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<refentry id="glPointParameter">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glPointParameter</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glPointParameter</refname>
        <refpurpose>specify point parameters</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glPointParameterf</function></funcdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLfloat <parameter>param</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
        <para></para>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glPointParameteri</function></funcdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLint <parameter>param</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <!-- eqn: ignoring delim $$ -->
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>pname</parameter></term>
            <listitem>
                <para>
                    Specifies a single-valued point parameter.
                    <constant>GL_POINT_SIZE_MIN</constant>,
                    <constant>GL_POINT_SIZE_MAX</constant>,
                    <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant>, and
                    <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant>
                    are accepted.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>param</parameter></term>
            <listitem>
                <para>
                    Specifies the value that <parameter>pname</parameter> will be set to.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glPointParameterfv</function></funcdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>const GLfloat * <parameter>params</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
        <para></para>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glPointParameteriv</function></funcdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>const GLint * <parameter>params</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters2"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>pname</parameter></term>
            <listitem>
                <para>
                    Specifies a point parameter.
                    <constant>GL_POINT_SIZE_MIN</constant>,
                    <constant>GL_POINT_SIZE_MAX</constant>,
                    <constant>GL_POINT_DISTANCE_ATTENUATION</constant>,
                    <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant>, and
                    <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant>
                    are accepted.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>params</parameter></term>
            <listitem>
                <para>
                    Specifies the value or values to be assigned to <parameter>pname</parameter>.
                    <constant>GL_POINT_DISTANCE_ATTENUATION</constant> requires an array of three values.
                    All other parameters accept an array containing only a single value.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            The following values are accepted for <parameter>pname</parameter>:
        </para>
        <variablelist>
            <varlistentry>
                <term><constant>GL_POINT_SIZE_MIN</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> is a single floating-point value that specifies the minimum point size.  The default value is 0.0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_POINT_SIZE_MAX</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> is a single floating-point value that specifies the maximum point size.  The default value is 1.0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_POINT_FADE_THRESHOLD_SIZE</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> is a single floating-point value that specifies the threshold value
                        to which point sizes are clamped if they exceed the specified value.  The
                        default value is 1.0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_POINT_DISTANCE_ATTENUATION</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> is an array of three floating-point values that specify the
                        coefficients used for scaling the computed point size.  The default values
                        are 
                        <inlineequation><mml:math>
                            <!-- eqn: (1,  0,  0):-->
                            <mml:mfenced open="(" close=")">
                                <mml:mn>1</mml:mn>
                                <mml:mn>0</mml:mn>
                                <mml:mn>0</mml:mn>
                            </mml:mfenced>
                        </mml:math></inlineequation>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_POINT_SPRITE_COORD_ORIGIN</constant></term>
                <listitem>
                    <para>
                    </para>
                    <para>
                        <parameter>params</parameter> is a single enum specifying the point sprite texture coordinate origin, either <constant>GL_LOWER_LEFT</constant> or <constant>GL_UPPER_LEFT</constant>. 
                        The default value is <constant>GL_UPPER_LEFT</constant>.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            <function>glPointParameter</function> is available only if the GL version is 1.4 or greater.
        </para>
        <para>
            <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant> is available only if the GL version is 2.0 or greater.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated If the value specified for
            <constant>GL_POINT_SIZE_MIN</constant>, <constant>GL_POINT_SIZE_MAX</constant>, or
            <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant> is less than zero.
        </para>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated If the value specified for
            <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant> is not <constant>GL_LOWER_LEFT</constant> or <constant>GL_UPPER_LEFT</constant>.
        </para>
        <para>
            If the value for <constant>GL_POINT_SIZE_MIN</constant> is greater than
            <constant>GL_POINT_SIZE_MAX</constant>, the point size after clamping is undefined, but no
            error is generated.
        </para>
        <para>
        </para>
    </refsect1>
    <refsect1 id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_SIZE_MIN</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_SIZE_MAX</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_FADE_THRESHOLD_SIZE</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_DISTANCE_ATTENUATION</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POINT_SPRITE_COORD_ORIGIN</constant>
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glPointSize</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>
