xref: /third_party/EGL/sdk/docs/man/docbook4/eglGetProcAddress.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
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<refentry xml:base="" id="eglGetProcAddress">
    <refentryinfo>
         <copyright>
             <year>2003-2014</year>
             <holder>The Khronos Group Inc.</holder>
         </copyright>
    </refentryinfo>
    <refmeta>
        <refentrytitle>eglGetProcAddress</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>eglGetProcAddress</refname>
        <refpurpose>
            return a <acronym>GL</acronym> or an <acronym>EGL</acronym>
            extension function
        </refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void (* <function>eglGetProcAddress</function>)()</funcdef>
                <paramdef>char const * <parameter>procname</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
            <varlistentry>
                <term><parameter>procname</parameter></term>
                <listitem>
                    <para>
                        Specifies the name of the function to return.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>eglGetProcAddress</function> returns the address of
            the extension function named by <parameter>procname</parameter>.
            <parameter>procname</parameter>
            must be a null-terminated string. The pointer returned
            should be cast to a function pointer type matching the extension
            function's definition in that extension specification. A return value
            of <constant>NULL</constant> indicates that the specific
            function does not exist for the <acronym>EGL</acronym> implementation.
        </para>
        <para>
            A non-<constant>NULL</constant> return value does not guarantee
            that an extension function is actually supported at runtime. The client
            must also query
            <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>(<constant>GL_EXTENSIONS</constant>) or
            <citerefentry><refentrytitle>eglQueryString</refentrytitle></citerefentry>(<parameter>display</parameter>,
            <constant>EGL_EXTENSIONS</constant>) to determine if an
            extension is supported by a particular context or display.
        </para>
        <para>
            Function pointers returned by
            <function>eglGetProcAddress</function> are independent of the
            display and the currently bound context and may be used by any context
            which supports the extension.
        </para>
        <para>
            <function>eglGetProcAddress</function> may be queried for all
            <acronym>GL</acronym> and <acronym>EGL</acronym> extension functions.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>eglQueryString</refentrytitle></citerefentry>    </para>
    </refsect1>
    <refsect3 id="Copyright"><title></title>
        <!-- Content included from copyright.inc.xsl -->
        <imageobject>
                <imagedata fileref="KhronosLogo.jpg" format="jpg" />
        </imageobject>
        <para />
    </refsect3>
</refentry>