<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><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>

Specifies the target texture.

Must be <code class="constant">GL_TEXTURE_2D</code>, <code class="constant">GL_PROXY_TEXTURE_2D</code>,

<code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_X</code>,

<code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_X</code>,

<code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Y</code>,

<code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</code>,

<code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Z</code>,

<code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</code>, or

<code class="constant">GL_PROXY_TEXTURE_CUBE_MAP</code>.

</p></dd><dt><span class="term"><em class="parameter"><code>level</code></em></span></dt><dd><p>

Specifies the level-of-detail number.

Level 0 is the base image level.

Level <span class="emphasis"><em>n</em></span> is the <span class="emphasis"><em>n</em></span>th mipmap reduction image.

</p></dd><dt><span class="term"><em class="parameter"><code>internalformat</code></em></span></dt><dd><p>

Specifies the format of the compressed image data stored at address <em class="parameter"><code>data</code></em>.

</p></dd><dt><span class="term"><em class="parameter"><code>width</code></em></span></dt><dd><p>

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

<math overflow="scroll">

<mrow>

<msup><mn>2</mn>

<mi mathvariant="italic">n</mi>

</msup>

<mo>+</mo>

<mrow>

<mn>2</mn>

<mo>⁡</mo>

<mfenced open="(" close=")">

<mi mathvariant="italic">border</mi>

</mfenced>

</mrow>

</mrow>

</math>

for some integer

<math overflow="scroll"><mi mathvariant="italic">n</mi></math>.

All

implementations support 2D texture images that are at least 64 texels

wide and cube-mapped texture images that are at least 16 texels wide.

</p></dd><dt><span class="term"><em class="parameter"><code>height</code></em></span></dt><dd><p>

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

Must be

<math overflow="scroll">

<mrow>

<msup><mn>2</mn>

<mi mathvariant="italic">n</mi>

</msup>

<mo>+</mo>

<mrow>

<mn>2</mn>

<mo>⁡</mo>

<mfenced open="(" close=")">

<mi mathvariant="italic">border</mi>

</mfenced>

</mrow>

</mrow>

</math>

for some integer

<math overflow="scroll"><mi mathvariant="italic">n</mi></math>.

All

implementations support 2D texture images that are at least 64 texels

high and cube-mapped texture images that are at least 16 texels high.

</p></dd><dt><span class="term"><em class="parameter"><code>border</code></em></span></dt><dd><p>

Specifies the width of the border.

Must be either 0 or 1.

</p></dd><dt><span class="term"><em class="parameter"><code>imageSize</code></em></span></dt><dd><p>

Specifies the number of unsigned bytes of image data starting at the

address specified by <em class="parameter"><code>data</code></em>.

</p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>

Specifies a pointer to the compressed 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>

Texturing maps a portion of a specified texture image onto each graphical

primitive for which texturing is enabled. To enable and disable

two-dimensional texturing, call <a class="citerefentry" href="glEnable"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> and <a class="citerefentry" href="glDisable"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> with argument

<code class="constant">GL_TEXTURE_2D</code>. To enable and disable texturing using

cube-mapped textures, call <a class="citerefentry" href="glEnable"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> and <a class="citerefentry" href="glDisable"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> with argument

<code class="constant">GL_TEXTURE_CUBE_MAP</code>.

</p><p>

<code class="function">glCompressedTexImage2D</code> loads a previously defined, and retrieved, compressed two-dimensional

texture image if <em class="parameter"><code>target</code></em> is <code class="constant">GL_TEXTURE_2D</code> (see <a class="citerefentry" href="glTexImage2D"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>).

</p><p>

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

all of the texture image state is recalculated, checked for consistency,

and checked against the implementation's capabilities. If the

implementation cannot handle a texture of the requested texture size, it

sets all of the image state to 0, but does not generate an error (see

<a class="citerefentry" href="glGetError"><span class="citerefentry"><span class="refentrytitle">glGetError</span></span></a>). To query for an entire mipmap array, use an image array level

greater than or equal to 1.

</p><p>

<em class="parameter"><code>internalformat</code></em> must be an extension-specified compressed-texture format.

When a texture is loaded with <a class="citerefentry" href="glTexImage2D"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a> using a generic compressed

texture format (e.g., <code class="constant">GL_COMPRESSED_RGB</code>), the GL selects from one of

its extensions supporting compressed textures. In order to load the

compressed texture image using <code class="function">glCompressedTexImage2D</code>, query the compressed texture image's

size and format using <a class="citerefentry" href="glGetTexLevelParameter"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a>.

</p><p>

If a non-zero named buffer object is bound to the <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target

(see <a class="citerefentry" href="glBindBuffer"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>) while a texture image is

specified, <em class="parameter"><code>data</code></em> is treated as a byte offset into the buffer object's data store.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>

<code class="function">glCompressedTexImage2D</code> is available only if the GL version is 1.3 or greater.

</p><p>

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.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>

<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>,

<code class="constant">GL_COMPRESSED_LUMINANCE</code>, <code class="constant">GL_COMPRESSED_LUMINANCE_ALPHA</code>,

<code class="constant">GL_COMPRESSED_INTENSITY</code>, <code class="constant">GL_COMPRESSED_RGB</code>, or

<code class="constant">GL_COMPRESSED_RGBA</code>.

</p><p>

<code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>imageSize</code></em> is not consistent with

the format, dimensions, and contents of the specified compressed image

data.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if parameter combinations are not

supported by the specific compressed internal format as specified in the

specific texture compression extension.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the

<code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the buffer object's data store is currently mapped.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the

<code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the data would be unpacked from the buffer

object such that the memory reads required would exceed the data store size.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glCompressedTexImage2D</code>

is executed between the execution of <a class="citerefentry" href="glBegin"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>

and the corresponding execution of <a class="citerefentry" href="glEnd"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.

</p><p>

Undefined results, including abnormal program termination, are generated if

<em class="parameter"><code>data</code></em> is not encoded in a manner consistent with the extension

specification defining the internal compression format.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>

<a class="citerefentry" href="glGetCompressedTexImage"><span class="citerefentry"><span class="refentrytitle">glGetCompressedTexImage</span></span></a>

</p><p>

<a class="citerefentry" href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_TEXTURE_COMPRESSED</code>

</p><p>

<a class="citerefentry" href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PIXEL_UNPACK_BUFFER_BINDING</code>

</p><p>

<a class="citerefentry" href="glGetTexLevelParameter"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a> with arguments <code class="constant">GL_TEXTURE_INTERNAL_FORMAT</code>

and <code class="constant">GL_TEXTURE_COMPRESSED_IMAGE_SIZE</code>

</p><p>

<a class="citerefentry" href="glIsEnabled"><span class="citerefentry"><span class="refentrytitle">glIsEnabled</span></span></a> with argument

<code class="constant">GL_TEXTURE_2D</code> or <code class="constant">GL_TEXTURE_CUBE_MAP</code>

</p></div>

{$pipelinestall}{$examples}

<div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>

<a class="citerefentry" href="glActiveTexture"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,

<a class="citerefentry" href="glColorTable"><span class="citerefentry"><span class="refentrytitle">glColorTable</span></span></a>,

<a class="citerefentry" href="glCompressedTexImage1D"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage1D</span></span></a>,

<a class="citerefentry" href="glCompressedTexImage3D"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage3D</span></span></a>,

<a class="citerefentry" href="glCompressedTexSubImage1D"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage1D</span></span></a>,

<a class="citerefentry" href="glCompressedTexSubImage2D"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage2D</span></span></a>,

<a class="citerefentry" href="glCompressedTexSubImage3D"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage3D</span></span></a>,

<a class="citerefentry" href="glConvolutionFilter1D"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter1D</span></span></a>,

<a class="citerefentry" href="glCopyPixels"><span class="citerefentry"><span class="refentrytitle">glCopyPixels</span></span></a>,

<a class="citerefentry" href="glCopyTexImage1D"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>,

<a class="citerefentry" href="glCopyTexSubImage1D"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage1D</span></span></a>,

<a class="citerefentry" href="glCopyTexSubImage2D"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>,

<a class="citerefentry" href="glCopyTexSubImage3D"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>,

<a class="citerefentry" href="glDrawPixels"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,

<a class="citerefentry" href="glMatrixMode"><span class="citerefentry"><span class="refentrytitle">glMatrixMode</span></span></a>,

<a class="citerefentry" href="glPixelStore"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,

<a class="citerefentry" href="glPixelTransfer"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a>,

<a class="citerefentry" href="glTexEnv"><span class="citerefentry"><span class="refentrytitle">glTexEnv</span></span></a>,

<a class="citerefentry" href="glTexGen"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>,

<a class="citerefentry" href="glTexImage2D"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,

<a class="citerefentry" href="glTexImage3D"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,

<a class="citerefentry" href="glTexSubImage1D"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,

<a class="citerefentry" href="glTexSubImage2D"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,

<a class="citerefentry" href="glTexSubImage3D"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>,

<a class="citerefentry" href="glTexParameter"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>

</p></div><div class="refsect1" lang="en" xml:lang="en"><div id="Copyright"><h2>Copyright</h2><p>

Copyright © 1991-2006

Silicon Graphics, Inc. This document is licensed under the SGI

Free Software B License. For details, see

<a class="ulink" href="https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/" target="_top">https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/</a>.

</p></div></div></div>