HCoop / clinton / guile-figl.git / blame
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| 7faf1d71 AW |
1 | <?xml version="1.0" encoding="UTF-8"?>\r |
| 2 | <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r | |
| 3 | "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r | |
| 4 | <refentry id="glSamplerParameter">\r | |
| 5 | <refmeta>\r | |
| 6 | <refmetainfo>\r | |
| 7 | <copyright>\r | |
| 8 | <year>2010</year>\r | |
| 9 | <holder>KhronosGroup</holder>\r | |
| 10 | </copyright>\r | |
| 11 | </refmetainfo>\r | |
| 12 | <refentrytitle>glSamplerParameter</refentrytitle>\r | |
| 13 | <manvolnum>3G</manvolnum>\r | |
| 14 | </refmeta>\r | |
| 15 | <refnamediv>\r | |
| 16 | <refname>glSamplerParameter</refname>\r | |
| 17 | <refpurpose>set sampler parameters</refpurpose>\r | |
| 18 | </refnamediv>\r | |
| 19 | <refsynopsisdiv><title>C Specification</title>\r | |
| 20 | <funcsynopsis>\r | |
| 21 | <funcprototype>\r | |
| 22 | <funcdef>void <function>glSamplerParameterf</function></funcdef>\r | |
| 23 | <paramdef>GLuint <parameter>sampler</parameter></paramdef>\r | |
| 24 | <paramdef>GLenum <parameter>pname</parameter></paramdef>\r | |
| 25 | <paramdef>GLfloat <parameter>param</parameter></paramdef>\r | |
| 26 | </funcprototype>\r | |
| 27 | </funcsynopsis>\r | |
| 28 | <funcsynopsis>\r | |
| 29 | <funcprototype>\r | |
| 30 | <funcdef>void <function>glSamplerParameteri</function></funcdef>\r | |
| 31 | <paramdef>GLuint <parameter>sampler</parameter></paramdef>\r | |
| 32 | <paramdef>GLenum <parameter>pname</parameter></paramdef>\r | |
| 33 | <paramdef>GLint <parameter>param</parameter></paramdef>\r | |
| 34 | </funcprototype>\r | |
| 35 | </funcsynopsis>\r | |
| 36 | </refsynopsisdiv>\r | |
| 37 | <!-- eqn: ignoring delim $$ -->\r | |
| 38 | <refsect1 id="parameters"><title>Parameters</title>\r | |
| 39 | <variablelist>\r | |
| 40 | <varlistentry>\r | |
| 41 | <term><parameter>sampler</parameter></term>\r | |
| 42 | <listitem>\r | |
| 43 | <para>\r | |
| 44 | Specifies the sampler object whose parameter to modify.\r | |
| 45 | </para>\r | |
| 46 | </listitem>\r | |
| 47 | </varlistentry>\r | |
| 48 | <varlistentry>\r | |
| 49 | <term><parameter>pname</parameter></term>\r | |
| 50 | <listitem>\r | |
| 51 | <para>\r | |
| 52 | Specifies the symbolic name of a single-valued sampler parameter.\r | |
| 53 | <parameter>pname</parameter> can be one of the following:\r | |
| 54 | <constant>GL_TEXTURE_WRAP_S</constant>,\r | |
| 55 | <constant>GL_TEXTURE_WRAP_T</constant>,\r | |
| 56 | <constant>GL_TEXTURE_WRAP_R</constant>,\r | |
| 57 | <constant>GL_TEXTURE_MIN_FILTER</constant>,\r | |
| 58 | <constant>GL_TEXTURE_MAG_FILTER</constant>,\r | |
| 59 | <constant>GL_TEXTURE_MIN_LOD</constant>,\r | |
| 60 | <constant>GL_TEXTURE_MAX_LOD</constant>,\r | |
| 61 | <constant>GL_TEXTURE_LOD_BIAS</constant>\r | |
| 62 | <constant>GL_TEXTURE_COMPARE_MODE</constant>, or\r | |
| 63 | <constant>GL_TEXTURE_COMPARE_FUNC</constant>.\r | |
| 64 | </para>\r | |
| 65 | </listitem>\r | |
| 66 | </varlistentry>\r | |
| 67 | <varlistentry>\r | |
| 68 | <term><parameter>param</parameter></term>\r | |
| 69 | <listitem>\r | |
| 70 | <para>\r | |
| 71 | Specifies the value of <parameter>pname</parameter>.\r | |
| 72 | </para>\r | |
| 73 | </listitem>\r | |
| 74 | </varlistentry>\r | |
| 75 | </variablelist>\r | |
| 76 | </refsect1>\r | |
| 77 | <refsynopsisdiv><title>C Specification</title>\r | |
| 78 | <funcsynopsis>\r | |
| 79 | <funcprototype>\r | |
| 80 | <funcdef>void <function>glSamplerParameterfv</function></funcdef>\r | |
| 81 | <paramdef>GLuint <parameter>sampler</parameter></paramdef>\r | |
| 82 | <paramdef>GLenum <parameter>pname</parameter></paramdef>\r | |
| 83 | <paramdef>const GLfloat * <parameter>params</parameter></paramdef>\r | |
| 84 | </funcprototype>\r | |
| 85 | </funcsynopsis>\r | |
| 86 | <funcsynopsis>\r | |
| 87 | <funcprototype>\r | |
| 88 | <funcdef>void <function>glSamplerParameteriv</function></funcdef>\r | |
| 89 | <paramdef>GLuint <parameter>sampler</parameter></paramdef>\r | |
| 90 | <paramdef>GLenum <parameter>pname</parameter></paramdef>\r | |
| 91 | <paramdef>const GLint * <parameter>params</parameter></paramdef>\r | |
| 92 | </funcprototype>\r | |
| 93 | </funcsynopsis>\r | |
| 94 | <funcsynopsis>\r | |
| 95 | <funcprototype>\r | |
| 96 | <funcdef>void <function>glSamplerParameterIiv</function></funcdef>\r | |
| 97 | <paramdef>GLuint <parameter>sampler</parameter></paramdef>\r | |
| 98 | <paramdef>GLenum <parameter>pname</parameter></paramdef>\r | |
| 99 | <paramdef>const GLint * <parameter>params</parameter></paramdef>\r | |
| 100 | </funcprototype>\r | |
| 101 | </funcsynopsis>\r | |
| 102 | <funcsynopsis>\r | |
| 103 | <funcprototype>\r | |
| 104 | <funcdef>void <function>glSamplerParameterIuiv</function></funcdef>\r | |
| 105 | <paramdef>GLuint <parameter>sampler</parameter></paramdef>\r | |
| 106 | <paramdef>GLenum <parameter>pname</parameter></paramdef>\r | |
| 107 | <paramdef>const GLuint * <parameter>params</parameter></paramdef>\r | |
| 108 | </funcprototype>\r | |
| 109 | </funcsynopsis>\r | |
| 110 | </refsynopsisdiv>\r | |
| 111 | <refsect1 id="parameters2"><title>Parameters</title>\r | |
| 112 | <variablelist>\r | |
| 113 | <varlistentry>\r | |
| 114 | <term><parameter>sampler</parameter></term>\r | |
| 115 | <listitem>\r | |
| 116 | <para>\r | |
| 117 | Specifies the sampler object whose parameter to modify.\r | |
| 118 | </para>\r | |
| 119 | </listitem>\r | |
| 120 | </varlistentry>\r | |
| 121 | <varlistentry>\r | |
| 122 | <term><parameter>pname</parameter></term>\r | |
| 123 | <listitem>\r | |
| 124 | <para>\r | |
| 125 | Specifies the symbolic name of a sampler parameter.\r | |
| 126 | <parameter>pname</parameter> can be one of the following:\r | |
| 127 | <constant>GL_TEXTURE_WRAP_S</constant>,\r | |
| 128 | <constant>GL_TEXTURE_WRAP_T</constant>,\r | |
| 129 | <constant>GL_TEXTURE_WRAP_R</constant>,\r | |
| 130 | <constant>GL_TEXTURE_MIN_FILTER</constant>,\r | |
| 131 | <constant>GL_TEXTURE_MAG_FILTER</constant>,\r | |
| 132 | <constant>GL_TEXTURE_BORDER_COLOR</constant>,\r | |
| 133 | <constant>GL_TEXTURE_MIN_LOD</constant>,\r | |
| 134 | <constant>GL_TEXTURE_MAX_LOD</constant>,\r | |
| 135 | <constant>GL_TEXTURE_LOD_BIAS</constant>\r | |
| 136 | <constant>GL_TEXTURE_COMPARE_MODE</constant>, or\r | |
| 137 | <constant>GL_TEXTURE_COMPARE_FUNC</constant>.\r | |
| 138 | </para>\r | |
| 139 | </listitem>\r | |
| 140 | </varlistentry>\r | |
| 141 | <varlistentry>\r | |
| 142 | <term><parameter>params</parameter></term>\r | |
| 143 | <listitem>\r | |
| 144 | <para>\r | |
| 145 | Specifies a pointer to an array where the value or values of <parameter>pname</parameter>\r | |
| 146 | are stored.\r | |
| 147 | </para>\r | |
| 148 | </listitem>\r | |
| 149 | </varlistentry>\r | |
| 150 | </variablelist>\r | |
| 151 | </refsect1>\r | |
| 152 | <refsect1 id="description"><title>Description</title>\r | |
| 153 | <para>\r | |
| 154 | <function>glSamplerParameter</function> assigns the value or values in <parameter>params</parameter> to the sampler parameter\r | |
| 155 | specified as <parameter>pname</parameter>.\r | |
| 156 | <parameter>sampler</parameter> specifies the sampler object to be modified, and must be the name of a sampler object previously\r | |
| 157 | returned from a call to <citerefentry><refentrytitle>glGenSamplers</refentrytitle></citerefentry>.\r | |
| 158 | The following symbols are accepted in <parameter>pname</parameter>:\r | |
| 159 | </para>\r | |
| 160 | <variablelist>\r | |
| 161 | <varlistentry>\r | |
| 162 | <term><constant>GL_TEXTURE_MIN_FILTER</constant></term>\r | |
| 163 | <listitem>\r | |
| 164 | <para>\r | |
| 165 | The texture minifying function is used whenever the pixel being textured\r | |
| 166 | maps to an area greater than one texture element.\r | |
| 167 | There are six defined minifying functions.\r | |
| 168 | Two of them use the nearest one or nearest four texture elements\r | |
| 169 | to compute the texture value.\r | |
| 170 | The other four use mipmaps.\r | |
| 171 | </para>\r | |
| 172 | <para>\r | |
| 173 | A mipmap is an ordered set of arrays representing the same image\r | |
| 174 | at progressively lower resolutions.\r | |
| 175 | If the texture has dimensions \r | |
| 176 | <inlineequation><mml:math>\r | |
| 177 | <!-- eqn: 2 sup n times 2 sup m: -->\r | |
| 178 | <mml:mrow>\r | |
| 179 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 180 | <mml:mi mathvariant="italic">n</mml:mi>\r | |
| 181 | </mml:msup>\r | |
| 182 | <mml:mo>×</mml:mo>\r | |
| 183 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 184 | <mml:mi mathvariant="italic">m</mml:mi>\r | |
| 185 | </mml:msup>\r | |
| 186 | </mml:mrow>\r | |
| 187 | </mml:math></inlineequation>,\r | |
| 188 | there are\r | |
| 189 | <inlineequation><mml:math>\r | |
| 190 | <!-- eqn: max ( n, m ) + 1: -->\r | |
| 191 | <mml:mrow>\r | |
| 192 | <mml:mrow>\r | |
| 193 | <mml:mi mathvariant="italic">max</mml:mi>\r | |
| 194 | <mml:mo>⁡</mml:mo>\r | |
| 195 | <mml:mfenced open="(" close=")">\r | |
| 196 | <mml:mi mathvariant="italic">n</mml:mi>\r | |
| 197 | <mml:mi mathvariant="italic">m</mml:mi>\r | |
| 198 | </mml:mfenced>\r | |
| 199 | </mml:mrow>\r | |
| 200 | <mml:mo>+</mml:mo>\r | |
| 201 | <mml:mn>1</mml:mn>\r | |
| 202 | </mml:mrow>\r | |
| 203 | </mml:math></inlineequation>\r | |
| 204 | mipmaps.\r | |
| 205 | The first mipmap is the original texture,\r | |
| 206 | with dimensions \r | |
| 207 | <inlineequation><mml:math>\r | |
| 208 | <!-- eqn: 2 sup n times 2 sup m: -->\r | |
| 209 | <mml:mrow>\r | |
| 210 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 211 | <mml:mi mathvariant="italic">n</mml:mi>\r | |
| 212 | </mml:msup>\r | |
| 213 | <mml:mo>×</mml:mo>\r | |
| 214 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 215 | <mml:mi mathvariant="italic">m</mml:mi>\r | |
| 216 | </mml:msup>\r | |
| 217 | </mml:mrow>\r | |
| 218 | </mml:math></inlineequation>.\r | |
| 219 | Each subsequent mipmap has dimensions \r | |
| 220 | <inlineequation><mml:math>\r | |
| 221 | <!-- eqn: 2 sup { k - 1 } times 2 sup { l - 1 }: -->\r | |
| 222 | <mml:mrow>\r | |
| 223 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 224 | <mml:mfenced open="" close="">\r | |
| 225 | <mml:mrow>\r | |
| 226 | <mml:mi mathvariant="italic">k</mml:mi>\r | |
| 227 | <mml:mo>-</mml:mo>\r | |
| 228 | <mml:mn>1</mml:mn>\r | |
| 229 | </mml:mrow>\r | |
| 230 | </mml:mfenced>\r | |
| 231 | </mml:msup>\r | |
| 232 | <mml:mo>×</mml:mo>\r | |
| 233 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 234 | <mml:mfenced open="" close="">\r | |
| 235 | <mml:mrow>\r | |
| 236 | <mml:mi mathvariant="italic">l</mml:mi>\r | |
| 237 | <mml:mo>-</mml:mo>\r | |
| 238 | <mml:mn>1</mml:mn>\r | |
| 239 | </mml:mrow>\r | |
| 240 | </mml:mfenced>\r | |
| 241 | </mml:msup>\r | |
| 242 | </mml:mrow>\r | |
| 243 | </mml:math></inlineequation>,\r | |
| 244 | where \r | |
| 245 | <inlineequation><mml:math>\r | |
| 246 | <!-- eqn: 2 sup k times 2 sup l: -->\r | |
| 247 | <mml:mrow>\r | |
| 248 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 249 | <mml:mi mathvariant="italic">k</mml:mi>\r | |
| 250 | </mml:msup>\r | |
| 251 | <mml:mo>×</mml:mo>\r | |
| 252 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 253 | <mml:mi mathvariant="italic">l</mml:mi>\r | |
| 254 | </mml:msup>\r | |
| 255 | </mml:mrow>\r | |
| 256 | </mml:math></inlineequation>\r | |
| 257 | are the dimensions of the previous mipmap,\r | |
| 258 | until either \r | |
| 259 | <inlineequation><mml:math>\r | |
| 260 | <!-- eqn: k = 0: -->\r | |
| 261 | <mml:mrow>\r | |
| 262 | <mml:mi mathvariant="italic">k</mml:mi>\r | |
| 263 | <mml:mo>=</mml:mo>\r | |
| 264 | <mml:mn>0</mml:mn>\r | |
| 265 | </mml:mrow>\r | |
| 266 | </mml:math></inlineequation>\r | |
| 267 | or \r | |
| 268 | <inlineequation><mml:math>\r | |
| 269 | <!-- eqn: l = 0: -->\r | |
| 270 | <mml:mrow>\r | |
| 271 | <mml:mi mathvariant="italic">l</mml:mi>\r | |
| 272 | <mml:mo>=</mml:mo>\r | |
| 273 | <mml:mn>0</mml:mn>\r | |
| 274 | </mml:mrow>\r | |
| 275 | </mml:math></inlineequation>.\r | |
| 276 | At that point,\r | |
| 277 | subsequent mipmaps have dimension \r | |
| 278 | <inlineequation><mml:math>\r | |
| 279 | <!-- eqn: 1 times 2 sup { l - 1 }: -->\r | |
| 280 | <mml:mrow>\r | |
| 281 | <mml:mn>1</mml:mn>\r | |
| 282 | <mml:mo>×</mml:mo>\r | |
| 283 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 284 | <mml:mfenced open="" close="">\r | |
| 285 | <mml:mrow>\r | |
| 286 | <mml:mi mathvariant="italic">l</mml:mi>\r | |
| 287 | <mml:mo>-</mml:mo>\r | |
| 288 | <mml:mn>1</mml:mn>\r | |
| 289 | </mml:mrow>\r | |
| 290 | </mml:mfenced>\r | |
| 291 | </mml:msup>\r | |
| 292 | </mml:mrow>\r | |
| 293 | </mml:math></inlineequation>\r | |
| 294 | or \r | |
| 295 | <inlineequation><mml:math>\r | |
| 296 | <!-- eqn: 2 sup { k - 1} times 1: -->\r | |
| 297 | <mml:mrow>\r | |
| 298 | <mml:msup><mml:mn>2</mml:mn>\r | |
| 299 | <mml:mfenced open="" close="">\r | |
| 300 | <mml:mrow>\r | |
| 301 | <mml:mi mathvariant="italic">k</mml:mi>\r | |
| 302 | <mml:mo>-</mml:mo>\r | |
| 303 | <mml:mn>1</mml:mn>\r | |
| 304 | </mml:mrow>\r | |
| 305 | </mml:mfenced>\r | |
| 306 | </mml:msup>\r | |
| 307 | <mml:mo>×</mml:mo>\r | |
| 308 | <mml:mn>1</mml:mn>\r | |
| 309 | </mml:mrow>\r | |
| 310 | </mml:math></inlineequation>\r | |
| 311 | until the final mipmap,\r | |
| 312 | which has dimension \r | |
| 313 | <inlineequation><mml:math>\r | |
| 314 | <!-- eqn: 1 times 1: -->\r | |
| 315 | <mml:mrow>\r | |
| 316 | <mml:mn>1</mml:mn>\r | |
| 317 | <mml:mo>×</mml:mo>\r | |
| 318 | <mml:mn>1</mml:mn>\r | |
| 319 | </mml:mrow>\r | |
| 320 | </mml:math></inlineequation>.\r | |
| 321 | To define the mipmaps, call <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,\r | |
| 322 | <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,\r | |
| 323 | <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>, or <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>\r | |
| 324 | with the <emphasis>level</emphasis> argument indicating the order of the mipmaps.\r | |
| 325 | Level 0 is the original texture;\r | |
| 326 | level \r | |
| 327 | <inlineequation><mml:math>\r | |
| 328 | <!-- eqn: max ( n, m ): -->\r | |
| 329 | <mml:mrow>\r | |
| 330 | <mml:mi mathvariant="italic">max</mml:mi>\r | |
| 331 | <mml:mo>⁡</mml:mo>\r | |
| 332 | <mml:mfenced open="(" close=")">\r | |
| 333 | <mml:mi mathvariant="italic">n</mml:mi>\r | |
| 334 | <mml:mi mathvariant="italic">m</mml:mi>\r | |
| 335 | </mml:mfenced>\r | |
| 336 | </mml:mrow>\r | |
| 337 | </mml:math></inlineequation>\r | |
| 338 | is the final \r | |
| 339 | <inlineequation><mml:math>\r | |
| 340 | <!-- eqn: 1 times 1: -->\r | |
| 341 | <mml:mrow>\r | |
| 342 | <mml:mn>1</mml:mn>\r | |
| 343 | <mml:mo>×</mml:mo>\r | |
| 344 | <mml:mn>1</mml:mn>\r | |
| 345 | </mml:mrow>\r | |
| 346 | </mml:math></inlineequation>\r | |
| 347 | mipmap.\r | |
| 348 | </para>\r | |
| 349 | <para>\r | |
| 350 | <parameter>params</parameter> supplies a function for minifying the texture as one of the\r | |
| 351 | following:\r | |
| 352 | <variablelist>\r | |
| 353 | <varlistentry>\r | |
| 354 | <term><constant>GL_NEAREST</constant></term>\r | |
| 355 | <listitem>\r | |
| 356 | <para>\r | |
| 357 | Returns the value of the texture element that is nearest\r | |
| 358 | (in Manhattan distance)\r | |
| 359 | to the center of the pixel being textured.\r | |
| 360 | </para>\r | |
| 361 | </listitem>\r | |
| 362 | </varlistentry>\r | |
| 363 | <varlistentry>\r | |
| 364 | <term><constant>GL_LINEAR</constant></term>\r | |
| 365 | <listitem>\r | |
| 366 | <para>\r | |
| 367 | Returns the weighted average of the four texture elements\r | |
| 368 | that are closest to the center of the pixel being textured.\r | |
| 369 | These can include border texture elements,\r | |
| 370 | depending on the values of <constant>GL_TEXTURE_WRAP_S</constant> and <constant>GL_TEXTURE_WRAP_T</constant>,\r | |
| 371 | and on the exact mapping.\r | |
| 372 | </para>\r | |
| 373 | </listitem>\r | |
| 374 | </varlistentry>\r | |
| 375 | <varlistentry>\r | |
| 376 | <term><constant>GL_NEAREST_MIPMAP_NEAREST</constant></term>\r | |
| 377 | <listitem>\r | |
| 378 | <para>\r | |
| 379 | Chooses the mipmap that most closely matches the size of the pixel\r | |
| 380 | being textured and uses the <constant>GL_NEAREST</constant> criterion\r | |
| 381 | (the texture element nearest to the center of the pixel)\r | |
| 382 | to produce a texture value.\r | |
| 383 | </para>\r | |
| 384 | </listitem>\r | |
| 385 | </varlistentry>\r | |
| 386 | <varlistentry>\r | |
| 387 | <term><constant>GL_LINEAR_MIPMAP_NEAREST</constant></term>\r | |
| 388 | <listitem>\r | |
| 389 | <para>\r | |
| 390 | Chooses the mipmap that most closely matches the size of the pixel\r | |
| 391 | being textured and uses the <constant>GL_LINEAR</constant> criterion\r | |
| 392 | (a weighted average of the four texture elements that are closest\r | |
| 393 | to the center of the pixel)\r | |
| 394 | to produce a texture value.\r | |
| 395 | </para>\r | |
| 396 | </listitem>\r | |
| 397 | </varlistentry>\r | |
| 398 | <varlistentry>\r | |
| 399 | <term><constant>GL_NEAREST_MIPMAP_LINEAR</constant></term>\r | |
| 400 | <listitem>\r | |
| 401 | <para>\r | |
| 402 | Chooses the two mipmaps that most closely match the size of the pixel\r | |
| 403 | being textured and uses the <constant>GL_NEAREST</constant> criterion\r | |
| 404 | (the texture element nearest to the center of the pixel)\r | |
| 405 | to produce a texture value from each mipmap.\r | |
| 406 | The final texture value is a weighted average of those two values.\r | |
| 407 | </para>\r | |
| 408 | </listitem>\r | |
| 409 | </varlistentry>\r | |
| 410 | <varlistentry>\r | |
| 411 | <term><constant>GL_LINEAR_MIPMAP_LINEAR</constant></term>\r | |
| 412 | <listitem>\r | |
| 413 | <para>\r | |
| 414 | Chooses the two mipmaps that most closely match the size of the pixel\r | |
| 415 | being textured and uses the <constant>GL_LINEAR</constant> criterion\r | |
| 416 | (a weighted average of the four texture elements that are closest\r | |
| 417 | to the center of the pixel)\r | |
| 418 | to produce a texture value from each mipmap.\r | |
| 419 | The final texture value is a weighted average of those two values.\r | |
| 420 | </para>\r | |
| 421 | </listitem>\r | |
| 422 | </varlistentry>\r | |
| 423 | </variablelist>\r | |
| 424 | </para>\r | |
| 425 | <para>\r | |
| 426 | As more texture elements are sampled in the minification process,\r | |
| 427 | fewer aliasing artifacts will be apparent.\r | |
| 428 | While the <constant>GL_NEAREST</constant> and <constant>GL_LINEAR</constant> minification functions can be\r | |
| 429 | faster than the other four,\r | |
| 430 | they sample only one or four texture elements to determine the texture value\r | |
| 431 | of the pixel being rendered and can produce moire patterns\r | |
| 432 | or ragged transitions.\r | |
| 433 | The initial value of <constant>GL_TEXTURE_MIN_FILTER</constant> is\r | |
| 434 | <constant>GL_NEAREST_MIPMAP_LINEAR</constant>.\r | |
| 435 | </para>\r | |
| 436 | </listitem>\r | |
| 437 | </varlistentry>\r | |
| 438 | <varlistentry>\r | |
| 439 | <term><constant>GL_TEXTURE_MAG_FILTER</constant></term>\r | |
| 440 | <listitem>\r | |
| 441 | <para>\r | |
| 442 | The texture magnification function is used when the pixel being textured\r | |
| 443 | maps to an area less than or equal to one texture element.\r | |
| 444 | It sets the texture magnification function to either <constant>GL_NEAREST</constant>\r | |
| 445 | or <constant>GL_LINEAR</constant> (see below). <constant>GL_NEAREST</constant> is generally faster\r | |
| 446 | than <constant>GL_LINEAR</constant>,\r | |
| 447 | but it can produce textured images with sharper edges\r | |
| 448 | because the transition between texture elements is not as smooth.\r | |
| 449 | The initial value of <constant>GL_TEXTURE_MAG_FILTER</constant> is <constant>GL_LINEAR</constant>.\r | |
| 450 | <variablelist>\r | |
| 451 | <varlistentry>\r | |
| 452 | <term><constant>GL_NEAREST</constant></term>\r | |
| 453 | <listitem>\r | |
| 454 | <para>\r | |
| 455 | Returns the value of the texture element that is nearest\r | |
| 456 | (in Manhattan distance)\r | |
| 457 | to the center of the pixel being textured.\r | |
| 458 | </para>\r | |
| 459 | </listitem>\r | |
| 460 | </varlistentry>\r | |
| 461 | <varlistentry>\r | |
| 462 | <term><constant>GL_LINEAR</constant></term>\r | |
| 463 | <listitem>\r | |
| 464 | <para>\r | |
| 465 | Returns the weighted average of the four texture elements\r | |
| 466 | that are closest to the center of the pixel being textured.\r | |
| 467 | These can include border texture elements,\r | |
| 468 | depending on the values of <constant>GL_TEXTURE_WRAP_S</constant> and <constant>GL_TEXTURE_WRAP_T</constant>,\r | |
| 469 | and on the exact mapping.\r | |
| 470 | </para>\r | |
| 471 | </listitem>\r | |
| 472 | </varlistentry>\r | |
| 473 | </variablelist>\r | |
| 474 | <para>\r | |
| 475 | </para>\r | |
| 476 | </para>\r | |
| 477 | </listitem>\r | |
| 478 | </varlistentry>\r | |
| 479 | </variablelist>\r | |
| 480 | <para>\r | |
| 481 | </para>\r | |
| 482 | <variablelist>\r | |
| 483 | <varlistentry>\r | |
| 484 | <term><constant>GL_TEXTURE_MIN_LOD</constant></term>\r | |
| 485 | <listitem>\r | |
| 486 | <para>\r | |
| 487 | Sets the minimum level-of-detail parameter. This floating-point value\r | |
| 488 | limits the selection of highest resolution mipmap (lowest mipmap\r | |
| 489 | level). The initial value is -1000.\r | |
| 490 | </para>\r | |
| 491 | </listitem>\r | |
| 492 | </varlistentry>\r | |
| 493 | </variablelist>\r | |
| 494 | <para>\r | |
| 495 | </para>\r | |
| 496 | <variablelist>\r | |
| 497 | <varlistentry>\r | |
| 498 | <term><constant>GL_TEXTURE_MAX_LOD</constant></term>\r | |
| 499 | <listitem>\r | |
| 500 | <para>\r | |
| 501 | Sets the maximum level-of-detail parameter. This floating-point value\r | |
| 502 | limits the selection of the lowest resolution mipmap (highest mipmap\r | |
| 503 | level). The initial value is 1000.\r | |
| 504 | </para>\r | |
| 505 | </listitem>\r | |
| 506 | </varlistentry>\r | |
| 507 | </variablelist>\r | |
| 508 | <para>\r | |
| 509 | </para>\r | |
| 510 | <variablelist>\r | |
| 511 | <varlistentry>\r | |
| 512 | <term><constant>GL_TEXTURE_WRAP_S</constant></term>\r | |
| 513 | <listitem>\r | |
| 514 | <para>\r | |
| 515 | Sets the wrap parameter for texture coordinate \r | |
| 516 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 517 | to either <constant>GL_CLAMP_TO_EDGE</constant>, <constant>GL_MIRRORED_REPEAT</constant>, or\r | |
| 518 | <constant>GL_REPEAT</constant>. <constant>GL_CLAMP_TO_BORDER</constant> causes the \r | |
| 519 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 520 | coordinate to be clamped to the range\r | |
| 521 | <inlineequation><mml:math>\r | |
| 522 | <!-- eqn: left [ {-1 over 2N}, 1 + {1 over 2N} right ]: -->\r | |
| 523 | <mml:mfenced open="[" close="]">\r | |
| 524 | <mml:mfenced open="" close="">\r | |
| 525 | <mml:mrow>\r | |
| 526 | <mml:mfrac>\r | |
| 527 | <mml:mn>-1</mml:mn>\r | |
| 528 | <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>\r | |
| 529 | </mml:mfrac>\r | |
| 530 | </mml:mrow>\r | |
| 531 | </mml:mfenced>\r | |
| 532 | <mml:mrow>\r | |
| 533 | <mml:mn>1</mml:mn>\r | |
| 534 | <mml:mo>+</mml:mo>\r | |
| 535 | <mml:mfenced open="" close="">\r | |
| 536 | <mml:mrow>\r | |
| 537 | <mml:mfrac>\r | |
| 538 | <mml:mn>1</mml:mn>\r | |
| 539 | <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>\r | |
| 540 | </mml:mfrac>\r | |
| 541 | </mml:mrow>\r | |
| 542 | </mml:mfenced>\r | |
| 543 | </mml:mrow>\r | |
| 544 | </mml:mfenced>\r | |
| 545 | </mml:math></inlineequation>,\r | |
| 546 | where \r | |
| 547 | <inlineequation><mml:math><mml:mi mathvariant="italic">N</mml:mi></mml:math></inlineequation>\r | |
| 548 | is the size of the texture in the direction of\r | |
| 549 | clamping.<constant>GL_CLAMP_TO_EDGE</constant> causes \r | |
| 550 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 551 | coordinates to be clamped to the\r | |
| 552 | range \r | |
| 553 | <inlineequation><mml:math>\r | |
| 554 | <!-- eqn: left [ {1 over 2N}, 1 - {1 over 2N} right ]: -->\r | |
| 555 | <mml:mfenced open="[" close="]">\r | |
| 556 | <mml:mfenced open="" close="">\r | |
| 557 | <mml:mrow>\r | |
| 558 | <mml:mfrac>\r | |
| 559 | <mml:mn>1</mml:mn>\r | |
| 560 | <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>\r | |
| 561 | </mml:mfrac>\r | |
| 562 | </mml:mrow>\r | |
| 563 | </mml:mfenced>\r | |
| 564 | <mml:mrow>\r | |
| 565 | <mml:mn>1</mml:mn>\r | |
| 566 | <mml:mo>-</mml:mo>\r | |
| 567 | <mml:mfenced open="" close="">\r | |
| 568 | <mml:mrow>\r | |
| 569 | <mml:mfrac>\r | |
| 570 | <mml:mn>1</mml:mn>\r | |
| 571 | <mml:mn>2<mml:mi mathvariant="italic">N</mml:mi></mml:mn>\r | |
| 572 | </mml:mfrac>\r | |
| 573 | </mml:mrow>\r | |
| 574 | </mml:mfenced>\r | |
| 575 | </mml:mrow>\r | |
| 576 | </mml:mfenced>\r | |
| 577 | </mml:math></inlineequation>,\r | |
| 578 | where \r | |
| 579 | <inlineequation><mml:math><mml:mi mathvariant="italic">N</mml:mi></mml:math></inlineequation>\r | |
| 580 | is the size\r | |
| 581 | of the texture in the direction of clamping. <constant>GL_REPEAT</constant> causes the\r | |
| 582 | integer part of the \r | |
| 583 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 584 | coordinate to be ignored; the GL uses only the\r | |
| 585 | fractional part, thereby creating a repeating pattern.\r | |
| 586 | <constant>GL_MIRRORED_REPEAT</constant> causes the \r | |
| 587 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 588 | coordinate to be set to the\r | |
| 589 | fractional part of the texture coordinate if the integer part of \r | |
| 590 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 591 | is\r | |
| 592 | even; if the integer part of \r | |
| 593 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 594 | is odd, then the \r | |
| 595 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>\r | |
| 596 | texture coordinate is\r | |
| 597 | set to \r | |
| 598 | <inlineequation><mml:math>\r | |
| 599 | <!-- eqn: 1 - frac(s): -->\r | |
| 600 | <mml:mrow>\r | |
| 601 | <mml:mn>1</mml:mn>\r | |
| 602 | <mml:mo>-</mml:mo>\r | |
| 603 | <mml:mrow>\r | |
| 604 | <mml:mi mathvariant="italic">frac</mml:mi>\r | |
| 605 | <mml:mo>⁡</mml:mo>\r | |
| 606 | <mml:mfenced open="(" close=")">\r | |
| 607 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
| 608 | </mml:mfenced>\r | |
| 609 | </mml:mrow>\r | |
| 610 | </mml:mrow>\r | |
| 611 | </mml:math></inlineequation>,\r | |
| 612 | where \r | |
| 613 | <inlineequation><mml:math>\r | |
| 614 | <!-- eqn: frac(s): -->\r | |
| 615 | <mml:mrow>\r | |
| 616 | <mml:mi mathvariant="italic">frac</mml:mi>\r | |
| 617 | <mml:mo>⁡</mml:mo>\r | |
| 618 | <mml:mfenced open="(" close=")">\r | |
| 619 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
| 620 | </mml:mfenced>\r | |
| 621 | </mml:mrow>\r | |
| 622 | </mml:math></inlineequation>\r | |
| 623 | represents the fractional part of\r | |
| 624 | <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>.\r | |
| 625 | Initially, <constant>GL_TEXTURE_WRAP_S</constant> is set to <constant>GL_REPEAT</constant>.\r | |
| 626 | </para>\r | |
| 627 | </listitem>\r | |
| 628 | </varlistentry>\r | |
| 629 | </variablelist>\r | |
| 630 | <para>\r | |
| 631 | </para>\r | |
| 632 | <variablelist>\r | |
| 633 | <varlistentry>\r | |
| 634 | <term><constant>GL_TEXTURE_WRAP_T</constant></term>\r | |
| 635 | <listitem>\r | |
| 636 | <para>\r | |
| 637 | Sets the wrap parameter for texture coordinate \r | |
| 638 | <inlineequation><mml:math><mml:mi mathvariant="italic">t</mml:mi></mml:math></inlineequation>\r | |
| 639 | to either <constant>GL_CLAMP_TO_EDGE</constant>, <constant>GL_MIRRORED_REPEAT</constant>, or\r | |
| 640 | <constant>GL_REPEAT</constant>. See the discussion under <constant>GL_TEXTURE_WRAP_S</constant>.\r | |
| 641 | Initially, <constant>GL_TEXTURE_WRAP_T</constant> is set to <constant>GL_REPEAT</constant>.\r | |
| 642 | </para>\r | |
| 643 | </listitem>\r | |
| 644 | </varlistentry>\r | |
| 645 | <varlistentry>\r | |
| 646 | <term><constant>GL_TEXTURE_WRAP_R</constant></term>\r | |
| 647 | <listitem>\r | |
| 648 | <para>\r | |
| 649 | Sets the wrap parameter for texture coordinate \r | |
| 650 | <inlineequation><mml:math><mml:mi mathvariant="italic">r</mml:mi></mml:math></inlineequation>\r | |
| 651 | to either <constant>GL_CLAMP_TO_EDGE</constant>, <constant>GL_MIRRORED_REPEAT</constant>, or\r | |
| 652 | <constant>GL_REPEAT</constant>. See the discussion under <constant>GL_TEXTURE_WRAP_S</constant>.\r | |
| 653 | Initially, <constant>GL_TEXTURE_WRAP_R</constant> is set to <constant>GL_REPEAT</constant>.\r | |
| 654 | </para>\r | |
| 655 | </listitem>\r | |
| 656 | </varlistentry>\r | |
| 657 | <varlistentry>\r | |
| 658 | <term><constant>GL_TEXTURE_BORDER_COLOR</constant></term>\r | |
| 659 | <listitem>\r | |
| 660 | <para>\r | |
| 661 | The data in <parameter>params</parameter> specifies four values that define the border values that\r | |
| 662 | should be used for border texels. If a texel is sampled from the border of the texture, the\r | |
| 663 | values of <constant>GL_TEXTURE_BORDER_COLOR</constant> are interpreted as an RGBA color to match the\r | |
| 664 | texture's internal format and substituted for the non-existent texel data. If the texture contains depth\r | |
| 665 | components, the first component of <constant>GL_TEXTURE_BORDER_COLOR</constant> is interpreted as a depth value.\r | |
| 666 | The initial value is\r | |
| 667 | <inlineequation><mml:math>\r | |
| 668 | <mml:mrow>\r | |
| 669 | <mml:mfenced open="(" close=")">\r | |
| 670 | <mml:mrow>\r | |
| 671 | <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>, <mml:mn>0.0</mml:mn>\r | |
| 672 | </mml:mrow>\r | |
| 673 | </mml:mfenced>\r | |
| 674 | </mml:mrow>\r | |
| 675 | </mml:math></inlineequation>.\r | |
| 676 | </para>\r | |
| 677 | </listitem>\r | |
| 678 | </varlistentry>\r | |
| 679 | <varlistentry>\r | |
| 680 | <term><constant>GL_TEXTURE_COMPARE_MODE</constant></term>\r | |
| 681 | <listitem>\r | |
| 682 | <para>\r | |
| 683 | Specifies the texture comparison mode for currently bound textures.\r | |
| 684 | That is, a texture whose internal format is <constant>GL_DEPTH_COMPONENT_*</constant>; see\r | |
| 685 | <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>)\r | |
| 686 | Permissible values are:\r | |
| 687 | <variablelist>\r | |
| 688 | <varlistentry>\r | |
| 689 | <term><constant>GL_COMPARE_REF_TO_TEXTURE</constant></term>\r | |
| 690 | <listitem>\r | |
| 691 | <para>\r | |
| 692 | Specifies that the interpolated and clamped \r | |
| 693 | <inlineequation><mml:math><mml:mi mathvariant="italic">r</mml:mi></mml:math></inlineequation>\r | |
| 694 | texture coordinate should\r | |
| 695 | be compared to the value in the currently bound texture. See the\r | |
| 696 | discussion of <constant>GL_TEXTURE_COMPARE_FUNC</constant> for details of how the comparison\r | |
| 697 | is evaluated. The result of the comparison is assigned to the red channel.\r | |
| 698 | </para>\r | |
| 699 | </listitem>\r | |
| 700 | </varlistentry>\r | |
| 701 | <varlistentry>\r | |
| 702 | <term><constant>GL_NONE</constant></term>\r | |
| 703 | <listitem>\r | |
| 704 | <para>\r | |
| 705 | Specifies that the red channel should be assigned the\r | |
| 706 | appropriate value from the currently bound texture.\r | |
| 707 | </para>\r | |
| 708 | </listitem>\r | |
| 709 | </varlistentry>\r | |
| 710 | </variablelist>\r | |
| 711 | </para>\r | |
| 712 | </listitem>\r | |
| 713 | </varlistentry>\r | |
| 714 | <varlistentry>\r | |
| 715 | <term><constant>GL_TEXTURE_COMPARE_FUNC</constant></term>\r | |
| 716 | <listitem>\r | |
| 717 | <para>\r | |
| 718 | Specifies the comparison operator used when <constant>GL_TEXTURE_COMPARE_MODE</constant> is\r | |
| 719 | set to <constant>GL_COMPARE_REF_TO_TEXTURE</constant>. Permissible values are:\r | |
| 720 | <informaltable frame="topbot">\r | |
| 721 | <tgroup cols="2" align="left">\r | |
| 722 | <colspec/>\r | |
| 723 | <colspec/>\r | |
| 724 | <thead>\r | |
| 725 | <row>\r | |
| 726 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
| 727 | Texture Comparison Function\r | |
| 728 | </emphasis></entry>\r | |
| 729 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
| 730 | Computed result \r | |
| 731 | </emphasis></entry>\r | |
| 732 | </row>\r | |
| 733 | </thead>\r | |
| 734 | <tbody>\r | |
| 735 | <row>\r | |
| 736 | <entry align="left">\r | |
| 737 | <constant>GL_LEQUAL</constant>\r | |
| 738 | </entry>\r | |
| 739 | <entry align="left">\r | |
| 740 | <informalequation><mml:math>\r | |
| 741 | <!-- eqn: result = left { cpile {1.0 above 0.0} lpile {r <= {D sub t} above r > {D sub t}}: -->\r | |
| 742 | <mml:mrow>\r | |
| 743 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 744 | <mml:mo>=</mml:mo>\r | |
| 745 | <mml:mfenced open="{" close="">\r | |
| 746 | <mml:mrow>\r | |
| 747 | <mml:mtable>\r | |
| 748 | <mml:mtr><mml:mtd>\r | |
| 749 | <mml:mn>1.0</mml:mn>\r | |
| 750 | </mml:mtd></mml:mtr>\r | |
| 751 | <mml:mtr><mml:mtd>\r | |
| 752 | <mml:mn>0.0</mml:mn>\r | |
| 753 | </mml:mtd></mml:mtr>\r | |
| 754 | </mml:mtable>\r | |
| 755 | <mml:mo>⁢ </mml:mo>\r | |
| 756 | <mml:mtable>\r | |
| 757 | <mml:mtr><mml:mtd>\r | |
| 758 | <mml:mrow>\r | |
| 759 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 760 | <mml:mo><=</mml:mo>\r | |
| 761 | <mml:mfenced open="" close="">\r | |
| 762 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 763 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 764 | </mml:msub>\r | |
| 765 | </mml:mfenced>\r | |
| 766 | </mml:mrow>\r | |
| 767 | </mml:mtd></mml:mtr>\r | |
| 768 | <mml:mtr><mml:mtd>\r | |
| 769 | <mml:mrow>\r | |
| 770 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 771 | <mml:mo>></mml:mo>\r | |
| 772 | <mml:mfenced open="" close="">\r | |
| 773 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 774 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 775 | </mml:msub>\r | |
| 776 | </mml:mfenced>\r | |
| 777 | </mml:mrow>\r | |
| 778 | </mml:mtd></mml:mtr>\r | |
| 779 | </mml:mtable>\r | |
| 780 | </mml:mrow>\r | |
| 781 | </mml:mfenced>\r | |
| 782 | </mml:mrow>\r | |
| 783 | </mml:math></informalequation>\r | |
| 784 | </entry>\r | |
| 785 | </row>\r | |
| 786 | <row>\r | |
| 787 | <entry align="left">\r | |
| 788 | <constant>GL_GEQUAL</constant>\r | |
| 789 | </entry>\r | |
| 790 | <entry align="left">\r | |
| 791 | <informalequation><mml:math>\r | |
| 792 | <!-- eqn: result = left { cpile {1.0 above 0.0} lpile {r <= {D sub t} above r > {D sub t}}: -->\r | |
| 793 | <mml:mrow>\r | |
| 794 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 795 | <mml:mo>=</mml:mo>\r | |
| 796 | <mml:mfenced open="{" close="">\r | |
| 797 | <mml:mrow>\r | |
| 798 | <mml:mtable>\r | |
| 799 | <mml:mtr><mml:mtd>\r | |
| 800 | <mml:mn>1.0</mml:mn>\r | |
| 801 | </mml:mtd></mml:mtr>\r | |
| 802 | <mml:mtr><mml:mtd>\r | |
| 803 | <mml:mn>0.0</mml:mn>\r | |
| 804 | </mml:mtd></mml:mtr>\r | |
| 805 | </mml:mtable>\r | |
| 806 | <mml:mo>⁢ </mml:mo>\r | |
| 807 | <mml:mtable>\r | |
| 808 | <mml:mtr><mml:mtd>\r | |
| 809 | <mml:mrow>\r | |
| 810 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 811 | <mml:mo>>=</mml:mo>\r | |
| 812 | <mml:mfenced open="" close="">\r | |
| 813 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 814 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 815 | </mml:msub>\r | |
| 816 | </mml:mfenced>\r | |
| 817 | </mml:mrow>\r | |
| 818 | </mml:mtd></mml:mtr>\r | |
| 819 | <mml:mtr><mml:mtd>\r | |
| 820 | <mml:mrow>\r | |
| 821 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 822 | <mml:mo><</mml:mo>\r | |
| 823 | <mml:mfenced open="" close="">\r | |
| 824 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 825 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 826 | </mml:msub>\r | |
| 827 | </mml:mfenced>\r | |
| 828 | </mml:mrow>\r | |
| 829 | </mml:mtd></mml:mtr>\r | |
| 830 | </mml:mtable>\r | |
| 831 | </mml:mrow>\r | |
| 832 | </mml:mfenced>\r | |
| 833 | </mml:mrow>\r | |
| 834 | </mml:math></informalequation>\r | |
| 835 | </entry>\r | |
| 836 | </row>\r | |
| 837 | <row>\r | |
| 838 | <entry align="left">\r | |
| 839 | <constant>GL_LESS</constant>\r | |
| 840 | </entry>\r | |
| 841 | <entry align="left">\r | |
| 842 | <informalequation><mml:math>\r | |
| 843 | <!-- eqn: result = left { cpile {1.0 above 0.0} lpile {r <= {D sub t} above r > {D sub t}}: -->\r | |
| 844 | <mml:mrow>\r | |
| 845 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 846 | <mml:mo>=</mml:mo>\r | |
| 847 | <mml:mfenced open="{" close="">\r | |
| 848 | <mml:mrow>\r | |
| 849 | <mml:mtable>\r | |
| 850 | <mml:mtr><mml:mtd>\r | |
| 851 | <mml:mn>1.0</mml:mn>\r | |
| 852 | </mml:mtd></mml:mtr>\r | |
| 853 | <mml:mtr><mml:mtd>\r | |
| 854 | <mml:mn>0.0</mml:mn>\r | |
| 855 | </mml:mtd></mml:mtr>\r | |
| 856 | </mml:mtable>\r | |
| 857 | <mml:mo>⁢ </mml:mo>\r | |
| 858 | <mml:mtable>\r | |
| 859 | <mml:mtr><mml:mtd>\r | |
| 860 | <mml:mrow>\r | |
| 861 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 862 | <mml:mo><</mml:mo>\r | |
| 863 | <mml:mfenced open="" close="">\r | |
| 864 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 865 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 866 | </mml:msub>\r | |
| 867 | </mml:mfenced>\r | |
| 868 | </mml:mrow>\r | |
| 869 | </mml:mtd></mml:mtr>\r | |
| 870 | <mml:mtr><mml:mtd>\r | |
| 871 | <mml:mrow>\r | |
| 872 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 873 | <mml:mo>>=</mml:mo>\r | |
| 874 | <mml:mfenced open="" close="">\r | |
| 875 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 876 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 877 | </mml:msub>\r | |
| 878 | </mml:mfenced>\r | |
| 879 | </mml:mrow>\r | |
| 880 | </mml:mtd></mml:mtr>\r | |
| 881 | </mml:mtable>\r | |
| 882 | </mml:mrow>\r | |
| 883 | </mml:mfenced>\r | |
| 884 | </mml:mrow>\r | |
| 885 | </mml:math></informalequation>\r | |
| 886 | </entry>\r | |
| 887 | </row>\r | |
| 888 | <row>\r | |
| 889 | <entry align="left">\r | |
| 890 | <constant>GL_GREATER</constant>\r | |
| 891 | </entry>\r | |
| 892 | <entry align="left">\r | |
| 893 | <informalequation><mml:math>\r | |
| 894 | <!-- eqn: result = left { cpile {1.0 above 0.0} lpile {r <= {D sub t} above r > {D sub t}}: -->\r | |
| 895 | <mml:mrow>\r | |
| 896 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 897 | <mml:mo>=</mml:mo>\r | |
| 898 | <mml:mfenced open="{" close="">\r | |
| 899 | <mml:mrow>\r | |
| 900 | <mml:mtable>\r | |
| 901 | <mml:mtr><mml:mtd>\r | |
| 902 | <mml:mn>1.0</mml:mn>\r | |
| 903 | </mml:mtd></mml:mtr>\r | |
| 904 | <mml:mtr><mml:mtd>\r | |
| 905 | <mml:mn>0.0</mml:mn>\r | |
| 906 | </mml:mtd></mml:mtr>\r | |
| 907 | </mml:mtable>\r | |
| 908 | <mml:mo>⁢ </mml:mo>\r | |
| 909 | <mml:mtable>\r | |
| 910 | <mml:mtr><mml:mtd>\r | |
| 911 | <mml:mrow>\r | |
| 912 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 913 | <mml:mo>></mml:mo>\r | |
| 914 | <mml:mfenced open="" close="">\r | |
| 915 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 916 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 917 | </mml:msub>\r | |
| 918 | </mml:mfenced>\r | |
| 919 | </mml:mrow>\r | |
| 920 | </mml:mtd></mml:mtr>\r | |
| 921 | <mml:mtr><mml:mtd>\r | |
| 922 | <mml:mrow>\r | |
| 923 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 924 | <mml:mo><=</mml:mo>\r | |
| 925 | <mml:mfenced open="" close="">\r | |
| 926 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 927 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 928 | </mml:msub>\r | |
| 929 | </mml:mfenced>\r | |
| 930 | </mml:mrow>\r | |
| 931 | </mml:mtd></mml:mtr>\r | |
| 932 | </mml:mtable>\r | |
| 933 | </mml:mrow>\r | |
| 934 | </mml:mfenced>\r | |
| 935 | </mml:mrow>\r | |
| 936 | </mml:math></informalequation>\r | |
| 937 | </entry>\r | |
| 938 | </row>\r | |
| 939 | <row>\r | |
| 940 | <entry align="left">\r | |
| 941 | <constant>GL_EQUAL</constant>\r | |
| 942 | </entry>\r | |
| 943 | <entry align="left">\r | |
| 944 | <informalequation><mml:math>\r | |
| 945 | <!-- eqn: result = left { cpile {1.0 above 0.0} lpile {r <= {D sub t} above r > {D sub t}}: -->\r | |
| 946 | <mml:mrow>\r | |
| 947 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 948 | <mml:mo>=</mml:mo>\r | |
| 949 | <mml:mfenced open="{" close="">\r | |
| 950 | <mml:mrow>\r | |
| 951 | <mml:mtable>\r | |
| 952 | <mml:mtr><mml:mtd>\r | |
| 953 | <mml:mn>1.0</mml:mn>\r | |
| 954 | </mml:mtd></mml:mtr>\r | |
| 955 | <mml:mtr><mml:mtd>\r | |
| 956 | <mml:mn>0.0</mml:mn>\r | |
| 957 | </mml:mtd></mml:mtr>\r | |
| 958 | </mml:mtable>\r | |
| 959 | <mml:mo>⁢ </mml:mo>\r | |
| 960 | <mml:mtable>\r | |
| 961 | <mml:mtr><mml:mtd>\r | |
| 962 | <mml:mrow>\r | |
| 963 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 964 | <mml:mo>=</mml:mo>\r | |
| 965 | <mml:mfenced open="" close="">\r | |
| 966 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 967 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 968 | </mml:msub>\r | |
| 969 | </mml:mfenced>\r | |
| 970 | </mml:mrow>\r | |
| 971 | </mml:mtd></mml:mtr>\r | |
| 972 | <mml:mtr><mml:mtd>\r | |
| 973 | <mml:mrow>\r | |
| 974 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 975 | <mml:mo>≠</mml:mo>\r | |
| 976 | <mml:mfenced open="" close="">\r | |
| 977 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 978 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 979 | </mml:msub>\r | |
| 980 | </mml:mfenced>\r | |
| 981 | </mml:mrow>\r | |
| 982 | </mml:mtd></mml:mtr>\r | |
| 983 | </mml:mtable>\r | |
| 984 | </mml:mrow>\r | |
| 985 | </mml:mfenced>\r | |
| 986 | </mml:mrow>\r | |
| 987 | </mml:math></informalequation>\r | |
| 988 | </entry>\r | |
| 989 | </row>\r | |
| 990 | <row>\r | |
| 991 | <entry align="left">\r | |
| 992 | <constant>GL_NOTEQUAL</constant>\r | |
| 993 | </entry>\r | |
| 994 | <entry align="left">\r | |
| 995 | <informalequation><mml:math>\r | |
| 996 | <!-- eqn: result = left { cpile {1.0 above 0.0} lpile {r <= {D sub t} above r > {D sub t}}: -->\r | |
| 997 | <mml:mrow>\r | |
| 998 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 999 | <mml:mo>=</mml:mo>\r | |
| 1000 | <mml:mfenced open="{" close="">\r | |
| 1001 | <mml:mrow>\r | |
| 1002 | <mml:mtable>\r | |
| 1003 | <mml:mtr><mml:mtd>\r | |
| 1004 | <mml:mn>1.0</mml:mn>\r | |
| 1005 | </mml:mtd></mml:mtr>\r | |
| 1006 | <mml:mtr><mml:mtd>\r | |
| 1007 | <mml:mn>0.0</mml:mn>\r | |
| 1008 | </mml:mtd></mml:mtr>\r | |
| 1009 | </mml:mtable>\r | |
| 1010 | <mml:mo>⁢ </mml:mo>\r | |
| 1011 | <mml:mtable>\r | |
| 1012 | <mml:mtr><mml:mtd>\r | |
| 1013 | <mml:mrow>\r | |
| 1014 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 1015 | <mml:mo>≠</mml:mo>\r | |
| 1016 | <mml:mfenced open="" close="">\r | |
| 1017 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 1018 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 1019 | </mml:msub>\r | |
| 1020 | </mml:mfenced>\r | |
| 1021 | </mml:mrow>\r | |
| 1022 | </mml:mtd></mml:mtr>\r | |
| 1023 | <mml:mtr><mml:mtd>\r | |
| 1024 | <mml:mrow>\r | |
| 1025 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
| 1026 | <mml:mo>=</mml:mo>\r | |
| 1027 | <mml:mfenced open="" close="">\r | |
| 1028 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 1029 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 1030 | </mml:msub>\r | |
| 1031 | </mml:mfenced>\r | |
| 1032 | </mml:mrow>\r | |
| 1033 | </mml:mtd></mml:mtr>\r | |
| 1034 | </mml:mtable>\r | |
| 1035 | </mml:mrow>\r | |
| 1036 | </mml:mfenced>\r | |
| 1037 | </mml:mrow>\r | |
| 1038 | </mml:math></informalequation>\r | |
| 1039 | </entry>\r | |
| 1040 | </row>\r | |
| 1041 | <row>\r | |
| 1042 | <entry align="left">\r | |
| 1043 | <constant>GL_ALWAYS</constant>\r | |
| 1044 | </entry>\r | |
| 1045 | <entry align="left">\r | |
| 1046 | <informalequation>\r | |
| 1047 | <mml:math>\r | |
| 1048 | <mml:mrow>\r | |
| 1049 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 1050 | <mml:mo>=</mml:mo>\r | |
| 1051 | <mml:mi>1.0</mml:mi>\r | |
| 1052 | </mml:mrow>\r | |
| 1053 | </mml:math>\r | |
| 1054 | </informalequation>\r | |
| 1055 | </entry>\r | |
| 1056 | </row>\r | |
| 1057 | <row>\r | |
| 1058 | <entry align="left">\r | |
| 1059 | <constant>GL_NEVER</constant>\r | |
| 1060 | </entry>\r | |
| 1061 | <entry align="left">\r | |
| 1062 | <informalequation>\r | |
| 1063 | <mml:math>\r | |
| 1064 | <mml:mrow>\r | |
| 1065 | <mml:mi mathvariant="italic">result</mml:mi>\r | |
| 1066 | <mml:mo>=</mml:mo>\r | |
| 1067 | <mml:mi>0.0</mml:mi>\r | |
| 1068 | </mml:mrow>\r | |
| 1069 | </mml:math>\r | |
| 1070 | </informalequation>\r | |
| 1071 | </entry>\r | |
| 1072 | </row>\r | |
| 1073 | </tbody>\r | |
| 1074 | </tgroup>\r | |
| 1075 | </informaltable>\r | |
| 1076 | where <inlineequation><mml:math><mml:mi mathvariant="italic">r</mml:mi></mml:math></inlineequation>\r | |
| 1077 | is the current interpolated texture coordinate, and \r | |
| 1078 | <inlineequation><mml:math>\r | |
| 1079 | <!-- eqn: D sub t: -->\r | |
| 1080 | <mml:msub><mml:mi mathvariant="italic">D</mml:mi>\r | |
| 1081 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 1082 | </mml:msub>\r | |
| 1083 | </mml:math></inlineequation>\r | |
| 1084 | is the texture value sampled from the currently bound texture.\r | |
| 1085 | <inlineequation><mml:math><mml:mi mathvariant="italic">result</mml:mi></mml:math></inlineequation>\r | |
| 1086 | is assigned to\r | |
| 1087 | <inlineequation><mml:math>\r | |
| 1088 | <!-- eqn: R sub t: -->\r | |
| 1089 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
| 1090 | <mml:mi mathvariant="italic">t</mml:mi>\r | |
| 1091 | </mml:msub>\r | |
| 1092 | </mml:math></inlineequation>.\r | |
| 1093 | </para>\r | |
| 1094 | </listitem>\r | |
| 1095 | </varlistentry>\r | |
| 1096 | </variablelist>\r | |
| 1097 | </refsect1>\r | |
| 1098 | <refsect1 id="notes"><title>Notes</title>\r | |
| 1099 | <para>\r | |
| 1100 | <function>glSamplerParameter</function> is available only if the GL version is 3.3 or higher.\r | |
| 1101 | </para>\r | |
| 1102 | <para>\r | |
| 1103 | 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\r | |
| 1104 | are used to sample from the texture, rather than the equivalent parameters in the texture object bound to that unit. This\r | |
| 1105 | introduces the possibility of sampling from the same texture object with different sets of sampler state, which may lead to\r | |
| 1106 | a condition where a texture is <emphasis>incomplete</emphasis> with respect to one sampler object and not with respect to\r | |
| 1107 | another. Thus, completeness can be considered a function of a sampler object and a texture object bound to a single\r | |
| 1108 | texture unit, rather than a property of the texture object itself.\r | |
| 1109 | </para>\r | |
| 1110 | </refsect1>\r | |
| 1111 | <refsect1 id="errors"><title>Errors</title>\r | |
| 1112 | <para>\r | |
| 1113 | <constant>GL_INVALID_VALUE</constant> is generated if <parameter>sampler</parameter> is not the name of a sampler object previously\r | |
| 1114 | returned from a call to <citerefentry><refentrytitle>glGenSamplers</refentrytitle></citerefentry>.\r | |
| 1115 | </para>\r | |
| 1116 | <para>\r | |
| 1117 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>params</parameter> should have a defined\r | |
| 1118 | constant value (based on the value of <parameter>pname</parameter>) and does not.\r | |
| 1119 | </para>\r | |
| 1120 | </refsect1>\r | |
| 1121 | <refsect1 id="associatedgets"><title>Associated Gets</title>\r | |
| 1122 | <para>\r | |
| 1123 | <citerefentry><refentrytitle>glGetSamplerParameter</refentrytitle></citerefentry>\r | |
| 1124 | </para>\r | |
| 1125 | </refsect1>\r | |
| 1126 | <refsect1 id="seealso"><title>See Also</title>\r | |
| 1127 | <para>\r | |
| 1128 | <citerefentry><refentrytitle>glGenSamplers</refentrytitle></citerefentry>,\r | |
| 1129 | <citerefentry><refentrytitle>glBindSampler</refentrytitle></citerefentry>,\r | |
| 1130 | <citerefentry><refentrytitle>glDeleteSamplers</refentrytitle></citerefentry>,\r | |
| 1131 | <citerefentry><refentrytitle>glIsSampler</refentrytitle></citerefentry>,\r | |
| 1132 | <citerefentry><refentrytitle>glBindTexture</refentrytitle></citerefentry>,\r | |
| 1133 | <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>\r | |
| 1134 | </para>\r | |
| 1135 | </refsect1>\r | |
| 1136 | <refsect1 id="Copyright"><title>Copyright</title>\r | |
| 1137 | <para>\r | |
| 1138 | Copyright <trademark class="copyright"></trademark> 2010 Khronos Group. \r | |
| 1139 | This material may be distributed subject to the terms and conditions set forth in \r | |
| 1140 | the Open Publication License, v 1.0, 8 June 1999.\r | |
| 1141 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r | |
| 1142 | </para>\r | |
| 1143 | </refsect1>\r | |
| 1144 | </refentry>\r |