upstream-doc/man2/xhtml/glCompressedTexImage2D.xml

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   3 <?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>glCompressedTexImage2D</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glCompressedTexImage2D"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glCompressedTexImage2D — specify a two-dimensional texture image in a compressed format</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">void <b class="fsfunc">glCompressedTexImage2D</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">level</var>, </td></tr><tr><td> </td><td>GLenum  </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>GLint  </td><td><var class="pdparam">border</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">imageSize</var>, </td></tr><tr><td> </td><td>const GLvoid *  </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>
   4                     Specifies the target texture.
   5                     Must be <code class="constant">GL_TEXTURE_2D</code>, <code class="constant">GL_PROXY_TEXTURE_2D</code>,
   6                     <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_X</code>,
   7                     <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_X</code>,
   8                     <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Y</code>,
   9                     <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</code>,
  10                     <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Z</code>,
  11                     <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</code>, or
  12                     <code class="constant">GL_PROXY_TEXTURE_CUBE_MAP</code>.
  13                 </p></dd><dt><span class="term"><em class="parameter"><code>level</code></em></span></dt><dd><p>
  14                     Specifies the level-of-detail number.
  15                     Level 0 is the base image level.
  16                     Level <span class="emphasis"><em>n</em></span> is the <span class="emphasis"><em>n</em></span>th mipmap reduction image.
  17                 </p></dd><dt><span class="term"><em class="parameter"><code>internalformat</code></em></span></dt><dd><p>
  18                     Specifies the format of the compressed image data stored at address <em class="parameter"><code>data</code></em>.
  19                 </p></dd><dt><span class="term"><em class="parameter"><code>width</code></em></span></dt><dd><p>
  20                     Specifies the width of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be
  21                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  22
  23                         <mml:mrow>
  24                             <mml:msup><mml:mn>2</mml:mn>
  25                             <mml:mi mathvariant="italic">n</mml:mi>
  26                             </mml:msup>
  27                             <mml:mo>+</mml:mo>
  28                             <mml:mrow>
  29                                 <mml:mn>2</mml:mn>
  30                                 <mml:mo>⁡</mml:mo>
  31                                 <mml:mfenced open="(" close=")">
  32                                     <mml:mi mathvariant="italic">border</mml:mi>
  33                                 </mml:mfenced>
  34                             </mml:mrow>
  35                         </mml:mrow>
  36                     </mml:math>
  37                     for some integer
  38                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>.
  39                     All
  40                     implementations support 2D texture images that are at least 64 texels
  41                     wide and cube-mapped texture images that are at least 16 texels wide.
  42                 </p></dd><dt><span class="term"><em class="parameter"><code>height</code></em></span></dt><dd><p>
  43                     Specifies the height of the texture image including the border if any. If the GL version does not support non-power-of-two sizes, this value must be
  44                     Must be
  45                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  46
  47                         <mml:mrow>
  48                             <mml:msup><mml:mn>2</mml:mn>
  49                             <mml:mi mathvariant="italic">n</mml:mi>
  50                             </mml:msup>
  51                             <mml:mo>+</mml:mo>
  52                             <mml:mrow>
  53                                 <mml:mn>2</mml:mn>
  54                                 <mml:mo>⁡</mml:mo>
  55                                 <mml:mfenced open="(" close=")">
  56                                     <mml:mi mathvariant="italic">border</mml:mi>
  57                                 </mml:mfenced>
  58                             </mml:mrow>
  59                         </mml:mrow>
  60                     </mml:math>
  61                     for some integer
  62                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>.
  63                     All
  64                     implementations support 2D texture images that are at least 64 texels
  65                     high and cube-mapped texture images that are at least 16 texels high.
  66                 </p></dd><dt><span class="term"><em class="parameter"><code>border</code></em></span></dt><dd><p>
  67                     Specifies the width of the border.
  68                     Must be either 0 or 1.
  69                 </p></dd><dt><span class="term"><em class="parameter"><code>imageSize</code></em></span></dt><dd><p>
  70                     Specifies the number of unsigned bytes of image data starting at the
  71                     address specified by <em class="parameter"><code>data</code></em>.
  72                 </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
  73                     Specifies a pointer to the compressed image data in memory.
  74                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  75             Texturing maps a portion of a specified texture image onto each graphical
  76             primitive for which texturing is enabled.  To enable and disable
  77             two-dimensional texturing, call <a class="citerefentry" href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> and <a class="citerefentry" href="glDisable.xml"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> with argument
  78             <code class="constant">GL_TEXTURE_2D</code>.  To enable and disable texturing using
  79             cube-mapped textures, call <a class="citerefentry" href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> and <a class="citerefentry" href="glDisable.xml"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> with argument
  80             <code class="constant">GL_TEXTURE_CUBE_MAP</code>.
  81         </p><p>
  82             <code class="function">glCompressedTexImage2D</code> loads a previously defined, and retrieved, compressed two-dimensional
  83             texture image if <em class="parameter"><code>target</code></em> is <code class="constant">GL_TEXTURE_2D</code> (see <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>).
  84         </p><p>
  85             If <em class="parameter"><code>target</code></em> is <code class="constant">GL_PROXY_TEXTURE_2D</code>, no data is read from <em class="parameter"><code>data</code></em>, but
  86             all of the texture image state is recalculated, checked for consistency,
  87             and checked against the implementation's capabilities.  If the
  88             implementation cannot handle a texture of the requested texture size, it
  89             sets all of the image state to 0, but does not generate an error (see
  90             <a class="citerefentry" href="glGetError.xml"><span class="citerefentry"><span class="refentrytitle">glGetError</span></span></a>). To query for an entire mipmap array, use an image array level
  91             greater than or equal to 1.
  92         </p><p>
  93             <em class="parameter"><code>internalformat</code></em> must be an extension-specified compressed-texture format.
  94             When a texture is loaded with <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a> using a generic compressed
  95             texture format (e.g., <code class="constant">GL_COMPRESSED_RGB</code>), the GL selects from one of
  96             its extensions supporting compressed textures.  In order to load the
  97             compressed texture image using <code class="function">glCompressedTexImage2D</code>, query the compressed texture image's
  98             size and format using <a class="citerefentry" href="glGetTexLevelParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a>.
  99         </p><p>
 100             If a non-zero named buffer object is bound to the <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target
 101             (see <a class="citerefentry" href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>) while a texture image is
 102             specified, <em class="parameter"><code>data</code></em> is treated as a byte offset into the buffer object's data store.
 103         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 104             <code class="function">glCompressedTexImage2D</code> is available only if the GL version is 1.3 or greater.
 105         </p><p>
 106                         Non-power-of-two textures are supported if the GL version is 2.0 or greater, or if the implementation exports the <code class="constant">GL_ARB_texture_non_power_of_two</code> extension.
 107         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 108             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>internalformat</code></em> is one of the generic compressed internal formats: <code class="constant">GL_COMPRESSED_ALPHA</code>,
 109             <code class="constant">GL_COMPRESSED_LUMINANCE</code>, <code class="constant">GL_COMPRESSED_LUMINANCE_ALPHA</code>,
 110             <code class="constant">GL_COMPRESSED_INTENSITY</code>, <code class="constant">GL_COMPRESSED_RGB</code>, or
 111             <code class="constant">GL_COMPRESSED_RGBA</code>.
 112         </p><p>
 113             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>imageSize</code></em> is not consistent with
 114             the format, dimensions, and contents of the specified compressed image
 115             data.
 116         </p><p>
 117             <code class="constant">GL_INVALID_OPERATION</code> is generated if parameter combinations are not
 118             supported by the specific compressed internal format as specified in the
 119             specific texture compression extension.
 120         </p><p>
 121             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
 122             <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the buffer object's data store is currently mapped.
 123         </p><p>
 124             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
 125             <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the data would be unpacked from the buffer
 126             object such that the memory reads required would exceed the data store size.
 127         </p><p>
 128             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glCompressedTexImage2D</code>
 129             is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
 130             and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
 131         </p><p>
 132             Undefined results, including abnormal program termination, are generated if
 133             <em class="parameter"><code>data</code></em> is not encoded in a manner consistent with the extension
 134             specification defining the internal compression format.
 135         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 136             <a class="citerefentry" href="glGetCompressedTexImage.xml"><span class="citerefentry"><span class="refentrytitle">glGetCompressedTexImage</span></span></a>
 137         </p><p>
 138             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_TEXTURE_COMPRESSED</code>
 139         </p><p>
 140             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PIXEL_UNPACK_BUFFER_BINDING</code>
 141         </p><p>
 142             <a class="citerefentry" href="glGetTexLevelParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a> with arguments <code class="constant">GL_TEXTURE_INTERNAL_FORMAT</code>
 143             and <code class="constant">GL_TEXTURE_COMPRESSED_IMAGE_SIZE</code>
 144         </p><p>
 145             <a class="citerefentry" href="glIsEnabled.xml"><span class="citerefentry"><span class="refentrytitle">glIsEnabled</span></span></a> with argument
 146             <code class="constant">GL_TEXTURE_2D</code> or <code class="constant">GL_TEXTURE_CUBE_MAP</code>
 147         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 148             <a class="citerefentry" href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,
 149             <a class="citerefentry" href="glColorTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorTable</span></span></a>,
 150             <a class="citerefentry" href="glCompressedTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage1D</span></span></a>,
 151             <a class="citerefentry" href="glCompressedTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage3D</span></span></a>,
 152             <a class="citerefentry" href="glCompressedTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage1D</span></span></a>,
 153             <a class="citerefentry" href="glCompressedTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage2D</span></span></a>,
 154             <a class="citerefentry" href="glCompressedTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage3D</span></span></a>,
 155             <a class="citerefentry" href="glConvolutionFilter1D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter1D</span></span></a>,
 156             <a class="citerefentry" href="glCopyPixels.xml"><span class="citerefentry"><span class="refentrytitle">glCopyPixels</span></span></a>,
 157             <a class="citerefentry" href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>,
 158             <a class="citerefentry" href="glCopyTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage1D</span></span></a>,
 159             <a class="citerefentry" href="glCopyTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>,
 160             <a class="citerefentry" href="glCopyTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>,
 161             <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
 162             <a class="citerefentry" href="glMatrixMode.xml"><span class="citerefentry"><span class="refentrytitle">glMatrixMode</span></span></a>,
 163             <a class="citerefentry" href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
 164             <a class="citerefentry" href="glPixelTransfer.xml"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a>,
 165             <a class="citerefentry" href="glTexEnv.xml"><span class="citerefentry"><span class="refentrytitle">glTexEnv</span></span></a>,
 166             <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>,
 167             <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
 168             <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
 169             <a class="citerefentry" href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
 170             <a class="citerefentry" href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
 171             <a class="citerefentry" href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>,
 172             <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>
 173         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 174             Copyright <span class="trademark"></span>© 1991-2006
 175             Silicon Graphics, Inc. This document is licensed under the SGI
 176             Free Software B License. For details, see
 177             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 178         </p></div></div></body></html>