1<?xml version="1.0" encoding="UTF-8"?> 2<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN" 3 "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd"> 4<refentry xml:base="" id="eglSwapBuffers"> 5 <refentryinfo> 6 <copyright> 7 <year>2003-2014</year> 8 <holder>The Khronos Group Inc.</holder> 9 </copyright> 10 </refentryinfo> 11 <refmeta> 12 <refentrytitle>eglSwapBuffers</refentrytitle> 13 <manvolnum>3G</manvolnum> 14 </refmeta> 15 <refnamediv> 16 <refname>eglSwapBuffers</refname> 17 <refpurpose> 18 post <acronym>EGL</acronym> surface color buffer to a native window 19 </refpurpose> 20 </refnamediv> 21 <refsynopsisdiv> 22 <title>C Specification</title> 23 <funcsynopsis> 24 <funcprototype> 25 <funcdef>EGLBoolean <function>eglSwapBuffers</function></funcdef> 26 <paramdef>EGLDisplay <parameter>display</parameter></paramdef> 27 <paramdef>EGLSurface <parameter>surface</parameter></paramdef> 28 </funcprototype> 29 </funcsynopsis> 30 </refsynopsisdiv> 31 <refsect1 id="parameters"><title>Parameters</title> 32 <variablelist> 33 <varlistentry> 34 <term><parameter>display</parameter></term> 35 <listitem> 36 <para> 37 Specifies the EGL display connection. 38 </para> 39 </listitem> 40 </varlistentry> 41 <varlistentry> 42 <term><parameter>surface</parameter></term> 43 <listitem> 44 <para> 45 Specifies the EGL drawing surface whose buffers are to be swapped. 46 </para> 47 </listitem> 48 </varlistentry> 49 </variablelist> 50 </refsect1> 51 <refsect1 id="description"><title>Description</title> 52 <para> 53 If <parameter>surface</parameter> is a window surface, 54 <function>eglSwapBuffers</function> posts its color buffer 55 to the associated native window. 56 </para> 57 <para> 58 The contents of ancillary buffers are always undefined after 59 calling <function>eglSwapBuffers</function>. The contents of 60 the color buffer are left unchanged if the value of the 61 <constant>EGL_SWAP_BEHAVIOR</constant> attribute of 62 <parameter>surface</parameter> is 63 <constant>EGL_BUFFER_PRESERVED</constant>, and are undefined 64 if the value is <constant>EGL_BUFFER_DESTROYED</constant>. 65 The value of <constant>EGL_SWAP_BEHAVIOR</constant> can be 66 set for some surfaces using 67 <citerefentry><refentrytitle>eglSurfaceAttrib</refentrytitle></citerefentry>. 68 </para> 69 <para> 70 <function>eglSwapBuffers</function> performs an implicit 71 flush operation on the context (<function>glFlush</function> 72 for an OpenGL ES or OpenGL context, 73 <function>vgFlush</function> for an OpenVG context) bound to 74 <parameter>surface</parameter> before swapping. Subsequent 75 client API commands may be issued on that context 76 immediately after calling 77 <function>eglSwapBuffers</function>, but are not executed 78 until the buffer exchange is completed. 79 </para> 80 <para> 81 If <parameter>surface</parameter> is a pixel buffer or a pixmap, 82 <function>eglSwapBuffers</function> 83 has no effect, and no error is generated. 84 </para> 85 </refsect1> 86 <refsect1 id="notes"><title>Notes</title> 87 <para> 88 Attribute <constant>EGL_SWAP_BEHAVIOR</constant> is 89 supported only if the EGL version is 1.2 or greater. In 90 earlier versions, behavior is as though the attribute 91 exists, and always has the value 92 <constant>EGL_BUFFER_DESTROYED</constant>. 93 </para> 94 <para> 95 The EGL 1.4 specification was updated to acknowledge that 96 ancillary buffers are not necessarily preserved after a 97 swap, and that the <constant>EGL_SWAP_BEHAVIOR</constant> 98 attribute applies only to the color buffer. This change in 99 the specification acknowledged the behavior of many shipping 100 implementations, and is not intended to result in behavior 101 changes in any existing implementation. Applications which 102 require preservation of ancillary buffers across a swap 103 should be aware that not all implementations can preserve 104 them, and that EGL 1.4 has no way to query whether or not 105 they are preserved. 106 </para> 107 </refsect1> 108 <refsect1 id="errors"><title>Errors</title> 109 <para> 110 <constant>EGL_FALSE</constant> is returned if swapping of the 111 surface buffers fails, <constant>EGL_TRUE</constant> otherwise. 112 </para> 113 <para> 114 <constant>EGL_BAD_DISPLAY</constant> is generated if 115 <parameter>display</parameter> is not an EGL display connection. 116 </para> 117 <para> 118 <constant>EGL_NOT_INITIALIZED</constant> is generated if 119 <parameter>display</parameter> has not been initialized. 120 </para> 121 <para> 122 <constant>EGL_BAD_SURFACE</constant> is generated if 123 <parameter>surface</parameter> is not an EGL drawing surface. 124 </para> 125 <para> 126 <constant>EGL_CONTEXT_LOST</constant> is generated if a power management 127 event has occurred. The application must destroy all contexts and 128 reinitialise OpenGL ES state and objects to continue rendering. 129 </para> 130 </refsect1> 131 <refsect1 id="seealso"><title>See Also</title> 132 <para> 133 <citerefentry><refentrytitle>glFlush</refentrytitle></citerefentry>, 134 <citerefentry><refentrytitle>eglCopyBuffers</refentrytitle></citerefentry> 135 </para> 136 </refsect1> 137 <refsect3 id="Copyright"><title></title> 138 <!-- Content included from copyright.inc.xsl --> 139 <imageobject> 140 <imagedata fileref="KhronosLogo.jpg" format="jpg" /> 141 </imageobject> 142 <para /> 143 </refsect3> 144</refentry> 145
