[clinton/guile-figl.git] / upstream-doc / man2 / xhtml / gluBuild2DMipmapLevels.xml

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<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>gluBuild2DMipmapLevels</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gluBuild2DMipmapLevels"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gluBuild2DMipmapLevels — builds a subset of two-dimensional mipmap levels</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">GLint <b class="fsfunc">gluBuild2DMipmapLevels</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">internalFormat</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">width</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">height</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">format</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">type</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">level</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">base</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">max</var>, </td></tr><tr><td> </td><td>const void *  </td><td><var class="pdparam">data</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>target</code></em></span></dt><dd><p>
                    Specifies the target texture.  Must be <code class="constant">GLU_TEXTURE_2D</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>internalFormat</code></em></span></dt><dd><p>
                    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:
                    <code class="constant">GLU_ALPHA</code>,
                    <code class="constant">GLU_ALPHA4</code>,
                    <code class="constant">GLU_ALPHA8</code>,
                    <code class="constant">GLU_ALPHA12</code>,
                    <code class="constant">GLU_ALPHA16</code>,
                    <code class="constant">GLU_LUMINANCE</code>,
                    <code class="constant">GLU_LUMINANCE4</code>,
                    <code class="constant">GLU_LUMINANCE8</code>,
                    <code class="constant">GLU_LUMINANCE12</code>,
                    <code class="constant">GLU_LUMINANCE16</code>,
                    <code class="constant">GLU_LUMINANCE_ALPHA</code>,
                    <code class="constant">GLU_LUMINANCE4_ALPHA4</code>,
                    <code class="constant">GLU_LUMINANCE6_ALPHA2</code>,
                    <code class="constant">GLU_LUMINANCE8_ALPHA8</code>,
                    <code class="constant">GLU_LUMINANCE12_ALPHA4</code>,
                    <code class="constant">GLU_LUMINANCE12_ALPHA12</code>,
                    <code class="constant">GLU_LUMINANCE16_ALPHA16</code>,
                    <code class="constant">GLU_INTENSITY</code>,
                    <code class="constant">GLU_INTENSITY4</code>,
                    <code class="constant">GLU_INTENSITY8</code>,
                    <code class="constant">GLU_INTENSITY12</code>,
                    <code class="constant">GLU_INTENSITY16</code>,
                    <code class="constant">GLU_RGB</code>,
                    <code class="constant">GLU_R3_G3_B2</code>,
                    <code class="constant">GLU_RGB4</code>,
                    <code class="constant">GLU_RGB5</code>,
                    <code class="constant">GLU_RGB8</code>,
                    <code class="constant">GLU_RGB10</code>,
                    <code class="constant">GLU_RGB12</code>,
                    <code class="constant">GLU_RGB16</code>,
                    <code class="constant">GLU_RGBA</code>,
                    <code class="constant">GLU_RGBA2</code>,
                    <code class="constant">GLU_RGBA4</code>,
                    <code class="constant">GLU_RGB5_A1</code>,
                    <code class="constant">GLU_RGBA8</code>,
                    <code class="constant">GLU_RGB10_A2</code>,
                    <code class="constant">GLU_RGBA12</code>, or
                    <code class="constant">GLU_RGBA16</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>width</code></em>, </span><span class="term"><em class="parameter"><code>height</code></em></span></dt><dd><p>
                    Specifies the width and height, respectively, in pixels of the texture image. 
                    These should be a power of 2.
                </p></dd><dt><span class="term"><em class="parameter"><code>format</code></em></span></dt><dd><p>
                    Specifies the format of the pixel data.
                    Must be one of
                    <code class="constant">GLU_COLOR_INDEX</code>,
                    <code class="constant">GLU_DEPTH_COMPONENT</code>,
                    <code class="constant">GLU_RED</code>,
                    <code class="constant">GLU_GREEN</code>,
                    <code class="constant">GLU_BLUE</code>,
                    <code class="constant">GLU_ALPHA</code>,
                    <code class="constant">GLU_RGB</code>,
                    <code class="constant">GLU_RGBA</code>,
                    <code class="constant">GLU_BGR</code>,
                    <code class="constant">GLU_BGRA</code>,
                    <code class="constant">GLU_LUMINANCE</code>, or
                    <code class="constant">GLU_LUMINANCE_ALPHA</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p>
                    Specifies the data type for <em class="parameter"><code>data</code></em>.
                    Must be one of
                    <code class="constant">GLU_UNSIGNED_BYTE</code>,
                    <code class="constant">GLU_BYTE</code>,
                    <code class="constant">GLU_BITMAP</code>,
                    <code class="constant">GLU_UNSIGNED_SHORT</code>,
                    <code class="constant">GLU_SHORT</code>,
                    <code class="constant">GLU_UNSIGNED_INT</code>,
                    <code class="constant">GLU_INT</code>, 
                    <code class="constant">GLU_FLOAT</code>, 
                    <code class="constant">GLU_UNSIGNED_BYTE_3_3_2</code>,
                    <code class="constant">GLU_UNSIGNED_BYTE_2_3_3_REV</code>,
                    <code class="constant">GLU_UNSIGNED_SHORT_5_6_5</code>,
                    <code class="constant">GLU_UNSIGNED_SHORT_5_6_5_REV</code>,
                    <code class="constant">GLU_UNSIGNED_SHORT_4_4_4_4</code>,
                    <code class="constant">GLU_UNSIGNED_SHORT_4_4_4_4_REV</code>,
                    <code class="constant">GLU_UNSIGNED_SHORT_5_5_5_1</code>,
                    <code class="constant">GLU_UNSIGNED_SHORT_1_5_5_5_REV</code>,
                    <code class="constant">GLU_UNSIGNED_INT_8_8_8_8</code>,
                    <code class="constant">GLU_UNSIGNED_INT_8_8_8_8_REV</code>,
                    <code class="constant">GLU_UNSIGNED_INT_10_10_10_2</code>, or
                    <code class="constant">GLU_UNSIGNED_INT_2_10_10_10_REV</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>level</code></em></span></dt><dd><p>
                    Specifies the mipmap level of the image data.
                </p></dd><dt><span class="term"><em class="parameter"><code>base</code></em></span></dt><dd><p>
                    Specifies the minimum mipmap level to pass to <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>.
                </p></dd><dt><span class="term"><em class="parameter"><code>max</code></em></span></dt><dd><p>
                    Specifies the maximum mipmap level to pass to <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>.
                </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
                    Specifies a pointer to the image data in memory.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">gluBuild2DMipmapLevels</code> builds a subset of prefiltered two-dimensional texture maps of decreasing
            resolutions called a mipmap. This is used for the antialiasing of
            texture mapped primitives.
        </p><p>
            A return value of zero indicates success, otherwise a GLU error code is
            returned (see <a class="citerefentry" href="gluErrorString.xml"><span class="citerefentry"><span class="refentrytitle">gluErrorString</span></span></a>).
        </p><p>
            A series of mipmap levels from <em class="parameter"><code>base</code></em> to <em class="parameter"><code>max</code></em> is built by decimating 
            <em class="parameter"><code>data</code></em> in half along
            both dimensions until size 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>1</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>
            is reached. At each level, each texel in the
            halved mipmap level is an average of the corresponding four texels in the larger
            mipmap level. (In the case of rectangular images, the decimation will ultimately 
            reach an 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mi mathvariant="italic">N</mml:mi>
                    <mml:mo>×</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>
            or 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>1</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mi mathvariant="italic">N</mml:mi>
                </mml:mrow>
            </mml:math>
            configuration. Here, two texels are
            averaged instead.)
            <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a> is called to load these mipmap levels from <em class="parameter"><code>base</code></em>
            to <em class="parameter"><code>max</code></em>. If <em class="parameter"><code>max</code></em> is larger than the highest mipmap level for the
            texture of the specified size, then a GLU error code is returned (see
            <a class="citerefentry" href="gluErrorString.xml"><span class="citerefentry"><span class="refentrytitle">gluErrorString</span></span></a>) and nothing is loaded.
        </p><p>
            For example, if <em class="parameter"><code>level</code></em> is 2 and <em class="parameter"><code>width</code></em> is 16 and <em class="parameter"><code>height</code></em> is 8, the
            following levels are possible: 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>16</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>8</mml:mn>
                </mml:mrow>
            </mml:math>, 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>8</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>4</mml:mn>
                </mml:mrow>
            </mml:math>, 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>4</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>2</mml:mn>
                </mml:mrow>
            </mml:math>,
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>2</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>, 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>1</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>.
            These correspond to levels 2 through 6
            respectively.  If <em class="parameter"><code>base</code></em> is 3 and <em class="parameter"><code>max</code></em> is 5, then only mipmap levels
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>8</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>4</mml:mn>
                </mml:mrow>
            </mml:math>, 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>4</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>2</mml:mn>
                </mml:mrow>
            </mml:math>,
            and 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>2</mml:mn>
                    <mml:mo>×</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>
            are loaded. However, if <em class="parameter"><code>max</code></em>
            is 7, then an error is returned and nothing is loaded since <em class="parameter"><code>max</code></em> is
            larger than the highest mipmap level which is, in this case, 6.
        </p><p>
            The highest mipmap level can be derived from the formula
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
                    <mml:mn>2</mml:mn>
                    </mml:msub>
                    <mml:mo>⁡</mml:mo>
                    <mml:mfenced open="(" close=")">
                        <mml:mrow>
                            <mml:mrow>
                                <mml:mi mathvariant="italic">max</mml:mi>
                                <mml:mo>⁡</mml:mo>
                                <mml:mfenced open="(" close=")">
                                    <mml:mi mathvariant="italic">width</mml:mi>
                                    <mml:mi mathvariant="italic">height</mml:mi>
                                </mml:mfenced>
                            </mml:mrow>
                            <mml:mo>×</mml:mo>
                            <mml:msup><mml:mn>2</mml:mn>
                            <mml:mi mathvariant="italic">level</mml:mi>
                            </mml:msup>
                        </mml:mrow>
                    </mml:mfenced>
                </mml:mrow>
            </mml:math>.
        </p><p>
            See the <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a> reference page for a description of the
            acceptable values for <em class="parameter"><code>format</code></em> parameter. See the <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a> 
            reference page for a description of the acceptable values 
            for <em class="parameter"><code>type</code></em> parameter.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            <code class="function">gluBuild2DMipmapLevels</code> is only available if the GLU version is 1.3 or greater.
        </p><p>
            Formats <code class="constant">GLU_BGR</code>, and <code class="constant">GLU_BGRA</code>, and types 
            <code class="constant">GLU_UNSIGNED_BYTE_3_3_2</code>,
            <code class="constant">GLU_UNSIGNED_BYTE_2_3_3_REV</code>,
            <code class="constant">GLU_UNSIGNED_SHORT_5_6_5</code>,
            <code class="constant">GLU_UNSIGNED_SHORT_5_6_5_REV</code>,
            <code class="constant">GLU_UNSIGNED_SHORT_4_4_4_4</code>,
            <code class="constant">GLU_UNSIGNED_SHORT_4_4_4_4_REV</code>,
            <code class="constant">GLU_UNSIGNED_SHORT_5_5_5_1</code>,
            <code class="constant">GLU_UNSIGNED_SHORT_1_5_5_5_REV</code>,
            <code class="constant">GLU_UNSIGNED_INT_8_8_8_8</code>,
            <code class="constant">GLU_UNSIGNED_INT_8_8_8_8_REV</code>,
            <code class="constant">GLU_UNSIGNED_INT_10_10_10_2</code>, and
            <code class="constant">GLU_UNSIGNED_INT_2_10_10_10_REV</code> are only available if the GL version 
            is 1.2 or greater.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
            <code class="constant">GLU_INVALID_VALUE</code> is returned if <em class="parameter"><code>level</code></em> &gt; <em class="parameter"><code>base</code></em>, <em class="parameter"><code>base</code></em> &lt; 0,
            <em class="parameter"><code>max</code></em> &lt; <em class="parameter"><code>base</code></em>, or <em class="parameter"><code>max</code></em> is &gt; the highest mipmap level for <em class="parameter"><code>data</code></em>.
        </p><p>
            <code class="constant">GLU_INVALID_VALUE</code> is returned if <em class="parameter"><code>width</code></em> or <em class="parameter"><code>height</code></em> is &lt; 1.
        </p><p>
            <code class="constant">GLU_INVALID_ENUM</code> is returned if <em class="parameter"><code>internalFormat</code></em>, <em class="parameter"><code>format</code></em>, or <em class="parameter"><code>type</code></em> is not 
            legal.
        </p><p>
            <code class="constant">GLU_INVALID_OPERATION</code> is returned if <em class="parameter"><code>type</code></em> is <code class="constant">GLU_UNSIGNED_BYTE_3_3_2</code> or <code class="constant">GLU_UNSIGNED_BYTE_2_3_3_REV</code>
            and <em class="parameter"><code>format</code></em> is not <code class="constant">GLU_RGB</code>.
        </p><p>
            <code class="constant">GLU_INVALID_OPERATION</code> is returned if <em class="parameter"><code>type</code></em> is <code class="constant">GLU_UNSIGNED_SHORT_5_6_5</code> or <code class="constant">GLU_UNSIGNED_SHORT_5_6_5_REV</code>
            and <em class="parameter"><code>format</code></em> is not <code class="constant">GLU_RGB</code>.
        </p><p>
            <code class="constant">GLU_INVALID_OPERATION</code> is returned if <em class="parameter"><code>type</code></em> is <code class="constant">GLU_UNSIGNED_SHORT_4_4_4_4</code> or <code class="constant">GLU_UNSIGNED_SHORT_4_4_4_4_REV</code>
            and <em class="parameter"><code>format</code></em> is neither <code class="constant">GLU_RGBA</code> nor <code class="constant">GLU_BGRA</code>.
        </p><p>
            <code class="constant">GLU_INVALID_OPERATION</code> is returned if <em class="parameter"><code>type</code></em> is <code class="constant">GLU_UNSIGNED_SHORT_5_5_5_1</code> or <code class="constant">GLU_UNSIGNED_SHORT_1_5_5_5_REV</code>
            and <em class="parameter"><code>format</code></em> is neither <code class="constant">GLU_RGBA</code> nor <code class="constant">GLU_BGRA</code>.
        </p><p>
            <code class="constant">GLU_INVALID_OPERATION</code> is returned if <em class="parameter"><code>type</code></em> is <code class="constant">GLU_UNSIGNED_INT_8_8_8_8</code> or <code class="constant">GLU_UNSIGNED_INT_8_8_8_8_REV</code>
            and <em class="parameter"><code>format</code></em> is neither <code class="constant">GLU_RGBA</code> nor <code class="constant">GLU_BGRA</code>.
        </p><p>
            <code class="constant">GLU_INVALID_OPERATION</code> is returned if <em class="parameter"><code>type</code></em> is <code class="constant">GLU_UNSIGNED_INT_10_10_10_2</code> or <code class="constant">GLU_UNSIGNED_INT_2_10_10_10_REV</code>
            and <em class="parameter"><code>format</code></em> is neither <code class="constant">GLU_RGBA</code> nor <code class="constant">GLU_BGRA</code>.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="gluBuild1DMipmapLevels.xml"><span class="citerefentry"><span class="refentrytitle">gluBuild1DMipmapLevels</span></span></a>,
            <a class="citerefentry" href="gluBuild1DMipmaps.xml"><span class="citerefentry"><span class="refentrytitle">gluBuild1DMipmaps</span></span></a>,
            <a class="citerefentry" href="gluBuild2DMipmaps.xml"><span class="citerefentry"><span class="refentrytitle">gluBuild2DMipmaps</span></span></a>,
            <a class="citerefentry" href="gluBuild3DMipmapLevels.xml"><span class="citerefentry"><span class="refentrytitle">gluBuild3DMipmapLevels</span></span></a>,
            <a class="citerefentry" href="gluBuild3DMipmaps.xml"><span class="citerefentry"><span class="refentrytitle">gluBuild3DMipmaps</span></span></a>, 
            <a class="citerefentry" href="gluErrorString.xml"><span class="citerefentry"><span class="refentrytitle">gluErrorString</span></span></a>, 
            <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
            <a class="citerefentry" href="glGetTexImage.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexImage</span></span></a>,
            <a class="citerefentry" href="glGetTexLevelParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a>,
            <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
            <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>, 
            <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>