102f4aeb0Sopenharmony_ci<?xml version="1.0" encoding="UTF-8" standalone="no"?> 202f4aeb0Sopenharmony_ci<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"> 302f4aeb0Sopenharmony_ci <head> 402f4aeb0Sopenharmony_ci <title xmlns:xlink="http://www.w3.org/1999/xlink">eglQueryContext - EGL Reference Pages</title> 502f4aeb0Sopenharmony_ci <link rel="stylesheet" type="text/css" href="khronos-man.css"/> 602f4aeb0Sopenharmony_ci <meta name="generator" content="DocBook XSL Stylesheets V1.79.1"/> 702f4aeb0Sopenharmony_ci </head> 802f4aeb0Sopenharmony_ci <body> 902f4aeb0Sopenharmony_ci <header/> 1002f4aeb0Sopenharmony_ci <div class="refentry" id="eglQueryContext"> 1102f4aeb0Sopenharmony_ci <div class="titlepage"/> 1202f4aeb0Sopenharmony_ci <div class="refnamediv"> 1302f4aeb0Sopenharmony_ci <h2>Name</h2> 1402f4aeb0Sopenharmony_ci <p>eglQueryContext — 1502f4aeb0Sopenharmony_ci return <abbr class="acronym">EGL</abbr> rendering context information 1602f4aeb0Sopenharmony_ci </p> 1702f4aeb0Sopenharmony_ci </div> 1802f4aeb0Sopenharmony_ci <div class="refsynopsisdiv"> 1902f4aeb0Sopenharmony_ci <h2>C Specification</h2> 2002f4aeb0Sopenharmony_ci <div class="funcsynopsis"> 2102f4aeb0Sopenharmony_ci <table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table"> 2202f4aeb0Sopenharmony_ci <tr> 2302f4aeb0Sopenharmony_ci <td> 2402f4aeb0Sopenharmony_ci <code class="funcdef">EGLBoolean <strong class="fsfunc">eglQueryContext</strong>(</code> 2502f4aeb0Sopenharmony_ci </td> 2602f4aeb0Sopenharmony_ci <td>EGLDisplay <var class="pdparam">display</var>, </td> 2702f4aeb0Sopenharmony_ci </tr> 2802f4aeb0Sopenharmony_ci <tr> 2902f4aeb0Sopenharmony_ci <td> </td> 3002f4aeb0Sopenharmony_ci <td>EGLContext <var class="pdparam">context</var>, </td> 3102f4aeb0Sopenharmony_ci </tr> 3202f4aeb0Sopenharmony_ci <tr> 3302f4aeb0Sopenharmony_ci <td> </td> 3402f4aeb0Sopenharmony_ci <td>EGLint <var class="pdparam">attribute</var>, </td> 3502f4aeb0Sopenharmony_ci </tr> 3602f4aeb0Sopenharmony_ci <tr> 3702f4aeb0Sopenharmony_ci <td> </td> 3802f4aeb0Sopenharmony_ci <td>EGLint * <var class="pdparam">value</var><code>)</code>;</td> 3902f4aeb0Sopenharmony_ci </tr> 4002f4aeb0Sopenharmony_ci </table> 4102f4aeb0Sopenharmony_ci <div class="funcprototype-spacer"> </div> 4202f4aeb0Sopenharmony_ci </div> 4302f4aeb0Sopenharmony_ci </div> 4402f4aeb0Sopenharmony_ci <div class="refsect1" id="parameters"> 4502f4aeb0Sopenharmony_ci <h2>Parameters</h2> 4602f4aeb0Sopenharmony_ci <div class="variablelist"> 4702f4aeb0Sopenharmony_ci <dl class="variablelist"> 4802f4aeb0Sopenharmony_ci <dt> 4902f4aeb0Sopenharmony_ci <span class="term"> 5002f4aeb0Sopenharmony_ci <em class="parameter"> 5102f4aeb0Sopenharmony_ci <code>display</code> 5202f4aeb0Sopenharmony_ci </em> 5302f4aeb0Sopenharmony_ci </span> 5402f4aeb0Sopenharmony_ci </dt> 5502f4aeb0Sopenharmony_ci <dd> 5602f4aeb0Sopenharmony_ci <p> 5702f4aeb0Sopenharmony_ci Specifies the EGL display connection. 5802f4aeb0Sopenharmony_ci </p> 5902f4aeb0Sopenharmony_ci </dd> 6002f4aeb0Sopenharmony_ci <dt> 6102f4aeb0Sopenharmony_ci <span class="term"> 6202f4aeb0Sopenharmony_ci <em class="parameter"> 6302f4aeb0Sopenharmony_ci <code>context</code> 6402f4aeb0Sopenharmony_ci </em> 6502f4aeb0Sopenharmony_ci </span> 6602f4aeb0Sopenharmony_ci </dt> 6702f4aeb0Sopenharmony_ci <dd> 6802f4aeb0Sopenharmony_ci <p> 6902f4aeb0Sopenharmony_ci Specifies the EGL rendering context to query. 7002f4aeb0Sopenharmony_ci </p> 7102f4aeb0Sopenharmony_ci </dd> 7202f4aeb0Sopenharmony_ci <dt> 7302f4aeb0Sopenharmony_ci <span class="term"> 7402f4aeb0Sopenharmony_ci <em class="parameter"> 7502f4aeb0Sopenharmony_ci <code>attribute</code> 7602f4aeb0Sopenharmony_ci </em> 7702f4aeb0Sopenharmony_ci </span> 7802f4aeb0Sopenharmony_ci </dt> 7902f4aeb0Sopenharmony_ci <dd> 8002f4aeb0Sopenharmony_ci <p> 8102f4aeb0Sopenharmony_ci Specifies the EGL rendering context attribute to be returned. 8202f4aeb0Sopenharmony_ci </p> 8302f4aeb0Sopenharmony_ci </dd> 8402f4aeb0Sopenharmony_ci <dt> 8502f4aeb0Sopenharmony_ci <span class="term"> 8602f4aeb0Sopenharmony_ci <em class="parameter"> 8702f4aeb0Sopenharmony_ci <code>value</code> 8802f4aeb0Sopenharmony_ci </em> 8902f4aeb0Sopenharmony_ci </span> 9002f4aeb0Sopenharmony_ci </dt> 9102f4aeb0Sopenharmony_ci <dd> 9202f4aeb0Sopenharmony_ci <p> 9302f4aeb0Sopenharmony_ci Returns the requested value. 9402f4aeb0Sopenharmony_ci </p> 9502f4aeb0Sopenharmony_ci </dd> 9602f4aeb0Sopenharmony_ci </dl> 9702f4aeb0Sopenharmony_ci </div> 9802f4aeb0Sopenharmony_ci </div> 9902f4aeb0Sopenharmony_ci <div class="refsect1" id="description"> 10002f4aeb0Sopenharmony_ci <h2>Description</h2> 10102f4aeb0Sopenharmony_ci <p> 10202f4aeb0Sopenharmony_ci <code class="function">eglQueryContext</code> returns in 10302f4aeb0Sopenharmony_ci <em class="parameter"><code>value</code></em> the value of 10402f4aeb0Sopenharmony_ci <em class="parameter"><code>attribute</code></em> for <em class="parameter"><code>context</code></em>. 10502f4aeb0Sopenharmony_ci <em class="parameter"><code>attribute</code></em> can be one of the following: 10602f4aeb0Sopenharmony_ci </p> 10702f4aeb0Sopenharmony_ci <div class="variablelist"> 10802f4aeb0Sopenharmony_ci <dl class="variablelist"> 10902f4aeb0Sopenharmony_ci <dt> 11002f4aeb0Sopenharmony_ci <span class="term"> 11102f4aeb0Sopenharmony_ci <code class="constant">EGL_CONFIG_ID</code> 11202f4aeb0Sopenharmony_ci </span> 11302f4aeb0Sopenharmony_ci </dt> 11402f4aeb0Sopenharmony_ci <dd> 11502f4aeb0Sopenharmony_ci <p> 11602f4aeb0Sopenharmony_ci Returns the ID of the EGL frame buffer configuration 11702f4aeb0Sopenharmony_ci with respect to which the context was created. 11802f4aeb0Sopenharmony_ci </p> 11902f4aeb0Sopenharmony_ci </dd> 12002f4aeb0Sopenharmony_ci <dt> 12102f4aeb0Sopenharmony_ci <span class="term"> 12202f4aeb0Sopenharmony_ci <code class="constant">EGL_CONTEXT_CLIENT_TYPE</code> 12302f4aeb0Sopenharmony_ci </span> 12402f4aeb0Sopenharmony_ci </dt> 12502f4aeb0Sopenharmony_ci <dd> 12602f4aeb0Sopenharmony_ci <p> 12702f4aeb0Sopenharmony_ci Returns the type of client API which the context 12802f4aeb0Sopenharmony_ci supports (one of 12902f4aeb0Sopenharmony_ci <code class="constant">EGL_OPENGL_API</code>, 13002f4aeb0Sopenharmony_ci <code class="constant">EGL_OPENGL_ES_API</code>, or 13102f4aeb0Sopenharmony_ci <code class="constant">EGL_OPENVG_API</code>). 13202f4aeb0Sopenharmony_ci </p> 13302f4aeb0Sopenharmony_ci </dd> 13402f4aeb0Sopenharmony_ci <dt> 13502f4aeb0Sopenharmony_ci <span class="term"> 13602f4aeb0Sopenharmony_ci <code class="constant">EGL_CONTEXT_CLIENT_VERSION</code> 13702f4aeb0Sopenharmony_ci </span> 13802f4aeb0Sopenharmony_ci </dt> 13902f4aeb0Sopenharmony_ci <dd> 14002f4aeb0Sopenharmony_ci <p> 14102f4aeb0Sopenharmony_ci Returns the version of the client API which the 14202f4aeb0Sopenharmony_ci context supports, as specified at context creation 14302f4aeb0Sopenharmony_ci time. The resulting value is only meaningful for an 14402f4aeb0Sopenharmony_ci OpenGL ES context. 14502f4aeb0Sopenharmony_ci </p> 14602f4aeb0Sopenharmony_ci </dd> 14702f4aeb0Sopenharmony_ci <dt> 14802f4aeb0Sopenharmony_ci <span class="term"> 14902f4aeb0Sopenharmony_ci <code class="constant">EGL_RENDER_BUFFER</code> 15002f4aeb0Sopenharmony_ci </span> 15102f4aeb0Sopenharmony_ci </dt> 15202f4aeb0Sopenharmony_ci <dd> 15302f4aeb0Sopenharmony_ci <p> 15402f4aeb0Sopenharmony_ci Returns the buffer which client API rendering 15502f4aeb0Sopenharmony_ci via the context will use. The value returned 15602f4aeb0Sopenharmony_ci depends on properties of both the context, and 15702f4aeb0Sopenharmony_ci the surface to which the context is bound: 15802f4aeb0Sopenharmony_ci </p> 15902f4aeb0Sopenharmony_ci <div class="itemizedlist"> 16002f4aeb0Sopenharmony_ci <ul style="list-style-type: disc; " class="itemizedlist"> 16102f4aeb0Sopenharmony_ci <li class="listitem"> 16202f4aeb0Sopenharmony_ci <p> 16302f4aeb0Sopenharmony_ci If the context is bound to a pixmap surface, 16402f4aeb0Sopenharmony_ci then <code class="constant">EGL_SINGLE_BUFFER</code> will 16502f4aeb0Sopenharmony_ci be returned. 16602f4aeb0Sopenharmony_ci </p> 16702f4aeb0Sopenharmony_ci </li> 16802f4aeb0Sopenharmony_ci <li class="listitem"> 16902f4aeb0Sopenharmony_ci <p> 17002f4aeb0Sopenharmony_ci If the context is bound to a pbuffer surface, 17102f4aeb0Sopenharmony_ci then <code class="constant">EGL_BACK_BUFFER</code> will 17202f4aeb0Sopenharmony_ci be returned. 17302f4aeb0Sopenharmony_ci </p> 17402f4aeb0Sopenharmony_ci </li> 17502f4aeb0Sopenharmony_ci <li class="listitem"> 17602f4aeb0Sopenharmony_ci <p> 17702f4aeb0Sopenharmony_ci If the context is bound to a window surface, 17802f4aeb0Sopenharmony_ci then either <code class="constant">EGL_BACK_BUFFER</code> 17902f4aeb0Sopenharmony_ci or <code class="constant">EGL_SINGLE_BUFFER</code> may be 18002f4aeb0Sopenharmony_ci returned. The value returned depends on both the 18102f4aeb0Sopenharmony_ci buffer requested by the setting of the 18202f4aeb0Sopenharmony_ci <code class="constant">EGL_RENDER_BUFFER</code> property 18302f4aeb0Sopenharmony_ci of the surface (which may be queried by calling 18402f4aeb0Sopenharmony_ci <code class="function">eglQuerySurface</code>), and on 18502f4aeb0Sopenharmony_ci the client API (not all client APIs support 18602f4aeb0Sopenharmony_ci single-buffer rendering to window surfaces). 18702f4aeb0Sopenharmony_ci </p> 18802f4aeb0Sopenharmony_ci </li> 18902f4aeb0Sopenharmony_ci <li class="listitem"> 19002f4aeb0Sopenharmony_ci <p> 19102f4aeb0Sopenharmony_ci If the context is not bound to a surface, such 19202f4aeb0Sopenharmony_ci as an OpenGL ES context bound to a framebuffer 19302f4aeb0Sopenharmony_ci object, then <code class="constant">EGL_NONE</code> will 19402f4aeb0Sopenharmony_ci be returned. 19502f4aeb0Sopenharmony_ci </p> 19602f4aeb0Sopenharmony_ci </li> 19702f4aeb0Sopenharmony_ci </ul> 19802f4aeb0Sopenharmony_ci </div> 19902f4aeb0Sopenharmony_ci </dd> 20002f4aeb0Sopenharmony_ci </dl> 20102f4aeb0Sopenharmony_ci </div> 20202f4aeb0Sopenharmony_ci </div> 20302f4aeb0Sopenharmony_ci <div class="refsect1" id="notes"> 20402f4aeb0Sopenharmony_ci <h2>Notes</h2> 20502f4aeb0Sopenharmony_ci <p> 20602f4aeb0Sopenharmony_ci Attributes <code class="constant">EGL_CONTEXT_CLIENT_TYPE</code> and 20702f4aeb0Sopenharmony_ci <code class="constant">EGL_RENDER_BUFFER</code> are supported only if 20802f4aeb0Sopenharmony_ci the EGL version is 1.2 or greater. 20902f4aeb0Sopenharmony_ci </p> 21002f4aeb0Sopenharmony_ci <p> 21102f4aeb0Sopenharmony_ci Attribute <code class="constant">EGL_CONTEXT_CLIENT_VERSION</code> is 21202f4aeb0Sopenharmony_ci supported only if the EGL version is 1.3 or greater. 21302f4aeb0Sopenharmony_ci </p> 21402f4aeb0Sopenharmony_ci </div> 21502f4aeb0Sopenharmony_ci <div class="refsect1" id="errors"> 21602f4aeb0Sopenharmony_ci <h2>Errors</h2> 21702f4aeb0Sopenharmony_ci <p> 21802f4aeb0Sopenharmony_ci <code class="constant">EGL_FALSE</code> is returned on failure, 21902f4aeb0Sopenharmony_ci <code class="constant">EGL_TRUE</code> otherwise. 22002f4aeb0Sopenharmony_ci <em class="parameter"><code>value</code></em> is not modified when 22102f4aeb0Sopenharmony_ci <code class="constant">EGL_FALSE</code> is returned. 22202f4aeb0Sopenharmony_ci </p> 22302f4aeb0Sopenharmony_ci <p> 22402f4aeb0Sopenharmony_ci <code class="constant">EGL_BAD_DISPLAY</code> is generated if 22502f4aeb0Sopenharmony_ci <em class="parameter"><code>display</code></em> is not an EGL display connection. 22602f4aeb0Sopenharmony_ci </p> 22702f4aeb0Sopenharmony_ci <p> 22802f4aeb0Sopenharmony_ci <code class="constant">EGL_NOT_INITIALIZED</code> is generated if 22902f4aeb0Sopenharmony_ci <em class="parameter"><code>display</code></em> has not been initialized. 23002f4aeb0Sopenharmony_ci </p> 23102f4aeb0Sopenharmony_ci <p> 23202f4aeb0Sopenharmony_ci <code class="constant">EGL_BAD_CONTEXT</code> is generated if 23302f4aeb0Sopenharmony_ci <em class="parameter"><code>context</code></em> is not an EGL rendering context. 23402f4aeb0Sopenharmony_ci </p> 23502f4aeb0Sopenharmony_ci <p> 23602f4aeb0Sopenharmony_ci <code class="constant">EGL_BAD_ATTRIBUTE</code> is generated if 23702f4aeb0Sopenharmony_ci <em class="parameter"><code>attribute</code></em> is not a valid context attribute. 23802f4aeb0Sopenharmony_ci </p> 23902f4aeb0Sopenharmony_ci </div> 24002f4aeb0Sopenharmony_ci <div class="refsect1" id="seealso"> 24102f4aeb0Sopenharmony_ci <h2>See Also</h2> 24202f4aeb0Sopenharmony_ci <p> 24302f4aeb0Sopenharmony_ci <a class="citerefentry" href="eglCreateContext.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreateContext</span></span></a> 24402f4aeb0Sopenharmony_ci </p> 24502f4aeb0Sopenharmony_ci </div> 24602f4aeb0Sopenharmony_ci <p> 24702f4aeb0Sopenharmony_ci </p> 24802f4aeb0Sopenharmony_ci <div class="refsect3" id="copyright"> 24902f4aeb0Sopenharmony_ci <img src="KhronosLogo.jpg"/> 25002f4aeb0Sopenharmony_ci <p> 25102f4aeb0Sopenharmony_ci Copyright © 2003-2014 The Khronos Group Inc. 25202f4aeb0Sopenharmony_ci Permission is hereby granted, free of charge, to any person obtaining a 25302f4aeb0Sopenharmony_ci copy of this software and/or associated documentation files (the 25402f4aeb0Sopenharmony_ci "Materials"), to deal in the Materials without restriction, including 25502f4aeb0Sopenharmony_ci without limitation the rights to use, copy, modify, merge, publish, 25602f4aeb0Sopenharmony_ci distribute, sublicense, and/or sell copies of the Materials, and to 25702f4aeb0Sopenharmony_ci permit persons to whom the Materials are furnished to do so, subject to 25802f4aeb0Sopenharmony_ci the condition that this copyright notice and permission notice shall be included 25902f4aeb0Sopenharmony_ci in all copies or substantial portions of the Materials. 26002f4aeb0Sopenharmony_ci </p> 26102f4aeb0Sopenharmony_ci </div> 26202f4aeb0Sopenharmony_ci <p> 26302f4aeb0Sopenharmony_ci</p> 26402f4aeb0Sopenharmony_ci </div> 26502f4aeb0Sopenharmony_ci <footer/> 26602f4aeb0Sopenharmony_ci </body> 26702f4aeb0Sopenharmony_ci</html> 268
