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

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
                            "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
<refentry xml:base="" id="eglSwapInterval">
    <refentryinfo>
         <copyright>
             <year>2003-2014</year>
             <holder>The Khronos Group Inc.</holder>
         </copyright>
    </refentryinfo>
    <refmeta>
        <refentrytitle>eglSwapInterval</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>eglSwapInterval</refname>
        <refpurpose>
            specifies the minimum number of video frame periods
            per buffer swap for the window associated with the current context.
        </refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>EGLBoolean <function>eglSwapInterval</function></funcdef>
                <paramdef>EGLDisplay <parameter>display</parameter></paramdef>
                <paramdef>EGLint <parameter>interval</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
            <varlistentry>
                <term><parameter>display</parameter></term>
                <listitem>
                    <para>
                        Specifies the EGL display connection.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><parameter>interval</parameter></term>
                <listitem>
                    <para>
                        Specifies the minimum number of video frames that are displayed before
                        a buffer swap will occur.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            The interval takes effect when <citerefentry><refentrytitle>eglSwapBuffers</refentrytitle></citerefentry> is
            first called subsequent to the <function>eglSwapInterval</function> call.
        </para>
        <para>
            The <parameter>interval</parameter> specified by the function applies to the draw surface
            bound to the context that is current on the calling thread.
        </para>
        <para>
            If <parameter>interval</parameter> is set to a value of <constant>0</constant>, buffer swaps are not synchronized to a
            video frame, and the swap happens as soon as the render is complete. interval
            is silently clamped to minimum and maximum implementation dependent
            valuesbefore being stored; these values are defined by <type>EGLConfig</type> attributes
            <constant>EGL_MIN_SWAP_INTERVAL</constant> and <constant>EGL_MAX_SWAP_INTERVAL</constant> respectively.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            The swap interval has no effect on <citerefentry><refentrytitle>eglCopyBuffers</refentrytitle></citerefentry>.
        </para>
        <para>
            The default swap interval is 1.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>EGL_FALSE</constant> is returned on failure, <constant>EGL_TRUE</constant> otherwise.
        </para>
        <para>
            <constant>EGL_BAD_CONTEXT</constant> is generated if there is no current context
            on the calling thread.
        </para>
        <para>
            <constant>EGL_BAD_SURFACE</constant> is generated if there is no surface
            bound to the current context.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>eglSwapBuffers</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>