| 1 | <?xml version="1.0" encoding="UTF-8"?> |
| 2 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd"> |
| 3 | <!-- saved from url=(0013)about:internet --> |
| 4 | <?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>glCompressedTexSubImage2D - 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="glCompressedTexSubImage2D"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glCompressedTexSubImage2D — specify a two-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">glCompressedTexSubImage2D</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>GLint </td><td><var class="pdparam">yoffset</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>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> |
| 5 | Specifies the target texture. |
| 6 | Must be <code class="constant">GL_TEXTURE_2D</code>, |
| 7 | <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_X</code>, |
| 8 | <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_X</code>, |
| 9 | <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Y</code>, |
| 10 | <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</code>, |
| 11 | <code class="constant">GL_TEXTURE_CUBE_MAP_POSITIVE_Z</code>, or |
| 12 | <code class="constant">GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</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>xoffset</code></em></span></dt><dd><p> |
| 18 | Specifies a texel offset in the x direction within the texture array. |
| 19 | </p></dd><dt><span class="term"><em class="parameter"><code>yoffset</code></em></span></dt><dd><p> |
| 20 | Specifies a texel offset in the y direction within the texture array. |
| 21 | </p></dd><dt><span class="term"><em class="parameter"><code>width</code></em></span></dt><dd><p> |
| 22 | Specifies the width of the texture subimage. |
| 23 | </p></dd><dt><span class="term"><em class="parameter"><code>height</code></em></span></dt><dd><p> |
| 24 | Specifies the height of the texture subimage. |
| 25 | </p></dd><dt><span class="term"><em class="parameter"><code>format</code></em></span></dt><dd><p> |
| 26 | Specifies the format of the compressed image data stored at address <em class="parameter"><code>data</code></em>. |
| 27 | </p></dd><dt><span class="term"><em class="parameter"><code>imageSize</code></em></span></dt><dd><p> |
| 28 | Specifies the number of unsigned bytes of image data starting at the |
| 29 | address specified by <em class="parameter"><code>data</code></em>. |
| 30 | </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p> |
| 31 | Specifies a pointer to the compressed image data in memory. |
| 32 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> |
| 33 | Texturing allows elements of an image array to be read by shaders. |
| 34 | </p><p> |
| 35 | <code class="function">glCompressedTexSubImage2D</code> redefines a contiguous subregion of an existing two-dimensional |
| 36 | texture image. The texels referenced by <em class="parameter"><code>data</code></em> replace the portion of the |
| 37 | existing texture array with x indices <em class="parameter"><code>xoffset</code></em> and |
| 38 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 39 | |
| 40 | <mml:mrow> |
| 41 | <mml:mi mathvariant="italic">xoffset</mml:mi> |
| 42 | <mml:mo>+</mml:mo> |
| 43 | <mml:mi mathvariant="italic">width</mml:mi> |
| 44 | <mml:mo>-</mml:mo> |
| 45 | <mml:mn>1</mml:mn> |
| 46 | </mml:mrow> |
| 47 | </mml:math>, |
| 48 | and the y indices <em class="parameter"><code>yoffset</code></em> and |
| 49 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 50 | |
| 51 | <mml:mrow> |
| 52 | <mml:mi mathvariant="italic">yoffset</mml:mi> |
| 53 | <mml:mo>+</mml:mo> |
| 54 | <mml:mi mathvariant="italic">height</mml:mi> |
| 55 | <mml:mo>-</mml:mo> |
| 56 | <mml:mn>1</mml:mn> |
| 57 | </mml:mrow> |
| 58 | </mml:math>, |
| 59 | inclusive. |
| 60 | This region may not include any texels |
| 61 | outside the range of the texture array as it was originally specified. It |
| 62 | is not an error to specify a subtexture with width of 0, but such a |
| 63 | specification has no effect. |
| 64 | </p><p> |
| 65 | <em class="parameter"><code>internalformat</code></em> must be a known compressed image format (such as <code class="constant">GL_RGTC</code>) |
| 66 | or an extension-specified compressed-texture format. |
| 67 | The <em class="parameter"><code>format</code></em> of the compressed texture |
| 68 | image is selected by the GL implementation that compressed it (see |
| 69 | <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>) and should be queried at the time the texture was |
| 70 | compressed with <a href="glGetTexLevelParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a>. |
| 71 | </p><p> |
| 72 | If a non-zero named buffer object is bound to the <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target |
| 73 | (see <a href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>) while a texture image is |
| 74 | specified, <em class="parameter"><code>data</code></em> is treated as a byte offset into the buffer object's data store. |
| 75 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> |
| 76 | <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>internalformat</code></em> is of the generic compressed internal formats: |
| 77 | <code class="constant">GL_COMPRESSED_RED</code>, |
| 78 | <code class="constant">GL_COMPRESSED_RG</code>, |
| 79 | <code class="constant">GL_COMPRESSED_RGB</code>, |
| 80 | <code class="constant">GL_COMPRESSED_RGBA</code>. |
| 81 | <code class="constant">GL_COMPRESSED_SRGB</code>, or |
| 82 | <code class="constant">GL_COMPRESSED_SRGB_ALPHA</code>. |
| 83 | </p><p> |
| 84 | <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>imageSize</code></em> is not consistent with |
| 85 | the format, dimensions, and contents of the specified compressed image |
| 86 | data. |
| 87 | </p><p> |
| 88 | <code class="constant">GL_INVALID_OPERATION</code> is generated if parameter combinations are not |
| 89 | supported by the specific compressed internal format as specified in the |
| 90 | specific texture compression extension. |
| 91 | </p><p> |
| 92 | <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the |
| 93 | <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the buffer object's data store is currently mapped. |
| 94 | </p><p> |
| 95 | <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the |
| 96 | <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the data would be unpacked from the buffer |
| 97 | object such that the memory reads required would exceed the data store size. |
| 98 | </p><p> |
| 99 | Undefined results, including abnormal program termination, are generated if |
| 100 | <em class="parameter"><code>data</code></em> is not encoded in a manner consistent with the extension |
| 101 | specification defining the internal compression format. |
| 102 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p> |
| 103 | <a href="glGetCompressedTexImage.xml"><span class="citerefentry"><span class="refentrytitle">glGetCompressedTexImage</span></span></a> |
| 104 | </p><p> |
| 105 | <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_TEXTURE_COMPRESSED</code> |
| 106 | </p><p> |
| 107 | <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> |
| 108 | </p><p> |
| 109 | <a href="glGetTexLevelParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a> with arguments <code class="constant">GL_TEXTURE_INTERNAL_FORMAT</code> |
| 110 | and <code class="constant">GL_TEXTURE_COMPRESSED_IMAGE_SIZE</code> |
| 111 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> |
| 112 | <a href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>, |
| 113 | <a href="glCompressedTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage1D</span></span></a>, |
| 114 | <a href="glCompressedTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage2D</span></span></a>, |
| 115 | <a href="glCompressedTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage3D</span></span></a>, |
| 116 | <a href="glCompressedTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage1D</span></span></a>, |
| 117 | <a href="glCompressedTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCompressedTexSubImage3D</span></span></a>, |
| 118 | <a href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>, |
| 119 | <a href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>, |
| 120 | <a href="glCopyTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage1D</span></span></a>, |
| 121 | <a href="glCopyTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>, |
| 122 | <a href="glCopyTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>, |
| 123 | <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>, |
| 124 | <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>, |
| 125 | <a href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>, |
| 126 | <a href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>, |
| 127 | <a href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>, |
| 128 | <a href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>, |
| 129 | <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a> |
| 130 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> |
| 131 | Copyright <span class="trademark"></span>© 1991-2006 |
| 132 | Silicon Graphics, Inc. This document is licensed under the SGI |
| 133 | Free Software B License. For details, see |
| 134 | <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>. |
| 135 | </p></div></div></body></html> |