upstream-doc/man4/xhtml/glSamplerParameter.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
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   4 <?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" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glSamplerParameter - OpenGL 4 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glSamplerParameter"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glSamplerParameter — set sampler 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">glSamplerParameterf</b>(</code></td><td>GLuint  </td><td><var class="pdparam">sampler</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">glSamplerParameteri</b>(</code></td><td>GLuint  </td><td><var class="pdparam">sampler</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>sampler</code></em></span></dt><dd><p>
   5                     Specifies the sampler object whose parameter to modify.
   6                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
   7                     Specifies the symbolic name of a single-valued sampler parameter.
   8                     <em class="parameter"><code>pname</code></em> can be one of the following:
   9                     <code class="constant">GL_TEXTURE_WRAP_S</code>,
  10                     <code class="constant">GL_TEXTURE_WRAP_T</code>,
  11                     <code class="constant">GL_TEXTURE_WRAP_R</code>,
  12                     <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
  13                     <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
  14                     <code class="constant">GL_TEXTURE_MIN_LOD</code>,
  15                     <code class="constant">GL_TEXTURE_MAX_LOD</code>,
  16                     <code class="constant">GL_TEXTURE_LOD_BIAS</code>
  17                     <code class="constant">GL_TEXTURE_COMPARE_MODE</code>, or
  18                     <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>.
  19                 </p></dd><dt><span class="term"><em class="parameter"><code>param</code></em></span></dt><dd><p>
  20                     Specifies the value of <em class="parameter"><code>pname</code></em>.
  21                 </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">glSamplerParameterfv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">sampler</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">glSamplerParameteriv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">sampler</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 class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glSamplerParameterIiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">sampler</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 class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glSamplerParameterIuiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">sampler</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>const GLuint * </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>sampler</code></em></span></dt><dd><p>
  22                     Specifies the sampler object whose parameter to modify.
  23                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
  24                     Specifies the symbolic name of a sampler parameter.
  25                     <em class="parameter"><code>pname</code></em> can be one of the following:
  26                     <code class="constant">GL_TEXTURE_WRAP_S</code>,
  27                     <code class="constant">GL_TEXTURE_WRAP_T</code>,
  28                     <code class="constant">GL_TEXTURE_WRAP_R</code>,
  29                     <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
  30                     <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
  31                     <code class="constant">GL_TEXTURE_BORDER_COLOR</code>,
  32                     <code class="constant">GL_TEXTURE_MIN_LOD</code>,
  33                     <code class="constant">GL_TEXTURE_MAX_LOD</code>,
  34                     <code class="constant">GL_TEXTURE_LOD_BIAS</code>
  35                     <code class="constant">GL_TEXTURE_COMPARE_MODE</code>, or
  36                     <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>.
  37                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  38                     Specifies a pointer to an array where the value or values of <em class="parameter"><code>pname</code></em>
  39                     are stored.
  40                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  41             <code class="function">glSamplerParameter</code> assigns the value or values in <em class="parameter"><code>params</code></em> to the sampler parameter
  42             specified as <em class="parameter"><code>pname</code></em>.
  43             <em class="parameter"><code>sampler</code></em> specifies the sampler object to be modified, and must be the name of a sampler object previously
  44             returned from a call to <a href="glGenSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glGenSamplers</span></span></a>.
  45             The following symbols are accepted in <em class="parameter"><code>pname</code></em>:
  46         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_FILTER</code></span></dt><dd><p>
  47                         The texture minifying function is used whenever the pixel being textured
  48                         maps to an area greater than one texture element.
  49                         There are six defined minifying functions.
  50                         Two of them use the nearest one or nearest four texture elements
  51                         to compute the texture value.
  52                         The other four use mipmaps.
  53                     </p><p>
  54                         A mipmap is an ordered set of arrays representing the same image
  55                         at progressively lower resolutions.
  56                         If the texture has dimensions
  57                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  58
  59                             <mml:mrow>
  60                                 <mml:msup><mml:mn>2</mml:mn>
  61                                 <mml:mi mathvariant="italic">n</mml:mi>
  62                                 </mml:msup>
  63                                 <mml:mo>×</mml:mo>
  64                                 <mml:msup><mml:mn>2</mml:mn>
  65                                 <mml:mi mathvariant="italic">m</mml:mi>
  66                                 </mml:msup>
  67                             </mml:mrow>
  68                         </mml:math>,
  69                         there are
  70                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  71
  72                             <mml:mrow>
  73                                 <mml:mrow>
  74                                     <mml:mi mathvariant="italic">max</mml:mi>
  75                                     <mml:mo>⁡</mml:mo>
  76                                     <mml:mfenced open="(" close=")">
  77                                         <mml:mi mathvariant="italic">n</mml:mi>
  78                                         <mml:mi mathvariant="italic">m</mml:mi>
  79                                     </mml:mfenced>
  80                                 </mml:mrow>
  81                                 <mml:mo>+</mml:mo>
  82                                 <mml:mn>1</mml:mn>
  83                             </mml:mrow>
  84                         </mml:math>
  85                         mipmaps.
  86                         The first mipmap is the original texture,
  87                         with dimensions
  88                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  89
  90                             <mml:mrow>
  91                                 <mml:msup><mml:mn>2</mml:mn>
  92                                 <mml:mi mathvariant="italic">n</mml:mi>
  93                                 </mml:msup>
  94                                 <mml:mo>×</mml:mo>
  95                                 <mml:msup><mml:mn>2</mml:mn>
  96                                 <mml:mi mathvariant="italic">m</mml:mi>
  97                                 </mml:msup>
  98                             </mml:mrow>
  99                         </mml:math>.
 100                         Each subsequent mipmap has dimensions
 101                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 102
 103                             <mml:mrow>
 104                                 <mml:msup><mml:mn>2</mml:mn>
 105                                 <mml:mfenced open="" close="">
 106                                     <mml:mrow>
 107                                         <mml:mi mathvariant="italic">k</mml:mi>
 108                                         <mml:mo>-</mml:mo>
 109                                         <mml:mn>1</mml:mn>
 110                                     </mml:mrow>
 111                                 </mml:mfenced>
 112                                 </mml:msup>
 113                                 <mml:mo>×</mml:mo>
 114                                 <mml:msup><mml:mn>2</mml:mn>
 115                                 <mml:mfenced open="" close="">
 116                                     <mml:mrow>
 117                                         <mml:mi mathvariant="italic">l</mml:mi>
 118                                         <mml:mo>-</mml:mo>
 119                                         <mml:mn>1</mml:mn>
 120                                     </mml:mrow>
 121                                 </mml:mfenced>
 122                                 </mml:msup>
 123                             </mml:mrow>
 124                         </mml:math>,
 125                         where
 126                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 127
 128                             <mml:mrow>
 129                                 <mml:msup><mml:mn>2</mml:mn>
 130                                 <mml:mi mathvariant="italic">k</mml:mi>
 131                                 </mml:msup>
 132                                 <mml:mo>×</mml:mo>
 133                                 <mml:msup><mml:mn>2</mml:mn>
 134                                 <mml:mi mathvariant="italic">l</mml:mi>
 135                                 </mml:msup>
 136                             </mml:mrow>
 137                         </mml:math>
 138                         are the dimensions of the previous mipmap,
 139                         until either
 140                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 141
 142                             <mml:mrow>
 143                                 <mml:mi mathvariant="italic">k</mml:mi>
 144                                 <mml:mo>=</mml:mo>
 145                                 <mml:mn>0</mml:mn>
 146                             </mml:mrow>
 147                         </mml:math>
 148                         or
 149                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 150
 151                             <mml:mrow>
 152                                 <mml:mi mathvariant="italic">l</mml:mi>
 153                                 <mml:mo>=</mml:mo>
 154                                 <mml:mn>0</mml:mn>
 155                             </mml:mrow>
 156                         </mml:math>.
 157                         At that point,
 158                         subsequent mipmaps have dimension
 159                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 160
 161                             <mml:mrow>
 162                                 <mml:mn>1</mml:mn>
 163                                 <mml:mo>×</mml:mo>
 164                                 <mml:msup><mml:mn>2</mml:mn>
 165                                 <mml:mfenced open="" close="">
 166                                     <mml:mrow>
 167                                         <mml:mi mathvariant="italic">l</mml:mi>
 168                                         <mml:mo>-</mml:mo>
 169                                         <mml:mn>1</mml:mn>
 170                                     </mml:mrow>
 171                                 </mml:mfenced>
 172                                 </mml:msup>
 173                             </mml:mrow>
 174                         </mml:math>
 175                         or
 176                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 177
 178                             <mml:mrow>
 179                                 <mml:msup><mml:mn>2</mml:mn>
 180                                 <mml:mfenced open="" close="">
 181                                     <mml:mrow>
 182                                         <mml:mi mathvariant="italic">k</mml:mi>
 183                                         <mml:mo>-</mml:mo>
 184                                         <mml:mn>1</mml:mn>
 185                                     </mml:mrow>
 186                                 </mml:mfenced>
 187                                 </mml:msup>
 188                                 <mml:mo>×</mml:mo>
 189                                 <mml:mn>1</mml:mn>
 190                             </mml:mrow>
 191                         </mml:math>
 192                         until the final mipmap,
 193                         which has dimension
 194                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 195
 196                             <mml:mrow>
 197                                 <mml:mn>1</mml:mn>
 198                                 <mml:mo>×</mml:mo>
 199                                 <mml:mn>1</mml:mn>
 200                             </mml:mrow>
 201                         </mml:math>.
 202                         To define the mipmaps, call <a href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>, <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
 203                         <a href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
 204                         <a href="glCopyTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage1D</span></span></a>, or <a href="glCopyTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glCopyTexImage2D</span></span></a>
 205                         with the <span class="emphasis"><em>level</em></span> argument indicating the order of the mipmaps.
 206                         Level 0 is the original texture;
 207                         level
 208                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 209
 210                             <mml:mrow>
 211                                 <mml:mi mathvariant="italic">max</mml:mi>
 212                                 <mml:mo>⁡</mml:mo>
 213                                 <mml:mfenced open="(" close=")">
 214                                     <mml:mi mathvariant="italic">n</mml:mi>
 215                                     <mml:mi mathvariant="italic">m</mml:mi>
 216                                 </mml:mfenced>
 217                             </mml:mrow>
 218                         </mml:math>
 219                         is the final
 220                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 221
 222                             <mml:mrow>
 223                                 <mml:mn>1</mml:mn>
 224                                 <mml:mo>×</mml:mo>
 225                                 <mml:mn>1</mml:mn>
 226                             </mml:mrow>
 227                         </mml:math>
 228                         mipmap.
 229                     </p><p>
 230                         <em class="parameter"><code>params</code></em> supplies a function for minifying the texture as one of the
 231                         following:
 232                         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_NEAREST</code></span></dt><dd><p>
 233                                         Returns the value of the texture element that is nearest
 234                                         (in Manhattan distance)
 235                                         to the center of the pixel being textured.
 236                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR</code></span></dt><dd><p>
 237                                         Returns the weighted average of the four texture elements
 238                                         that are closest to the center of the pixel being textured.
 239                                         These can include border texture elements,
 240                                         depending on the values of <code class="constant">GL_TEXTURE_WRAP_S</code> and <code class="constant">GL_TEXTURE_WRAP_T</code>,
 241                                         and on the exact mapping.
 242                                     </p></dd><dt><span class="term"><code class="constant">GL_NEAREST_MIPMAP_NEAREST</code></span></dt><dd><p>
 243                                         Chooses the mipmap that most closely matches the size of the pixel
 244                                         being textured and uses the <code class="constant">GL_NEAREST</code> criterion
 245                                         (the texture element nearest to the center of the pixel)
 246                                         to produce a texture value.
 247                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR_MIPMAP_NEAREST</code></span></dt><dd><p>
 248                                         Chooses the mipmap that most closely matches the size of the pixel
 249                                         being textured and uses the <code class="constant">GL_LINEAR</code> criterion
 250                                         (a weighted average of the four texture elements that are closest
 251                                         to the center of the pixel)
 252                                         to produce a texture value.
 253                                     </p></dd><dt><span class="term"><code class="constant">GL_NEAREST_MIPMAP_LINEAR</code></span></dt><dd><p>
 254                                         Chooses the two mipmaps that most closely match the size of the pixel
 255                                         being textured and uses the <code class="constant">GL_NEAREST</code> criterion
 256                                         (the texture element nearest to the center of the pixel)
 257                                         to produce a texture value from each mipmap.
 258                                         The final texture value is a weighted average of those two values.
 259                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR_MIPMAP_LINEAR</code></span></dt><dd><p>
 260                                         Chooses the two mipmaps that most closely match the size of the pixel
 261                                         being textured and uses the <code class="constant">GL_LINEAR</code> criterion
 262                                         (a weighted average of the four texture elements that are closest
 263                                         to the center of the pixel)
 264                                         to produce a texture value from each mipmap.
 265                                         The final texture value is a weighted average of those two values.
 266                                     </p></dd></dl></div><p>
 267                     </p><p>
 268                         As more texture elements are sampled in the minification process,
 269                         fewer aliasing artifacts will be apparent.
 270                         While the <code class="constant">GL_NEAREST</code> and <code class="constant">GL_LINEAR</code> minification functions can be
 271                         faster than the other four,
 272                         they sample only one or four texture elements to determine the texture value
 273                         of the pixel being rendered and can produce moire patterns
 274                         or ragged transitions.
 275                         The initial value of <code class="constant">GL_TEXTURE_MIN_FILTER</code> is
 276                         <code class="constant">GL_NEAREST_MIPMAP_LINEAR</code>.
 277                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAG_FILTER</code></span></dt><dd><p>
 278                         The texture magnification function is used when the pixel being textured
 279                         maps to an area less than or equal to one texture element.
 280                         It sets the texture magnification function to either <code class="constant">GL_NEAREST</code>
 281                         or <code class="constant">GL_LINEAR</code> (see below). <code class="constant">GL_NEAREST</code> is generally faster
 282                         than <code class="constant">GL_LINEAR</code>,
 283                         but it can produce textured images with sharper edges
 284                         because the transition between texture elements is not as smooth.
 285                         The initial value of <code class="constant">GL_TEXTURE_MAG_FILTER</code> is <code class="constant">GL_LINEAR</code>.
 286                         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_NEAREST</code></span></dt><dd><p>
 287                                         Returns the value of the texture element that is nearest
 288                                         (in Manhattan distance)
 289                                         to the center of the pixel being textured.
 290                                     </p></dd><dt><span class="term"><code class="constant">GL_LINEAR</code></span></dt><dd><p>
 291                                         Returns the weighted average of the four texture elements
 292                                         that are closest to the center of the pixel being textured.
 293                                         These can include border texture elements,
 294                                         depending on the values of <code class="constant">GL_TEXTURE_WRAP_S</code> and <code class="constant">GL_TEXTURE_WRAP_T</code>,
 295                                         and on the exact mapping.
 296                                     </p></dd></dl></div><p>
 297                         </p><p>
 298                         </p><p>
 299                     </p></dd></dl></div><p>
 300         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_LOD</code></span></dt><dd><p>
 301                         Sets the minimum level-of-detail parameter.  This floating-point value
 302                         limits the selection of highest resolution mipmap (lowest mipmap
 303                         level). The initial value is -1000.
 304                     </p></dd></dl></div><p>
 305         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LOD</code></span></dt><dd><p>
 306                         Sets the maximum level-of-detail parameter.  This floating-point value
 307                         limits the selection of the lowest resolution mipmap (highest mipmap
 308                         level). The initial value is 1000.
 309                     </p></dd></dl></div><p>
 310         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_S</code></span></dt><dd><p>
 311                         Sets the wrap parameter for texture coordinate
 312                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 313                         to either <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
 314                         <code class="constant">GL_REPEAT</code>.  <code class="constant">GL_CLAMP_TO_BORDER</code> causes the
 315                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 316                         coordinate to be clamped to the range
 317                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 318
 319                             <mml:mfenced open="[" close="]">
 320                                 <mml:mfenced open="" close="">
 321                                     <mml:mrow>
 322                                         <mml:mfrac>
 323                                             <mml:mn>-1</mml:mn>
 324                                             <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 325                                         </mml:mfrac>
 326                                     </mml:mrow>
 327                                 </mml:mfenced>
 328                                 <mml:mrow>
 329                                     <mml:mn>1</mml:mn>
 330                                     <mml:mo>+</mml:mo>
 331                                     <mml:mfenced open="" close="">
 332                                         <mml:mrow>
 333                                             <mml:mfrac>
 334                                                 <mml:mn>1</mml:mn>
 335                                                 <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 336                                             </mml:mfrac>
 337                                         </mml:mrow>
 338                                     </mml:mfenced>
 339                                 </mml:mrow>
 340                             </mml:mfenced>
 341                         </mml:math>,
 342                         where
 343                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi></mml:math>
 344                         is the size of the texture in the direction of
 345                         clamping.<code class="constant">GL_CLAMP_TO_EDGE</code> causes
 346                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 347                         coordinates to be clamped to the
 348                         range
 349                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 350
 351                             <mml:mfenced open="[" close="]">
 352                                 <mml:mfenced open="" close="">
 353                                     <mml:mrow>
 354                                         <mml:mfrac>
 355                                             <mml:mn>1</mml:mn>
 356                                             <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 357                                         </mml:mfrac>
 358                                     </mml:mrow>
 359                                 </mml:mfenced>
 360                                 <mml:mrow>
 361                                     <mml:mn>1</mml:mn>
 362                                     <mml:mo>-</mml:mo>
 363                                     <mml:mfenced open="" close="">
 364                                         <mml:mrow>
 365                                             <mml:mfrac>
 366                                                 <mml:mn>1</mml:mn>
 367                                                 <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>
 368                                             </mml:mfrac>
 369                                         </mml:mrow>
 370                                     </mml:mfenced>
 371                                 </mml:mrow>
 372                             </mml:mfenced>
 373                         </mml:math>,
 374                         where
 375                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi></mml:math>
 376                         is the size
 377                         of the texture in the direction of clamping.  <code class="constant">GL_REPEAT</code> causes the
 378                         integer part of the
 379                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 380                         coordinate to be ignored; the GL uses only the
 381                         fractional part, thereby creating a repeating pattern.
 382                         <code class="constant">GL_MIRRORED_REPEAT</code> causes the
 383                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 384                         coordinate to be set to the
 385                         fractional part of the texture coordinate if the integer part of
 386                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 387                         is
 388                         even; if the integer part of
 389                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 390                         is odd, then the
 391                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
 392                         texture coordinate is
 393                         set to
 394                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 395
 396                             <mml:mrow>
 397                                 <mml:mn>1</mml:mn>
 398                                 <mml:mo>-</mml:mo>
 399                                 <mml:mrow>
 400                                     <mml:mi mathvariant="italic">frac</mml:mi>
 401                                     <mml:mo>⁡</mml:mo>
 402                                     <mml:mfenced open="(" close=")">
 403                                         <mml:mi mathvariant="italic">s</mml:mi>
 404                                     </mml:mfenced>
 405                                 </mml:mrow>
 406                             </mml:mrow>
 407                         </mml:math>,
 408                         where
 409                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 410
 411                             <mml:mrow>
 412                                 <mml:mi mathvariant="italic">frac</mml:mi>
 413                                 <mml:mo>⁡</mml:mo>
 414                                 <mml:mfenced open="(" close=")">
 415                                     <mml:mi mathvariant="italic">s</mml:mi>
 416                                 </mml:mfenced>
 417                             </mml:mrow>
 418                         </mml:math>
 419                         represents the fractional 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                         Initially, <code class="constant">GL_TEXTURE_WRAP_S</code> is set to <code class="constant">GL_REPEAT</code>.
 422                     </p></dd></dl></div><p>
 423         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_T</code></span></dt><dd><p>
 424                         Sets the wrap parameter for texture coordinate
 425                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math>
 426                         to either <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
 427                         <code class="constant">GL_REPEAT</code>.  See the discussion under <code class="constant">GL_TEXTURE_WRAP_S</code>.
 428                         Initially, <code class="constant">GL_TEXTURE_WRAP_T</code> is set to <code class="constant">GL_REPEAT</code>.
 429                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_R</code></span></dt><dd><p>
 430                         Sets the wrap parameter for texture coordinate
 431                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
 432                         to either <code class="constant">GL_CLAMP_TO_EDGE</code>, <code class="constant">GL_MIRRORED_REPEAT</code>, or
 433                         <code class="constant">GL_REPEAT</code>.  See the discussion under <code class="constant">GL_TEXTURE_WRAP_S</code>.
 434                         Initially, <code class="constant">GL_TEXTURE_WRAP_R</code> is set to <code class="constant">GL_REPEAT</code>.
 435                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BORDER_COLOR</code></span></dt><dd><p>
 436                         The data in <em class="parameter"><code>params</code></em> specifies four values that define the border values that
 437                         should be used for border texels. If a texel is sampled from the border of the texture, the
 438                         values of <code class="constant">GL_TEXTURE_BORDER_COLOR</code> are interpreted as an RGBA color to match the
 439                         texture's internal format and substituted for the non-existent texel data. If the texture contains depth
 440                         components, the first component of <code class="constant">GL_TEXTURE_BORDER_COLOR</code> is interpreted as a depth value.
 441                         The initial value is
 442                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 443                             <mml:mrow>
 444                                 <mml:mfenced open="(" close=")">
 445                                     <mml:mrow>
 446                                         <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>
 447                                     </mml:mrow>
 448                                 </mml:mfenced>
 449                             </mml:mrow>
 450                         </mml:math>.
 451                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_MODE</code></span></dt><dd><p>
 452                         Specifies the texture comparison mode for currently bound textures.
 453                         That is, a texture whose internal format is <code class="constant">GL_DEPTH_COMPONENT_*</code>; see
 454                         <a href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>)
 455                         Permissible values are:
 456                         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_COMPARE_REF_TO_TEXTURE</code></span></dt><dd><p>
 457                                         Specifies that the interpolated and clamped
 458                                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
 459                                         texture coordinate should
 460                                         be compared to the value in the currently bound texture.  See the
 461                                         discussion of <code class="constant">GL_TEXTURE_COMPARE_FUNC</code> for details of how the comparison
 462                                         is evaluated.  The result of the comparison is assigned to the red channel.
 463                                     </p></dd><dt><span class="term"><code class="constant">GL_NONE</code></span></dt><dd><p>
 464                                         Specifies that the red channel should be assigned the
 465                                         appropriate value from the currently bound texture.
 466                                     </p></dd></dl></div><p>
 467                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_FUNC</code></span></dt><dd><p>
 468                         Specifies the comparison operator used when <code class="constant">GL_TEXTURE_COMPARE_MODE</code> is
 469                         set to <code class="constant">GL_COMPARE_REF_TO_TEXTURE</code>.  Permissible values are:
 470                         </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
 471                                         Texture Comparison Function
 472                                         </strong></span></th><th align="left"><span class="bold"><strong>
 473                                         Computed result
 474                                         </strong></span></th></tr></thead><tbody><tr><td align="left">
 475                                         <code class="constant">GL_LEQUAL</code>
 476                                         </td><td align="left">
 477                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 478
 479                                                 <mml:mrow>
 480                                                     <mml:mi mathvariant="italic">result</mml:mi>
 481                                                     <mml:mo>=</mml:mo>
 482                                                     <mml:mfenced open="{" close="">
 483                                                         <mml:mrow>
 484                                                             <mml:mtable>
 485                                                                 <mml:mtr><mml:mtd>
 486                                                                     <mml:mn>1.0</mml:mn>
 487                                                                 </mml:mtd></mml:mtr>
 488                                                                 <mml:mtr><mml:mtd>
 489                                                                     <mml:mn>0.0</mml:mn>
 490                                                                 </mml:mtd></mml:mtr>
 491                                                             </mml:mtable>
 492                                                             <mml:mo>⁢  </mml:mo>
 493                                                             <mml:mtable>
 494                                                                 <mml:mtr><mml:mtd>
 495                                                                     <mml:mrow>
 496                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 497                                                                         <mml:mo>&lt;=</mml:mo>
 498                                                                         <mml:mfenced open="" close="">
 499                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 500                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 501                                                                             </mml:msub>
 502                                                                         </mml:mfenced>
 503                                                                     </mml:mrow>
 504                                                                 </mml:mtd></mml:mtr>
 505                                                                 <mml:mtr><mml:mtd>
 506                                                                     <mml:mrow>
 507                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 508                                                                         <mml:mo>&gt;</mml:mo>
 509                                                                         <mml:mfenced open="" close="">
 510                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 511                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 512                                                                             </mml:msub>
 513                                                                         </mml:mfenced>
 514                                                                     </mml:mrow>
 515                                                                 </mml:mtd></mml:mtr>
 516                                                             </mml:mtable>
 517                                                         </mml:mrow>
 518                                                     </mml:mfenced>
 519                                                 </mml:mrow>
 520                                             </mml:math></div>
 521                                         </td></tr><tr><td align="left">
 522                                         <code class="constant">GL_GEQUAL</code>
 523                                         </td><td align="left">
 524                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 525
 526                                                 <mml:mrow>
 527                                                     <mml:mi mathvariant="italic">result</mml:mi>
 528                                                     <mml:mo>=</mml:mo>
 529                                                     <mml:mfenced open="{" close="">
 530                                                         <mml:mrow>
 531                                                             <mml:mtable>
 532                                                                 <mml:mtr><mml:mtd>
 533                                                                     <mml:mn>1.0</mml:mn>
 534                                                                 </mml:mtd></mml:mtr>
 535                                                                 <mml:mtr><mml:mtd>
 536                                                                     <mml:mn>0.0</mml:mn>
 537                                                                 </mml:mtd></mml:mtr>
 538                                                             </mml:mtable>
 539                                                             <mml:mo>⁢  </mml:mo>
 540                                                             <mml:mtable>
 541                                                                 <mml:mtr><mml:mtd>
 542                                                                     <mml:mrow>
 543                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 544                                                                         <mml:mo>&gt;=</mml:mo>
 545                                                                         <mml:mfenced open="" close="">
 546                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 547                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 548                                                                             </mml:msub>
 549                                                                         </mml:mfenced>
 550                                                                     </mml:mrow>
 551                                                                 </mml:mtd></mml:mtr>
 552                                                                 <mml:mtr><mml:mtd>
 553                                                                     <mml:mrow>
 554                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 555                                                                         <mml:mo>&lt;</mml:mo>
 556                                                                         <mml:mfenced open="" close="">
 557                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 558                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 559                                                                             </mml:msub>
 560                                                                         </mml:mfenced>
 561                                                                     </mml:mrow>
 562                                                                 </mml:mtd></mml:mtr>
 563                                                             </mml:mtable>
 564                                                         </mml:mrow>
 565                                                     </mml:mfenced>
 566                                                 </mml:mrow>
 567                                             </mml:math></div>
 568                                         </td></tr><tr><td align="left">
 569                                         <code class="constant">GL_LESS</code>
 570                                         </td><td align="left">
 571                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 572
 573                                                 <mml:mrow>
 574                                                     <mml:mi mathvariant="italic">result</mml:mi>
 575                                                     <mml:mo>=</mml:mo>
 576                                                     <mml:mfenced open="{" close="">
 577                                                         <mml:mrow>
 578                                                             <mml:mtable>
 579                                                                 <mml:mtr><mml:mtd>
 580                                                                     <mml:mn>1.0</mml:mn>
 581                                                                 </mml:mtd></mml:mtr>
 582                                                                 <mml:mtr><mml:mtd>
 583                                                                     <mml:mn>0.0</mml:mn>
 584                                                                 </mml:mtd></mml:mtr>
 585                                                             </mml:mtable>
 586                                                             <mml:mo>⁢  </mml:mo>
 587                                                             <mml:mtable>
 588                                                                 <mml:mtr><mml:mtd>
 589                                                                     <mml:mrow>
 590                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 591                                                                         <mml:mo>&lt;</mml:mo>
 592                                                                         <mml:mfenced open="" close="">
 593                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 594                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 595                                                                             </mml:msub>
 596                                                                         </mml:mfenced>
 597                                                                     </mml:mrow>
 598                                                                 </mml:mtd></mml:mtr>
 599                                                                 <mml:mtr><mml:mtd>
 600                                                                     <mml:mrow>
 601                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 602                                                                         <mml:mo>&gt;=</mml:mo>
 603                                                                         <mml:mfenced open="" close="">
 604                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 605                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 606                                                                             </mml:msub>
 607                                                                         </mml:mfenced>
 608                                                                     </mml:mrow>
 609                                                                 </mml:mtd></mml:mtr>
 610                                                             </mml:mtable>
 611                                                         </mml:mrow>
 612                                                     </mml:mfenced>
 613                                                 </mml:mrow>
 614                                             </mml:math></div>
 615                                         </td></tr><tr><td align="left">
 616                                         <code class="constant">GL_GREATER</code>
 617                                         </td><td align="left">
 618                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 619
 620                                                 <mml:mrow>
 621                                                     <mml:mi mathvariant="italic">result</mml:mi>
 622                                                     <mml:mo>=</mml:mo>
 623                                                     <mml:mfenced open="{" close="">
 624                                                         <mml:mrow>
 625                                                             <mml:mtable>
 626                                                                 <mml:mtr><mml:mtd>
 627                                                                     <mml:mn>1.0</mml:mn>
 628                                                                 </mml:mtd></mml:mtr>
 629                                                                 <mml:mtr><mml:mtd>
 630                                                                     <mml:mn>0.0</mml:mn>
 631                                                                 </mml:mtd></mml:mtr>
 632                                                             </mml:mtable>
 633                                                             <mml:mo>⁢  </mml:mo>
 634                                                             <mml:mtable>
 635                                                                 <mml:mtr><mml:mtd>
 636                                                                     <mml:mrow>
 637                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 638                                                                         <mml:mo>&gt;</mml:mo>
 639                                                                         <mml:mfenced open="" close="">
 640                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 641                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 642                                                                             </mml:msub>
 643                                                                         </mml:mfenced>
 644                                                                     </mml:mrow>
 645                                                                 </mml:mtd></mml:mtr>
 646                                                                 <mml:mtr><mml:mtd>
 647                                                                     <mml:mrow>
 648                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 649                                                                         <mml:mo>&lt;=</mml:mo>
 650                                                                         <mml:mfenced open="" close="">
 651                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 652                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 653                                                                             </mml:msub>
 654                                                                         </mml:mfenced>
 655                                                                     </mml:mrow>
 656                                                                 </mml:mtd></mml:mtr>
 657                                                             </mml:mtable>
 658                                                         </mml:mrow>
 659                                                     </mml:mfenced>
 660                                                 </mml:mrow>
 661                                             </mml:math></div>
 662                                         </td></tr><tr><td align="left">
 663                                         <code class="constant">GL_EQUAL</code>
 664                                         </td><td align="left">
 665                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 666
 667                                                 <mml:mrow>
 668                                                     <mml:mi mathvariant="italic">result</mml:mi>
 669                                                     <mml:mo>=</mml:mo>
 670                                                     <mml:mfenced open="{" close="">
 671                                                         <mml:mrow>
 672                                                             <mml:mtable>
 673                                                                 <mml:mtr><mml:mtd>
 674                                                                     <mml:mn>1.0</mml:mn>
 675                                                                 </mml:mtd></mml:mtr>
 676                                                                 <mml:mtr><mml:mtd>
 677                                                                     <mml:mn>0.0</mml:mn>
 678                                                                 </mml:mtd></mml:mtr>
 679                                                             </mml:mtable>
 680                                                             <mml:mo>⁢  </mml:mo>
 681                                                             <mml:mtable>
 682                                                                 <mml:mtr><mml:mtd>
 683                                                                     <mml:mrow>
 684                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 685                                                                         <mml:mo>=</mml:mo>
 686                                                                         <mml:mfenced open="" close="">
 687                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 688                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 689                                                                             </mml:msub>
 690                                                                         </mml:mfenced>
 691                                                                     </mml:mrow>
 692                                                                 </mml:mtd></mml:mtr>
 693                                                                 <mml:mtr><mml:mtd>
 694                                                                     <mml:mrow>
 695                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 696                                                                         <mml:mo>≠</mml:mo>
 697                                                                         <mml:mfenced open="" close="">
 698                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 699                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 700                                                                             </mml:msub>
 701                                                                         </mml:mfenced>
 702                                                                     </mml:mrow>
 703                                                                 </mml:mtd></mml:mtr>
 704                                                             </mml:mtable>
 705                                                         </mml:mrow>
 706                                                     </mml:mfenced>
 707                                                 </mml:mrow>
 708                                             </mml:math></div>
 709                                         </td></tr><tr><td align="left">
 710                                         <code class="constant">GL_NOTEQUAL</code>
 711                                         </td><td align="left">
 712                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 713
 714                                                 <mml:mrow>
 715                                                     <mml:mi mathvariant="italic">result</mml:mi>
 716                                                     <mml:mo>=</mml:mo>
 717                                                     <mml:mfenced open="{" close="">
 718                                                         <mml:mrow>
 719                                                             <mml:mtable>
 720                                                                 <mml:mtr><mml:mtd>
 721                                                                     <mml:mn>1.0</mml:mn>
 722                                                                 </mml:mtd></mml:mtr>
 723                                                                 <mml:mtr><mml:mtd>
 724                                                                     <mml:mn>0.0</mml:mn>
 725                                                                 </mml:mtd></mml:mtr>
 726                                                             </mml:mtable>
 727                                                             <mml:mo>⁢  </mml:mo>
 728                                                             <mml:mtable>
 729                                                                 <mml:mtr><mml:mtd>
 730                                                                     <mml:mrow>
 731                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 732                                                                         <mml:mo>≠</mml:mo>
 733                                                                         <mml:mfenced open="" close="">
 734                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 735                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 736                                                                             </mml:msub>
 737                                                                         </mml:mfenced>
 738                                                                     </mml:mrow>
 739                                                                 </mml:mtd></mml:mtr>
 740                                                                 <mml:mtr><mml:mtd>
 741                                                                     <mml:mrow>
 742                                                                         <mml:mi mathvariant="italic">r</mml:mi>
 743                                                                         <mml:mo>=</mml:mo>
 744                                                                         <mml:mfenced open="" close="">
 745                                                                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 746                                                                             <mml:mi mathvariant="italic">t</mml:mi>
 747                                                                             </mml:msub>
 748                                                                         </mml:mfenced>
 749                                                                     </mml:mrow>
 750                                                                 </mml:mtd></mml:mtr>
 751                                                             </mml:mtable>
 752                                                         </mml:mrow>
 753                                                     </mml:mfenced>
 754                                                 </mml:mrow>
 755                                             </mml:math></div>
 756                                         </td></tr><tr><td align="left">
 757                                         <code class="constant">GL_ALWAYS</code>
 758                                         </td><td align="left">
 759                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 760                                                 <mml:mrow>
 761                                                     <mml:mi mathvariant="italic">result</mml:mi>
 762                                                     <mml:mo>=</mml:mo>
 763                                                     <mml:mi>1.0</mml:mi>
 764                                                 </mml:mrow>
 765                                                 </mml:math></div>
 766                                         </td></tr><tr><td align="left">
 767                                         <code class="constant">GL_NEVER</code>
 768                                         </td><td align="left">
 769                                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 770                                                 <mml:mrow>
 771                                                     <mml:mi mathvariant="italic">result</mml:mi>
 772                                                     <mml:mo>=</mml:mo>
 773                                                     <mml:mi>0.0</mml:mi>
 774                                                 </mml:mrow>
 775                                                 </mml:math></div>
 776                                         </td></tr></tbody></table></div><p>
 777                         where <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>
 778                         is the current interpolated texture coordinate, and
 779                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 780
 781                             <mml:msub><mml:mi mathvariant="italic">D</mml:mi>
 782                             <mml:mi mathvariant="italic">t</mml:mi>
 783                             </mml:msub>
 784                         </mml:math>
 785                         is the texture value sampled from the currently bound texture.
 786                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">result</mml:mi></mml:math>
 787                         is assigned to
 788                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 789
 790                             <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 791                             <mml:mi mathvariant="italic">t</mml:mi>
 792                             </mml:msub>
 793                         </mml:math>.
 794                     </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 795             <code class="function">glSamplerParameter</code> is available only if the GL version is 3.3 or higher.
 796         </p><p>
 797             If a sampler object is bound to a texture unit and that unit is used to sample from a texture, the parameters in the sampler
 798             are used to sample from the texture, rather than the equivalent parameters in the texture object bound to that unit. This
 799             introduces the possibility of sampling from the same texture object with different sets of sampler state, which may lead to
 800             a condition where a texture is <span class="emphasis"><em>incomplete</em></span> with respect to one sampler object and not with respect to
 801             another. Thus, completeness can be considered a function of a sampler object and a texture object bound to a single
 802             texture unit, rather than a property of the texture object itself.
 803         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 804             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>sampler</code></em> is not the name of a sampler object previously
 805             returned from a call to <a href="glGenSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glGenSamplers</span></span></a>.
 806         </p><p>
 807             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>params</code></em> should have a defined
 808             constant value (based on the value of <em class="parameter"><code>pname</code></em>) and does not.
 809         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 810             <a href="glGetSamplerParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetSamplerParameter</span></span></a>
 811         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 812             <a href="glGenSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glGenSamplers</span></span></a>,
 813             <a href="glBindSampler.xml"><span class="citerefentry"><span class="refentrytitle">glBindSampler</span></span></a>,
 814             <a href="glDeleteSamplers.xml"><span class="citerefentry"><span class="refentrytitle">glDeleteSamplers</span></span></a>,
 815             <a href="glIsSampler.xml"><span class="citerefentry"><span class="refentrytitle">glIsSampler</span></span></a>,
 816             <a href="glBindTexture.xml"><span class="citerefentry"><span class="refentrytitle">glBindTexture</span></span></a>,
 817             <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>
 818         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 819             Copyright <span class="trademark"></span>© 2010 Khronos Group.
 820             This material may be distributed subject to the terms and conditions set forth in
 821             the Open Publication License, v 1.0, 8 June 1999.
 822             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
 823         </p></div></div></body></html>