src/mesa/main/macros.h

   1 /**
   2  * \file macros.h
   3  * A collection of useful macros.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  * Version:  6.5.2
   9  *
  10  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  27  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28  */
  29
  30
  31 #ifndef MACROS_H
  32 #define MACROS_H
  33
  34 #include "imports.h"
  35
  36
  37 /**
  38  * \name Integer / float conversion for colors, normals, etc.
  39  */
  40 /*@{*/
  41
  42 /** Convert GLubyte in [0,255] to GLfloat in [0.0,1.0] */
  43 extern GLfloat _mesa_ubyte_to_float_color_tab[256];
  44 #define UBYTE_TO_FLOAT(u) _mesa_ubyte_to_float_color_tab[(unsigned int)(u)]
  45
  46 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
  47 #define FLOAT_TO_UBYTE(X)   ((GLubyte) (GLint) ((X) * 255.0F))
  48
  49
  50 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
  51 #define BYTE_TO_FLOAT(B)    ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
  52
  53 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
  54 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
  55
  56
  57 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
  58 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
  59
  60 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
  61 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0))
  62
  63 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
  64 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
  65
  66 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767] */
  67 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
  68
  69
  70 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
  71 #define UINT_TO_FLOAT(U)    ((GLfloat) (U) * (1.0F / 4294967295.0F))
  72
  73 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
  74 #define FLOAT_TO_UINT(X)    ((GLuint) ((X) * 4294967295.0))
  75
  76
  77 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
  78 #define INT_TO_FLOAT(I)     ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0F))
  79
  80 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
  81 /* causes overflow:
  82 #define FLOAT_TO_INT(X)     ( (((GLint) (4294967294.0F * (X))) - 1) / 2 )
  83 */
  84 /* a close approximation: */
  85 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
  86
  87
  88 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
  89 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
  90 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))
  91 #define INT_TO_UBYTE(i)    ((GLubyte) ((i) < 0 ? 0 : (GLubyte) ((i) >> 23)))
  92 #define UINT_TO_UBYTE(i)   ((GLubyte) ((i) >> 24))
  93
  94
  95 #define BYTE_TO_USHORT(b)  ((b) < 0 ? 0 : ((GLushort) (((b) * 65535) / 255)))
  96 #define UBYTE_TO_USHORT(b) (((GLushort) (b) << 8) | (GLushort) (b))
  97 #define SHORT_TO_USHORT(s) ((s) < 0 ? 0 : ((GLushort) (((s) * 65535 / 32767))))
  98 #define INT_TO_USHORT(i)   ((i) < 0 ? 0 : ((GLushort) ((i) >> 15)))
  99 #define UINT_TO_USHORT(i)  ((i) < 0 ? 0 : ((GLushort) ((i) >> 16)))
 100 #define UNCLAMPED_FLOAT_TO_USHORT(us, f)  \
 101         us = ( (GLushort) IROUND( CLAMP((f), 0.0, 1.0) * 65535.0F) )
 102 #define CLAMPED_FLOAT_TO_USHORT(us, f)  \
 103         us = ( (GLushort) IROUND( (f) * 65535.0F) )
 104
 105 /*@}*/
 106
 107
 108 /** Stepping a GLfloat pointer by a byte stride */
 109 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
 110 /** Stepping a GLuint pointer by a byte stride */
 111 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
 112 /** Stepping a GLubyte[4] pointer by a byte stride */
 113 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
 114 /** Stepping a GLfloat[4] pointer by a byte stride */
 115 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
 116 /** Stepping a GLchan[4] pointer by a byte stride */
 117 #define STRIDE_4CHAN(p, i)  (p = (GLchan (*)[4])((GLubyte *)p + i))
 118 /** Stepping a GLchan pointer by a byte stride */
 119 #define STRIDE_CHAN(p, i)  (p = (GLchan *)((GLubyte *)p + i))
 120 /** Stepping a \p t pointer by a byte stride */
 121 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
 122
 123
 124 /**********************************************************************/
 125 /** \name 4-element vector operations */
 126 /*@{*/
 127
 128 /** Zero */
 129 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
 130
 131 /** Test for equality */
 132 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
 133               (a)[1] == (b)[1] &&   \
 134               (a)[2] == (b)[2] &&   \
 135               (a)[3] == (b)[3])
 136
 137 /** Test for equality (unsigned bytes) */
 138 #if defined(__i386__)
 139 #define TEST_EQ_4UBV(DST, SRC) *((GLuint*)(DST)) == *((GLuint*)(SRC))
 140 #else
 141 #define TEST_EQ_4UBV(DST, SRC) TEST_EQ_4V(DST, SRC)
 142 #endif
 143
 144 /** Copy a 4-element vector */
 145 #define COPY_4V( DST, SRC )         \
 146 do {                                \
 147    (DST)[0] = (SRC)[0];             \
 148    (DST)[1] = (SRC)[1];             \
 149    (DST)[2] = (SRC)[2];             \
 150    (DST)[3] = (SRC)[3];             \
 151 } while (0)
 152
 153 /** Copy a 4-element vector with cast */
 154 #define COPY_4V_CAST( DST, SRC, CAST )  \
 155 do {                                    \
 156    (DST)[0] = (CAST)(SRC)[0];           \
 157    (DST)[1] = (CAST)(SRC)[1];           \
 158    (DST)[2] = (CAST)(SRC)[2];           \
 159    (DST)[3] = (CAST)(SRC)[3];           \
 160 } while (0)
 161
 162 /** Copy a 4-element unsigned byte vector */
 163 #if defined(__i386__)
 164 #define COPY_4UBV(DST, SRC)                 \
 165 do {                                        \
 166    *((GLuint*)(DST)) = *((GLuint*)(SRC));   \
 167 } while (0)
 168 #else
 169 /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
 170 #define COPY_4UBV(DST, SRC)         \
 171 do {                                \
 172    (DST)[0] = (SRC)[0];             \
 173    (DST)[1] = (SRC)[1];             \
 174    (DST)[2] = (SRC)[2];             \
 175    (DST)[3] = (SRC)[3];             \
 176 } while (0)
 177 #endif
 178
 179 /**
 180  * Copy a 4-element float vector (avoid using FPU registers)
 181  * XXX Could use two 64-bit moves on 64-bit systems
 182  */
 183 #define COPY_4FV( DST, SRC )                  \
 184 do {                                          \
 185    const GLuint *_s = (const GLuint *) (SRC); \
 186    GLuint *_d = (GLuint *) (DST);             \
 187    _d[0] = _s[0];                             \
 188    _d[1] = _s[1];                             \
 189    _d[2] = _s[2];                             \
 190    _d[3] = _s[3];                             \
 191 } while (0)
 192
 193 /** Copy \p SZ elements into a 4-element vector */
 194 #define COPY_SZ_4V(DST, SZ, SRC)  \
 195 do {                              \
 196    switch (SZ) {                  \
 197    case 4: (DST)[3] = (SRC)[3];   \
 198    case 3: (DST)[2] = (SRC)[2];   \
 199    case 2: (DST)[1] = (SRC)[1];   \
 200    case 1: (DST)[0] = (SRC)[0];   \
 201    }                              \
 202 } while(0)
 203
 204 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
 205  * default values to the remaining */
 206 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
 207 do {                                 \
 208       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
 209       COPY_SZ_4V( DST, SZ, SRC );    \
 210 } while (0)
 211
 212 /** Subtraction */
 213 #define SUB_4V( DST, SRCA, SRCB )           \
 214 do {                                        \
 215       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 216       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 217       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
 218       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
 219 } while (0)
 220
 221 /** Addition */
 222 #define ADD_4V( DST, SRCA, SRCB )           \
 223 do {                                        \
 224       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 225       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 226       (DST)[2] = (SRCA)[2] + (SRCB)[2];     \
 227       (DST)[3] = (SRCA)[3] + (SRCB)[3];     \
 228 } while (0)
 229
 230 /** Element-wise multiplication */
 231 #define SCALE_4V( DST, SRCA, SRCB )         \
 232 do {                                        \
 233       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 234       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 235       (DST)[2] = (SRCA)[2] * (SRCB)[2];     \
 236       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
 237 } while (0)
 238
 239 /** In-place addition */
 240 #define ACC_4V( DST, SRC )          \
 241 do {                                \
 242       (DST)[0] += (SRC)[0];         \
 243       (DST)[1] += (SRC)[1];         \
 244       (DST)[2] += (SRC)[2];         \
 245       (DST)[3] += (SRC)[3];         \
 246 } while (0)
 247
 248 /** Element-wise multiplication and addition */
 249 #define ACC_SCALE_4V( DST, SRCA, SRCB )     \
 250 do {                                        \
 251       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 252       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 253       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 254       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
 255 } while (0)
 256
 257 /** In-place scalar multiplication and addition */
 258 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
 259 do {                                        \
 260       (DST)[0] += S * (SRCB)[0];            \
 261       (DST)[1] += S * (SRCB)[1];            \
 262       (DST)[2] += S * (SRCB)[2];            \
 263       (DST)[3] += S * (SRCB)[3];            \
 264 } while (0)
 265
 266 /** Scalar multiplication */
 267 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
 268 do {                                    \
 269       (DST)[0] = S * (SRCB)[0];         \
 270       (DST)[1] = S * (SRCB)[1];         \
 271       (DST)[2] = S * (SRCB)[2];         \
 272       (DST)[3] = S * (SRCB)[3];         \
 273 } while (0)
 274
 275 /** In-place scalar multiplication */
 276 #define SELF_SCALE_SCALAR_4V( DST, S ) \
 277 do {                                   \
 278       (DST)[0] *= S;                   \
 279       (DST)[1] *= S;                   \
 280       (DST)[2] *= S;                   \
 281       (DST)[3] *= S;                   \
 282 } while (0)
 283
 284 /** Assignment */
 285 #define ASSIGN_4V( V, V0, V1, V2, V3 )  \
 286 do {                                    \
 287     V[0] = V0;                          \
 288     V[1] = V1;                          \
 289     V[2] = V2;                          \
 290     V[3] = V3;                          \
 291 } while(0)
 292
 293 /*@}*/
 294
 295
 296 /**********************************************************************/
 297 /** \name 3-element vector operations*/
 298 /*@{*/
 299
 300 /** Zero */
 301 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
 302
 303 /** Test for equality */
 304 #define TEST_EQ_3V(a,b)  \
 305    ((a)[0] == (b)[0] &&  \
 306     (a)[1] == (b)[1] &&  \
 307     (a)[2] == (b)[2])
 308
 309 /** Copy a 3-element vector */
 310 #define COPY_3V( DST, SRC )         \
 311 do {                                \
 312    (DST)[0] = (SRC)[0];             \
 313    (DST)[1] = (SRC)[1];             \
 314    (DST)[2] = (SRC)[2];             \
 315 } while (0)
 316
 317 /** Copy a 3-element vector with cast */
 318 #define COPY_3V_CAST( DST, SRC, CAST )  \
 319 do {                                    \
 320    (DST)[0] = (CAST)(SRC)[0];           \
 321    (DST)[1] = (CAST)(SRC)[1];           \
 322    (DST)[2] = (CAST)(SRC)[2];           \
 323 } while (0)
 324
 325 /** Copy a 3-element float vector */
 326 #define COPY_3FV( DST, SRC )        \
 327 do {                                \
 328    const GLfloat *_tmp = (SRC);     \
 329    (DST)[0] = _tmp[0];              \
 330    (DST)[1] = _tmp[1];              \
 331    (DST)[2] = _tmp[2];              \
 332 } while (0)
 333
 334 /** Subtraction */
 335 #define SUB_3V( DST, SRCA, SRCB )        \
 336 do {                                     \
 337       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
 338       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
 339       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
 340 } while (0)
 341
 342 /** Addition */
 343 #define ADD_3V( DST, SRCA, SRCB )       \
 344 do {                                    \
 345       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
 346       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
 347       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
 348 } while (0)
 349
 350 /** In-place scalar multiplication */
 351 #define SCALE_3V( DST, SRCA, SRCB )     \
 352 do {                                    \
 353       (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
 354       (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
 355       (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
 356 } while (0)
 357
 358 /** In-place element-wise multiplication */
 359 #define SELF_SCALE_3V( DST, SRC )   \
 360 do {                                \
 361       (DST)[0] *= (SRC)[0];         \
 362       (DST)[1] *= (SRC)[1];         \
 363       (DST)[2] *= (SRC)[2];         \
 364 } while (0)
 365
 366 /** In-place addition */
 367 #define ACC_3V( DST, SRC )          \
 368 do {                                \
 369       (DST)[0] += (SRC)[0];         \
 370       (DST)[1] += (SRC)[1];         \
 371       (DST)[2] += (SRC)[2];         \
 372 } while (0)
 373
 374 /** Element-wise multiplication and addition */
 375 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
 376 do {                                        \
 377       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 378       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 379       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 380 } while (0)
 381
 382 /** Scalar multiplication */
 383 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
 384 do {                                    \
 385       (DST)[0] = S * (SRCB)[0];         \
 386       (DST)[1] = S * (SRCB)[1];         \
 387       (DST)[2] = S * (SRCB)[2];         \
 388 } while (0)
 389
 390 /** In-place scalar multiplication and addition */
 391 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
 392 do {                                        \
 393       (DST)[0] += S * (SRCB)[0];            \
 394       (DST)[1] += S * (SRCB)[1];            \
 395       (DST)[2] += S * (SRCB)[2];            \
 396 } while (0)
 397
 398 /** In-place scalar multiplication */
 399 #define SELF_SCALE_SCALAR_3V( DST, S ) \
 400 do {                                   \
 401       (DST)[0] *= S;                   \
 402       (DST)[1] *= S;                   \
 403       (DST)[2] *= S;                   \
 404 } while (0)
 405
 406 /** In-place scalar addition */
 407 #define ACC_SCALAR_3V( DST, S )     \
 408 do {                                \
 409       (DST)[0] += S;                \
 410       (DST)[1] += S;                \
 411       (DST)[2] += S;                \
 412 } while (0)
 413
 414 /** Assignment */
 415 #define ASSIGN_3V( V, V0, V1, V2 )  \
 416 do {                                \
 417     V[0] = V0;                      \
 418     V[1] = V1;                      \
 419     V[2] = V2;                      \
 420 } while(0)
 421
 422 /*@}*/
 423
 424
 425 /**********************************************************************/
 426 /** \name 2-element vector operations*/
 427 /*@{*/
 428
 429 /** Zero */
 430 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
 431
 432 /** Copy a 2-element vector */
 433 #define COPY_2V( DST, SRC )         \
 434 do {                        \
 435    (DST)[0] = (SRC)[0];             \
 436    (DST)[1] = (SRC)[1];             \
 437 } while (0)
 438
 439 /** Copy a 2-element vector with cast */
 440 #define COPY_2V_CAST( DST, SRC, CAST )      \
 441 do {                        \
 442    (DST)[0] = (CAST)(SRC)[0];           \
 443    (DST)[1] = (CAST)(SRC)[1];           \
 444 } while (0)
 445
 446 /** Copy a 2-element float vector */
 447 #define COPY_2FV( DST, SRC )            \
 448 do {                        \
 449    const GLfloat *_tmp = (SRC);         \
 450    (DST)[0] = _tmp[0];              \
 451    (DST)[1] = _tmp[1];              \
 452 } while (0)
 453
 454 /** Subtraction */
 455 #define SUB_2V( DST, SRCA, SRCB )       \
 456 do {                        \
 457       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 458       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 459 } while (0)
 460
 461 /** Addition */
 462 #define ADD_2V( DST, SRCA, SRCB )       \
 463 do {                        \
 464       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 465       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 466 } while (0)
 467
 468 /** In-place scalar multiplication */
 469 #define SCALE_2V( DST, SRCA, SRCB )     \
 470 do {                        \
 471       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 472       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 473 } while (0)
 474
 475 /** In-place addition */
 476 #define ACC_2V( DST, SRC )          \
 477 do {                        \
 478       (DST)[0] += (SRC)[0];         \
 479       (DST)[1] += (SRC)[1];         \
 480 } while (0)
 481
 482 /** Element-wise multiplication and addition */
 483 #define ACC_SCALE_2V( DST, SRCA, SRCB )     \
 484 do {                        \
 485       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 486       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 487 } while (0)
 488
 489 /** Scalar multiplication */
 490 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
 491 do {                        \
 492       (DST)[0] = S * (SRCB)[0];         \
 493       (DST)[1] = S * (SRCB)[1];         \
 494 } while (0)
 495
 496 /** In-place scalar multiplication and addition */
 497 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
 498 do {                        \
 499       (DST)[0] += S * (SRCB)[0];        \
 500       (DST)[1] += S * (SRCB)[1];        \
 501 } while (0)
 502
 503 /** In-place scalar multiplication */
 504 #define SELF_SCALE_SCALAR_2V( DST, S )      \
 505 do {                        \
 506       (DST)[0] *= S;                \
 507       (DST)[1] *= S;                \
 508 } while (0)
 509
 510 /** In-place scalar addition */
 511 #define ACC_SCALAR_2V( DST, S )         \
 512 do {                        \
 513       (DST)[0] += S;                \
 514       (DST)[1] += S;                \
 515 } while (0)
 516
 517 /** Assign scalers to short vectors */
 518 #define ASSIGN_2V( V, V0, V1 )  \
 519 do {                            \
 520     V[0] = V0;                  \
 521     V[1] = V1;                  \
 522 } while(0)
 523
 524 /*@}*/
 525
 526
 527 /** \name Linear interpolation macros */
 528 /*@{*/
 529
 530 /**
 531  * Linear interpolation
 532  *
 533  * \note \p OUT argument is evaluated twice!
 534  * \note Be wary of using *coord++ as an argument to any of these macros!
 535  */
 536 #define LINTERP(T, OUT, IN) ((OUT) + (T) * ((IN) - (OUT)))
 537
 538 /* Can do better with integer math
 539  */
 540 #define INTERP_UB( t, dstub, outub, inub )  \
 541 do {                        \
 542    GLfloat inf = UBYTE_TO_FLOAT( inub );    \
 543    GLfloat outf = UBYTE_TO_FLOAT( outub );  \
 544    GLfloat dstf = LINTERP( t, outf, inf );  \
 545    UNCLAMPED_FLOAT_TO_UBYTE( dstub, dstf ); \
 546 } while (0)
 547
 548 #define INTERP_CHAN( t, dstc, outc, inc )   \
 549 do {                        \
 550    GLfloat inf = CHAN_TO_FLOAT( inc );      \
 551    GLfloat outf = CHAN_TO_FLOAT( outc );    \
 552    GLfloat dstf = LINTERP( t, outf, inf );  \
 553    UNCLAMPED_FLOAT_TO_CHAN( dstc, dstf );   \
 554 } while (0)
 555
 556 #define INTERP_UI( t, dstui, outui, inui )  \
 557    dstui = (GLuint) (GLint) LINTERP( (t), (GLfloat) (outui), (GLfloat) (inui) )
 558
 559 #define INTERP_F( t, dstf, outf, inf )      \
 560    dstf = LINTERP( t, outf, inf )
 561
 562 #define INTERP_4F( t, dst, out, in )        \
 563 do {                        \
 564    dst[0] = LINTERP( (t), (out)[0], (in)[0] );  \
 565    dst[1] = LINTERP( (t), (out)[1], (in)[1] );  \
 566    dst[2] = LINTERP( (t), (out)[2], (in)[2] );  \
 567    dst[3] = LINTERP( (t), (out)[3], (in)[3] );  \
 568 } while (0)
 569
 570 #define INTERP_3F( t, dst, out, in )        \
 571 do {                        \
 572    dst[0] = LINTERP( (t), (out)[0], (in)[0] );  \
 573    dst[1] = LINTERP( (t), (out)[1], (in)[1] );  \
 574    dst[2] = LINTERP( (t), (out)[2], (in)[2] );  \
 575 } while (0)
 576
 577 #define INTERP_4CHAN( t, dst, out, in )         \
 578 do {                            \
 579    INTERP_CHAN( (t), (dst)[0], (out)[0], (in)[0] ); \
 580    INTERP_CHAN( (t), (dst)[1], (out)[1], (in)[1] ); \
 581    INTERP_CHAN( (t), (dst)[2], (out)[2], (in)[2] ); \
 582    INTERP_CHAN( (t), (dst)[3], (out)[3], (in)[3] ); \
 583 } while (0)
 584
 585 #define INTERP_3CHAN( t, dst, out, in )         \
 586 do {                            \
 587    INTERP_CHAN( (t), (dst)[0], (out)[0], (in)[0] ); \
 588    INTERP_CHAN( (t), (dst)[1], (out)[1], (in)[1] ); \
 589    INTERP_CHAN( (t), (dst)[2], (out)[2], (in)[2] ); \
 590 } while (0)
 591
 592 #define INTERP_SZ( t, vec, to, out, in, sz )                \
 593 do {                                    \
 594    switch (sz) {                            \
 595    case 4: vec[to][3] = LINTERP( (t), (vec)[out][3], (vec)[in][3] );    \
 596    case 3: vec[to][2] = LINTERP( (t), (vec)[out][2], (vec)[in][2] );    \
 597    case 2: vec[to][1] = LINTERP( (t), (vec)[out][1], (vec)[in][1] );    \
 598    case 1: vec[to][0] = LINTERP( (t), (vec)[out][0], (vec)[in][0] );    \
 599    }                                    \
 600 } while(0)
 601
 602 /*@}*/
 603
 604
 605
 606 /** Clamp X to [MIN,MAX] */
 607 #define CLAMP( X, MIN, MAX )  ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
 608
 609 /** Assign X to CLAMP(X, MIN, MAX) */
 610 #define CLAMP_SELF(x, mn, mx)  \
 611    ( (x)<(mn) ? ((x) = (mn)) : ((x)>(mx) ? ((x)=(mx)) : (x)) )
 612
 613
 614
 615 /** Minimum of two values: */
 616 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
 617
 618 /** Maximum of two values: */
 619 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
 620
 621 /** Dot product of two 2-element vectors */
 622 #define DOT2( a, b )  ( (a)[0]*(b)[0] + (a)[1]*(b)[1] )
 623
 624 /** Dot product of two 3-element vectors */
 625 #define DOT3( a, b )  ( (a)[0]*(b)[0] + (a)[1]*(b)[1] + (a)[2]*(b)[2] )
 626
 627 /** Dot product of two 4-element vectors */
 628 #define DOT4( a, b )  ( (a)[0]*(b)[0] + (a)[1]*(b)[1] + \
 629             (a)[2]*(b)[2] + (a)[3]*(b)[3] )
 630
 631 /** Dot product of two 4-element vectors */
 632 #define DOT4V(v,a,b,c,d) (v[0]*(a) + v[1]*(b) + v[2]*(c) + v[3]*(d))
 633
 634
 635 /** Cross product of two 3-element vectors */
 636 #define CROSS3(n, u, v)             \
 637 do {                        \
 638    (n)[0] = (u)[1]*(v)[2] - (u)[2]*(v)[1];  \
 639    (n)[1] = (u)[2]*(v)[0] - (u)[0]*(v)[2];  \
 640    (n)[2] = (u)[0]*(v)[1] - (u)[1]*(v)[0];  \
 641 } while (0)
 642
 643
 644 /* Normalize a 3-element vector to unit length. */
 645 #define NORMALIZE_3FV( V )          \
 646 do {                        \
 647    GLfloat len = (GLfloat) LEN_SQUARED_3FV(V);  \
 648    if (len) {                   \
 649       len = INV_SQRTF(len);         \
 650       (V)[0] = (GLfloat) ((V)[0] * len);    \
 651       (V)[1] = (GLfloat) ((V)[1] * len);    \
 652       (V)[2] = (GLfloat) ((V)[2] * len);    \
 653    }                        \
 654 } while(0)
 655
 656 #define LEN_3FV( V ) (SQRTF((V)[0]*(V)[0]+(V)[1]*(V)[1]+(V)[2]*(V)[2]))
 657 #define LEN_2FV( V ) (SQRTF((V)[0]*(V)[0]+(V)[1]*(V)[1]))
 658
 659 #define LEN_SQUARED_3FV( V ) ((V)[0]*(V)[0]+(V)[1]*(V)[1]+(V)[2]*(V)[2])
 660 #define LEN_SQUARED_2FV( V ) ((V)[0]*(V)[0]+(V)[1]*(V)[1])
 661
 662
 663 /** casts to silence warnings with some compilers */
 664 #define ENUM_TO_INT(E)     ((GLint)(E))
 665 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
 666 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
 667 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
 668
 669
 670 #endif