upstream-doc/man3/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                 </para>
 119             </listitem>
 120         </varlistentry>
 121         <varlistentry>
 122             <term><parameter>height</parameter></term>
 123             <listitem>
 124                 <para>
 125                     Specifies the height of the texture image.
 126                 </para>
 127             </listitem>
 128         </varlistentry>
 129         <varlistentry>
 130             <term><parameter>border</parameter></term>
 131             <listitem>
 132                 <para>
 133                     Must be 0.
 134                 </para>
 135             </listitem>
 136         </varlistentry>
 137         </variablelist>
 138     </refsect1>
 139     <refsect1 id="description"><title>Description</title>
 140         <para>
 141             <function>glCopyTexImage2D</function> defines a two-dimensional texture image, or cube-map texture image
 142             with pixels from the current
 143             <constant>GL_READ_BUFFER</constant>.
 144         </para>
 145         <para>
 146             The screen-aligned pixel rectangle with lower left corner at (<parameter>x</parameter>,
 147             <parameter>y</parameter>) and with a width of
 148             <inlineequation><mml:math>
 149                 <!-- eqn: width  +  2 ( border ): -->
 150                 <mml:mrow>
 151                     <mml:mi mathvariant="italic">width</mml:mi>
 152                 </mml:mrow>
 153             </mml:math></inlineequation>
 154             and a height of
 155             <inlineequation><mml:math>
 156                 <!-- eqn: height  +  2 ( border ): -->
 157                 <mml:mrow>
 158                     <mml:mi mathvariant="italic">height</mml:mi>
 159                 </mml:mrow>
 160             </mml:math></inlineequation>
 161             defines the texture array
 162             at the mipmap level specified by <parameter>level</parameter>.
 163             <parameter>internalformat</parameter> specifies the internal format of the texture array.
 164         </para>
 165         <para>
 166             The pixels in the rectangle are processed exactly as if
 167             <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry> had been called, but the process stops just before
 168             final conversion.
 169             At this point all pixel component values are clamped to the range
 170             <inlineequation><mml:math>
 171                 <!-- eqn: [0,1]: -->
 172                 <mml:mfenced open="[" close="]">
 173                     <mml:mn>0</mml:mn>
 174                     <mml:mn>1</mml:mn>
 175                 </mml:mfenced>
 176             </mml:math></inlineequation>
 177             and then converted to the texture's internal format for storage in the texel
 178             array.
 179         </para>
 180         <para>
 181             Pixel ordering is such that lower
 182             <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>
 183             and
 184             <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>
 185             screen coordinates correspond to
 186             lower
 187             <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
 188             and
 189             <inlineequation><mml:math><mml:mi mathvariant="italic">t</mml:mi></mml:math></inlineequation>
 190             texture coordinates.
 191         </para>
 192         <para>
 193             If any of the pixels within the specified rectangle of the current
 194             <constant>GL_READ_BUFFER</constant> are outside the window associated with the current
 195             rendering context, then the values obtained for those pixels are undefined.
 196         </para>
 197          <para>
 198             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.
 199         </para>
 200     </refsect1>
 201     <refsect1 id="notes"><title>Notes</title>
 202         <para>
 203             1, 2, 3, and 4 are not accepted values for <parameter>internalformat</parameter>.
 204         </para>
 205         <para>
 206             An image with height or width of 0 indicates a NULL texture.
 207         </para>
 208     </refsect1>
 209     <refsect1 id="errors"><title>Errors</title>
 210         <para>
 211             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not <constant>GL_TEXTURE_2D</constant>,
 212             <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
 213             <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
 214             <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
 215             <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
 216             <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>, or
 217             <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>.
 218         </para>
 219         <para>
 220             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>level</parameter> is less than 0.
 221         </para>
 222         <para>
 223             <constant>GL_INVALID_VALUE</constant> may be generated if <parameter>level</parameter> is greater
 224             than
 225             <inlineequation><mml:math>
 226                 <!-- eqn: log sub 2 max: -->
 227                 <mml:mrow>
 228                     <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
 229                     <mml:mn>2</mml:mn>
 230                     </mml:msub>
 231                     <mml:mo>&it;</mml:mo>
 232                     <mml:mi mathvariant="italic">max</mml:mi>
 233                 </mml:mrow>
 234             </mml:math></inlineequation>,
 235             where
 236             <inlineequation><mml:math><mml:mi mathvariant="italic">max</mml:mi></mml:math></inlineequation>
 237             is the returned value of <constant>GL_MAX_TEXTURE_SIZE</constant>.
 238         </para>
 239         <para>
 240             <constant>GL_INVALID_VALUE</constant> is generated if either <parameter>width</parameter> or <parameter>height</parameter> is less than 0
 241             or greater than
 242             <constant>GL_MAX_TEXTURE_SIZE</constant>.
 243         </para>
 244         <para>
 245             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>border</parameter> is not 0.
 246         </para>
 247         <para>
 248             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>internalformat</parameter> is not an
 249             accepted format.
 250         </para>
 251         <para>
 252             <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>internalformat</parameter> is
 253             <constant>GL_DEPTH_COMPONENT</constant>, <constant>GL_DEPTH_COMPONENT16</constant>,
 254             <constant>GL_DEPTH_COMPONENT24</constant>, or <constant>GL_DEPTH_COMPONENT32</constant> and there is no depth
 255             buffer.
 256         </para>
 257     </refsect1>
 258     <refsect1 id="associatedgets"><title>Associated Gets</title>
 259         <para>
 260             <citerefentry><refentrytitle>glGetTexImage</refentrytitle></citerefentry>
 261         </para>
 262     </refsect1>
 263     <refsect1 id="seealso"><title>See Also</title>
 264         <para>
 265             <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
 266             <citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
 267             <citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
 268             <citerefentry><refentrytitle>glPixelStore</refentrytitle></citerefentry>,
 269             <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
 270             <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
 271             <citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
 272             <citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>,
 273             <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
 274         </para>
 275     </refsect1>
 276     <refsect1 id="Copyright"><title>Copyright</title>
 277         <para>
 278             Copyright <trademark class="copyright"></trademark> 1991-2006
 279             Silicon Graphics, Inc. This document is licensed under the SGI
 280             Free Software B License. For details, see
 281             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 282         </para>
 283     </refsect1>
 284 </refentry>