
<refentry id="gluBuild3DMipmaps">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>gluBuild3DMipmaps</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>gluBuild3DMipmaps</refname>
        <refpurpose>builds a three-dimensional mipmap</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>GLint <function>gluBuild3DMipmaps</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLint <parameter>internalFormat</parameter></paramdef>
                <paramdef>GLsizei <parameter>width</parameter></paramdef>
                <paramdef>GLsizei <parameter>height</parameter></paramdef>
                <paramdef>GLsizei <parameter>depth</parameter></paramdef>
                <paramdef>GLenum <parameter>format</parameter></paramdef>
                <paramdef>GLenum <parameter>type</parameter></paramdef>
                <paramdef>const void * <parameter>data</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 target texture.  Must be <constant>GLU_TEXTURE_3D</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>internalFormat</parameter></term>
            <listitem>
                <para>
                    Requests the internal storage format of the texture image.  The most
                    current version of the SGI implementation of GLU does not check this
                    value for validity before passing it on to the underlying OpenGL
                    implementation.  A value that is not accepted by the OpenGL
                    implementation will lead to an OpenGL error.  The benefit of not
                    checking this value at the GLU level is that OpenGL extensions can add
                    new internal texture formats without requiring a revision of the GLU
                    implementation.  Older implementations of GLU check this value and
                    raise a GLU error if it is not 1, 2, 3, or 4 or one of the following
                    symbolic constants:
                    <constant>GLU_ALPHA</constant>,
                    <constant>GLU_ALPHA4</constant>,
                    <constant>GLU_ALPHA8</constant>,
                    <constant>GLU_ALPHA12</constant>,
                    <constant>GLU_ALPHA16</constant>,
                    <constant>GLU_LUMINANCE</constant>,
                    <constant>GLU_LUMINANCE4</constant>,
                    <constant>GLU_LUMINANCE8</constant>,
                    <constant>GLU_LUMINANCE12</constant>,
                    <constant>GLU_LUMINANCE16</constant>,
                    <constant>GLU_LUMINANCE_ALPHA</constant>,
                    <constant>GLU_LUMINANCE4_ALPHA4</constant>,
                    <constant>GLU_LUMINANCE6_ALPHA2</constant>,
                    <constant>GLU_LUMINANCE8_ALPHA8</constant>,
                    <constant>GLU_LUMINANCE12_ALPHA4</constant>,
                    <constant>GLU_LUMINANCE12_ALPHA12</constant>,
                    <constant>GLU_LUMINANCE16_ALPHA16</constant>,
                    <constant>GLU_INTENSITY</constant>,
                    <constant>GLU_INTENSITY4</constant>,
                    <constant>GLU_INTENSITY8</constant>,
                    <constant>GLU_INTENSITY12</constant>,
                    <constant>GLU_INTENSITY16</constant>,
                    <constant>GLU_RGB</constant>,
                    <constant>GLU_R3_G3_B2</constant>,
                    <constant>GLU_RGB4</constant>,
                    <constant>GLU_RGB5</constant>,
                    <constant>GLU_RGB8</constant>,
                    <constant>GLU_RGB10</constant>,
                    <constant>GLU_RGB12</constant>,
                    <constant>GLU_RGB16</constant>,
                    <constant>GLU_RGBA</constant>,
                    <constant>GLU_RGBA2</constant>,
                    <constant>GLU_RGBA4</constant>,
                    <constant>GLU_RGB5_A1</constant>,
                    <constant>GLU_RGBA8</constant>,
                    <constant>GLU_RGB10_A2</constant>,
                    <constant>GLU_RGBA12</constant>, or
                    <constant>GLU_RGBA16</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>width</parameter></term>
            <term><parameter>height</parameter></term>
            <term><parameter>depth</parameter></term>
            <listitem>
                <para>
                    Specifies in pixels the width, height and depth respectively, in pixels
                    of the texture image. 
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>format</parameter></term>
            <listitem>
                <para>
                    Specifies the format of the pixel data.
                    Must be one of
                    <constant>GLU_COLOR_INDEX</constant>,
                    <constant>GLU_DEPTH_COMPONENT</constant>,
                    <constant>GLU_RED</constant>,
                    <constant>GLU_GREEN</constant>,
                    <constant>GLU_BLUE</constant>,
                    <constant>GLU_ALPHA</constant>,
                    <constant>GLU_RGB</constant>,
                    <constant>GLU_RGBA</constant>,
                    <constant>GLU_BGR</constant>,
                    <constant>GLU_BGRA</constant>,
                    <constant>GLU_LUMINANCE</constant>, or
                    <constant>GLU_LUMINANCE_ALPHA</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>type</parameter></term>
            <listitem>
                <para>
                    Specifies the data type for <parameter>data</parameter>.
                    Must be one of:
                    <constant>GLU_UNSIGNED_BYTE</constant>,
                    <constant>GLU_BYTE</constant>,
                    <constant>GLU_BITMAP</constant>,
                    <constant>GLU_UNSIGNED_SHORT</constant>,
                    <constant>GLU_SHORT</constant>,
                    <constant>GLU_UNSIGNED_INT</constant>,
                    <constant>GLU_INT</constant>, 
                    <constant>GLU_FLOAT</constant>, 
                    <constant>GLU_UNSIGNED_BYTE_3_3_2</constant>,
                    <constant>GLU_UNSIGNED_BYTE_2_3_3_REV</constant>,
                    <constant>GLU_UNSIGNED_SHORT_5_6_5</constant>,
                    <constant>GLU_UNSIGNED_SHORT_5_6_5_REV</constant>,
                    <constant>GLU_UNSIGNED_SHORT_4_4_4_4</constant>,
                    <constant>GLU_UNSIGNED_SHORT_4_4_4_4_REV</constant>,
                    <constant>GLU_UNSIGNED_SHORT_5_5_5_1</constant>,
                    <constant>GLU_UNSIGNED_SHORT_1_5_5_5_REV</constant>,
                    <constant>GLU_UNSIGNED_INT_8_8_8_8</constant>,
                    <constant>GLU_UNSIGNED_INT_8_8_8_8_REV</constant>,
                    <constant>GLU_UNSIGNED_INT_10_10_10_2</constant>, or
                    <constant>GLU_UNSIGNED_INT_2_10_10_10_REV</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>data</parameter></term>
            <listitem>
                <para>
                    Specifies a pointer to the image data in memory.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>gluBuild3DMipmaps</function> builds a series of prefiltered three-dimensional texture maps of
            decreasing resolutions called a mipmap. This is used for the antialiasing of
            texture-mapped primitives.
        </para>
        <para>
            A return value of zero indicates success, otherwise a GLU error code is
            returned (see <citerefentry><refentrytitle>gluErrorString</refentrytitle></citerefentry>).
        </para>
        <para>
            Initially, the <parameter>width</parameter>, <parameter>height</parameter> and <parameter>depth</parameter> of <parameter>data</parameter> are checked to
            see if they are a power of 2. If not, a copy of <parameter>data</parameter> is made and
            scaled up or down to the nearest power of 2. (If <parameter>width</parameter>, <parameter>height</parameter>, or
            <parameter>depth</parameter> is exactly between powers of 2, then the copy of <parameter>data</parameter> will
            scale upwards.) This copy will be used for subsequent mipmapping
            operations described below.  For example, if <parameter>width</parameter> is 57, <parameter>height</parameter> is
            23, and <parameter>depth</parameter> is 24, then a copy of <parameter>data</parameter> will scale up to 64 in
            width, down to 16 in height, and up to 32 in depth before mipmapping
            takes place.
        </para>
        <para>
            Then, proxy textures (see <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>) are used to determine if
            the implementation can fit the requested texture. If not, all three dimensions
            are continually halved until it fits. 
        </para>
        <para>
            Next, a series of mipmap levels is built by decimating a copy of <parameter>data</parameter>
            in half along all three dimensions until size 
            <inlineequation><mml:math>
                <!-- eqn: 1  times  1  times  1:-->
                <mml:mrow>
                    <mml:mn>1</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>1</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>
            is
            reached. At each level, each texel in the halved mipmap level is an
            average of the corresponding eight texels in the larger mipmap
            level. (If exactly one of the dimensions is 1, four texels are averaged.
            If exactly two of the dimensions are 1, two texels are averaged.)
        </para>
        <para>
            <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry> is called to load each of these mipmap levels.
            Level 0 is a copy of <parameter>data</parameter>.  The highest level is
            <inlineequation><mml:math>
                <!-- eqn: {log sub 2} ( max (width,height,depth)):-->
                <mml:mrow>
                    <mml:mfenced open="" close="">
                        <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
                        <mml:mn>2</mml:mn>
                        </mml:msub>
                    </mml:mfenced>
                    <mml:mo>&af;</mml:mo>
                    <mml:mfenced open="(" close=")">
                        <mml:mrow>
                            <mml:mi mathvariant="italic">max</mml:mi>
                            <mml:mo>&af;</mml:mo>
                            <mml:mfenced open="(" close=")">
                                <mml:mi mathvariant="italic">width</mml:mi>
                                <mml:mi mathvariant="italic">height</mml:mi>
                                <mml:mi mathvariant="italic">depth</mml:mi>
                            </mml:mfenced>
                        </mml:mrow>
                    </mml:mfenced>
                </mml:mrow>
            </mml:math></inlineequation>.
            For example, if <parameter>width</parameter> is 64, <parameter>height</parameter> is
            16, and <parameter>depth</parameter> is 32, and the implementation can store a texture of this
            size, the following mipmap levels are built: 
            <inlineequation><mml:math>
                <!-- eqn: 64  times  16  times  32:-->
                <mml:mrow>
                    <mml:mn>64</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>16</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>32</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>,
            <inlineequation><mml:math>
                <!-- eqn: 32  times  8  times  16:-->
                <mml:mrow>
                    <mml:mn>32</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>8</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>16</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>, 
            <inlineequation><mml:math>
                <!-- eqn: 16  times  4  times  8:-->
                <mml:mrow>
                    <mml:mn>16</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>4</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>8</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>,
            <inlineequation><mml:math>
                <!-- eqn: 8  times  2  times  4:-->
                <mml:mrow>
                    <mml:mn>8</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>2</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>4</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>, 
            <inlineequation><mml:math>
                <!-- eqn: 4  times  1  times  2:-->
                <mml:mrow>
                    <mml:mn>4</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>1</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>2</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>,
            <inlineequation><mml:math>
                <!-- eqn: 2  times  1  times  1:-->
                <mml:mrow>
                    <mml:mn>2</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>1</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>,
            and 
            <inlineequation><mml:math>
                <!-- eqn: 1  times  1  times  1:-->
                <mml:mrow>
                    <mml:mn>1</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>1</mml:mn>
                    <mml:mo>&times;</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math></inlineequation>.
            These correspond
            to levels 0 through 6, respectively.
        </para>
        <para>
            See the <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry> reference page for a description of the
            acceptable values for <parameter>format</parameter> parameter. See the <citerefentry><refentrytitle>glDrawPixels</refentrytitle></citerefentry> 
            reference page for a description of the acceptable values 
            for <parameter>type</parameter> parameter.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            Note that there is no direct way of querying the maximum level. This can
            be derived indirectly via <citerefentry><refentrytitle>glGetTexLevelParameter</refentrytitle></citerefentry>. First, query
            the width, height, and depth actually used at level 0.  (The width,
            height, and depth may not be equal to <parameter>width</parameter>, <parameter>height</parameter>, and <parameter>depth</parameter>
            respectively since proxy textures might have scaled them to fit the
            implementation.)  Then the maximum level can be derived from the formula
            <inlineequation><mml:math>
                <!-- eqn: {log sub 2} ( max (width,height,depth)):-->
                <mml:mrow>
                    <mml:mfenced open="" close="">
                        <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
                        <mml:mn>2</mml:mn>
                        </mml:msub>
                    </mml:mfenced>
                    <mml:mo>&af;</mml:mo>
                    <mml:mfenced open="(" close=")">
                        <mml:mrow>
                            <mml:mi mathvariant="italic">max</mml:mi>
                            <mml:mo>&af;</mml:mo>
                            <mml:mfenced open="(" close=")">
                                <mml:mi mathvariant="italic">width</mml:mi>
                                <mml:mi mathvariant="italic">height</mml:mi>
                                <mml:mi mathvariant="italic">depth</mml:mi>
                            </mml:mfenced>
                        </mml:mrow>
                    </mml:mfenced>
                </mml:mrow>
            </mml:math></inlineequation>.
        </para>
        <para>
            <function>gluBuild3DMipmaps</function> is only available if the GLU version is 1.3 or greater.
        </para>
        <para>
            Formats <constant>GLU_BGR</constant>, and <constant>GLU_BGRA</constant>, and types 
            <constant>GLU_UNSIGNED_BYTE_3_3_2</constant>,
            <constant>GLU_UNSIGNED_BYTE_2_3_3_REV</constant>,
            <constant>GLU_UNSIGNED_SHORT_5_6_5</constant>,
            <constant>GLU_UNSIGNED_SHORT_5_6_5_REV</constant>,
            <constant>GLU_UNSIGNED_SHORT_4_4_4_4</constant>,
            <constant>GLU_UNSIGNED_SHORT_4_4_4_4_REV</constant>,
            <constant>GLU_UNSIGNED_SHORT_5_5_5_1</constant>,
            <constant>GLU_UNSIGNED_SHORT_1_5_5_5_REV</constant>,
            <constant>GLU_UNSIGNED_INT_8_8_8_8</constant>,
            <constant>GLU_UNSIGNED_INT_8_8_8_8_REV</constant>,
            <constant>GLU_UNSIGNED_INT_10_10_10_2</constant>, and
            <constant>GLU_UNSIGNED_INT_2_10_10_10_REV</constant> are only available if the GL version 
            is 1.2 or greater.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GLU_INVALID_VALUE</constant> is returned if <parameter>width</parameter>, <parameter>height</parameter>, or <parameter>depth</parameter> is &lt; 1.
        </para>
        <para>
            <constant>GLU_INVALID_ENUM</constant> is returned if <parameter>internalFormat</parameter>, <parameter>format</parameter>, or <parameter>type</parameter> is not 
            legal.
        </para>
        <para>
            <constant>GLU_INVALID_OPERATION</constant> is returned if <parameter>type</parameter> is <constant>GLU_UNSIGNED_BYTE_3_3_2</constant> or <constant>GLU_UNSIGNED_BYTE_2_3_3_REV</constant>
            and <parameter>format</parameter> is not <constant>GLU_RGB</constant>.
        </para>
        <para>
            <constant>GLU_INVALID_OPERATION</constant> is returned if <parameter>type</parameter> is <constant>GLU_UNSIGNED_SHORT_5_6_5</constant> or <constant>GLU_UNSIGNED_SHORT_5_6_5_REV</constant>
            and <parameter>format</parameter> is not <constant>GLU_RGB</constant>.
        </para>
        <para>
            <constant>GLU_INVALID_OPERATION</constant> is returned if <parameter>type</parameter> is <constant>GLU_UNSIGNED_SHORT_4_4_4_4</constant> or <constant>GLU_UNSIGNED_SHORT_4_4_4_4_REV</constant>
            and <parameter>format</parameter> is neither <constant>GLU_RGBA</constant> nor <constant>GLU_BGRA</constant>.
        </para>
        <para>
            <constant>GLU_INVALID_OPERATION</constant> is returned if <parameter>type</parameter> is <constant>GLU_UNSIGNED_SHORT_5_5_5_1</constant> or <constant>GLU_UNSIGNED_SHORT_1_5_5_5_REV</constant>
            and <parameter>format</parameter> is neither <constant>GLU_RGBA</constant> nor <constant>GLU_BGRA</constant>.
        </para>
        <para>
            <constant>GLU_INVALID_OPERATION</constant> is returned if <parameter>type</parameter> is <constant>GLU_UNSIGNED_INT_8_8_8_8</constant> or <constant>GLU_UNSIGNED_INT_8_8_8_8_REV</constant>
            and <parameter>format</parameter> is neither <constant>GLU_RGBA</constant> nor <constant>GLU_BGRA</constant>.
        </para>
        <para>
            <constant>GLU_INVALID_OPERATION</constant> is returned if <parameter>type</parameter> is <constant>GLU_UNSIGNED_INT_10_10_10_2</constant> or <constant>GLU_UNSIGNED_INT_2_10_10_10_REV</constant>
            and <parameter>format</parameter> is neither <constant>GLU_RGBA</constant> nor <constant>GLU_BGRA</constant>.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>gluBuild1DMipmapLevels</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>gluBuild1DMipmaps</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>gluBuild2DMipmapLevels</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>gluBuild3DMipmapLevels</refentrytitle></citerefentry>,
            <function>gluBuild3DMipmaps</function>,
            <citerefentry><refentrytitle>gluErrorString</refentrytitle></citerefentry>, 
            <citerefentry><refentrytitle>glDrawPixels</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glGetTexImage</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glGetTexLevelParameter</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>, 
            <citerefentry><refentrytitle>glTexImage3D</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>
