upstream-doc/man4/glCopyTexImage2D.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="glCopyTexImage2D">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glCopyTexImage2D</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glCopyTexImage2D</refname>
  17         <refpurpose>copy pixels into a 2D texture image</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glCopyTexImage2D</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>GLint <parameter>x</parameter></paramdef>
  27                 <paramdef>GLint <parameter>y</parameter></paramdef>
  28                 <paramdef>GLsizei <parameter>width</parameter></paramdef>
  29                 <paramdef>GLsizei <parameter>height</parameter></paramdef>
  30                 <paramdef>GLint <parameter>border</parameter></paramdef>
  31             </funcprototype>
  32         </funcsynopsis>
  33     </refsynopsisdiv>
  34     <!-- eqn: ignoring delim $$ -->
  35     <refsect1 id="parameters"><title>Parameters</title>
  36         <variablelist>
  37         <varlistentry>
  38             <term><parameter>target</parameter></term>
  39             <listitem>
  40                 <para>
  41                     Specifies the target texture.
  42                     Must be <constant>GL_TEXTURE_2D</constant>,
  43                     <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
  44                     <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
  45                     <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
  46                     <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
  47                     <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>, or
  48                     <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>.
  49                 </para>
  50             </listitem>
  51         </varlistentry>
  52         <varlistentry>
  53             <term><parameter>level</parameter></term>
  54             <listitem>
  55                 <para>
  56                     Specifies the level-of-detail number.
  57                     Level 0 is the base image level.
  58                     Level <emphasis>n</emphasis> is the <emphasis>n</emphasis>th mipmap reduction image.
  59                 </para>
  60             </listitem>
  61         </varlistentry>
  62         <varlistentry>
  63             <term><parameter>internalformat</parameter></term>
  64             <listitem>
  65                 <para>
  66                     Specifies the internal format of the texture.
  67                     Must be one of the following symbolic constants:
  68                     <constant>GL_COMPRESSED_RED</constant>,
  69                     <constant>GL_COMPRESSED_RG</constant>,
  70                     <constant>GL_COMPRESSED_RGB</constant>,
  71                     <constant>GL_COMPRESSED_RGBA</constant>.
  72                     <constant>GL_COMPRESSED_SRGB</constant>,
  73                     <constant>GL_COMPRESSED_SRGB_ALPHA</constant>.
  74                     <constant>GL_DEPTH_COMPONENT</constant>,
  75                     <constant>GL_DEPTH_COMPONENT16</constant>,
  76                     <constant>GL_DEPTH_COMPONENT24</constant>,
  77                     <constant>GL_DEPTH_COMPONENT32</constant>,
  78                     <constant>GL_RED</constant>,
  79                     <constant>GL_RG</constant>,
  80                     <constant>GL_RGB</constant>,
  81                     <constant>GL_R3_G3_B2</constant>,
  82                     <constant>GL_RGB4</constant>,
  83                     <constant>GL_RGB5</constant>,
  84                     <constant>GL_RGB8</constant>,
  85                     <constant>GL_RGB10</constant>,
  86                     <constant>GL_RGB12</constant>,
  87                     <constant>GL_RGB16</constant>,
  88                     <constant>GL_RGBA</constant>,
  89                     <constant>GL_RGBA2</constant>,
  90                     <constant>GL_RGBA4</constant>,
  91                     <constant>GL_RGB5_A1</constant>,
  92                     <constant>GL_RGBA8</constant>,
  93                     <constant>GL_RGB10_A2</constant>,
  94                     <constant>GL_RGBA12</constant>,
  95                     <constant>GL_RGBA16</constant>,
  96                     <constant>GL_SRGB</constant>,
  97                     <constant>GL_SRGB8</constant>,
  98                     <constant>GL_SRGB_ALPHA</constant>, or
  99                     <constant>GL_SRGB8_ALPHA8</constant>.
 100                 </para>
 101             </listitem>
 102         </varlistentry>
 103         <varlistentry>
 104             <term><parameter>x</parameter></term>
 105             <term><parameter>y</parameter></term>
 106             <listitem>
 107                 <para>
 108                     Specify the window coordinates of the lower left corner
 109                     of the rectangular region of pixels to be copied.
 110                 </para>
 111             </listitem>
 112         </varlistentry>
 113         <varlistentry>
 114             <term><parameter>width</parameter></term>
 115             <listitem>
 116                 <para>
 117                     Specifies the width of the texture image.
 118                     Must be 0 or
 119                     <inlineequation><mml:math>
 120                         <!-- eqn: 2 sup n  +  2 ( border ): -->
 121                         <mml:mrow>
 122                             <mml:msup><mml:mn>2</mml:mn>
 123                             <mml:mi mathvariant="italic">n</mml:mi>
 124                             </mml:msup>
 125                             <mml:mo>+</mml:mo>
 126                             <mml:mrow>
 127                                 <mml:mn>2</mml:mn>
 128                                 <mml:mo>&af;</mml:mo>
 129                                 <mml:mfenced open="(" close=")">
 130                                     <mml:mi mathvariant="italic">border</mml:mi>
 131                                 </mml:mfenced>
 132                             </mml:mrow>
 133                         </mml:mrow>
 134                     </mml:math></inlineequation>
 135                     for some integer
 136                     <inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>.
 137                 </para>
 138             </listitem>
 139         </varlistentry>
 140         <varlistentry>
 141             <term><parameter>height</parameter></term>
 142             <listitem>
 143                 <para>
 144                     Specifies the height of the texture image.
 145                     Must be 0 or
 146                     <inlineequation><mml:math>
 147                         <!-- eqn: 2 sup m  +  2 ( border ): -->
 148                         <mml:mrow>
 149                             <mml:msup><mml:mn>2</mml:mn>
 150                             <mml:mi mathvariant="italic">m</mml:mi>
 151                             </mml:msup>
 152                             <mml:mo>+</mml:mo>
 153                             <mml:mrow>
 154                                 <mml:mn>2</mml:mn>
 155                                 <mml:mo>&af;</mml:mo>
 156                                 <mml:mfenced open="(" close=")">
 157                                     <mml:mi mathvariant="italic">border</mml:mi>
 158                                 </mml:mfenced>
 159                             </mml:mrow>
 160                         </mml:mrow>
 161                     </mml:math></inlineequation>
 162                     for some integer
 163                     <inlineequation><mml:math><mml:mi mathvariant="italic">m</mml:mi></mml:math></inlineequation>.
 164                 </para>
 165             </listitem>
 166         </varlistentry>
 167         <varlistentry>
 168             <term><parameter>border</parameter></term>
 169             <listitem>
 170                 <para>
 171                     Specifies the width of the border.
 172                     Must be either 0 or 1.
 173                 </para>
 174             </listitem>
 175         </varlistentry>
 176         </variablelist>
 177     </refsect1>
 178     <refsect1 id="description"><title>Description</title>
 179         <para>
 180             <function>glCopyTexImage2D</function> defines a two-dimensional texture image, or cube-map texture image
 181             with pixels from the current
 182             <constant>GL_READ_BUFFER</constant>.
 183         </para>
 184         <para>
 185             The screen-aligned pixel rectangle with lower left corner at (<parameter>x</parameter>,
 186             <parameter>y</parameter>) and with a width of
 187             <inlineequation><mml:math>
 188                 <!-- eqn: width  +  2 ( border ): -->
 189                 <mml:mrow>
 190                     <mml:mi mathvariant="italic">width</mml:mi>
 191                     <mml:mo>+</mml:mo>
 192                     <mml:mrow>
 193                         <mml:mn>2</mml:mn>
 194                         <mml:mo>&af;</mml:mo>
 195                         <mml:mfenced open="(" close=")">
 196                             <mml:mi mathvariant="italic">border</mml:mi>
 197                         </mml:mfenced>
 198                     </mml:mrow>
 199                 </mml:mrow>
 200             </mml:math></inlineequation>
 201             and a height of
 202             <inlineequation><mml:math>
 203                 <!-- eqn: height  +  2 ( border ): -->
 204                 <mml:mrow>
 205                     <mml:mi mathvariant="italic">height</mml:mi>
 206                     <mml:mo>+</mml:mo>
 207                     <mml:mrow>
 208                         <mml:mn>2</mml:mn>
 209                         <mml:mo>&af;</mml:mo>
 210                         <mml:mfenced open="(" close=")">
 211                             <mml:mi mathvariant="italic">border</mml:mi>
 212                         </mml:mfenced>
 213                     </mml:mrow>
 214                 </mml:mrow>
 215             </mml:math></inlineequation>
 216             defines the texture array
 217             at the mipmap level specified by <parameter>level</parameter>.
 218             <parameter>internalformat</parameter> specifies the internal format of the texture array.
 219         </para>
 220         <para>
 221             The pixels in the rectangle are processed exactly as if
 222             <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry> had been called, but the process stops just before
 223             final conversion.
 224             At this point all pixel component values are clamped to the range
 225             <inlineequation><mml:math>
 226                 <!-- eqn: [0,1]: -->
 227                 <mml:mfenced open="[" close="]">
 228                     <mml:mn>0</mml:mn>
 229                     <mml:mn>1</mml:mn>
 230                 </mml:mfenced>
 231             </mml:math></inlineequation>
 232             and then converted to the texture's internal format for storage in the texel
 233             array.
 234         </para>
 235         <para>
 236             Pixel ordering is such that lower
 237             <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>
 238             and
 239             <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>
 240             screen coordinates correspond to
 241             lower
 242             <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
 243             and
 244             <inlineequation><mml:math><mml:mi mathvariant="italic">t</mml:mi></mml:math></inlineequation>
 245             texture coordinates.
 246         </para>
 247         <para>
 248             If any of the pixels within the specified rectangle of the current
 249             <constant>GL_READ_BUFFER</constant> are outside the window associated with the current
 250             rendering context, then the values obtained for those pixels are undefined.
 251         </para>
 252          <para>
 253             When <parameter>internalformat</parameter> is one of the sRGB  types, the GL does not automatically convert the source pixels to the sRGB color space.  In this case, the <function>glPixelMap</function> function can be used to accomplish the conversion.
 254         </para>
 255     </refsect1>
 256     <refsect1 id="notes"><title>Notes</title>
 257         <para>
 258             1, 2, 3, and 4 are not accepted values for <parameter>internalformat</parameter>.
 259         </para>
 260         <para>
 261             An image with height or width of 0 indicates a NULL texture.
 262         </para>
 263     </refsect1>
 264     <refsect1 id="errors"><title>Errors</title>
 265         <para>
 266             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not <constant>GL_TEXTURE_2D</constant>,
 267             <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
 268             <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
 269             <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
 270             <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
 271             <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>, or
 272             <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>.
 273         </para>
 274         <para>
 275             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>level</parameter> is less than 0.
 276         </para>
 277         <para>
 278             <constant>GL_INVALID_VALUE</constant> may be generated if <parameter>level</parameter> is greater
 279             than
 280             <inlineequation><mml:math>
 281                 <!-- eqn: log sub 2 max: -->
 282                 <mml:mrow>
 283                     <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
 284                     <mml:mn>2</mml:mn>
 285                     </mml:msub>
 286                     <mml:mo>&it;</mml:mo>
 287                     <mml:mi mathvariant="italic">max</mml:mi>
 288                 </mml:mrow>
 289             </mml:math></inlineequation>,
 290             where
 291             <inlineequation><mml:math><mml:mi mathvariant="italic">max</mml:mi></mml:math></inlineequation>
 292             is the returned value of <constant>GL_MAX_TEXTURE_SIZE</constant>.
 293         </para>
 294         <para>
 295             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>width</parameter> is less than 0
 296             or greater than
 297             <constant>GL_MAX_TEXTURE_SIZE</constant>.
 298         </para>
 299         <para>
 300             <constant>GL_INVALID_VALUE</constant> is generated if non-power-of-two textures are not supported and the <parameter>width</parameter> or <parameter>depth</parameter> cannot be represented as
 301             <inlineequation><mml:math>
 302                 <!-- eqn: 2 sup k  +  2 ( border ): -->
 303                 <mml:mrow>
 304                     <mml:msup><mml:mn>2</mml:mn>
 305                     <mml:mi mathvariant="italic">k</mml:mi>
 306                     </mml:msup>
 307                     <mml:mo>+</mml:mo>
 308                     <mml:mrow>
 309                         <mml:mn>2</mml:mn>
 310                         <mml:mo>&af;</mml:mo>
 311                         <mml:mfenced open="(" close=")">
 312                             <mml:mi mathvariant="italic">border</mml:mi>
 313                         </mml:mfenced>
 314                     </mml:mrow>
 315                 </mml:mrow>
 316             </mml:math></inlineequation>
 317             for some integer
 318             <inlineequation><mml:math><mml:mi mathvariant="italic">k</mml:mi></mml:math></inlineequation>.
 319         </para>
 320         <para>
 321             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>border</parameter> is not 0 or 1.
 322         </para>
 323         <para>
 324             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>internalformat</parameter> is not an
 325             accepted format.
 326         </para>
 327         <para>
 328             <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>internalformat</parameter> is
 329             <constant>GL_DEPTH_COMPONENT</constant>, <constant>GL_DEPTH_COMPONENT16</constant>,
 330             <constant>GL_DEPTH_COMPONENT24</constant>, or <constant>GL_DEPTH_COMPONENT32</constant> and there is no depth
 331             buffer.
 332         </para>
 333     </refsect1>
 334     <refsect1 id="associatedgets"><title>Associated Gets</title>
 335         <para>
 336             <citerefentry><refentrytitle>glGetTexImage</refentrytitle></citerefentry>
 337         </para>
 338     </refsect1>
 339     <refsect1 id="seealso"><title>See Also</title>
 340         <para>
 341             <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
 342             <citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
 343             <citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
 344             <citerefentry><refentrytitle>glPixelStore</refentrytitle></citerefentry>,
 345             <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
 346             <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
 347             <citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
 348             <citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>,
 349             <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
 350         </para>
 351     </refsect1>
 352     <refsect1 id="Copyright"><title>Copyright</title>
 353         <para>
 354             Copyright <trademark class="copyright"></trademark> 1991-2006
 355             Silicon Graphics, Inc. This document is licensed under the SGI
 356             Free Software B License. For details, see
 357             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 358         </para>
 359     </refsect1>
 360 </refentry>