="constant">GL_ANY_SAMPLES_PASSED</code> query result is available only if the GL version is 3.3 or greater. | |
| 33 | </p></div><div class="refsect1" title="Errors"><a id="errors"></a><h2>Errors</h2><p> | |
| 34 | <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>id</code></em> is not the name of an existing query object. | |
| 35 | </p><p> | |
| 36 | <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not one of the accepted tokens. | |
| 37 | </p><p> | |
| 38 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glBeginConditionalRender</code> is called while conditional rendering is active, | |
| 39 | or if <code class="function">glEndConditionalRender</code> is called while conditional rendering is inactive. | |
| 40 | </p><p> | |
| 41 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>id</code></em> is the name of a query object with a target other than | |
| 42 | <code class="constant">GL_SAMPLES_PASSED</code> or <code class="constant">GL_ANY_SAMPLES_PASSED</code>. | |
| 43 | </p><p> | |
| 44 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>id</code></em> is the name of a query currently in progress. | |
| 45 | </p></div><div class="refsect1" title="See Also"><a id="seealso"></a><h2>See Also</h2><p> | |
| 46 | <a class="citerefentry" href="glGenQueries.xml"><span class="citerefentry"><span class="refentrytitle">glGenQueries</span></span></a>, | |
| 47 | <a class="citerefentry" href="glDeleteQueries.xml"><span class="citerefentry"><span class="refentrytitle">glDeleteQueries</span></span></a>, | |
| 48 | <a class="citerefentry" href="glBeginQuery.xml"><span class="citerefentry"><span class="refentrytitle">glBeginQuery</span></span></a> | |
| 49 | </p></div><div class="refsect1" title="Copyright"><a id="Copyright"></a><h2>Copyright</h2><p> | |
| 50 | Copyright <span class="trademark"></span>© 2009 Khronos Group. | |
| 51 | This material may be distributed subject to the terms and conditions set forth in | |
| 52 | the Open Publication License, v 1.0, 8 June 1999. | |
| 53 | <a class="ulink" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>. | |
| 54 | </p></div></div></body></html> |