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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" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glCompressedTexImage1D - OpenGL 4 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glCompressedTexImage1D"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glCompressedTexImage1D — specify a one-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">glCompressedTexImage1D</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>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_1D</code> or <code class="constant">GL_PROXY_TEXTURE_1D</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.
                    All implementations support texture images that are at least 64 texels wide. The height of the 1D texture image is 1.
                </p></dd><dt><span class="term"><em class="parameter"><code>border</code></em></span></dt><dd><p>
                    This value must be 0.
                </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 allows elements of an image array to be read by shaders.
        </p><p>
            <code class="function">glCompressedTexImage1D</code> loads a previously defined, and retrieved, compressed
            one-dimensional texture image if <em class="parameter"><code>target</code></em> is <code class="constant">GL_TEXTURE_1D</code>
            (see <a href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>).
        </p><p>
            If <em class="parameter"><code>target</code></em> is <code class="constant">GL_PROXY_TEXTURE_1D</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 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 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 href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</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">glCompressedTexImage1D</code>, query the compressed texture image's size and
            format using <a href="glGetTexLevelParameter.xml"><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 href="glBindBuffer.xml"><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><p>
            If the compressed data are arranged into fixed-size blocks of texels, the pixel
            storage modes can be used to select a sub-rectangle from a larger containing rectangle.
            These pixel storage modes operate in the same way as they do for <a href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>.
            In the following description, denote by <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>s</mml:mi></mml:msub></mml:mrow></mml:math>,
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:mrow></mml:math>,
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>h</mml:mi></mml:msub></mml:mrow></mml:math>, and
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>d</mml:mi></mml:msub></mml:mrow></mml:math>,
            the values of pixel storage modes <code class="constant">GL_UNPACK_COMPRESSED_BLOCK_SIZE</code>,
            <code class="constant">GL_UNPACK_COMPRESSED_BLOCK_WIDTH</code>, <code class="constant">GL_UNPACK_COMPRESSED_BLOCK_HEIGHT</code>,
            and <code class="constant">GL_UNPACK_COMPRESSED_BLOCK_DEPTH</code>, respectively.
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>s</mml:mi></mml:msub></mml:mrow></mml:math> is
            the compressed block size in bytes; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:mrow></mml:math>,
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>h</mml:mi></mml:msub></mml:mrow></mml:math>,
            and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>d</mml:mi></mml:msub></mml:mrow></mml:math> are the compressed block width, height, and depth in pixels.
        </p><p>
            By default the pixel storage modes <code class="constant">GL_UNPACK_ROW_LENGTH</code>,
            <code class="constant">GL_UNPACK_SKIP_ROWS</code>, <code class="constant">GL_UNPACK_SKIP_PIXELS</code>,
            <code class="constant">GL_UNPACK_IMAGE_HEIGHT</code> and <code class="constant">GL_UNPACK_SKIP_IMAGES</code>
            are ignored for compressed images. To enable <code class="constant">GL_UNPACK_SKIP_PIXELS</code>
            and <code class="constant">GL_UNPACK_ROW_LENGTH</code>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>s</mml:mi></mml:msub></mml:mrow></mml:math>
            and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:mrow></mml:math> must both be non-zero.
            To also enable <code class="constant">GL_UNPACK_SKIP_ROWS</code> and <code class="constant">GL_UNPACK_IMAGE_HEIGHT</code>,
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>h</mml:mi></mml:msub></mml:mrow></mml:math> must be non-zero.
            To also enable <code class="constant">GL_UNPACK_SKIP_IMAGES</code>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>d</mml:mi></mml:msub></mml:mrow></mml:math>
            must be non-zero. All parameters must be consistent with the compressed format to produce the desired results.
        </p><p>
            When selecting a sub-rectangle from a compressed image:
            </p><div class="itemizedlist"><ul type="disc"><li>the value of <code class="constant">GL_UNPACK_SKIP_PIXELS</code> must be a multiple of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:mrow></mml:math>;</li></ul></div><p>
        </p><p>
            <em class="parameter"><code>imageSize</code></em> must be equal to:
        </p><p>
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="block" overflow="scroll">
  <mml:mrow>
    <mml:msub>
      <mml:mi>b</mml:mi>
      <mml:mi>s</mml:mi>
    </mml:msub>
    <mml:mo lspace="2px" rspace="2px">×</mml:mo>
    <mml:mfenced open="&#x2308;" close="&#x2309;">
      <mml:mfrac>
        <mml:mi>width</mml:mi>
        <mml:msub>
          <mml:mi>b</mml:mi>
          <mml:mi>w</mml:mi>
        </mml:msub>
      </mml:mfrac>
    </mml:mfenced>
  </mml:mrow>
</mml:math>
        </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 not
          a supported specific compressed internal formats, or is one of the generic
          compressed internal formats:
          <code class="constant">GL_COMPRESSED_RED</code>,
          <code class="constant">GL_COMPRESSED_RG</code>,
          <code class="constant">GL_COMPRESSED_RGB</code>,
          <code class="constant">GL_COMPRESSED_RGBA</code>.
          <code class="constant">GL_COMPRESSED_SRGB</code>, or
          <code class="constant">GL_COMPRESSED_SRGB_ALPHA</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_VALUE</code> is generated if <em class="parameter"><code>border</code></em> is not 0.
        </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>
            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 href="glGetCompressedTexImage.xml"><span class="citerefentry"><span class="refentrytitle">glGetCompressedTexImage</span></span></a>
        </p><p>
            <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_TEXTURE_COMPRESSED</code>
        </p><p>
            <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_NUM_COMPRESSED_TEXTURE_FORMATS</code>
        </p><p>
            <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_COMPRESSED_TEXTURE_FORMATS</code>
        </p><p>
            <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PIXEL_UNPACK_BUFFER_BINDING</code>
        </p><p>
            <a href="glGetTexLevelParameter.xml"><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></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,
            <a href="glCompressedTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage2D</span></span></a>,
            <a href="glCompressedTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage3D</span></span></a>,
            <a href="glCompressedTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage1D</span></span></a>,
            <a href="glCompressedTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage2D</span></span></a>,
            <a href="glCompressedTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage3D</span></span></a>,
            <a href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>,
            <a href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>,
            <a href="glCopyTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage1D</span></span></a>,
            <a href="glCopyTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>,
            <a href="glCopyTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>,
            <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
            <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
            <a href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
            <a href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
            <a href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
            <a href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>,
            <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</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. <span class="trademark"></span>© 2011
            Khronos Group. This document is licensed under the SGI
            Free Software B License. For details, see
            <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>
