upstream-man-pages/man4/glCompressedTexImage1D.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="glCompressedTexImage1D">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glCompressedTexImage1D</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glCompressedTexImage1D</refname>
  17         <refpurpose>specify a one-dimensional texture image in a compressed format</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glCompressedTexImage1D</function></funcdef>
  23                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  24                 <paramdef>GLint <parameter>level</parameter></paramdef>
  25                 <paramdef>GLenum <parameter>internalformat</parameter></paramdef>
  26                 <paramdef>GLsizei <parameter>width</parameter></paramdef>
  27                 <paramdef>GLint <parameter>border</parameter></paramdef>
  28                 <paramdef>GLsizei <parameter>imageSize</parameter></paramdef>
  29                 <paramdef>const GLvoid * <parameter>data</parameter></paramdef>
  30             </funcprototype>
  31         </funcsynopsis>
  32     </refsynopsisdiv>
  33     <!-- eqn: ignoring delim $$ -->
  34     <refsect1 id="parameters"><title>Parameters</title>
  35         <variablelist>
  36         <varlistentry>
  37             <term><parameter>target</parameter></term>
  38             <listitem>
  39                 <para>
  40                     Specifies the target texture.
  41                     Must be <constant>GL_TEXTURE_1D</constant> or <constant>GL_PROXY_TEXTURE_1D</constant>.
  42                 </para>
  43             </listitem>
  44         </varlistentry>
  45         <varlistentry>
  46             <term><parameter>level</parameter></term>
  47             <listitem>
  48                 <para>
  49                     Specifies the level-of-detail number.
  50                     Level 0 is the base image level.
  51                     Level <emphasis>n</emphasis> is the <emphasis>n</emphasis>th mipmap reduction image.
  52                 </para>
  53             </listitem>
  54         </varlistentry>
  55         <varlistentry>
  56             <term><parameter>internalformat</parameter></term>
  57             <listitem>
  58                 <para>
  59                     Specifies the format of the compressed image data stored at address <parameter>data</parameter>.
  60                 </para>
  61             </listitem>
  62         </varlistentry>
  63         <varlistentry>
  64             <term><parameter>width</parameter></term>
  65             <listitem>
  66                 <para>
  67                     Specifies the width of the texture image.
  68                     All implementations support texture images that are at least 64 texels wide. The height of the 1D texture image is 1.
  69                 </para>
  70             </listitem>
  71         </varlistentry>
  72         <varlistentry>
  73             <term><parameter>border</parameter></term>
  74             <listitem>
  75                 <para>
  76                     This value must be 0.
  77                 </para>
  78             </listitem>
  79         </varlistentry>
  80         <varlistentry>
  81             <term><parameter>imageSize</parameter></term>
  82             <listitem>
  83                 <para>
  84                     Specifies the number of unsigned bytes of image data starting at the address specified by <parameter>data</parameter>.
  85                 </para>
  86             </listitem>
  87         </varlistentry>
  88         <varlistentry>
  89             <term><parameter>data</parameter></term>
  90             <listitem>
  91                 <para>
  92                     Specifies a pointer to the compressed image data in memory.
  93                 </para>
  94             </listitem>
  95         </varlistentry>
  96         </variablelist>
  97     </refsect1>
  98     <refsect1 id="description"><title>Description</title>
  99         <para>
 100             Texturing allows elements of an image array to be read by shaders.
 101         </para>
 102         <para>
 103             <function>glCompressedTexImage1D</function> loads a previously defined, and retrieved, compressed
 104             one-dimensional texture image if <parameter>target</parameter> is <constant>GL_TEXTURE_1D</constant>
 105             (see <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>).
 106         </para>
 107         <para>
 108             If <parameter>target</parameter> is <constant>GL_PROXY_TEXTURE_1D</constant>, no data is read from <parameter>data</parameter>, but
 109             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 <citerefentry><refentrytitle>glGetError</refentrytitle></citerefentry>). To query for an entire mipmap array, use an image array level greater than or equal to 1.
 110         </para>
 111         <para>
 112             <parameter>internalformat</parameter> must be an extension-specified compressed-texture format.
 113             When a texture is loaded with
 114             <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry> using a generic compressed  texture format
 115             (e.g., <constant>GL_COMPRESSED_RGB</constant>) the GL selects from one of
 116             its extensions supporting compressed textures.  In order to load the
 117             compressed texture image using <function>glCompressedTexImage1D</function>, query the compressed texture image's size and
 118             format using <citerefentry><refentrytitle>glGetTexLevelParameter</refentrytitle></citerefentry>.
 119         </para>
 120         <para>
 121             If a non-zero named buffer object is bound to the <constant>GL_PIXEL_UNPACK_BUFFER</constant> target
 122             (see <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>) while a texture image is
 123             specified, <parameter>data</parameter> is treated as a byte offset into the buffer object's data store.
 124         </para>
 125         <para>
 126             If the compressed data are arranged into fixed-size blocks of texels, the pixel
 127             storage modes can be used to select a sub-rectangle from a larger containing rectangle.
 128             These pixel storage modes operate in the same way as they do for <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>.
 129             In the following description, denote by <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>s</mml:mi></mml:msub></mml:mrow></mml:math>,
 130             <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:mrow></mml:math>,
 131             <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>h</mml:mi></mml:msub></mml:mrow></mml:math>, and
 132             <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>d</mml:mi></mml:msub></mml:mrow></mml:math>,
 133             the values of pixel storage modes <constant>GL_UNPACK_COMPRESSED_BLOCK_SIZE</constant>,
 134             <constant>GL_UNPACK_COMPRESSED_BLOCK_WIDTH</constant>, <constant>GL_UNPACK_COMPRESSED_BLOCK_HEIGHT</constant>,
 135             and <constant>GL_UNPACK_COMPRESSED_BLOCK_DEPTH</constant>, respectively.
 136             <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>s</mml:mi></mml:msub></mml:mrow></mml:math> is
 137             the compressed block size in bytes; <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:mrow></mml:math>,
 138             <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>h</mml:mi></mml:msub></mml:mrow></mml:math>,
 139             and <mml:math><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.
 140         </para>
 141         <para>
 142             By default the pixel storage modes <constant>GL_UNPACK_ROW_LENGTH</constant>,
 143             <constant>GL_UNPACK_SKIP_ROWS</constant>, <constant>GL_UNPACK_SKIP_PIXELS</constant>,
 144             <constant>GL_UNPACK_IMAGE_HEIGHT</constant> and <constant>GL_UNPACK_SKIP_IMAGES</constant>
 145             are ignored for compressed images. To enable <constant>GL_UNPACK_SKIP_PIXELS</constant>
 146             and <constant>GL_UNPACK_ROW_LENGTH</constant>, <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>s</mml:mi></mml:msub></mml:mrow></mml:math>
 147             and <mml:math><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.
 148             To also enable <constant>GL_UNPACK_SKIP_ROWS</constant> and <constant>GL_UNPACK_IMAGE_HEIGHT</constant>,
 149             <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>h</mml:mi></mml:msub></mml:mrow></mml:math> must be non-zero.
 150             To also enable <constant>GL_UNPACK_SKIP_IMAGES</constant>, <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>d</mml:mi></mml:msub></mml:mrow></mml:math>
 151             must be non-zero. All parameters must be consistent with the compressed format to produce the desired results.
 152         </para>
 153         <para>
 154             When selecting a sub-rectangle from a compressed image:
 155             <itemizedlist>
 156                 <listitem>the value of <constant>GL_UNPACK_SKIP_PIXELS</constant> must be a multiple of <mml:math><mml:mrow><mml:msub><mml:mi>b</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:mrow></mml:math>;</listitem>
 157             </itemizedlist>
 158         </para>
 159         <para>
 160             <parameter>imageSize</parameter> must be equal to:
 161         </para>
 162         <para>
 163 <mml:math display = 'block'>
 164   <mml:mrow>
 165     <mml:msub>
 166       <mml:mi>b</mml:mi>
 167       <mml:mi>s</mml:mi>
 168     </mml:msub>
 169     <mml:mo lspace='2px' rspace='2px'>&times;</mml:mo>
 170     <mml:mfenced open = '&lceil;' close = '&rceil;'>
 171       <mml:mfrac>
 172         <mml:mi>width</mml:mi>
 173         <mml:msub>
 174           <mml:mi>b</mml:mi>
 175           <mml:mi>w</mml:mi>
 176         </mml:msub>
 177       </mml:mfrac>
 178     </mml:mfenced>
 179   </mml:mrow>
 180 </mml:math>
 181         </para>
 182     </refsect1>
 183     <refsect1 id="errors"><title>Errors</title>
 184         <para>
 185           <constant>GL_INVALID_ENUM</constant> is generated if <parameter>internalformat</parameter> is not
 186           a supported specific compressed internal formats, or is one of the generic
 187           compressed internal formats:
 188           <constant>GL_COMPRESSED_RED</constant>,
 189           <constant>GL_COMPRESSED_RG</constant>,
 190           <constant>GL_COMPRESSED_RGB</constant>,
 191           <constant>GL_COMPRESSED_RGBA</constant>.
 192           <constant>GL_COMPRESSED_SRGB</constant>, or
 193           <constant>GL_COMPRESSED_SRGB_ALPHA</constant>.
 194         </para>
 195         <para>
 196             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>imageSize</parameter> is not consistent with
 197             the format, dimensions, and contents of the specified compressed image data.
 198         </para>
 199         <para>
 200             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>border</parameter> is not 0.
 201         </para>
 202         <para>
 203             <constant>GL_INVALID_OPERATION</constant> is generated if parameter combinations are not
 204             supported by the specific compressed internal format as specified in the
 205             specific texture compression extension.
 206         </para>
 207         <para>
 208             <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to the
 209             <constant>GL_PIXEL_UNPACK_BUFFER</constant> target and the buffer object's data store is currently mapped.
 210         </para>
 211         <para>
 212             <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to the
 213             <constant>GL_PIXEL_UNPACK_BUFFER</constant> target and the data would be unpacked from the buffer
 214             object such that the memory reads required would exceed the data store size.
 215         </para>
 216         <para>
 217             Undefined results, including abnormal program termination, are generated if
 218             <parameter>data</parameter> is not encoded in a manner consistent with the extension
 219             specification defining the internal compression format.
 220         </para>
 221     </refsect1>
 222     <refsect1 id="associatedgets"><title>Associated Gets</title>
 223         <para>
 224             <citerefentry><refentrytitle>glGetCompressedTexImage</refentrytitle></citerefentry>
 225         </para>
 226         <para>
 227             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_TEXTURE_COMPRESSED</constant>
 228         </para>
 229         <para>
 230             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_NUM_COMPRESSED_TEXTURE_FORMATS</constant>
 231         </para>
 232         <para>
 233             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_COMPRESSED_TEXTURE_FORMATS</constant>
 234         </para>
 235         <para>
 236             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_UNPACK_BUFFER_BINDING</constant>
 237         </para>
 238         <para>
 239             <citerefentry><refentrytitle>glGetTexLevelParameter</refentrytitle></citerefentry> with arguments <constant>GL_TEXTURE_INTERNAL_FORMAT</constant>
 240             and <constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant>
 241         </para>
 242     </refsect1>
 243     <refsect1 id="seealso"><title>See Also</title>
 244         <para>
 245             <citerefentry><refentrytitle>glActiveTexture</refentrytitle></citerefentry>,
 246             <citerefentry><refentrytitle>glCompressedTexImage2D</refentrytitle></citerefentry>,
 247             <citerefentry><refentrytitle>glCompressedTexImage3D</refentrytitle></citerefentry>,
 248             <citerefentry><refentrytitle>glCompressedTexSubImage1D</refentrytitle></citerefentry>,
 249             <citerefentry><refentrytitle>glCompressedTexSubImage2D</refentrytitle></citerefentry>,
 250             <citerefentry><refentrytitle>glCompressedTexSubImage3D</refentrytitle></citerefentry>,
 251             <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
 252             <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>,
 253             <citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
 254             <citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
 255             <citerefentry><refentrytitle>glCopyTexSubImage3D</refentrytitle></citerefentry>,
 256             <citerefentry><refentrytitle>glPixelStore</refentrytitle></citerefentry>,
 257             <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
 258             <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,
 259             <citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
 260             <citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>,
 261             <citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>,
 262             <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
 263         </para>
 264     </refsect1>
 265     <refsect1 id="Copyright"><title>Copyright</title>
 266         <para>
 267             Copyright <trademark class="copyright"></trademark> 1991-2006
 268             Silicon Graphics, Inc. <trademark class="copyright"></trademark> 2011
 269             Khronos Group. This document is licensed under the SGI
 270             Free Software B License. For details, see
 271             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 272         </para>
 273     </refsect1>
 274 </refentry>