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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 3.3 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><=</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>></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>>=</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><</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><</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>>=</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>></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><=</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> |