 %mathent; ]>

<!-- Converted by db4-upgrade version 1.1 -->

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glClearBuffer">
    <info>
        <copyright>
            <year>2010-2013</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
        <refentrytitle>glClearBuffer</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glClearBuffer</refname>
        <refpurpose>clear individual buffers of the currently bound draw framebuffer</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glClearBufferiv</function></funcdef>
                <paramdef>GLenum <parameter>buffer</parameter></paramdef>
                <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
                <paramdef>const GLint * <parameter>value</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glClearBufferuiv</function></funcdef>
                <paramdef>GLenum <parameter>buffer</parameter></paramdef>
                <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
                <paramdef>const GLuint * <parameter>value</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glClearBufferfv</function></funcdef>
                <paramdef>GLenum <parameter>buffer</parameter></paramdef>
                <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
                <paramdef>const GLfloat * <parameter>value</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glClearBufferfi</function></funcdef>
                <paramdef>GLenum <parameter>buffer</parameter></paramdef>
                <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
                <paramdef>GLfloat <parameter>depth</parameter></paramdef>
                <paramdef>GLint <parameter>stencil</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 xml:id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>buffer</parameter></term>
            <listitem>
                <para>
                    Specify the buffer to clear.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>drawBuffer</parameter></term>
            <listitem>
                <para>
                    Specify a particular draw buffer to clear.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>value</parameter></term>
            <listitem>
                <para>
                    For color buffers, a pointer to a four-element vector specifying R, G, B and A values to clear the buffer to.
                    For depth buffers, a pointer to a single depth value to clear the buffer to.
                    For stencil buffers, a pointer to a single stencil value to clear the buffer to.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>depth</parameter></term>
            <listitem>
                <para>
                    The value to clear a depth render buffer to.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>stencil</parameter></term>
            <listitem>
                <para>
                    The value to clear a stencil render buffer to.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>glClearBuffer*</function> clears the specified buffer to the specified value(s). If <parameter>buffer</parameter> is
            <constant>GL_COLOR</constant>, a particular draw buffer <constant>GL_DRAW_BUFFER</constant><parameter>i</parameter> is specified
            by passing <parameter>i</parameter> as <parameter>drawBuffer</parameter>. In this case, <parameter>value</parameter> points to
            a four-element vector specifying the R, G, B and A color to clear that draw buffer to. If <parameter>buffer</parameter> is
            one of <constant>GL_FRONT</constant>, <constant>GL_BACK</constant>, <constant>GL_LEFT</constant>, <constant>GL_RIGHT</constant>,
            or <constant>GL_FRONT_AND_BACK</constant>, identifying multiple buffers, each selected buffer is cleared to the same value.
            Clamping and conversion for fixed-point color buffers are performed in the same fashion as
            <citerefentry><refentrytitle>glClearColor</refentrytitle></citerefentry>.
        </para>
        <para>
            If <parameter>buffer</parameter> is <constant>GL_DEPTH</constant>, <parameter>drawBuffer</parameter> must be zero, and <parameter>value</parameter>
            points to a single value to clear the depth buffer to. Only <function>glClearBufferfv</function> should be used to clear
            depth buffers. Clamping and conversion for fixed-point depth buffers are performed in the same fashion as
            <citerefentry><refentrytitle>glClearDepth</refentrytitle></citerefentry>.
        </para>
        <para>
            If <parameter>buffer</parameter> is <constant>GL_STENCIL</constant>, <parameter>drawBuffer</parameter> must be zero, and <parameter>value</parameter>
            points to a single value to clear the stencil buffer to. Only <function>glClearBufferiv</function> should be used to clear
            stencil buffers. Masking and type conversion are performed in the same fashion as
            <citerefentry><refentrytitle>glClearStencil</refentrytitle></citerefentry>.
        </para>
        <para>
            <function>glClearBufferfi</function> may be used to clear the depth and stencil buffers. <parameter>buffer</parameter> must be
            <constant>GL_DEPTH_STENCIL</constant> and <parameter>drawBuffer</parameter> must be zero. <parameter>depth</parameter> and
            <parameter>stencil</parameter> are the depth and stencil values, respectively.
        </para>
        <para>
            The result of <function>glClearBuffer</function> is undefined if no conversion between the type of <parameter>value</parameter>
            and the buffer being cleared is defined. However, this is not an error.
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated by <function>glClearBufferif</function>, <function>glClearBufferfv</function>
            and <function>glClearBufferuiv</function> if <parameter>buffer</parameter> is not <constant>GL_COLOR</constant>,
            <constant>GL_FRONT</constant>, <constant>GL_BACK</constant>, <constant>GL_LEFT</constant>, <constant>GL_RIGHT</constant>,
            <constant>GL_FRONT_AND_BACK</constant>, <constant>GL_DEPTH</constant> or <constant>GL_STENCIL</constant>.
        </para>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated by <function>glClearBufferfi</function> if <parameter>buffer</parameter>
            is not <constant>GL_DEPTH_STENCIL</constant>.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>buffer</parameter> is <constant>GL_COLOR</constant>,
            <constant>GL_FRONT</constant>, <constant>GL_BACK</constant>, <constant>GL_LEFT</constant>, <constant>GL_RIGHT</constant>,
            or <constant>GL_FRONT_AND_BACK</constant> and <parameter>drawBuffer</parameter> is greater than or equal to <constant>GL_MAX_DRAW_BUFFERS</constant>.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>buffer</parameter> is <constant>GL_DEPTH</constant>,
             <constant>GL_STENCIL</constant> or <constant>GL_DEPTH_STENCIL</constant> and <parameter>drawBuffer</parameter> is not zero.
        </para>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glClearColor</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glClearDepth</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glClearStencil</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glClear</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 xml:id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"/> 2010-2013 Khronos Group.
            This material may be distributed subject to the terms and conditions set forth in
            the Open Publication License, v 1.0, 8 June 1999.
            <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://opencontent.org/openpub/">http://opencontent.org/openpub/</link>.
        </para>
    </refsect1>
</refentry>
