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<refentry id="glLineWidth">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glLineWidth</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glLineWidth</refname>
        <refpurpose>specify the width of rasterized lines</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glLineWidth</function></funcdef>
                <paramdef>GLfloat <parameter>width</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <!-- eqn: ignoring delim $$ -->
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>width</parameter></term>
            <listitem>
                <para>
                    Specifies the width of rasterized lines.
                    The initial value is 1.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glLineWidth</function> specifies the rasterized width of
            lines.
        </para>
        <para>
            The actual width is determined by rounding the supplied width
            to the nearest integer.
            (If the rounding results in the value 0,
            it is as if the line width were 1.)
            If
            <inlineequation><mml:math>
                <!-- eqn: | DELTA x |  >=  | DELTA y |:-->
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                    <mml:mfenced open="&VerticalBar;" close="&VerticalBar;">
                        <mml:mrow>
                            <mml:mo>&Delta;</mml:mo>
                            <mml:mi mathvariant="italic">x</mml:mi>
                        </mml:mrow>
                    </mml:mfenced>
                    <mml:mo>&gt;=</mml:mo>
                    <mml:mfenced open="&VerticalBar;" close="&VerticalBar;">
                        <mml:mrow>
                            <mml:mo>&Delta;</mml:mo>
                            <mml:mi mathvariant="italic">y</mml:mi>
                        </mml:mrow>
                    </mml:mfenced>
                </mml:mrow>
            </mml:math></inlineequation>,
            <emphasis>i</emphasis> pixels are filled in each column that is rasterized,
            where <emphasis>i</emphasis> is the rounded value of <parameter>width</parameter>.
            Otherwise,
            <emphasis>i</emphasis> pixels are filled in each row that is rasterized.
        </para>
        <para>
            There is a range of supported line widths.  Only width 1 is guaranteed to be supported; others depend on the
            implementation.  
            To query the range of supported widths, call <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry>
            with argument <constant>GL_ALIASED_LINE_WIDTH_RANGE</constant>.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            The line width specified by <function>glLineWidth</function> is always returned when <constant>GL_LINE_WIDTH</constant>
            is queried.
            Clamping and rounding have no effect on the specified value.
        </para>
        <para>
            Line width may be clamped to an implementation-dependent maximum.  Call <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with <constant>GL_ALIASED_LINE_WIDTH_RANGE</constant> to determine the maximum width.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>width</parameter> is less than or equal to 0.
        </para>
    </refsect1>
    <refsect1 id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_LINE_WIDTH</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_ALIASED_LINE_WIDTH_RANGE</constant>
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
        </para>
    </refsect1>
</refentry>
