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<refentry id="glGetTexParameter">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glGetTexParameter</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetTexParameter</refname>
        <refpurpose>return texture parameter values</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetTexParameterfv</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLfloat * <parameter>params</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetTexParameteriv</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLint * <parameter>params</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <!-- eqn: ignoring delim $$ -->
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>target</parameter></term>
            <listitem>
                <para>
                    Specifies the symbolic name of the target texture.
                    <constant>GL_TEXTURE_1D</constant>,
                    <constant>GL_TEXTURE_2D</constant>,
                    <constant>GL_TEXTURE_3D</constant>, and
                    <constant>GL_TEXTURE_CUBE_MAP</constant>
                    are accepted.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>pname</parameter></term>
            <listitem>
                <para>
                    Specifies the symbolic name of a texture parameter.
                    <constant>GL_TEXTURE_MAG_FILTER</constant>,
                    <constant>GL_TEXTURE_MIN_FILTER</constant>,
                    <constant>GL_TEXTURE_MIN_LOD</constant>,
                    <constant>GL_TEXTURE_MAX_LOD</constant>,
                    <constant>GL_TEXTURE_BASE_LEVEL</constant>,
                    <constant>GL_TEXTURE_MAX_LEVEL</constant>,
                    <constant>GL_TEXTURE_WRAP_S</constant>,
                    <constant>GL_TEXTURE_WRAP_T</constant>,
                    <constant>GL_TEXTURE_WRAP_R</constant>,
                    <constant>GL_TEXTURE_BORDER_COLOR</constant>,
                    <constant>GL_TEXTURE_PRIORITY</constant>,
                    <constant>GL_TEXTURE_RESIDENT</constant>,
                    <constant>GL_TEXTURE_COMPARE_MODE</constant>,
                    <constant>GL_TEXTURE_COMPARE_FUNC</constant>,
                    <constant>GL_DEPTH_TEXTURE_MODE</constant>, and
                    <constant>GL_GENERATE_MIPMAP</constant>
                    are accepted.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>params</parameter></term>
            <listitem>
                <para>
                    Returns the texture parameters.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glGetTexParameter</function> returns in <parameter>params</parameter> the value or values of the texture parameter
            specified as <parameter>pname</parameter>.
            <parameter>target</parameter> defines the target texture,
            either <constant>GL_TEXTURE_1D</constant>, <constant>GL_TEXTURE_2D</constant>, <constant>GL_TEXTURE_3D</constant>, or <constant>GL_TEXTURE_CUBE_MAP</constant>,
            to specify one-, two-, or three-dimensional or cube-mapped texturing.
            <parameter>pname</parameter> accepts the same symbols as <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>,
            with the same interpretations:
        </para>
        <variablelist>
            <varlistentry>
                <term><constant>GL_TEXTURE_MAG_FILTER</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued texture magnification filter,
                        a symbolic constant. The initial value is <constant>GL_LINEAR</constant>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_MIN_FILTER</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued texture minification filter,
                        a symbolic constant. The initial value is <constant>GL_NEAREST_MIPMAP_LINEAR</constant>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_MIN_LOD</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued texture minimum level-of-detail value.  The
                        initial value is 
                        <inlineequation><mml:math>
                            <!-- eqn: -1000:-->
                            <mml:mn>-1000</mml:mn>
                        </mml:math></inlineequation>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_MAX_LOD</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued texture maximum level-of-detail value. The
                        initial value is 1000.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_BASE_LEVEL</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued base texture mipmap level.  The initial value is 0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_MAX_LEVEL</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued maximum texture mipmap array level.  The initial
                        value is 1000.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_WRAP_S</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued wrapping function for texture coordinate 
                        <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>,
                        a symbolic constant. The initial value is <constant>GL_REPEAT</constant>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_WRAP_T</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued wrapping function for texture coordinate 
                        <inlineequation><mml:math><mml:mi mathvariant="italic">t</mml:mi></mml:math></inlineequation>,
                        a symbolic constant. The initial value is <constant>GL_REPEAT</constant>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_WRAP_R</constant></term>
                <listitem>
                    <para>
                        Returns the single-valued wrapping function for texture coordinate 
                        <inlineequation><mml:math><mml:mi mathvariant="italic">r</mml:mi></mml:math></inlineequation>,
                        a symbolic constant. The initial value is <constant>GL_REPEAT</constant>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_BORDER_COLOR</constant></term>
                <listitem>
                    <para>
                        Returns four integer or floating-point numbers that comprise the RGBA color
                        of the texture border.
                        Floating-point values are returned in the range 
                        <inlineequation><mml:math>
                            <!-- eqn: [0,1]:-->
                            <mml:mfenced open="[" close="]">
                                <mml:mn>0</mml:mn>
                                <mml:mn>1</mml:mn>
                            </mml:mfenced>
                        </mml:math></inlineequation>.
                        Integer values are returned as a linear mapping of the internal floating-point
                        representation such that 1.0 maps to the most positive representable
                        integer and 
                        <inlineequation><mml:math>
                            <!-- eqn: -1.0:-->
                            <mml:mn>-1.0</mml:mn>
                        </mml:math></inlineequation>
                        maps to the most negative representable
                        integer. The initial value is (0, 0, 0, 0).
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_PRIORITY</constant></term>
                <listitem>
                    <para>
                        Returns the residence priority of the target texture (or the named
                        texture bound to it). The initial value is 1.
                        See <citerefentry><refentrytitle>glPrioritizeTextures</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_RESIDENT</constant></term>
                <listitem>
                    <para>
                        Returns the residence status of the target texture.
                        If the value returned in <parameter>params</parameter> is <constant>GL_TRUE</constant>, the texture is
                        resident in texture memory.
                        See <citerefentry><refentrytitle>glAreTexturesResident</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_COMPARE_MODE</constant></term>
                <listitem>
                    <para>
                        Returns a single-valued texture comparison mode, a symbolic constant.  The
                        initial value is <constant>GL_NONE</constant>. See <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_TEXTURE_COMPARE_FUNC</constant></term>
                <listitem>
                    <para>
                        Returns a single-valued texture comparison function, a symbolic constant.  The
                        initial value is <constant>GL_LEQUAL</constant>. See <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_DEPTH_TEXTURE_MODE</constant></term>
                <listitem>
                    <para>
                        Returns a single-valued texture format indicating how the depth values
                        should be converted into color components.  The initial value is
                        <constant>GL_LUMINANCE</constant>.  See <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_GENERATE_MIPMAP</constant></term>
                <listitem>
                    <para>
                        Returns a single boolean value indicating if automatic mipmap level updates
                        are enabled.
                        See <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            <constant>GL_TEXTURE_PRIORITY</constant> and <constant>GL_TEXTURE_RESIDENT</constant> are
            available only if the GL version is 1.1 or greater.
        </para>
        <para>
            <constant>GL_TEXTURE_3D</constant>,
            <constant>GL_TEXTURE_MIN_LOD</constant>, <constant>GL_TEXTURE_MAX_LOD</constant>, <constant>GL_TEXTURE_BASE_LEVEL</constant>,
            <constant>GL_TEXTURE_MAX_LEVEL</constant>, and <constant>GL_TEXTURE_WRAP_R</constant> are available only
            if the GL version is 1.2 or greater.
        </para>
        <para>
            <constant>GL_TEXTURE_COMPARE_MODE</constant>, <constant>GL_TEXTURE_COMPARE_FUNC</constant>, and
            <constant>GL_GENERATE_MIPMAP</constant> is available only if the GL version is 1.4 or
            greater.
        </para>
        <para>
            If an error is generated,
            no change is made to the contents of <parameter>params</parameter>.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> or <parameter>pname</parameter> is not an
            accepted value.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if <function>glGetTexParameter</function>
            is executed between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry>
            and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glAreTexturesResident</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glPrioritizeTextures</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexParameter</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>
