1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 <title xmlns:xlink="http://www.w3.org/1999/xlink">eglMakeCurrent - EGL Reference Pages</title> 5 <link rel="stylesheet" type="text/css" href="khronos-man.css"/> 6 <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"/> 7 </head> 8 <body> 9 <header/> 10 <div class="refentry" id="eglMakeCurrent"> 11 <div class="titlepage"/> 12 <div class="refnamediv"> 13 <h2>Name</h2> 14 <p>eglMakeCurrent — 15 attach an EGL rendering context to EGL surfaces 16 </p> 17 </div> 18 <div class="refsynopsisdiv"> 19 <h2>C Specification</h2> 20 <div class="funcsynopsis"> 21 <table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table"> 22 <tr> 23 <td> 24 <code class="funcdef">EGLBoolean <strong class="fsfunc">eglMakeCurrent</strong>(</code> 25 </td> 26 <td>EGLDisplay <var class="pdparam">display</var>, </td> 27 </tr> 28 <tr> 29 <td> </td> 30 <td>EGLSurface <var class="pdparam">draw</var>, </td> 31 </tr> 32 <tr> 33 <td> </td> 34 <td>EGLSurface <var class="pdparam">read</var>, </td> 35 </tr> 36 <tr> 37 <td> </td> 38 <td>EGLContext <var class="pdparam">context</var><code>)</code>;</td> 39 </tr> 40 </table> 41 <div class="funcprototype-spacer"> </div> 42 </div> 43 </div> 44 <div class="refsect1" id="parameters"> 45 <h2>Parameters</h2> 46 <div class="variablelist"> 47 <dl class="variablelist"> 48 <dt> 49 <span class="term"> 50 <em class="parameter"> 51 <code>display</code> 52 </em> 53 </span> 54 </dt> 55 <dd> 56 <p>Specifies the <abbr class="acronym">EGL</abbr> display connection.</p> 57 </dd> 58 <dt> 59 <span class="term"> 60 <em class="parameter"> 61 <code>draw</code> 62 </em> 63 </span> 64 </dt> 65 <dd> 66 <p>Specifies the <abbr class="acronym">EGL</abbr> draw surface.</p> 67 </dd> 68 <dt> 69 <span class="term"> 70 <em class="parameter"> 71 <code>read</code> 72 </em> 73 </span> 74 </dt> 75 <dd> 76 <p>Specifies the <abbr class="acronym">EGL</abbr> read surface.</p> 77 </dd> 78 <dt> 79 <span class="term"> 80 <em class="parameter"> 81 <code>context</code> 82 </em> 83 </span> 84 </dt> 85 <dd> 86 <p>Specifies the <abbr class="acronym">EGL</abbr> rendering context 87 to be attached to the surfaces. 88 </p> 89 </dd> 90 </dl> 91 </div> 92 </div> 93 <div class="refsect1" id="description"> 94 <h2>Description</h2> 95 <p> 96 <code class="function">eglMakeCurrent</code> binds <em class="parameter"><code>context</code></em> 97 to the current rendering thread and to the <em class="parameter"><code>draw</code></em> 98 and <em class="parameter"><code>read</code></em> surfaces. <em class="parameter"><code>draw</code></em> 99 is used for all GL operations except for any pixel data read back 100 (<a class="citerefentry" href="glReadPixels.xhtml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>, 101 <a class="citerefentry" href="glCopyTexImage2D.xhtml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>, and 102 <a class="citerefentry" href="glCopyTexSubImage2D.xhtml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>), 103 which is taken from the frame buffer values of 104 <em class="parameter"><code>read</code></em>. 105 </p> 106 <p> 107 If the calling thread has already a current rendering context, that 108 context is flushed and marked as no longer current. 109 </p> 110 <p> 111 The first time that <em class="parameter"><code>context</code></em> is made current, 112 the viewport and scissor dimensions are set to the size of the 113 <em class="parameter"><code>draw</code></em> surface. The viewport and 114 scissor are not modified when <em class="parameter"><code>context</code></em> is 115 subsequently made current. 116 </p> 117 <p> 118 To release the current context without assigning a new one, call 119 <code class="function">eglMakeCurrent</code> with <em class="parameter"><code>draw</code></em> 120 and <em class="parameter"><code>read</code></em> set to 121 <code class="constant">EGL_NO_SURFACE</code> and <em class="parameter"><code>context</code></em> 122 set to <code class="constant">EGL_NO_CONTEXT</code>. 123 </p> 124 <p> 125 Use 126 <a class="citerefentry" href="eglGetCurrentContext.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetCurrentContext</span></span></a>, 127 <a class="citerefentry" href="eglGetCurrentDisplay.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetCurrentDisplay</span></span></a>, and 128 <a class="citerefentry" href="eglGetCurrentSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetCurrentSurface</span></span></a> 129 to query the current rendering context and associated display connection and surfaces. 130 </p> 131 </div> 132 <div class="refsect1" id="errors"> 133 <h2>Errors</h2> 134 <p> 135 <code class="constant">EGL_FALSE</code> is returned on failure, 136 <code class="constant">EGL_TRUE</code> otherwise. If <code class="constant">EGL_FALSE</code> 137 is returned, the previously current rendering context and 138 surfaces (if any) remain unchanged. 139 </p> 140 <p> 141 <code class="constant">EGL_BAD_DISPLAY</code> is generated if 142 <em class="parameter"><code>display</code></em> is not an EGL display connection. 143 </p> 144 <p> 145 <code class="constant">EGL_NOT_INITIALIZED</code> is generated if 146 <em class="parameter"><code>display</code></em> has not been initialized. 147 </p> 148 <p> 149 <code class="constant">EGL_BAD_SURFACE</code> is generated if 150 <em class="parameter"><code>draw</code></em> or <em class="parameter"><code>read</code></em> is not an 151 EGL surface. 152 </p> 153 <p> 154 <code class="constant">EGL_BAD_CONTEXT</code> is generated if 155 <em class="parameter"><code>context</code></em> is not an EGL rendering context. 156 </p> 157 <p> 158 <code class="constant">EGL_BAD_MATCH</code> is generated if 159 <em class="parameter"><code>draw</code></em> or 160 <em class="parameter"><code>read</code></em> 161 are not compatible with 162 <em class="parameter"><code>context</code></em>, or if 163 <em class="parameter"><code>context</code></em> is set to 164 <code class="constant">EGL_NO_CONTEXT</code> and 165 <em class="parameter"><code>draw</code></em> or 166 <em class="parameter"><code>read</code></em> 167 are not set to 168 <code class="constant">EGL_NO_SURFACE</code>, or if 169 <em class="parameter"><code>draw</code></em> or 170 <em class="parameter"><code>read</code></em> are set to 171 <code class="constant">EGL_NO_SURFACE</code> and 172 <em class="parameter"><code>context</code></em> is not set to 173 <code class="constant">EGL_NO_CONTEXT</code>. 174 </p> 175 <p> 176 <code class="constant">EGL_BAD_ACCESS</code> is generated if 177 <em class="parameter"><code>context</code></em> 178 is current to some other thread. 179 </p> 180 <p> 181 <code class="constant">EGL_BAD_NATIVE_PIXMAP</code> may be generated if 182 a native pixmap underlying either 183 <em class="parameter"><code>draw</code></em> or 184 <em class="parameter"><code>read</code></em> 185 is no longer valid. 186 </p> 187 <p> 188 <code class="constant">EGL_BAD_NATIVE_WINDOW</code> may be generated if 189 a native window underlying either 190 <em class="parameter"><code>draw</code></em> or 191 <em class="parameter"><code>read</code></em> 192 is no longer valid. 193 </p> 194 <p> 195 <code class="constant">EGL_BAD_CURRENT_SURFACE</code> is generated if 196 the previous context has unflushed commands and the previous surface 197 is no longer valid. 198 </p> 199 <p> 200 <code class="constant">EGL_BAD_ALLOC</code> may be generated if 201 allocation of ancillary buffers for <em class="parameter"><code>draw</code></em> or 202 <em class="parameter"><code>read</code></em> were delayed until 203 <code class="function">eglMakeCurrent</code> is called, and there are not 204 enough resources to allocate them. 205 </p> 206 <p> 207 <code class="constant">EGL_CONTEXT_LOST</code> is generated if a power management 208 event has occurred. The application must destroy all contexts and 209 reinitialise OpenGL ES state and objects to continue rendering. 210 </p> 211 </div> 212 <div class="refsect1" id="seealso"> 213 <h2>See Also</h2> 214 <p> 215 <a class="citerefentry" href="glReadPixels.xhtml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>, 216 <a class="citerefentry" href="glCopyTexImage2D.xhtml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>, 217 <a class="citerefentry" href="glCopyTexSubImage2D.xhtml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>, 218 <a class="citerefentry" href="eglCreateContext.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreateContext</span></span></a>, 219 <a class="citerefentry" href="eglCreatePbufferSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreatePbufferSurface</span></span></a>, 220 <a class="citerefentry" href="eglCreatePixmapSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreatePixmapSurface</span></span></a>, 221 <a class="citerefentry" href="eglCreateWindowSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreateWindowSurface</span></span></a>, 222 <a class="citerefentry" href="eglGetCurrentContext.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetCurrentContext</span></span></a>, 223 <a class="citerefentry" href="eglGetCurrentDisplay.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetCurrentDisplay</span></span></a>, 224 <a class="citerefentry" href="eglGetCurrentSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetCurrentSurface</span></span></a>, 225 <a class="citerefentry" href="eglGetDisplay.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetDisplay</span></span></a>, 226 <a class="citerefentry" href="eglInitialize.xhtml"><span class="citerefentry"><span class="refentrytitle">eglInitialize</span></span></a> 227 </p> 228 </div> 229 <p> 230 </p> 231 <div class="refsect3" id="copyright"> 232 <img src="KhronosLogo.jpg"/> 233 <p> 234 Copyright © 2003-2014 The Khronos Group Inc. 235 Permission is hereby granted, free of charge, to any person obtaining a 236 copy of this software and/or associated documentation files (the 237 "Materials"), to deal in the Materials without restriction, including 238 without limitation the rights to use, copy, modify, merge, publish, 239 distribute, sublicense, and/or sell copies of the Materials, and to 240 permit persons to whom the Materials are furnished to do so, subject to 241 the condition that this copyright notice and permission notice shall be included 242 in all copies or substantial portions of the Materials. 243 </p> 244 </div> 245 <p> 246</p> 247 </div> 248 <footer/> 249 </body> 250</html> 251
