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<refentry id="glGetDebugMessageLog">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>2012</year>
                <holder>Khronos Group</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glGetDebugMessageLog</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetDebugMessageLog</refname>
        <refpurpose>retrieve messages from the debug message log</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>GLuint <function>glGetDebugMessageLog</function></funcdef>
                <paramdef>GLuint <parameter>count</parameter></paramdef>
                <paramdef>GLsizei <parameter>bufSize</parameter></paramdef>
                <paramdef>GLenum *<parameter>sources</parameter></paramdef>
                <paramdef>Glenum *<parameter>types</parameter></paramdef>
                <paramdef>GLuint *<parameter>ids</parameter></paramdef>
                <paramdef>GLenum *<parameter>severities</parameter></paramdef>
                <paramdef>GLsizei *<parameter>lengths</parameter></paramdef>
                <paramdef>GLchar *<parameter>messageLog</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>count</parameter></term>
            <listitem>
                <para>
                    The number of debug messages to retrieve from the log.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>bufSize</parameter></term>
            <listitem>
                <para>
                    The size of the buffer whose address is given by <parameter>messageLog</parameter>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>sources</parameter></term>
            <listitem>
                <para>
                    The address of an array of variables to receive the sources of the retrieved messages.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>types</parameter></term>
            <listitem>
                <para>
                    The address of an array of variables to receive the types of the retrieved messages.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>ids</parameter></term>
            <listitem>
                <para>
                    The address of an array of unsigned integers to receive the ids of the retrieved messages.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>severities</parameter></term>
            <listitem>
                <para>
                    The address of an array of variables to receive the severites of the retrieved messages.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>lengths</parameter></term>
            <listitem>
                <para>
                    The address of an array of variables to receive the lengths of the received messages.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>messageLog</parameter></term>
            <listitem>
                <para>
                    The address of an array of characters that will receive the messages.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glGetDebugMessageLog</function> retrieves messages from the debug message log. A maximum of
            <parameter>count</parameter> messages are retrieved from the log. If <parameter>sources</parameter>
            is not NULL then the source of each message is written into up to <parameter>count</parameter> elements
            of the array. If <parameter>types</parameter>
            is not NULL then the type of each message is written into up to <parameter>count</parameter> elements
            of the array. If <parameter>id</parameter>
            is not NULL then the identifier of each message is written into up to <parameter>count</parameter> elements
            of the array. If <parameter>severities</parameter>
            is not NULL then the severity of each message is written into up to <parameter>count</parameter> elements
            of the array. If <parameter>lengths</parameter>
            is not NULL then the length of each message is written into up to <parameter>count</parameter> elements
            of the array.
        </para>
        <para>
            <parameter>messageLog</parameter> specifies the address of a character array into which the debug messages
            will be written. Each message will be concatenated onto the array starting at the first element of <parameter>messageLog</parameter>.
            <parameter>bufSize</parameter> specifies the size of the array <parameter>messageLog</parameter>. If a message will not
            fit into the remaining space in <parameter>messageLog</parameter> then the function terminates and returns the number
            of messages written so far, which may be zero.
        </para>
        <para>
            If <function>glGetDebugMessageLog</function> returns zero then no messages are present in the debug log, or there
            was not enough space in <parameter>messageLog</parameter> to retrieve the first message in the queue. If <parameter>messageLog</parameter>
            is NULL then no messages are written and the value of <parameter>bufSize</parameter> is ignored.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            Although debug messages may be enabled in a non-debug context, the quantity and detail of such messages may be substantially
            inferior to those in a debug context. In particular, a valid implementation of the debug message queue in a non-debug context
            may produce no messages at all.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>count</parameter> or <parameter>bufSize</parameter> is negative.
        </para>
    </refsect1>
    <refsect1 id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_DEBUG_LOGGED_MESSAGES</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_DEBUG_MESSAGE_LENGTH</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_DEBUG_LOGGED_MESSAGES</constant>
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glDebugMessageInsert</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDebugMessageCallback</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDebugMessageControl</refentrytitle></citerefentry>.
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 2012 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.
            <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
        </para>
    </refsect1>
</refentry>
