upstream-man-pages/man2/xhtml/glTexParameter.xml

   1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
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   3 <?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" /><title>glTexParameter</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glTexParameter"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glTexParameter — set texture parameters</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">glTexParameterf</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">param</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glTexParameteri</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">param</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>
   4                     Specifies the target texture,
   5                     which must be either <code class="constant">GL_TEXTURE_1D</code>, <code class="constant">GL_TEXTURE_2D</code>,
   6                     <code class="constant">GL_TEXTURE_3D</code>, or <code class="constant">GL_TEXTURE_CUBE_MAP</code>.
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
   8                     Specifies the symbolic name of a single-valued texture parameter.
   9                     <em class="parameter"><code>pname</code></em> can be one of the following:
  10                     <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
  11                     <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
  12                     <code class="constant">GL_TEXTURE_MIN_LOD</code>,
  13                     <code class="constant">GL_TEXTURE_MAX_LOD</code>,
  14                     <code class="constant">GL_TEXTURE_BASE_LEVEL</code>,
  15                     <code class="constant">GL_TEXTURE_MAX_LEVEL</code>,
  16                     <code class="constant">GL_TEXTURE_WRAP_S</code>,
  17                     <code class="constant">GL_TEXTURE_WRAP_T</code>,
  18                     <code class="constant">GL_TEXTURE_WRAP_R</code>,
  19                     <code class="constant">GL_TEXTURE_PRIORITY</code>,
  20                     <code class="constant">GL_TEXTURE_COMPARE_MODE</code>,
  21                     <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>,
  22                     <code class="constant">GL_DEPTH_TEXTURE_MODE</code>, or
  23                     <code class="constant">GL_GENERATE_MIPMAP</code>.
  24                 </p></dd><dt><span class="term"><em class="parameter"><code>param</code></em></span></dt><dd><p>
  25                     Specifies the value of <em class="parameter"><code>pname</code></em>.
  26                 </p></dd></dl></div></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">glTexParameterfv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>const GLfloat *  </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glTexParameteriv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>const GLint *  </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters2"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>target</code></em></span></dt><dd><p>
  27                     Specifies the target texture,
  28                     which must be either <code class="constant">GL_TEXTURE_1D</code>, <code class="constant">GL_TEXTURE_2D</code> or
  29                     <code class="constant">GL_TEXTURE_3D</code>.
  30                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
  31                     Specifies the symbolic name of a texture parameter.
  32                     <em class="parameter"><code>pname</code></em> can be one of the following:
  33                     <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
  34                     <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
  35                     <code class="constant">GL_TEXTURE_MIN_LOD</code>,
  36                     <code class="constant">GL_TEXTURE_MAX_LOD</code>,
  37                     <code class="constant">GL_TEXTURE_BASE_LEVEL</code>,
  38                     <code class="constant">GL_TEXTURE_MAX_LEVEL</code>,
  39                     <code class="constant">GL_TEXTURE_WRAP_S</code>,
  40                     <code class="constant">GL_TEXTURE_WRAP_T</code>,
  41                     <code class="constant">GL_TEXTURE_WRAP_R</code>,
  42                     <code class="constant">GL_TEXTURE_BORDER_COLOR</code>,
  43                     <code class="constant">GL_TEXTURE_PRIORITY</code>,
  44                     <code class="constant">GL_TEXTURE_COMPARE_MODE</code>,
  45                     <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>,
  46                     <code class="constant">GL_DEPTH_TEXTURE_MODE</code>, or
  47                     <code class="constant">GL_GENERATE_MIPMAP</code>.
  48                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  49                     Specifies a pointer to an array where the value or values of <em class="parameter"><code>pname</code></em>
  50                     are stored.
  51                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  52             Texture mapping is a technique that applies an image onto an object's surface
  53             as if the image were a decal or cellophane shrink-wrap.
  54             The image is created in texture space,
  55             with an
  56             (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>,
  57             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math>)
  58             coordinate system.
  59             A texture is a one- or two-dimensional image and a set of parameters
  60             that determine how samples are derived from the image.
  61         </p><p>
  62             <code class="function">glTexParameter</code> assigns the value or values in <em class="parameter"><code>params</code></em> to the texture parameter
  63             specified as <em class="parameter"><code>pname</code></em>.
  64             <em class="parameter"><code>target</code></em> defines the target texture,
  65             either <code class="constant">GL_TEXTURE_1D</code>, <code class="constant">GL_TEXTURE_2D</code>, or <code class="constant">GL_TEXTURE_3D</code>.
  66             The following symbols are accepted in <em class="parameter"><code>pname</code></em>:
  67         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_FILTER</code></span></dt><dd><p>
  68                         The texture minifying function is used whenever the pixel being textured
  69                         maps to an area greater than one texture element.
  70                         There are six defined minifying functions.
  71                         Two of them use the nearest one or nearest four texture elements
  72                         to compute the texture value.
  73                         The other four use mipmaps.
  74                     </p><p>
  75                         A mipmap is an ordered set of arrays representing the same image
  76                         at progressively lower resolutions.
  77                         If the texture has dimensions
  78                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  79
  80                             <mml:mrow>
  81                                 <mml:msup><mml:mn>2</mml:mn>
  82                                 <mml:mi mathvariant="italic">n</mml:mi>
  83                                 </mml:msup>
  84                                 <mml:mo>×</mml:mo>
  85                                 <mml:msup><mml:mn>2</mml:mn>
  86                                 <mml:mi mathvariant="italic">m</mml:mi>
  87                                 </mml:msup>
  88                             </mml:mrow>
  89                         </mml:math>,
  90                         there are
  91                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  92
  93                             <mml:mrow>
  94                                 <mml:mrow>
  95                                     <mml:mi mathvariant="italic">max</mml:mi>
  96                                     <mml:mo>⁡</mml:mo>
  97                                     <mml:mfenced open="(" close=")">
  98                                         <mml:mi mathvariant="italic">n</mml:mi>
  99                                         <mml:mi mathvariant="italic">m</mml:mi>
 100                                     </mml:mfenced>
 101                                 </mml:mrow>
 102                                 <mml:mo>+</mml:mo>
 103                                 <mml:mn>1</mml:mn>
 104                             </mml:mrow>
 105                         </mml:math>
 106                         mipmaps.
 107                         The first mipmap is the original texture,
 108                         with dimensions
 109                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 110
 111                             <mml:mrow>
 112                                 <mml:msup><mml:mn>2</mml:mn>
 113                                 <mml:mi mathvariant="italic">n</mml:mi>
 114                                 </mml:msup>
 115                                 <mml:mo>×</mml:mo>
 116                                 <mml:msup><mml:mn>2</mml:mn>
 117                                 <mml:mi mathvariant="italic">m</mml:mi>
 118                                 </mml:msup>
 119                             </mml:mrow>
 120                         </mml:math>.
 121                         Each subsequent mipmap has dimensions
 122                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 123
 124                             <mml:mrow>
 125                                 <mml:msup><mml:mn>2</mml:mn>
 126                                 <mml:mfenced open="" close="">
 127                                     <mml:mrow>
 128                                         <mml:mi mathvariant="italic">k</mml:mi>
 129                                         <mml:mo>-</mml:mo>
 130                                         <mml:mn>1</mml:mn>
 131                                     </mml:mrow>
 132                                 </mml:mfenced>
 133                                 </mml:msup>
 134                                 <mml:mo>×</mml:mo>
 135                                 <mml:msup><mml:mn>2</mml:mn>
 136                                 <mml:mfenced open="" close="">
 137                                     <mml:mrow>
 138                                         <mml:mi mathvariant="italic">l</mml:mi>
 139                                         <mml:mo>-</mml:mo>
 140                                         <mml:mn>1</mml:mn>
 141                                     </mml:mrow>
 142                                 </mml:mfenced>
 143                                 </mml:msup>
 144                             </mml:mrow>
 145                         </mml:math>,
 146                         where
 147                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 148
 149                             <mml:mrow>
 150                                 <mml:msup><mml:mn>2</mml:mn>
 151                                 <mml:mi mathvariant="italic">k</mml:mi>
 152                                 </mml:msup>
 153                                 <mml:mo>×</mml:mo>
 154                                 <mml:msup><mml:mn>2</mml:mn>
 155                                 <mml:mi mathvariant="italic">l</mml:mi>
 156                                 </mml:msup>
 157                             </mml:mrow>
 158                         </mml:math>
 159                         are the dimensions of the previous mipmap,
 160                         until either
 161                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 162
 163                             <mml:mrow>
 164                                 <mml:mi mathvariant="italic">k</mml:mi>
 165                                 <mml:mo>=</mml:mo>
 166                                 <mml:mn>0</mml:mn>
 167                             </mml:mrow>
 168                         </mml:math>
 169                         or
 170                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 171
 172                             <mml:mrow>
 173                                 <mml:mi mathvariant="italic">l</mml:mi>
 174                                 <mml:mo>=</mml:mo>
 175                                 <mml:mn>0</mml:mn>
 176                             </mml:mrow>
 177                         </mml:math>.
 178                         At that point,
 179                         subsequent mipmaps have dimension
 180                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 181
 182                             <mml:mrow>
 183                                 <mml:mn>1</mml:mn>
 184                                 <mml:mo>×</mml:mo>
 185                                 <mml:msup><mml:mn>2</mml:mn>
 186                                 <mml:mfenced open="" close="">
 187                                     <mml:mrow>
 188                                         <mml:mi mathvariant="italic">l</mml:mi>
 189                                         <mml:mo>-</mml:mo>
 190                                         <mml:mn>1</mml:mn>
 191                                     </mml:mrow>
 192                                 </mml:mfenced>
 193                                 </mml:msup>
 194                             </mml:mrow>
 195                         </mml:math>
 196                         or
 197                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 198
 199                             <mml:mrow>
 200                                 <mml:msup><mml:mn>2</mml:mn>
 201                                 <mml:mfenced open="" close="">
 202                                     <mml:mrow>
 203                                         <mml:mi mathvariant="italic">k</mml:mi>
 204                                         <mml:mo>-</mml:mo>
 205                                         <mml:mn>1</mml:mn>
 206                                     </mml:mrow>
 207                                 </mml:mfenced>
 208                                 </mml:msup>
 209                                 <mml:mo>×</mml:mo>
 210                                 <mml:mn>1</mml:mn>
 211                             </mml:mrow>
 212                         </mml:math>
 213                         until the final mipmap,
 214                         which has dimension
 215                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 216
 217                             <mml:mrow>
 218                                 <mml:mn>1</mml:mn>
 219                                 <mml:mo>×</mml:mo>
 220                                 <mml:mn>1</mml:mn>
 221                             </mml:mrow>
 222                         </mml:math>.
 223                         To define the mipmaps, call <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>, <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
 224                         <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
 225                         <a class="citerefentry" href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>, or <a class="citerefentry" href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>
 226                         with the <span class="emphasis"><em>level</em></span> argument indicating the order of the mipmaps.
 227                         Level 0 is the original texture;
 228                         level
 229                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 230
 231                             <mml:mrow>
 232                                 <mml:mi mathvariant="italic">max</mml:mi>
 233                                 <mml:mo>⁡</mml:mo>
 234                                 <mml:mfenced open="(" close=")">
 235                                     <mml:mi mathvariant="italic">n</mml:mi>
 236                                     <mml:mi mathvariant="italic">m</mml:mi>
 237                                 </mml:mfenced>
 238                             </mml:mrow>
 239                         </mml:math>
 240                         is the final
 241                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 242
 243                             <mml:mrow>
 244                                 <mml:mn>1</mml:mn>
 245                                 <mml:mo>×</mml:mo>
 246                                 <mml:mn>1</mml:mn>
 247                             </mml:mrow>
 248                         </mml:math>
 249                         mipmap.
 250                     </p><p>
 251                         <em class="parameter"><code>params</code></em> supplies a function for minifying the texture as one of the
 252                         following:
 253                         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_NEAREST</code></span></dt><dd><p>
 254                                         Returns the value of the texture element that is nearest
 255                                         (in Manhattan distance)
 256                                         to the center of the pixel being textured.
 257                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR</code></span></dt><dd><p>
 258                                         Returns the weighted average of the four texture elements
 259                                         that are closest to the center of the pixel being textured.
 260                                         These can include border texture elements,
 261                                         depending on the values of <code class="constant">GL_TEXTURE_WRAP_S</code> and <code class="constant">GL_TEXTURE_WRAP_T</code>,
 262                                         and on the exact mapping.
 263                                     </p></dd><dt><span class="term"><code class="constant">GL_NEAREST_MIPMAP_NEAREST</code></span></dt><dd><p>
 264                                         Chooses the mipmap that most closely matches the size of the pixel
 265                                         being textured and uses the <code class="constant">GL_NEAREST</code> criterion
 266                                         (the texture element nearest to the center of the pixel)
 267                                         to produce a texture value.
 268                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR_MIPMAP_NEAREST</code></span></dt><dd><p>
 269                                         Chooses the mipmap that most closely matches the size of the pixel
 270                                         being textured and uses the <code class="constant">GL_LINEAR</code> criterion
 271                                         (a weighted average of the four texture elements that are closest
 272                                         to the center of the pixel)
 273                                         to produce a texture value.
 274                                     </p></dd><dt><span class="term"><code class="constant">GL_NEAREST_MIPMAP_LINEAR</code></span></dt><dd><p>
 275                                         Chooses the two mipmaps that most closely match the size of the pixel
 276                                         being textured and uses the <code class="constant">GL_NEAREST</code> criterion
 277                                         (the texture element nearest to the center of the pixel)
 278                                         to produce a texture value from each mipmap.
 279                                         The final texture value is a weighted average of those two values.
 280                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR_MIPMAP_LINEAR</code></span></dt><dd><p>
 281                                         Chooses the two mipmaps that most closely match the size of the pixel
 282                                         being textured and uses the <code class="constant">GL_LINEAR</code> criterion
 283                                         (a weighted average of the four texture elements that are closest
 284                                         to the center of the pixel)
 285                                         to produce a texture value from each mipmap.
 286                                         The final texture value is a weighted average of those two values.
 287                                     </p></dd></dl></div><p>
 288                     </p><p>
 289                         As more texture elements are sampled in the minification process,
 290                         fewer aliasing artifacts will be apparent.
 291                         While the <code class="constant">GL_NEAREST</code> and <code class="constant">GL_LINEAR</code> minification functions can be
 292                         faster than the other four,
 293                         they sample only one or four texture elements to determine the texture value
 294                         of the pixel being rendered and can produce moire patterns
 295                         or ragged transitions.
 296                         The initial value of <code class="constant">GL_TEXTURE_MIN_FILTER</code> is
 297                         <code class="constant">GL_NEAREST_MIPMAP_LINEAR</code>.
 298                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAG_FILTER</code></span></dt><dd><p>
 299                         The texture magnification function is used when the pixel being textured
 300                         maps to an area less than or equal to one texture element.
 301                         It sets the texture magnification function to either <code class="constant">GL_NEAREST</code>
 302                         or <code class="constant">GL_LINEAR</code> (see below). <code class="constant">GL_NEAREST</code> is generally faster
 303                         than <code class="constant">GL_LINEAR</code>,
 304                         but it can produce textured images with sharper edges
 305                         because the transition between texture elements is not as smooth.
 306                         The initial value of <code class="constant">GL_TEXTURE_MAG_FILTER</code> is <code class="constant">GL_LINEAR</code>.
 307                         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_NEAREST</code></span></dt><dd><p>
 308                                         Returns the value of the texture element that is nearest
 309                                         (in Manhattan distance)
 310                                         to the center of the pixel being textured.
 311                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR</code></span></dt><dd><p>
 312                                         Returns the weighted average of the four texture elements
 313                                         that are closest to the center of the pixel being textured.
 314                                         These can include border texture elements,
 315                                         depending on the values of <code class="constant">GL_TEXTURE_WRAP_S</code> and <code class="constant">GL_TEXTURE_WRAP_T</code>,
 316                                         and on the exact mapping.
 317                                     </p></dd></dl></div><p>
 318                         </p><p>
 319                         </p><p>
 320                     </p></dd></dl></div><p>
 321         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_LOD</code></span></dt><dd><p>
 322                         Sets the minimum level-of-detail parameter.  This floating-point value
 323                         limits the selection of highest resolution mipmap (lowest mipmap
 324                         level). The initial value is -1000.
 325                     </p></dd></dl></div><p>
 326         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LOD</code></span></dt><dd><p>
 327                         Sets the maximum level-of-detail parameter.  This floating-point value
 328                         limits the selection of the lowest resolution mipmap (highest mipmap
 329                         level). The initial value is 1000.
 330                     </p></dd></dl></div><p>
 331         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_BASE_LEVEL</code></span></dt><dd><p>
 332                         Specifies the index of the lowest defined mipmap level. This is an
 333                         integer value. The initial value is 0.
 334                     </p></dd></dl></div><p>
 335         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LEVEL</code></span></dt><dd><p>
 336                         Sets the index of the highest defined mipmap level. This is an integer
 337                         value. The initial value is 1000.
 338                     </p></dd></dl></div><p>
 339         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_S</code></span></dt><dd><p>
 340                         Sets the wrap parameter for texture coordinate
 341                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 342                         to either <code class="constant">GL_CLAMP</code>,
 343                         <code class="constant">GL_CLAMP_TO_BORDER</code>, <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
 344                         <code class="constant">GL_REPEAT</code>.  <code class="constant">GL_CLAMP</code> causes
 345                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 346                         coordinates to be clamped to the
 347                         range [0,1] and is useful for preventing wrapping artifacts when mapping a
 348                         single image onto an object.  <code class="constant">GL_CLAMP_TO_BORDER</code> causes the
 349                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 350                         coordinate to be clamped to the range
 351                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 352
 353                             <mml:mfenced open="[" close="]">
 354                                 <mml:mfenced open="" close="">
 355                                     <mml:mrow>
 356                                         <mml:mfrac>
 357                                             <mml:mn>-1</mml:mn>
 358                                             <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 359                                         </mml:mfrac>
 360                                     </mml:mrow>
 361                                 </mml:mfenced>
 362                                 <mml:mrow>
 363                                     <mml:mn>1</mml:mn>
 364                                     <mml:mo>+</mml:mo>
 365                                     <mml:mfenced open="" close="">
 366                                         <mml:mrow>
 367                                             <mml:mfrac>
 368                                                 <mml:mn>1</mml:mn>
 369                                                 <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 370                                             </mml:mfrac>
 371                                         </mml:mrow>
 372                                     </mml:mfenced>
 373                                 </mml:mrow>
 374                             </mml:mfenced>
 375                         </mml:math>,
 376                         where
 377                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi></mml:math>
 378                         is the size of the texture in the direction of
 379                         clamping.<code class="constant">GL_CLAMP_TO_EDGE</code> causes
 380                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 381                         coordinates to be clamped to the
 382                         range
 383                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 384
 385                             <mml:mfenced open="[" close="]">
 386                                 <mml:mfenced open="" close="">
 387                                     <mml:mrow>
 388                                         <mml:mfrac>
 389                                             <mml:mn>1</mml:mn>
 390                                             <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 391                                         </mml:mfrac>
 392                                     </mml:mrow>
 393                                 </mml:mfenced>
 394                                 <mml:mrow>
 395                                     <mml:mn>1</mml:mn>
 396                                     <mml:mo>-</mml:mo>
 397                                     <mml:mfenced open="" close="">
 398                                         <mml:mrow>
 399                                             <mml:mfrac>
 400                                                 <mml:mn>1</mml:mn>
 401                                                 <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 402                                             </mml:mfrac>
 403                                         </mml:mrow>
 404                                     </mml:mfenced>
 405                                 </mml:mrow>
 406                             </mml:mfenced>
 407                         </mml:math>,
 408                         where
 409                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi></mml:math>
 410                         is the size
 411                         of the texture in the direction of clamping.  <code class="constant">GL_REPEAT</code> causes the
 412                         integer part of the
 413                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 414                         coordinate to be ignored; the GL uses only the
 415                         fractional part, thereby creating a repeating pattern.
 416                         <code class="constant">GL_MIRRORED_REPEAT</code> causes the
 417                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 418                         coordinate to be set to the
 419                         fractional part of the texture coordinate if the integer part of
 420                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 421                         is
 422                         even; if the integer part of
 423                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 424                         is odd, then the
 425                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 426                         texture coordinate is
 427                         set to
 428                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 429
 430                             <mml:mrow>
 431                                 <mml:mn>1</mml:mn>
 432                                 <mml:mo>-</mml:mo>
 433                                 <mml:mrow>
 434                                     <mml:mi mathvariant="italic">frac</mml:mi>
 435                                     <mml:mo>⁡</mml:mo>
 436                                     <mml:mfenced open="(" close=")">
 437                                         <mml:mi mathvariant="italic">s</mml:mi>
 438                                     </mml:mfenced>
 439                                 </mml:mrow>
 440                             </mml:mrow>
 441                         </mml:math>,
 442                         where
 443                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 444
 445                             <mml:mrow>
 446                                 <mml:mi mathvariant="italic">frac</mml:mi>
 447                                 <mml:mo>⁡</mml:mo>
 448                                 <mml:mfenced open="(" close=")">
 449                                     <mml:mi mathvariant="italic">s</mml:mi>
 450                                 </mml:mfenced>
 451                             </mml:mrow>
 452                         </mml:math>
 453                         represents the fractional part of
 454                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>.
 455                         Border texture
 456                         elements are accessed only if wrapping is set to <code class="constant">GL_CLAMP</code> or <code class="constant">GL_CLAMP_TO_BORDER</code>.  Initially,
 457                         <code class="constant">GL_TEXTURE_WRAP_S</code> is set to <code class="constant">GL_REPEAT</code>.
 458                     </p></dd></dl></div><p>
 459         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_T</code></span></dt><dd><p>
 460                         Sets the wrap parameter for texture coordinate
 461                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math>
 462                         to either <code class="constant">GL_CLAMP</code>,
 463                         <code class="constant">GL_CLAMP_TO_BORDER</code>, <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
 464                         <code class="constant">GL_REPEAT</code>.  See the discussion under <code class="constant">GL_TEXTURE_WRAP_S</code>.
 465                         Initially, <code class="constant">GL_TEXTURE_WRAP_T</code> is set to <code class="constant">GL_REPEAT</code>.
 466                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_R</code></span></dt><dd><p>
 467                         Sets the wrap parameter for texture coordinate
 468                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
 469                         to either <code class="constant">GL_CLAMP</code>,
 470                         <code class="constant">GL_CLAMP_TO_BORDER</code>, <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
 471                         <code class="constant">GL_REPEAT</code>.  See the discussion under <code class="constant">GL_TEXTURE_WRAP_S</code>.
 472                         Initially, <code class="constant">GL_TEXTURE_WRAP_R</code> is set to <code class="constant">GL_REPEAT</code>.
 473                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BORDER_COLOR</code></span></dt><dd><p>
 474                         Sets a border color.  <em class="parameter"><code>params</code></em> contains four values that comprise the RGBA
 475                         color of the texture border.  Integer color components are interpreted
 476                         linearly such that the most positive integer maps to 1.0, and the most
 477                         negative integer maps to -1.0.  The values are clamped to the range [0,1]
 478                         when they are specified.  Initially, the border color is (0, 0, 0, 0).
 479                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_PRIORITY</code></span></dt><dd><p>
 480                         Specifies the texture residence priority of the currently bound texture.
 481                         Permissible values are in the range
 482                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 483
 484                             <mml:mfenced open="[" close="]">
 485                                 <mml:mn>0</mml:mn>
 486                                 <mml:mn>1</mml:mn>
 487                             </mml:mfenced>
 488                         </mml:math>.
 489                         See <a class="citerefentry" href="glPrioritizeTextures.xml"><span class="citerefentry"><span class="refentrytitle">glPrioritizeTextures</span></span></a> and <a class="citerefentry" href="glBindTexture.xml"><span class="citerefentry"><span class="refentrytitle">glBindTexture</span></span></a> for more information.
 490                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_MODE</code></span></dt><dd><p>
 491                         Specifies the texture comparison mode for currently bound depth textures.
 492                         That is, a texture whose internal format is <code class="constant">GL_DEPTH_COMPONENT_*</code>; see
 493                         <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>)
 494                         Permissible values are:
 495                         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_COMPARE_R_TO_TEXTURE</code></span></dt><dd><p>
 496                                         Specifies that the interpolated and clamped
 497                                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
 498                                         texture coordinate should
 499                                         be compared to the value in the currently bound depth texture.  See the
 500                                         discussion of <code class="constant">GL_TEXTURE_COMPARE_FUNC</code> for details of how the comparison
 501                                         is evaluated.  The result of the comparison is assigned to luminance,
 502                                         intensity, or alpha (as specified by <code class="constant">GL_DEPTH_TEXTURE_MODE</code>).
 503                                     </p></dd><dt><span class="term"><code class="constant">GL_NONE</code></span></dt><dd><p>
 504                                         Specifies that the luminance, intensity, or alpha (as specified by
 505                                         <code class="constant">GL_DEPTH_TEXTURE_MODE</code>) should be assigned the
 506                                         appropriate value from the currently bound depth texture.
 507                                     </p></dd></dl></div><p>
 508                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_FUNC</code></span></dt><dd><p>
 509                         Specifies the comparison operator used when <code class="constant">GL_TEXTURE_COMPARE_MODE</code> is
 510                         set to <code class="constant">GL_COMPARE_R_TO_TEXTURE</code>.  Permissible values are:
 511                         </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
 512                                         Texture Comparison Function
 513                                         </strong></span></th><th align="left"><span class="bold"><strong>
 514                                         Computed result
 515                                         </strong></span></th></tr></thead><tbody><tr><td align="left">
 516                                         <code class="constant">GL_LEQUAL</code>
 517                                         </td><td align="left">
 518                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 519
 520                                                 <mml:mrow>
 521                                                     <mml:mi mathvariant="italic">result</mml:mi>
 522                                                     <mml:mo>=</mml:mo>
 523                                                     <mml:mfenced open="{" close="">
 524                                                         <mml:mrow>
 525                                                             <mml:mtable>
 526                                                                 <mml:mtr><mml:mtd>
 527                                                                     <mml:mn>1.0</mml:mn>
 528                                                                 </mml:mtd></mml:mtr>
 529                                                                 <mml:mtr><mml:mtd>
 530                                                                     <mml:mn>0.0</mml:mn>
 531                                                                 </mml:mtd></mml:mtr>
 532                                                             </mml:mtable>
 533                                                             <mml:mo>⁢  </mml:mo>
 534                                                             <mml:mtable>
 535                                                                 <mml:mtr><mml:mtd>
 536                                                                     <mml:mrow>
 537                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 538                                                                         <mml:mo>&lt;=</mml:mo>
 539                                                                         <mml:mfenced open="" close="">
 540                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 541                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 542                                                                             </mml:msub>
 543                                                                         </mml:mfenced>
 544                                                                     </mml:mrow>
 545                                                                 </mml:mtd></mml:mtr>
 546                                                                 <mml:mtr><mml:mtd>
 547                                                                     <mml:mrow>
 548                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 549                                                                         <mml:mo>&gt;</mml:mo>
 550                                                                         <mml:mfenced open="" close="">
 551                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 552                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 553                                                                             </mml:msub>
 554                                                                         </mml:mfenced>
 555                                                                     </mml:mrow>
 556                                                                 </mml:mtd></mml:mtr>
 557                                                             </mml:mtable>
 558                                                         </mml:mrow>
 559                                                     </mml:mfenced>
 560                                                 </mml:mrow>
 561                                             </mml:math></div>
 562                                         </td></tr><tr><td align="left">
 563                                         <code class="constant">GL_GEQUAL</code>
 564                                         </td><td align="left">
 565                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 566
 567                                                 <mml:mrow>
 568                                                     <mml:mi mathvariant="italic">result</mml:mi>
 569                                                     <mml:mo>=</mml:mo>
 570                                                     <mml:mfenced open="{" close="">
 571                                                         <mml:mrow>
 572                                                             <mml:mtable>
 573                                                                 <mml:mtr><mml:mtd>
 574                                                                     <mml:mn>1.0</mml:mn>
 575                                                                 </mml:mtd></mml:mtr>
 576                                                                 <mml:mtr><mml:mtd>
 577                                                                     <mml:mn>0.0</mml:mn>
 578                                                                 </mml:mtd></mml:mtr>
 579                                                             </mml:mtable>
 580                                                             <mml:mo>⁢  </mml:mo>
 581                                                             <mml:mtable>
 582                                                                 <mml:mtr><mml:mtd>
 583                                                                     <mml:mrow>
 584                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 585                                                                         <mml:mo>&gt;=</mml:mo>
 586                                                                         <mml:mfenced open="" close="">
 587                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 588                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 589                                                                             </mml:msub>
 590                                                                         </mml:mfenced>
 591                                                                     </mml:mrow>
 592                                                                 </mml:mtd></mml:mtr>
 593                                                                 <mml:mtr><mml:mtd>
 594                                                                     <mml:mrow>
 595                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 596                                                                         <mml:mo>&lt;</mml:mo>
 597                                                                         <mml:mfenced open="" close="">
 598                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 599                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 600                                                                             </mml:msub>
 601                                                                         </mml:mfenced>
 602                                                                     </mml:mrow>
 603                                                                 </mml:mtd></mml:mtr>
 604                                                             </mml:mtable>
 605                                                         </mml:mrow>
 606                                                     </mml:mfenced>
 607                                                 </mml:mrow>
 608                                             </mml:math></div>
 609                                         </td></tr><tr><td align="left">
 610                                         <code class="constant">GL_LESS</code>
 611                                         </td><td align="left">
 612                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 613
 614                                                 <mml:mrow>
 615                                                     <mml:mi mathvariant="italic">result</mml:mi>
 616                                                     <mml:mo>=</mml:mo>
 617                                                     <mml:mfenced open="{" close="">
 618                                                         <mml:mrow>
 619                                                             <mml:mtable>
 620                                                                 <mml:mtr><mml:mtd>
 621                                                                     <mml:mn>1.0</mml:mn>
 622                                                                 </mml:mtd></mml:mtr>
 623                                                                 <mml:mtr><mml:mtd>
 624                                                                     <mml:mn>0.0</mml:mn>
 625                                                                 </mml:mtd></mml:mtr>
 626                                                             </mml:mtable>
 627                                                             <mml:mo>⁢  </mml:mo>
 628                                                             <mml:mtable>
 629                                                                 <mml:mtr><mml:mtd>
 630                                                                     <mml:mrow>
 631                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 632                                                                         <mml:mo>&lt;</mml:mo>
 633                                                                         <mml:mfenced open="" close="">
 634                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 635                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 636                                                                             </mml:msub>
 637                                                                         </mml:mfenced>
 638                                                                     </mml:mrow>
 639                                                                 </mml:mtd></mml:mtr>
 640                                                                 <mml:mtr><mml:mtd>
 641                                                                     <mml:mrow>
 642                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 643                                                                         <mml:mo>&gt;=</mml:mo>
 644                                                                         <mml:mfenced open="" close="">
 645                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 646                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 647                                                                             </mml:msub>
 648                                                                         </mml:mfenced>
 649                                                                     </mml:mrow>
 650                                                                 </mml:mtd></mml:mtr>
 651                                                             </mml:mtable>
 652                                                         </mml:mrow>
 653                                                     </mml:mfenced>
 654                                                 </mml:mrow>
 655                                             </mml:math></div>
 656                                         </td></tr><tr><td align="left">
 657                                         <code class="constant">GL_GREATER</code>
 658                                         </td><td align="left">
 659                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 660
 661                                                 <mml:mrow>
 662                                                     <mml:mi mathvariant="italic">result</mml:mi>
 663                                                     <mml:mo>=</mml:mo>
 664                                                     <mml:mfenced open="{" close="">
 665                                                         <mml:mrow>
 666                                                             <mml:mtable>
 667                                                                 <mml:mtr><mml:mtd>
 668                                                                     <mml:mn>1.0</mml:mn>
 669                                                                 </mml:mtd></mml:mtr>
 670                                                                 <mml:mtr><mml:mtd>
 671                                                                     <mml:mn>0.0</mml:mn>
 672                                                                 </mml:mtd></mml:mtr>
 673                                                             </mml:mtable>
 674                                                             <mml:mo>⁢  </mml:mo>
 675                                                             <mml:mtable>
 676                                                                 <mml:mtr><mml:mtd>
 677                                                                     <mml:mrow>
 678                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 679                                                                         <mml:mo>&gt;</mml:mo>
 680                                                                         <mml:mfenced open="" close="">
 681                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 682                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 683                                                                             </mml:msub>
 684                                                                         </mml:mfenced>
 685                                                                     </mml:mrow>
 686                                                                 </mml:mtd></mml:mtr>
 687                                                                 <mml:mtr><mml:mtd>
 688                                                                     <mml:mrow>
 689                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 690                                                                         <mml:mo>&lt;=</mml:mo>
 691                                                                         <mml:mfenced open="" close="">
 692                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 693                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 694                                                                             </mml:msub>
 695                                                                         </mml:mfenced>
 696                                                                     </mml:mrow>
 697                                                                 </mml:mtd></mml:mtr>
 698                                                             </mml:mtable>
 699                                                         </mml:mrow>
 700                                                     </mml:mfenced>
 701                                                 </mml:mrow>
 702                                             </mml:math></div>
 703                                         </td></tr><tr><td align="left">
 704                                         <code class="constant">GL_EQUAL</code>
 705                                         </td><td align="left">
 706                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 707
 708                                                 <mml:mrow>
 709                                                     <mml:mi mathvariant="italic">result</mml:mi>
 710                                                     <mml:mo>=</mml:mo>
 711                                                     <mml:mfenced open="{" close="">
 712                                                         <mml:mrow>
 713                                                             <mml:mtable>
 714                                                                 <mml:mtr><mml:mtd>
 715                                                                     <mml:mn>1.0</mml:mn>
 716                                                                 </mml:mtd></mml:mtr>
 717                                                                 <mml:mtr><mml:mtd>
 718                                                                     <mml:mn>0.0</mml:mn>
 719                                                                 </mml:mtd></mml:mtr>
 720                                                             </mml:mtable>
 721                                                             <mml:mo>⁢  </mml:mo>
 722                                                             <mml:mtable>
 723                                                                 <mml:mtr><mml:mtd>
 724                                                                     <mml:mrow>
 725                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 726                                                                         <mml:mo>=</mml:mo>
 727                                                                         <mml:mfenced open="" close="">
 728                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 729                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 730                                                                             </mml:msub>
 731                                                                         </mml:mfenced>
 732                                                                     </mml:mrow>
 733                                                                 </mml:mtd></mml:mtr>
 734                                                                 <mml:mtr><mml:mtd>
 735                                                                     <mml:mrow>
 736                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 737                                                                         <mml:mo>≠</mml:mo>
 738                                                                         <mml:mfenced open="" close="">
 739                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 740                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 741                                                                             </mml:msub>
 742                                                                         </mml:mfenced>
 743                                                                     </mml:mrow>
 744                                                                 </mml:mtd></mml:mtr>
 745                                                             </mml:mtable>
 746                                                         </mml:mrow>
 747                                                     </mml:mfenced>
 748                                                 </mml:mrow>
 749                                             </mml:math></div>
 750                                         </td></tr><tr><td align="left">
 751                                         <code class="constant">GL_NOTEQUAL</code>
 752                                         </td><td align="left">
 753                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 754
 755                                                 <mml:mrow>
 756                                                     <mml:mi mathvariant="italic">result</mml:mi>
 757                                                     <mml:mo>=</mml:mo>
 758                                                     <mml:mfenced open="{" close="">
 759                                                         <mml:mrow>
 760                                                             <mml:mtable>
 761                                                                 <mml:mtr><mml:mtd>
 762                                                                     <mml:mn>1.0</mml:mn>
 763                                                                 </mml:mtd></mml:mtr>
 764                                                                 <mml:mtr><mml:mtd>
 765                                                                     <mml:mn>0.0</mml:mn>
 766                                                                 </mml:mtd></mml:mtr>
 767                                                             </mml:mtable>
 768                                                             <mml:mo>⁢  </mml:mo>
 769                                                             <mml:mtable>
 770                                                                 <mml:mtr><mml:mtd>
 771                                                                     <mml:mrow>
 772                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 773                                                                         <mml:mo>≠</mml:mo>
 774                                                                         <mml:mfenced open="" close="">
 775                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 776                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 777                                                                             </mml:msub>
 778                                                                         </mml:mfenced>
 779                                                                     </mml:mrow>
 780                                                                 </mml:mtd></mml:mtr>
 781                                                                 <mml:mtr><mml:mtd>
 782                                                                     <mml:mrow>
 783                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 784                                                                         <mml:mo>=</mml:mo>
 785                                                                         <mml:mfenced open="" close="">
 786                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 787                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 788                                                                             </mml:msub>
 789                                                                         </mml:mfenced>
 790                                                                     </mml:mrow>
 791                                                                 </mml:mtd></mml:mtr>
 792                                                             </mml:mtable>
 793                                                         </mml:mrow>
 794                                                     </mml:mfenced>
 795                                                 </mml:mrow>
 796                                             </mml:math></div>
 797                                         </td></tr><tr><td align="left">
 798                                         <code class="constant">GL_ALWAYS</code>
 799                                         </td><td align="left">
 800                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 801                                                 <mml:mrow>
 802                                                     <mml:mi mathvariant="italic">result</mml:mi>
 803                                                     <mml:mo>=</mml:mo>
 804                                                     <mml:mi>1.0</mml:mi>
 805                                                 </mml:mrow>
 806                                                 </mml:math></div>
 807                                         </td></tr><tr><td align="left">
 808                                         <code class="constant">GL_NEVER</code>
 809                                         </td><td align="left">
 810                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 811                                                 <mml:mrow>
 812                                                     <mml:mi mathvariant="italic">result</mml:mi>
 813                                                     <mml:mo>=</mml:mo>
 814                                                     <mml:mi>0.0</mml:mi>
 815                                                 </mml:mrow>
 816                                                 </mml:math></div>
 817                                         </td></tr></tbody></table></div><p>
 818                         where <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
 819                         is the current interpolated texture coordinate, and
 820                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 821
 822                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 823                             <mml:mi mathvariant="italic">t</mml:mi>
 824                             </mml:msub>
 825                         </mml:math>
 826                         is the depth texture value sampled from the currently bound depth texture.
 827                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">result</mml:mi></mml:math>
 828                         is assigned to the either the luminance, intensity, or alpha (as
 829                         specified by <code class="constant">GL_DEPTH_TEXTURE_MODE</code>.)
 830                     </p></dd><dt><span class="term"><code class="constant">GL_DEPTH_TEXTURE_MODE</code></span></dt><dd><p>
 831                         Specifies a single symbolic constant indicating how depth values should be
 832                         treated during filtering and texture application.  Accepted values are
 833                         <code class="constant">GL_LUMINANCE</code>, <code class="constant">GL_INTENSITY</code>, and <code class="constant">GL_ALPHA</code>.  The initial value
 834                         is <code class="constant">GL_LUMINANCE</code>.
 835                     </p></dd><dt><span class="term"><code class="constant">GL_GENERATE_MIPMAP</code></span></dt><dd><p>
 836                         Specifies a boolean value that indicates if all levels of a mipmap array
 837                         should be automatically updated when any modification to the base level
 838                         mipmap is done.  The initial value is <code class="constant">GL_FALSE</code>.
 839                     </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 840             <code class="constant">GL_TEXTURE_3D</code>, <code class="constant">GL_TEXTURE_MIN_LOD</code>, <code class="constant">GL_TEXTURE_MAX_LOD</code>,
 841             <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_TEXTURE_BASE_LEVEL</code>, and <code class="constant">GL_TEXTURE_MAX_LEVEL</code> are
 842             available only if the GL version is 1.2 or greater.
 843         </p><p>
 844             <code class="constant">GL_CLAMP_TO_BORDER</code> is available only if the GL version is 1.3 or greater.
 845         </p><p>
 846             <code class="constant">GL_MIRRORED_REPEAT</code>, <code class="constant">GL_TEXTURE_COMPARE_MODE</code>,
 847             <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>, <code class="constant">GL_DEPTH_TEXTURE_MODE</code>, and
 848             <code class="constant">GL_GENERATE_MIPMAP</code> are available only if the GL version is 1.4 or
 849             greater.
 850         </p><p>
 851             <code class="constant">GL_TEXTURE_COMPARE_FUNC</code> allows the following additional comparison modes only
 852             if the GL version is 1.5 or greater:
 853             <code class="constant">GL_LESS</code>, <code class="constant">GL_GREATER</code>,
 854             <code class="constant">GL_EQUAL</code>, <code class="constant">GL_NOTEQUAL</code>,
 855             <code class="constant">GL_ALWAYS</code>, and <code class="constant">GL_NEVER</code>.
 856         </p><p>
 857             Suppose that a program has enabled texturing (by calling <a class="citerefentry" href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> with
 858             argument <code class="constant">GL_TEXTURE_1D</code>, <code class="constant">GL_TEXTURE_2D</code>, or <code class="constant">GL_TEXTURE_3D</code>) and
 859             has set <code class="constant">GL_TEXTURE_MIN_FILTER</code> to one of the functions that requires a
 860             mipmap.  If either the dimensions of the texture images currently defined
 861             (with previous calls to <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>, <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
 862             <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>, <a class="citerefentry" href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>, or <a class="citerefentry" href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>) do not
 863             follow the proper sequence for mipmaps (described above), or there are
 864             fewer texture images defined than are needed, or the set of texture images
 865             have differing numbers of texture components, then it is as if texture
 866             mapping were disabled.
 867         </p><p>
 868             Linear filtering accesses the four nearest texture elements only in 2D
 869             textures.  In 1D textures, linear filtering accesses the two nearest
 870             texture elements.
 871         </p><p>
 872             For OpenGL versions 1.3 and greater, or when the <code class="code">ARB_multitexture</code> extension is supported, <code class="function">glTexParameter</code>
 873             specifies the texture parameters for the active texture unit, specified
 874             by calling <a class="citerefentry" href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>.
 875         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 876             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> or <em class="parameter"><code>pname</code></em> is not
 877             one of the accepted defined values.
 878         </p><p>
 879             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>params</code></em> should have a defined
 880             constant value (based on the value of <em class="parameter"><code>pname</code></em>) and does not.
 881         </p><p>
 882             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glTexParameter</code> is executed between the
 883             execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
 884         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 885             <a class="citerefentry" href="glGetTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexParameter</span></span></a>
 886         </p><p>
 887             <a class="citerefentry" href="glGetTexLevelParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetTexLevelParameter</span></span></a>
 888         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 889             <a class="citerefentry" href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,
 890             <a class="citerefentry" href="glBindTexture.xml"><span class="citerefentry"><span class="refentrytitle">glBindTexture</span></span></a>,
 891             <a class="citerefentry" href="glCopyPixels.xml"><span class="citerefentry"><span class="refentrytitle">glCopyPixels</span></span></a>,
 892             <a class="citerefentry" href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>,
 893             <a class="citerefentry" href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>,
 894             <a class="citerefentry" href="glCopyTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage1D</span></span></a>,
 895             <a class="citerefentry" href="glCopyTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage2D</span></span></a>,
 896             <a class="citerefentry" href="glCopyTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexSubImage3D</span></span></a>,
 897             <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
 898             <a class="citerefentry" href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
 899             <a class="citerefentry" href="glPixelTransfer.xml"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a>,
 900             <a class="citerefentry" href="glPrioritizeTextures.xml"><span class="citerefentry"><span class="refentrytitle">glPrioritizeTextures</span></span></a>,
 901             <a class="citerefentry" href="glTexEnv.xml"><span class="citerefentry"><span class="refentrytitle">glTexEnv</span></span></a>,
 902             <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>,
 903             <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
 904             <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
 905             <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
 906             <a class="citerefentry" href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
 907             <a class="citerefentry" href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
 908             <a class="citerefentry" href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>
 909         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 910             Copyright <span class="trademark"></span>© 1991-2006
 911             Silicon Graphics, Inc. This document is licensed under the SGI
 912             Free Software B License. For details, see
 913             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 914         </p></div></div></body></html>