upstream-doc/man4/glBindImageTexture.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="glBindImageTexture">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2010</year>
   9                 <holder>Khronos Group</holder>>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glBindImageTexture</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glBindImageTexture</refname>
  17         <refpurpose>bind a level of a texture to an image unit</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glBindImageTexture</function></funcdef>
  23                 <paramdef>GLuint <parameter>unit</parameter></paramdef>
  24                 <paramdef>GLuint <parameter>texture</parameter></paramdef>
  25                 <paramdef>GLint <parameter>level</parameter></paramdef>
  26                 <paramdef>GLboolean <parameter>layered</parameter></paramdef>
  27                 <paramdef>GLint <parameter>layer</parameter></paramdef>
  28                 <paramdef>GLenum <parameter>access</parameter></paramdef>
  29                 <paramdef>GLenum <parameter>format</parameter></paramdef>
  30             </funcprototype>
  31         </funcsynopsis>
  32     </refsynopsisdiv>
  33     <refsect1 id="parameters"><title>Parameters</title>
  34         <variablelist>
  35         <varlistentry>
  36             <term><parameter>unit</parameter></term>
  37             <listitem>
  38                 <para>
  39                     Specifies the index of the image unit to which to bind the texture
  40                 </para>
  41             </listitem>
  42         </varlistentry>
  43         <varlistentry>
  44             <term><parameter>texture</parameter></term>
  45             <listitem>
  46                 <para>
  47                     Specifies the name of the texture to bind to the image unit.
  48                 </para>
  49             </listitem>
  50         </varlistentry>
  51         <varlistentry>
  52             <term><parameter>level</parameter></term>
  53             <listitem>
  54                 <para>
  55                     Specifies the level of the texture that is to be bound.
  56                 </para>
  57             </listitem>
  58         </varlistentry>
  59         <varlistentry>
  60             <term><parameter>layered</parameter></term>
  61             <listitem>
  62                 <para>
  63                     Specifies whether a layered texture binding is to be established.
  64                 </para>
  65             </listitem>
  66         </varlistentry>
  67         <varlistentry>
  68             <term><parameter>layer</parameter></term>
  69             <listitem>
  70                 <para>
  71                     If <parameter>layered</parameter> is <constant>GL_FALSE</constant>, specifies the layer of <parameter>texture</parameter> to be bound to the image unit. Ignored otherwise.
  72                 </para>
  73             </listitem>
  74         </varlistentry>
  75         <varlistentry>
  76             <term><parameter>access</parameter></term>
  77             <listitem>
  78                 <para>
  79                     Specifies a token indicating the type of access that will be performed on the image.
  80                 </para>
  81             </listitem>
  82         </varlistentry>
  83         <varlistentry>
  84             <term><parameter>format</parameter></term>
  85             <listitem>
  86                 <para>
  87                     Specifies the format that the elements of the image will be treated as for the purposes of formatted stores.
  88                 </para>
  89             </listitem>
  90         </varlistentry>
  91         </variablelist>
  92     </refsect1>
  93     <refsect1 id="description"><title>Description</title>
  94         <para>
  95             <function>glBindImageTexture</function> binds a single level of a texture to an image unit for the purpose of
  96             reading and writing it from shaders. <parameter>unit</parameter> specifies the zero-based index of the image
  97             unit to which to bind the texture level. <parameter>texture</parameter> specifies the name of an existing texture
  98             object to bind to the image unit. If <parameter>texture</parameter> is zero, then any existing binding to
  99             the image unit is broken. <parameter>level</parameter> specifies the level of the texture to bind to the image
 100             unit.
 101         </para>
 102         <para>
 103             If <parameter>texture</parameter> is the name of a one-, two-, or three-dimensional array texture, a cube map
 104             or cube map array texture, or a two-dimensional multisample array texture, then it is possible to bind either
 105             the entire array, or only a single layer of the array to the image unit. In such cases, if <parameter>layered</parameter>
 106             is <constant>GL_TRUE</constant>, the entire array is attached to the image unit and <parameter>layer</parameter>
 107             is ignored. However, if <parameter>layered</parameter> is <constant>GL_FALSE</constant> then <parameter>layer</parameter>
 108             specifies the layer of the array to attach to the image unit.
 109         </para>
 110         <para>
 111             <parameter>access</parameter> specifies the access types to be performed by shaders and may be set to
 112             <constant>GL_READ_ONLY</constant>, <constant>GL_WRITE_ONLY</constant>, or <constant>GL_READ_WRITE</constant>
 113             to indicate read-only, write-only or read-write access, respectively. Violation of the access type specified in <parameter>access</parameter>
 114             (for example, if a shader writes to an image bound with <parameter>access</parameter> set to <constant>GL_READ_ONLY</constant>)
 115             will lead to undefined results, possibly including program termination.
 116         </para>
 117         <para>
 118             <parameter>format</parameter> specifies the format that is to be used when performing formatted stores into the
 119             image from shaders. <parameter>format</parameter> must be compatible with the texture's internal format and must
 120             be one of the formats listed in the following table.
 121         </para>
 122         <para>
 123             <table frame="topbot"><title>Internal Image Formats</title>
 124             <tgroup cols="2" align="left">
 125                 <colspec align="left"/>
 126                 <colspec align="left"/>
 127                 <thead>
 128                     <row>
 129                         <entry rowsep="1" align="left"><emphasis role="bold">
 130                         Image Unit Format
 131                         </emphasis></entry>
 132                         <entry rowsep="1" align="left"><emphasis role="bold">
 133                         Format Qualifier
 134                         </emphasis></entry>
 135                     </row>
 136                 </thead>
 137                 <tbody>
 138                     <row>
 139                         <entry><constant>GL_RGBA32F</constant></entry><entry><code>rgba32f</code></entry>
 140                     </row>
 141                     <row>
 142                         <entry><constant>GL_RGBA16F</constant></entry><entry><code>rgba16f</code></entry>
 143                     </row>
 144                     <row>
 145                         <entry><constant>GL_RG32F</constant></entry><entry><code>rg32f</code></entry>
 146                     </row>
 147                     <row>
 148                         <entry><constant>GL_RG16F</constant></entry><entry><code>rg16f</code></entry>
 149                     </row>
 150                     <row>
 151                         <entry><constant>GL_R11F_G11F_B10F</constant></entry><entry><code>r11f_g11f_b10f</code></entry>
 152                     </row>
 153                     <row>
 154                         <entry><constant>GL_R32F</constant></entry><entry><code>r32f</code></entry>
 155                     </row>
 156                     <row>
 157                         <entry><constant>GL_R16F</constant></entry><entry><code>r16f</code></entry>
 158                     </row>
 159                     <row>
 160                         <entry><constant>GL_RGBA32UI</constant></entry><entry><code>rgba32ui</code></entry>
 161                     </row>
 162                     <row>
 163                         <entry><constant>GL_RGBA16UI</constant></entry><entry><code>rgba16ui</code></entry>
 164                     </row>
 165                     <row>
 166                         <entry><constant>GL_RGB10_A2UI</constant></entry><entry><code>rgb10_a2ui</code></entry>
 167                     </row>
 168                     <row>
 169                         <entry><constant>GL_RGBA8UI</constant></entry><entry><code>rgba8ui</code></entry>
 170                     </row>
 171                     <row>
 172                         <entry><constant>GL_RG32UI</constant></entry><entry><code>rg32ui</code></entry>
 173                     </row>
 174                     <row>
 175                         <entry><constant>GL_RG16UI</constant></entry><entry><code>rg16ui</code></entry>
 176                     </row>
 177                     <row>
 178                         <entry><constant>GL_RG8UI</constant></entry><entry><code>rg8ui</code></entry>
 179                     </row>
 180                     <row>
 181                         <entry><constant>GL_R32UI</constant></entry><entry><code>r32ui</code></entry>
 182                     </row>
 183                     <row>
 184                         <entry><constant>GL_R16UI</constant></entry><entry><code>r16ui</code></entry>
 185                     </row>
 186                     <row>
 187                         <entry><constant>GL_R8UI</constant></entry><entry><code>r8ui</code></entry>
 188                     </row>
 189                     <row>
 190                         <entry><constant>GL_RGBA32I</constant></entry><entry><code>rgba32i</code></entry>
 191                     </row>
 192                     <row>
 193                         <entry><constant>GL_RGBA16I</constant></entry><entry><code>rgba16i</code></entry>
 194                     </row>
 195                     <row>
 196                         <entry><constant>GL_RGBA8I</constant></entry><entry><code>rgba8i</code></entry>
 197                     </row>
 198                     <row>
 199                         <entry><constant>GL_RG32I</constant></entry><entry><code>rg32i</code></entry>
 200                     </row>
 201                     <row>
 202                         <entry><constant>GL_RG16I</constant></entry><entry><code>rg16i</code></entry>
 203                     </row>
 204                     <row>
 205                         <entry><constant>GL_RG8I</constant></entry><entry><code>rg8i</code></entry>
 206                     </row>
 207                     <row>
 208                         <entry><constant>GL_R32I</constant></entry><entry><code>r32i</code></entry>
 209                     </row>
 210                     <row>
 211                         <entry><constant>GL_R16I</constant></entry><entry><code>r16i</code></entry>
 212                     </row>
 213                     <row>
 214                         <entry><constant>GL_R8I</constant></entry><entry><code>r8i</code></entry>
 215                     </row>
 216                     <row>
 217                         <entry><constant>GL_RGBA16</constant></entry><entry><code>rgba16</code></entry>
 218                     </row>
 219                     <row>
 220                         <entry><constant>GL_RGB10_A2</constant></entry><entry><code>rgb10_a2</code></entry>
 221                     </row>
 222                     <row>
 223                         <entry><constant>GL_RGBA8</constant></entry><entry><code>rgba8</code></entry>
 224                     </row>
 225                     <row>
 226                         <entry><constant>GL_RG16</constant></entry><entry><code>rg16</code></entry>
 227                     </row>
 228                     <row>
 229                         <entry><constant>GL_RG8</constant></entry><entry><code>rg8</code></entry>
 230                     </row>
 231                     <row>
 232                         <entry><constant>GL_R16</constant></entry><entry><code>r16</code></entry>
 233                     </row>
 234                     <row>
 235                         <entry><constant>GL_R8</constant></entry><entry><code>r8</code></entry>
 236                     </row>
 237                     <row>
 238                         <entry><constant>GL_RGBA16_SNORM</constant></entry><entry><code>rgba16_snorm</code></entry>
 239                     </row>
 240                     <row>
 241                         <entry><constant>GL_RGBA8_SNORM</constant></entry><entry><code>rgba8_snorm</code></entry>
 242                     </row>
 243                     <row>
 244                         <entry><constant>GL_RG16_SNORM</constant></entry><entry><code>rg16_snorm</code></entry>
 245                     </row>
 246                     <row>
 247                         <entry><constant>GL_RG8_SNORM</constant></entry><entry><code>rg8_snorm</code></entry>
 248                     </row>
 249                     <row>
 250                         <entry><constant>GL_R16_SNORM</constant></entry><entry><code>r16_snorm</code></entry>
 251                     </row>
 252                     <row>
 253                         <entry><constant>GL_R8_SNORM</constant></entry><entry><code>r8_snorm</code></entry>
 254                     </row>
 255                 </tbody>
 256             </tgroup>
 257             </table>
 258         </para>
 259         <para>
 260             When a texture is bound to an image unit, the <parameter>format</parameter> parameter for the image
 261             unit need not exactly match the texture internal format as long as the formats are
 262             considered compatible as defined in the OpenGL Specification. The matching criterion used
 263             for a given texture may be determined by calling <citerefentry><refentrytitle>glGetTexParameter</refentrytitle></citerefentry>
 264             with <parameter>value</parameter>
 265             set to <constant>GL_IMAGE_FORMAT_COMPATIBILITY_TYPE</constant>, with return values of <constant>GL_IMAGE_FORMAT_COMPATIBILITY_BY_SIZE</constant>
 266             and <constant>GL_IMAGE_FORMAT_COMPATIBILITY_BY_CLASS</constant>, specifying matches by size and class, respectively.
 267         </para>
 268     </refsect1>
 269     <refsect1 id="notes"><title>Notes</title>
 270         <para>
 271             The <function>glBindImageTexture</function> is available only if the GL version is 4.2 or greater.
 272         </para>
 273     </refsect1>
 274     <refsect1 id="errors"><title>Errors</title>
 275         <para>
 276             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>unit</parameter> greater than or equal to the
 277             value of <constant>GL_MAX_IMAGE_UNITS</constant>.
 278         </para>
 279         <para>
 280             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>texture</parameter> is not the name of
 281             an existing texture object.
 282         </para>
 283         <para>
 284             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>level</parameter> or <parameter>layer</parameter>
 285             is less than zero.
 286         </para>
 287         <para>
 288             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>access</parameter> or <parameter>format</parameter>
 289             is not one of the supported tokens.
 290         </para>
 291     </refsect1>
 292     <refsect1 id="associatedgets"><title>Associated Gets</title>
 293         <para>
 294             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_IMAGE_BINDING_NAME</constant>.
 295         </para>
 296         <para>
 297             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_IMAGE_BINDING_LEVEL</constant>.
 298         </para>
 299         <para>
 300             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_IMAGE_BINDING_LAYERED</constant>.
 301         </para>
 302         <para>
 303             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_IMAGE_BINDING_LAYER</constant>.
 304         </para>
 305         <para>
 306             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_IMAGE_BINDING_ACCESS</constant>.
 307         </para>
 308         <para>
 309             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_IMAGE_BINDING_FORMAT</constant>.
 310         </para>
 311     </refsect1>
 312     <refsect1 id="seealso"><title>See Also</title>
 313         <para>
 314             <citerefentry><refentrytitle>glGenTextures</refentrytitle></citerefentry>,
 315             <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
 316             <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
 317             <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,
 318             <citerefentry><refentrytitle>glTexStorage1D</refentrytitle></citerefentry>,
 319             <citerefentry><refentrytitle>glTexStorage2D</refentrytitle></citerefentry>,
 320             <citerefentry><refentrytitle>glTexStorage3D</refentrytitle></citerefentry>,
 321             <citerefentry><refentrytitle>glBindTexture</refentrytitle></citerefentry>
 322         </para>
 323     </refsect1>
 324     <refsect1 id="Copyright"><title>Copyright</title>
 325         <para>
 326             Copyright <trademark class="copyright"></trademark> 2011 Khronos Group.
 327             This material may be distributed subject to the terms and conditions set forth in
 328             the Open Publication License, v 1.0, 8 June 1999.
 329             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 330         </para>
 331     </refsect1>
 332 </refentry>