1<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:base="" xml:id="eglGetProcAddress"> 2 <info> 3 <copyright> 4 <year>2003-2014</year> 5 <holder>The Khronos Group Inc.</holder> 6 </copyright> 7 </info> 8 <refmeta> 9 <refentrytitle>eglGetProcAddress</refentrytitle> 10 <manvolnum>3G</manvolnum> 11 </refmeta> 12 <refnamediv> 13 <refname>eglGetProcAddress</refname> 14 <refpurpose> 15 return a <acronym>GL</acronym> or an <acronym>EGL</acronym> 16 extension function 17 </refpurpose> 18 </refnamediv> 19 <refsynopsisdiv> 20 <title>C Specification</title> 21 <funcsynopsis> 22 <funcprototype> 23 <funcdef>void (* <function>eglGetProcAddress</function>)()</funcdef> 24 <paramdef>char const * <parameter>procname</parameter></paramdef> 25 </funcprototype> 26 </funcsynopsis> 27 </refsynopsisdiv> 28 <refsect1 xml:id="parameters"><title>Parameters</title> 29 <variablelist> 30 <varlistentry> 31 <term><parameter>procname</parameter></term> 32 <listitem> 33 <para> 34 Specifies the name of the function to return. 35 </para> 36 </listitem> 37 </varlistentry> 38 </variablelist> 39 </refsect1> 40 <refsect1 xml:id="description"><title>Description</title> 41 <para> 42 <function>eglGetProcAddress</function> returns the address of 43 the extension function named by <parameter>procname</parameter>. 44 <parameter>procname</parameter> 45 must be a null-terminated string. The pointer returned 46 should be cast to a function pointer type matching the extension 47 function's definition in that extension specification. A return value 48 of <constant>NULL</constant> indicates that the specific 49 function does not exist for the <acronym>EGL</acronym> implementation. 50 </para> 51 <para> 52 A non-<constant>NULL</constant> return value does not guarantee 53 that an extension function is actually supported at runtime. The client 54 must also query 55 <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>(<constant>GL_EXTENSIONS</constant>) or 56 <citerefentry><refentrytitle>eglQueryString</refentrytitle></citerefentry>(<parameter>display</parameter>, 57 <constant>EGL_EXTENSIONS</constant>) to determine if an 58 extension is supported by a particular context or display. 59 </para> 60 <para> 61 Function pointers returned by 62 <function>eglGetProcAddress</function> are independent of the 63 display and the currently bound context and may be used by any context 64 which supports the extension. 65 </para> 66 <para> 67 <function>eglGetProcAddress</function> may be queried for all 68 <acronym>GL</acronym> and <acronym>EGL</acronym> extension functions. 69 </para> 70 </refsect1> 71 <refsect1 xml:id="seealso"><title>See Also</title> 72 <para> 73 <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>, 74 <citerefentry><refentrytitle>eglQueryString</refentrytitle></citerefentry> </para> 75 </refsect1> 76 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="copyright.xml"/> 77</refentry> 78