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">eglSwapBuffers - 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="eglSwapBuffers"> 1102f4aeb0Sopenharmony_ci <div class="titlepage"/> 1202f4aeb0Sopenharmony_ci <div class="refnamediv"> 1302f4aeb0Sopenharmony_ci <h2>Name</h2> 1402f4aeb0Sopenharmony_ci <p>eglSwapBuffers — 1502f4aeb0Sopenharmony_ci post <abbr class="acronym">EGL</abbr> surface color buffer to a native window 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">eglSwapBuffers</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>EGLSurface <var class="pdparam">surface</var><code>)</code>;</td> 3102f4aeb0Sopenharmony_ci </tr> 3202f4aeb0Sopenharmony_ci </table> 3302f4aeb0Sopenharmony_ci <div class="funcprototype-spacer"> </div> 3402f4aeb0Sopenharmony_ci </div> 3502f4aeb0Sopenharmony_ci </div> 3602f4aeb0Sopenharmony_ci <div class="refsect1" id="parameters"> 3702f4aeb0Sopenharmony_ci <h2>Parameters</h2> 3802f4aeb0Sopenharmony_ci <div class="variablelist"> 3902f4aeb0Sopenharmony_ci <dl class="variablelist"> 4002f4aeb0Sopenharmony_ci <dt> 4102f4aeb0Sopenharmony_ci <span class="term"> 4202f4aeb0Sopenharmony_ci <em class="parameter"> 4302f4aeb0Sopenharmony_ci <code>display</code> 4402f4aeb0Sopenharmony_ci </em> 4502f4aeb0Sopenharmony_ci </span> 4602f4aeb0Sopenharmony_ci </dt> 4702f4aeb0Sopenharmony_ci <dd> 4802f4aeb0Sopenharmony_ci <p> 4902f4aeb0Sopenharmony_ci Specifies the EGL display connection. 5002f4aeb0Sopenharmony_ci </p> 5102f4aeb0Sopenharmony_ci </dd> 5202f4aeb0Sopenharmony_ci <dt> 5302f4aeb0Sopenharmony_ci <span class="term"> 5402f4aeb0Sopenharmony_ci <em class="parameter"> 5502f4aeb0Sopenharmony_ci <code>surface</code> 5602f4aeb0Sopenharmony_ci </em> 5702f4aeb0Sopenharmony_ci </span> 5802f4aeb0Sopenharmony_ci </dt> 5902f4aeb0Sopenharmony_ci <dd> 6002f4aeb0Sopenharmony_ci <p> 6102f4aeb0Sopenharmony_ci Specifies the EGL drawing surface whose buffers are to be swapped. 6202f4aeb0Sopenharmony_ci </p> 6302f4aeb0Sopenharmony_ci </dd> 6402f4aeb0Sopenharmony_ci </dl> 6502f4aeb0Sopenharmony_ci </div> 6602f4aeb0Sopenharmony_ci </div> 6702f4aeb0Sopenharmony_ci <div class="refsect1" id="description"> 6802f4aeb0Sopenharmony_ci <h2>Description</h2> 6902f4aeb0Sopenharmony_ci <p> 7002f4aeb0Sopenharmony_ci If <em class="parameter"><code>surface</code></em> is a back-buffered window 7102f4aeb0Sopenharmony_ci surface, then the color 7202f4aeb0Sopenharmony_ci buffer is copied (posted) to the native window associated with that 7302f4aeb0Sopenharmony_ci surface. If <em class="parameter"><code>surface</code></em> is a single-buffered 7402f4aeb0Sopenharmony_ci window, pixmap, or pixel buffer surface, 7502f4aeb0Sopenharmony_ci <code class="function">eglSwapBuffers</code> has no effect. 7602f4aeb0Sopenharmony_ci </p> 7702f4aeb0Sopenharmony_ci <p> 7802f4aeb0Sopenharmony_ci The contents of ancillary buffers are always undefined after 7902f4aeb0Sopenharmony_ci calling <code class="function">eglSwapBuffers</code>. The contents of the 8002f4aeb0Sopenharmony_ci color buffer are undefined if the value of the 8102f4aeb0Sopenharmony_ci <code class="constant">EGL_SWAP_BEHAVIOR</code> attribute of 8202f4aeb0Sopenharmony_ci <em class="parameter"><code>surface</code></em> is not 8302f4aeb0Sopenharmony_ci <code class="constant">EGL_BUFFER_PRESERVED</code>. The value of 8402f4aeb0Sopenharmony_ci <code class="constant">EGL_SWAP_BEHAVIOR</code> can be set for some 8502f4aeb0Sopenharmony_ci surfaces using 8602f4aeb0Sopenharmony_ci <a class="citerefentry" href="eglSurfaceAttrib.xhtml"><span class="citerefentry"><span class="refentrytitle">eglSurfaceAttrib</span></span></a>. 8702f4aeb0Sopenharmony_ci <code class="constant">EGL_SWAP_BEHAVIOR</code> applies only to the color 8802f4aeb0Sopenharmony_ci buffer. EGL has no way to specify or query whether or not 8902f4aeb0Sopenharmony_ci ancillary buffers are preserved, and applications should not 9002f4aeb0Sopenharmony_ci rely on this behavior. 9102f4aeb0Sopenharmony_ci </p> 9202f4aeb0Sopenharmony_ci <p> 9302f4aeb0Sopenharmony_ci <code class="function">eglSwapBuffers</code> performs an implicit 9402f4aeb0Sopenharmony_ci flush operation on the context (<code class="function">glFlush</code> 9502f4aeb0Sopenharmony_ci for an OpenGL ES or OpenGL context, 9602f4aeb0Sopenharmony_ci <code class="function">vgFlush</code> for an OpenVG context) bound to 9702f4aeb0Sopenharmony_ci <em class="parameter"><code>surface</code></em> before swapping. Subsequent 9802f4aeb0Sopenharmony_ci client API commands may be issued on that context 9902f4aeb0Sopenharmony_ci immediately after calling 10002f4aeb0Sopenharmony_ci <code class="function">eglSwapBuffers</code>, but are not executed 10102f4aeb0Sopenharmony_ci until the buffer exchange is completed. 10202f4aeb0Sopenharmony_ci </p> 10302f4aeb0Sopenharmony_ci </div> 10402f4aeb0Sopenharmony_ci <div class="refsect1" id="resize"> 10502f4aeb0Sopenharmony_ci <h2>Native Window Resizing</h2> 10602f4aeb0Sopenharmony_ci <p> 10702f4aeb0Sopenharmony_ci If the native window corresponding to 10802f4aeb0Sopenharmony_ci <em class="parameter"><code>surface</code></em> has been resized prior to the 10902f4aeb0Sopenharmony_ci swap, <em class="parameter"><code>surface</code></em> must be resized to match. 11002f4aeb0Sopenharmony_ci <em class="parameter"><code>surface</code></em> will normally be resized by the 11102f4aeb0Sopenharmony_ci EGL implementation at the time the native window is resized. If 11202f4aeb0Sopenharmony_ci the implementation cannot do this transparently to the client, 11302f4aeb0Sopenharmony_ci then <code class="function">eglSwapBuffers</code> must detect the change 11402f4aeb0Sopenharmony_ci and resize surface prior to copying its pixels to the native 11502f4aeb0Sopenharmony_ci window. If <em class="parameter"><code>surface</code></em> shrinks as a result of 11602f4aeb0Sopenharmony_ci resizing, some rendered pixels are lost. If 11702f4aeb0Sopenharmony_ci <em class="parameter"><code>surface</code></em> grows, the newly allocated buffer 11802f4aeb0Sopenharmony_ci contents are undefined. The resizing behavior described here 11902f4aeb0Sopenharmony_ci only maintains consistency of EGL surfaces and native windows; 12002f4aeb0Sopenharmony_ci clients are still responsible for detecting window size changes 12102f4aeb0Sopenharmony_ci (using platform-specific means) and changing their viewport and 12202f4aeb0Sopenharmony_ci scissor regions accordingly. 12302f4aeb0Sopenharmony_ci </p> 12402f4aeb0Sopenharmony_ci </div> 12502f4aeb0Sopenharmony_ci <div class="refsect1" id="notes"> 12602f4aeb0Sopenharmony_ci <h2>Notes</h2> 12702f4aeb0Sopenharmony_ci <p> 12802f4aeb0Sopenharmony_ci Attribute <code class="constant">EGL_SWAP_BEHAVIOR</code> is supported 12902f4aeb0Sopenharmony_ci only if the EGL version is 1.2 or greater. In earlier versions, 13002f4aeb0Sopenharmony_ci behavior is as though the attribute exists, and always has the 13102f4aeb0Sopenharmony_ci value <code class="constant">EGL_BUFFER_DESTROYED</code>. 13202f4aeb0Sopenharmony_ci </p> 13302f4aeb0Sopenharmony_ci <p> 13402f4aeb0Sopenharmony_ci The EGL 1.4 specification was updated to acknowledge that 13502f4aeb0Sopenharmony_ci ancillary buffers are not necessarily preserved after a swap, 13602f4aeb0Sopenharmony_ci and that the <code class="constant">EGL_SWAP_BEHAVIOR</code> attribute 13702f4aeb0Sopenharmony_ci applies only to the color buffer. This change in the 13802f4aeb0Sopenharmony_ci specification acknowledged the behavior of many shipping 13902f4aeb0Sopenharmony_ci implementations, and is not intended to result in behavior 14002f4aeb0Sopenharmony_ci changes in any existing implementation. 14102f4aeb0Sopenharmony_ci </p> 14202f4aeb0Sopenharmony_ci </div> 14302f4aeb0Sopenharmony_ci <div class="refsect1" id="errors"> 14402f4aeb0Sopenharmony_ci <h2>Errors</h2> 14502f4aeb0Sopenharmony_ci <p> 14602f4aeb0Sopenharmony_ci <code class="constant">EGL_FALSE</code> is returned if swapping of the 14702f4aeb0Sopenharmony_ci surface buffers fails, <code class="constant">EGL_TRUE</code> otherwise. 14802f4aeb0Sopenharmony_ci </p> 14902f4aeb0Sopenharmony_ci <p> 15002f4aeb0Sopenharmony_ci <code class="constant">EGL_BAD_DISPLAY</code> is generated if 15102f4aeb0Sopenharmony_ci <em class="parameter"><code>display</code></em> is not an EGL display connection. 15202f4aeb0Sopenharmony_ci </p> 15302f4aeb0Sopenharmony_ci <p> 15402f4aeb0Sopenharmony_ci <code class="constant">EGL_NOT_INITIALIZED</code> is generated if 15502f4aeb0Sopenharmony_ci <em class="parameter"><code>display</code></em> has not been initialized. 15602f4aeb0Sopenharmony_ci </p> 15702f4aeb0Sopenharmony_ci <p> 15802f4aeb0Sopenharmony_ci <code class="constant">EGL_BAD_SURFACE</code> is generated if 15902f4aeb0Sopenharmony_ci <em class="parameter"><code>surface</code></em> is not an EGL drawing surface. 16002f4aeb0Sopenharmony_ci </p> 16102f4aeb0Sopenharmony_ci <p> 16202f4aeb0Sopenharmony_ci <code class="constant">EGL_CONTEXT_LOST</code> is generated if a power management 16302f4aeb0Sopenharmony_ci event has occurred. The application must destroy all contexts and 16402f4aeb0Sopenharmony_ci reinitialise OpenGL ES state and objects to continue rendering. 16502f4aeb0Sopenharmony_ci </p> 16602f4aeb0Sopenharmony_ci </div> 16702f4aeb0Sopenharmony_ci <div class="refsect1" id="seealso"> 16802f4aeb0Sopenharmony_ci <h2>See Also</h2> 16902f4aeb0Sopenharmony_ci <p> 17002f4aeb0Sopenharmony_ci <code class="function">glFlush</code>, 17102f4aeb0Sopenharmony_ci <a class="citerefentry" href="eglCopyBuffers.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCopyBuffers</span></span></a>, 17202f4aeb0Sopenharmony_ci <code class="function">vgFlush</code> 17302f4aeb0Sopenharmony_ci </p> 17402f4aeb0Sopenharmony_ci </div> 17502f4aeb0Sopenharmony_ci <p> 17602f4aeb0Sopenharmony_ci </p> 17702f4aeb0Sopenharmony_ci <div class="refsect3" id="copyright"> 17802f4aeb0Sopenharmony_ci <img src="KhronosLogo.jpg"/> 17902f4aeb0Sopenharmony_ci <p> 18002f4aeb0Sopenharmony_ci Copyright © 2003-2014 The Khronos Group Inc. 18102f4aeb0Sopenharmony_ci Permission is hereby granted, free of charge, to any person obtaining a 18202f4aeb0Sopenharmony_ci copy of this software and/or associated documentation files (the 18302f4aeb0Sopenharmony_ci "Materials"), to deal in the Materials without restriction, including 18402f4aeb0Sopenharmony_ci without limitation the rights to use, copy, modify, merge, publish, 18502f4aeb0Sopenharmony_ci distribute, sublicense, and/or sell copies of the Materials, and to 18602f4aeb0Sopenharmony_ci permit persons to whom the Materials are furnished to do so, subject to 18702f4aeb0Sopenharmony_ci the condition that this copyright notice and permission notice shall be included 18802f4aeb0Sopenharmony_ci in all copies or substantial portions of the Materials. 18902f4aeb0Sopenharmony_ci </p> 19002f4aeb0Sopenharmony_ci </div> 19102f4aeb0Sopenharmony_ci <p> 19202f4aeb0Sopenharmony_ci</p> 19302f4aeb0Sopenharmony_ci </div> 19402f4aeb0Sopenharmony_ci <footer/> 19502f4aeb0Sopenharmony_ci </body> 19602f4aeb0Sopenharmony_ci</html> 197
