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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>glCompressedTexSubImage1D - 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="glCompressedTexSubImage1D"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glCompressedTexSubImage1D — specify a one-dimensional texture subimage 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">glCompressedTexSubImage1D</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>GLint  </td><td><var class="pdparam">xoffset</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">width</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">format</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>.
                </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>xoffset</code></em></span></dt><dd><p>
                    Specifies a texel offset in the x direction within the texture array.
                </p></dd><dt><span class="term"><em class="parameter"><code>width</code></em></span></dt><dd><p>
                    Specifies the width of the texture subimage.
                </p></dd><dt><span class="term"><em class="parameter"><code>format</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>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">glCompressedTexSubImage1D</code> redefines a contiguous subregion of an existing one-dimensional
            texture image.  The texels referenced by <em class="parameter"><code>data</code></em> replace the portion of the
            existing texture array with x indices <em class="parameter"><code>xoffset</code></em> and 
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mi mathvariant="italic">xoffset</mml:mi>
                    <mml:mo>+</mml:mo>
                    <mml:mi mathvariant="italic">width</mml:mi>
                    <mml:mo>-</mml:mo>
                    <mml:mn>1</mml:mn>
                </mml:mrow>
            </mml:math>,
            inclusive.  This region may not include any texels
            outside the range of the texture array as it was originally specified.  It
            is not an error to specify a subtexture with width of 0, but such a
            specification has no effect.
        </p><p>
            <em class="parameter"><code>internalformat</code></em> must be a known compressed image format (such as <code class="constant">GL_RGTC</code>)
            or an extension-specified compressed-texture format.
            The <em class="parameter"><code>format</code></em> of the compressed texture
            image is selected by the GL implementation that compressed it (see
            <a href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>), and should be queried at the time the texture was
            compressed with <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></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 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_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_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="glCompressedTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage1D</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="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. 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>
