main/macros.h

   1 /**
   2  * \file macros.h
   3  * A collection of useful macros.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  *
   9  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a
  12  * copy of this software and associated documentation files (the "Software"),
  13  * to deal in the Software without restriction, including without limitation
  14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  15  * and/or sell copies of the Software, and to permit persons to whom the
  16  * Software is furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included
  19  * in all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  22  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  24  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  25  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  26  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  27  * 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 GLbyte to GLfloat while preserving zero */
  58 #define BYTE_TO_FLOATZ(B)   ((B) == 0 ? 0.0F : BYTE_TO_FLOAT(B))
  59
  60
  61 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0], texture/fb data */
  62 #define BYTE_TO_FLOAT_TEX(B)    ((B) == -128 ? -1.0F : (B) * (1.0F/127.0F))
  63
  64 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127], texture/fb data */
  65 #define FLOAT_TO_BYTE_TEX(X)    CLAMP( (GLint) (127.0F * (X)), -128, 127 )
  66
  67 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
  68 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
  69
  70 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
  71 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0F))
  72
  73
  74 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
  75 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
  76
  77 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767] */
  78 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
  79
  80 /** Convert GLshort to GLfloat while preserving zero */
  81 #define SHORT_TO_FLOATZ(S)   ((S) == 0 ? 0.0F : SHORT_TO_FLOAT(S))
  82
  83
  84 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0], texture/fb data */
  85 #define SHORT_TO_FLOAT_TEX(S)    ((S) == -32768 ? -1.0F : (S) * (1.0F/32767.0F))
  86
  87 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767], texture/fb data */
  88 #define FLOAT_TO_SHORT_TEX(X)    ( (GLint) (32767.0F * (X)) )
  89
  90
  91 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
  92 #define UINT_TO_FLOAT(U)    ((GLfloat) ((U) * (1.0F / 4294967295.0)))
  93
  94 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
  95 #define FLOAT_TO_UINT(X)    ((GLuint) ((X) * 4294967295.0))
  96
  97
  98 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
  99 #define INT_TO_FLOAT(I)     ((GLfloat) ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0)))
 100
 101 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
 102 /* causes overflow:
 103 #define FLOAT_TO_INT(X)     ( (((GLint) (4294967294.0 * (X))) - 1) / 2 )
 104 */
 105 /* a close approximation: */
 106 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
 107
 108 /** Convert GLfloat in [-1.0,1.0] to GLint64 in [-(1<<63),(1 << 63) -1] */
 109 #define FLOAT_TO_INT64(X)     ( (GLint64) (9223372036854775807.0 * (double)(X)) )
 110
 111
 112 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0], texture/fb data */
 113 #define INT_TO_FLOAT_TEX(I)    ((I) == -2147483648 ? -1.0F : (I) * (1.0F/2147483647.0))
 114
 115 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647], texture/fb data */
 116 #define FLOAT_TO_INT_TEX(X)    ( (GLint) (2147483647.0 * (X)) )
 117
 118
 119 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
 120 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
 121 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))
 122 #define INT_TO_UBYTE(i)    ((GLubyte) ((i) < 0 ? 0 : (GLubyte) ((i) >> 23)))
 123 #define UINT_TO_UBYTE(i)   ((GLubyte) ((i) >> 24))
 124
 125
 126 #define BYTE_TO_USHORT(b)  ((b) < 0 ? 0 : ((GLushort) (((b) * 65535) / 255)))
 127 #define UBYTE_TO_USHORT(b) (((GLushort) (b) << 8) | (GLushort) (b))
 128 #define SHORT_TO_USHORT(s) ((s) < 0 ? 0 : ((GLushort) (((s) * 65535 / 32767))))
 129 #define INT_TO_USHORT(i)   ((i) < 0 ? 0 : ((GLushort) ((i) >> 15)))
 130 #define UINT_TO_USHORT(i)  ((i) < 0 ? 0 : ((GLushort) ((i) >> 16)))
 131 #define UNCLAMPED_FLOAT_TO_USHORT(us, f)  \
 132         us = ( (GLushort) F_TO_I( CLAMP((f), 0.0F, 1.0F) * 65535.0F) )
 133 #define CLAMPED_FLOAT_TO_USHORT(us, f)  \
 134         us = ( (GLushort) F_TO_I( (f) * 65535.0F) )
 135
 136 #define UNCLAMPED_FLOAT_TO_SHORT(s, f)  \
 137         s = ( (GLshort) F_TO_I( CLAMP((f), -1.0F, 1.0F) * 32767.0F) )
 138
 139 /***
 140  *** UNCLAMPED_FLOAT_TO_UBYTE: clamp float to [0,1] and map to ubyte in [0,255]
 141  *** CLAMPED_FLOAT_TO_UBYTE: map float known to be in [0,1] to ubyte in [0,255]
 142  ***/
 143 #ifndef DEBUG
 144 /* This function/macro is sensitive to precision.  Test very carefully
 145  * if you change it!
 146  */
 147 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, FLT)                               \
 148         do {                                                            \
 149            fi_type __tmp;                                               \
 150            __tmp.f = (FLT);                                             \
 151            if (__tmp.i < 0)                                             \
 152               UB = (GLubyte) 0;                                         \
 153            else if (__tmp.i >= IEEE_ONE)                                \
 154               UB = (GLubyte) 255;                                       \
 155            else {                                                       \
 156               __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F;           \
 157               UB = (GLubyte) __tmp.i;                                   \
 158            }                                                            \
 159         } while (0)
 160 #define CLAMPED_FLOAT_TO_UBYTE(UB, FLT)                                 \
 161         do {                                                            \
 162            fi_type __tmp;                                               \
 163            __tmp.f = (FLT) * (255.0F/256.0F) + 32768.0F;                \
 164            UB = (GLubyte) __tmp.i;                                      \
 165         } while (0)
 166 #else
 167 #define UNCLAMPED_FLOAT_TO_UBYTE(ub, f) \
 168         ub = ((GLubyte) F_TO_I(CLAMP((f), 0.0F, 1.0F) * 255.0F))
 169 #define CLAMPED_FLOAT_TO_UBYTE(ub, f) \
 170         ub = ((GLubyte) F_TO_I((f) * 255.0F))
 171 #endif
 172
 173 static inline GLfloat INT_AS_FLT(GLint i)
 174 {
 175    fi_type tmp;
 176    tmp.i = i;
 177    return tmp.f;
 178 }
 179
 180 static inline GLfloat UINT_AS_FLT(GLuint u)
 181 {
 182    fi_type tmp;
 183    tmp.u = u;
 184    return tmp.f;
 185 }
 186
 187 static inline unsigned FLT_AS_UINT(float f)
 188 {
 189    fi_type tmp;
 190    tmp.f = f;
 191    return tmp.u;
 192 }
 193
 194 /**
 195  * Convert a floating point value to an unsigned fixed point value.
 196  *
 197  * \param frac_bits   The number of bits used to store the fractional part.
 198  */
 199 static inline uint32_t
 200 U_FIXED(float value, uint32_t frac_bits)
 201 {
 202    value *= (1 << frac_bits);
 203    return value < 0.0f ? 0 : (uint32_t) value;
 204 }
 205
 206 /**
 207  * Convert a floating point value to an signed fixed point value.
 208  *
 209  * \param frac_bits   The number of bits used to store the fractional part.
 210  */
 211 static inline int32_t
 212 S_FIXED(float value, uint32_t frac_bits)
 213 {
 214    return (int32_t) (value * (1 << frac_bits));
 215 }
 216 /*@}*/
 217
 218
 219 /** Stepping a GLfloat pointer by a byte stride */
 220 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
 221 /** Stepping a GLuint pointer by a byte stride */
 222 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
 223 /** Stepping a GLubyte[4] pointer by a byte stride */
 224 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
 225 /** Stepping a GLfloat[4] pointer by a byte stride */
 226 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
 227 /** Stepping a \p t pointer by a byte stride */
 228 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
 229
 230
 231 /**********************************************************************/
 232 /** \name 4-element vector operations */
 233 /*@{*/
 234
 235 /** Zero */
 236 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
 237
 238 /** Test for equality */
 239 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
 240               (a)[1] == (b)[1] &&   \
 241               (a)[2] == (b)[2] &&   \
 242               (a)[3] == (b)[3])
 243
 244 /** Test for equality (unsigned bytes) */
 245 static inline GLboolean
 246 TEST_EQ_4UBV(const GLubyte a[4], const GLubyte b[4])
 247 {
 248 #if defined(__i386__)
 249    return *((const GLuint *) a) == *((const GLuint *) b);
 250 #else
 251    return TEST_EQ_4V(a, b);
 252 #endif
 253 }
 254
 255
 256 /** Copy a 4-element vector */
 257 #define COPY_4V( DST, SRC )         \
 258 do {                                \
 259    (DST)[0] = (SRC)[0];             \
 260    (DST)[1] = (SRC)[1];             \
 261    (DST)[2] = (SRC)[2];             \
 262    (DST)[3] = (SRC)[3];             \
 263 } while (0)
 264
 265 /** Copy a 4-element unsigned byte vector */
 266 static inline void
 267 COPY_4UBV(GLubyte dst[4], const GLubyte src[4])
 268 {
 269 #if defined(__i386__)
 270    *((GLuint *) dst) = *((GLuint *) src);
 271 #else
 272    /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
 273    COPY_4V(dst, src);
 274 #endif
 275 }
 276
 277 /** Copy a 4-element float vector */
 278 static inline void
 279 COPY_4FV(GLfloat dst[4], const GLfloat src[4])
 280 {
 281    /* memcpy seems to be most efficient */
 282    memcpy(dst, src, sizeof(GLfloat) * 4);
 283 }
 284
 285 /** Copy \p SZ elements into a 4-element vector */
 286 #define COPY_SZ_4V(DST, SZ, SRC)  \
 287 do {                              \
 288    switch (SZ) {                  \
 289    case 4: (DST)[3] = (SRC)[3];   \
 290    case 3: (DST)[2] = (SRC)[2];   \
 291    case 2: (DST)[1] = (SRC)[1];   \
 292    case 1: (DST)[0] = (SRC)[0];   \
 293    }                              \
 294 } while(0)
 295
 296 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
 297  * default values to the remaining */
 298 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
 299 do {                                 \
 300       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
 301       COPY_SZ_4V( DST, SZ, SRC );    \
 302 } while (0)
 303
 304 /** Subtraction */
 305 #define SUB_4V( DST, SRCA, SRCB )           \
 306 do {                                        \
 307       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 308       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 309       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
 310       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
 311 } while (0)
 312
 313 /** Addition */
 314 #define ADD_4V( DST, SRCA, SRCB )           \
 315 do {                                        \
 316       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 317       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 318       (DST)[2] = (SRCA)[2] + (SRCB)[2];     \
 319       (DST)[3] = (SRCA)[3] + (SRCB)[3];     \
 320 } while (0)
 321
 322 /** Element-wise multiplication */
 323 #define SCALE_4V( DST, SRCA, SRCB )         \
 324 do {                                        \
 325       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 326       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 327       (DST)[2] = (SRCA)[2] * (SRCB)[2];     \
 328       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
 329 } while (0)
 330
 331 /** In-place addition */
 332 #define ACC_4V( DST, SRC )          \
 333 do {                                \
 334       (DST)[0] += (SRC)[0];         \
 335       (DST)[1] += (SRC)[1];         \
 336       (DST)[2] += (SRC)[2];         \
 337       (DST)[3] += (SRC)[3];         \
 338 } while (0)
 339
 340 /** Element-wise multiplication and addition */
 341 #define ACC_SCALE_4V( DST, SRCA, SRCB )     \
 342 do {                                        \
 343       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 344       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 345       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 346       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
 347 } while (0)
 348
 349 /** In-place scalar multiplication and addition */
 350 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
 351 do {                                        \
 352       (DST)[0] += S * (SRCB)[0];            \
 353       (DST)[1] += S * (SRCB)[1];            \
 354       (DST)[2] += S * (SRCB)[2];            \
 355       (DST)[3] += S * (SRCB)[3];            \
 356 } while (0)
 357
 358 /** Scalar multiplication */
 359 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
 360 do {                                    \
 361       (DST)[0] = S * (SRCB)[0];         \
 362       (DST)[1] = S * (SRCB)[1];         \
 363       (DST)[2] = S * (SRCB)[2];         \
 364       (DST)[3] = S * (SRCB)[3];         \
 365 } while (0)
 366
 367 /** In-place scalar multiplication */
 368 #define SELF_SCALE_SCALAR_4V( DST, S ) \
 369 do {                                   \
 370       (DST)[0] *= S;                   \
 371       (DST)[1] *= S;                   \
 372       (DST)[2] *= S;                   \
 373       (DST)[3] *= S;                   \
 374 } while (0)
 375
 376 /** Assignment */
 377 #define ASSIGN_4V( V, V0, V1, V2, V3 )  \
 378 do {                                    \
 379     V[0] = V0;                          \
 380     V[1] = V1;                          \
 381     V[2] = V2;                          \
 382     V[3] = V3;                          \
 383 } while(0)
 384
 385 /*@}*/
 386
 387
 388 /**********************************************************************/
 389 /** \name 3-element vector operations*/
 390 /*@{*/
 391
 392 /** Zero */
 393 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
 394
 395 /** Test for equality */
 396 #define TEST_EQ_3V(a,b)  \
 397    ((a)[0] == (b)[0] &&  \
 398     (a)[1] == (b)[1] &&  \
 399     (a)[2] == (b)[2])
 400
 401 /** Copy a 3-element vector */
 402 #define COPY_3V( DST, SRC )         \
 403 do {                                \
 404    (DST)[0] = (SRC)[0];             \
 405    (DST)[1] = (SRC)[1];             \
 406    (DST)[2] = (SRC)[2];             \
 407 } while (0)
 408
 409 /** Copy a 3-element vector with cast */
 410 #define COPY_3V_CAST( DST, SRC, CAST )  \
 411 do {                                    \
 412    (DST)[0] = (CAST)(SRC)[0];           \
 413    (DST)[1] = (CAST)(SRC)[1];           \
 414    (DST)[2] = (CAST)(SRC)[2];           \
 415 } while (0)
 416
 417 /** Copy a 3-element float vector */
 418 #define COPY_3FV( DST, SRC )        \
 419 do {                                \
 420    const GLfloat *_tmp = (SRC);     \
 421    (DST)[0] = _tmp[0];              \
 422    (DST)[1] = _tmp[1];              \
 423    (DST)[2] = _tmp[2];              \
 424 } while (0)
 425
 426 /** Subtraction */
 427 #define SUB_3V( DST, SRCA, SRCB )        \
 428 do {                                     \
 429       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
 430       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
 431       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
 432 } while (0)
 433
 434 /** Addition */
 435 #define ADD_3V( DST, SRCA, SRCB )       \
 436 do {                                    \
 437       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
 438       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
 439       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
 440 } while (0)
 441
 442 /** In-place scalar multiplication */
 443 #define SCALE_3V( DST, SRCA, SRCB )     \
 444 do {                                    \
 445       (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
 446       (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
 447       (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
 448 } while (0)
 449
 450 /** In-place element-wise multiplication */
 451 #define SELF_SCALE_3V( DST, SRC )   \
 452 do {                                \
 453       (DST)[0] *= (SRC)[0];         \
 454       (DST)[1] *= (SRC)[1];         \
 455       (DST)[2] *= (SRC)[2];         \
 456 } while (0)
 457
 458 /** In-place addition */
 459 #define ACC_3V( DST, SRC )          \
 460 do {                                \
 461       (DST)[0] += (SRC)[0];         \
 462       (DST)[1] += (SRC)[1];         \
 463       (DST)[2] += (SRC)[2];         \
 464 } while (0)
 465
 466 /** Element-wise multiplication and addition */
 467 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
 468 do {                                        \
 469       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 470       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 471       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 472 } while (0)
 473
 474 /** Scalar multiplication */
 475 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
 476 do {                                    \
 477       (DST)[0] = S * (SRCB)[0];         \
 478       (DST)[1] = S * (SRCB)[1];         \
 479       (DST)[2] = S * (SRCB)[2];         \
 480 } while (0)
 481
 482 /** In-place scalar multiplication and addition */
 483 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
 484 do {                                        \
 485       (DST)[0] += S * (SRCB)[0];            \
 486       (DST)[1] += S * (SRCB)[1];            \
 487       (DST)[2] += S * (SRCB)[2];            \
 488 } while (0)
 489
 490 /** In-place scalar multiplication */
 491 #define SELF_SCALE_SCALAR_3V( DST, S ) \
 492 do {                                   \
 493       (DST)[0] *= S;                   \
 494       (DST)[1] *= S;                   \
 495       (DST)[2] *= S;                   \
 496 } while (0)
 497
 498 /** In-place scalar addition */
 499 #define ACC_SCALAR_3V( DST, S )     \
 500 do {                                \
 501       (DST)[0] += S;                \
 502       (DST)[1] += S;                \
 503       (DST)[2] += S;                \
 504 } while (0)
 505
 506 /** Assignment */
 507 #define ASSIGN_3V( V, V0, V1, V2 )  \
 508 do {                                \
 509     V[0] = V0;                      \
 510     V[1] = V1;                      \
 511     V[2] = V2;                      \
 512 } while(0)
 513
 514 /*@}*/
 515
 516
 517 /**********************************************************************/
 518 /** \name 2-element vector operations*/
 519 /*@{*/
 520
 521 /** Zero */
 522 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
 523
 524 /** Copy a 2-element vector */
 525 #define COPY_2V( DST, SRC )         \
 526 do {                        \
 527    (DST)[0] = (SRC)[0];             \
 528    (DST)[1] = (SRC)[1];             \
 529 } while (0)
 530
 531 /** Copy a 2-element vector with cast */
 532 #define COPY_2V_CAST( DST, SRC, CAST )      \
 533 do {                        \
 534    (DST)[0] = (CAST)(SRC)[0];           \
 535    (DST)[1] = (CAST)(SRC)[1];           \
 536 } while (0)
 537
 538 /** Copy a 2-element float vector */
 539 #define COPY_2FV( DST, SRC )            \
 540 do {                        \
 541    const GLfloat *_tmp = (SRC);         \
 542    (DST)[0] = _tmp[0];              \
 543    (DST)[1] = _tmp[1];              \
 544 } while (0)
 545
 546 /** Subtraction */
 547 #define SUB_2V( DST, SRCA, SRCB )       \
 548 do {                        \
 549       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 550       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 551 } while (0)
 552
 553 /** Addition */
 554 #define ADD_2V( DST, SRCA, SRCB )       \
 555 do {                        \
 556       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 557       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 558 } while (0)
 559
 560 /** In-place scalar multiplication */
 561 #define SCALE_2V( DST, SRCA, SRCB )     \
 562 do {                        \
 563       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 564       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 565 } while (0)
 566
 567 /** In-place addition */
 568 #define ACC_2V( DST, SRC )          \
 569 do {                        \
 570       (DST)[0] += (SRC)[0];         \
 571       (DST)[1] += (SRC)[1];         \
 572 } while (0)
 573
 574 /** Element-wise multiplication and addition */
 575 #define ACC_SCALE_2V( DST, SRCA, SRCB )     \
 576 do {                        \
 577       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 578       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 579 } while (0)
 580
 581 /** Scalar multiplication */
 582 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
 583 do {                        \
 584       (DST)[0] = S * (SRCB)[0];         \
 585       (DST)[1] = S * (SRCB)[1];         \
 586 } while (0)
 587
 588 /** In-place scalar multiplication and addition */
 589 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
 590 do {                        \
 591       (DST)[0] += S * (SRCB)[0];        \
 592       (DST)[1] += S * (SRCB)[1];        \
 593 } while (0)
 594
 595 /** In-place scalar multiplication */
 596 #define SELF_SCALE_SCALAR_2V( DST, S )      \
 597 do {                        \
 598       (DST)[0] *= S;                \
 599       (DST)[1] *= S;                \
 600 } while (0)
 601
 602 /** In-place scalar addition */
 603 #define ACC_SCALAR_2V( DST, S )         \
 604 do {                        \
 605       (DST)[0] += S;                \
 606       (DST)[1] += S;                \
 607 } while (0)
 608
 609 /** Assign scalers to short vectors */
 610 #define ASSIGN_2V( V, V0, V1 )  \
 611 do {                            \
 612     V[0] = V0;                  \
 613     V[1] = V1;                  \
 614 } while(0)
 615
 616 /*@}*/
 617
 618 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
 619  * default values to the remaining components.
 620  * The default values are chosen based on \p type.
 621  */
 622 static inline void
 623 COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst[4], int sz, const GLfloat src[4],
 624                             GLenum type)
 625 {
 626    switch (type) {
 627    case GL_FLOAT:
 628       ASSIGN_4V(dst, 0, 0, 0, 1);
 629       break;
 630    case GL_INT:
 631       ASSIGN_4V(dst, INT_AS_FLT(0), INT_AS_FLT(0),
 632                      INT_AS_FLT(0), INT_AS_FLT(1));
 633       break;
 634    case GL_UNSIGNED_INT:
 635       ASSIGN_4V(dst, UINT_AS_FLT(0), UINT_AS_FLT(0),
 636                      UINT_AS_FLT(0), UINT_AS_FLT(1));
 637       break;
 638    default:
 639       ASSIGN_4V(dst, 0.0f, 0.0f, 0.0f, 1.0f); /* silence warnings */
 640       ASSERT(!"Unexpected type in COPY_CLEAN_4V_TYPE_AS_FLOAT macro");
 641    }
 642    COPY_SZ_4V(dst, sz, src);
 643 }
 644
 645 /** \name Linear interpolation functions */
 646 /*@{*/
 647
 648 static inline GLfloat
 649 LINTERP(GLfloat t, GLfloat out, GLfloat in)
 650 {
 651    return out + t * (in - out);
 652 }
 653
 654 static inline void
 655 INTERP_3F(GLfloat t, GLfloat dst[3], const GLfloat out[3], const GLfloat in[3])
 656 {
 657    dst[0] = LINTERP( t, out[0], in[0] );
 658    dst[1] = LINTERP( t, out[1], in[1] );
 659    dst[2] = LINTERP( t, out[2], in[2] );
 660 }
 661
 662 static inline void
 663 INTERP_4F(GLfloat t, GLfloat dst[4], const GLfloat out[4], const GLfloat in[4])
 664 {
 665    dst[0] = LINTERP( t, out[0], in[0] );
 666    dst[1] = LINTERP( t, out[1], in[1] );
 667    dst[2] = LINTERP( t, out[2], in[2] );
 668    dst[3] = LINTERP( t, out[3], in[3] );
 669 }
 670
 671 /*@}*/
 672
 673
 674
 675 /** Clamp X to [MIN,MAX] */
 676 #define CLAMP( X, MIN, MAX )  ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
 677
 678 /** Minimum of two values: */
 679 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
 680
 681 /** Maximum of two values: */
 682 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
 683
 684 /** Minimum and maximum of three values: */
 685 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
 686 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
 687
 688 static inline unsigned
 689 minify(unsigned value, unsigned levels)
 690 {
 691     return MAX2(1, value >> levels);
 692 }
 693
 694 /**
 695  * Return true if the given value is a power of two.
 696  *
 697  * Note that this considers 0 a power of two.
 698  */
 699 static inline bool
 700 is_power_of_two(unsigned value)
 701 {
 702    return (value & (value - 1)) == 0;
 703 }
 704
 705 /**
 706  * Align a value up to an alignment value
 707  *
 708  * If \c value is not already aligned to the requested alignment value, it
 709  * will be rounded up.
 710  *
 711  * \param value  Value to be rounded
 712  * \param alignment  Alignment value to be used.  This must be a power of two.
 713  *
 714  * \sa ROUND_DOWN_TO()
 715  */
 716 #define ALIGN(value, alignment)  (((value) + (alignment) - 1) & ~((alignment) - 1))
 717
 718 /**
 719  * Align a value down to an alignment value
 720  *
 721  * If \c value is not already aligned to the requested alignment value, it
 722  * will be rounded down.
 723  *
 724  * \param value  Value to be rounded
 725  * \param alignment  Alignment value to be used.  This must be a power of two.
 726  *
 727  * \sa ALIGN()
 728  */
 729 #define ROUND_DOWN_TO(value, alignment) ((value) & ~(alignment - 1))
 730
 731
 732 /** Cross product of two 3-element vectors */
 733 static inline void
 734 CROSS3(GLfloat n[3], const GLfloat u[3], const GLfloat v[3])
 735 {
 736    n[0] = u[1] * v[2] - u[2] * v[1];
 737    n[1] = u[2] * v[0] - u[0] * v[2];
 738    n[2] = u[0] * v[1] - u[1] * v[0];
 739 }
 740
 741
 742 /** Dot product of two 2-element vectors */
 743 static inline GLfloat
 744 DOT2(const GLfloat a[2], const GLfloat b[2])
 745 {
 746    return a[0] * b[0] + a[1] * b[1];
 747 }
 748
 749 static inline GLfloat
 750 DOT3(const GLfloat a[3], const GLfloat b[3])
 751 {
 752    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 753 }
 754
 755 static inline GLfloat
 756 DOT4(const GLfloat a[4], const GLfloat b[4])
 757 {
 758    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
 759 }
 760
 761
 762 static inline GLfloat
 763 LEN_SQUARED_3FV(const GLfloat v[3])
 764 {
 765    return DOT3(v, v);
 766 }
 767
 768 static inline GLfloat
 769 LEN_SQUARED_2FV(const GLfloat v[2])
 770 {
 771    return DOT2(v, v);
 772 }
 773
 774
 775 static inline GLfloat
 776 LEN_3FV(const GLfloat v[3])
 777 {
 778    return sqrtf(LEN_SQUARED_3FV(v));
 779 }
 780
 781 static inline GLfloat
 782 LEN_2FV(const GLfloat v[2])
 783 {
 784    return sqrtf(LEN_SQUARED_2FV(v));
 785 }
 786
 787
 788 /* Normalize a 3-element vector to unit length. */
 789 static inline void
 790 NORMALIZE_3FV(GLfloat v[3])
 791 {
 792    GLfloat len = (GLfloat) LEN_SQUARED_3FV(v);
 793    if (len) {
 794       len = INV_SQRTF(len);
 795       v[0] *= len;
 796       v[1] *= len;
 797       v[2] *= len;
 798    }
 799 }
 800
 801
 802 /** Test two floats have opposite signs */
 803 static inline GLboolean
 804 DIFFERENT_SIGNS(GLfloat x, GLfloat y)
 805 {
 806    return signbit(x) != signbit(y);
 807 }
 808
 809
 810 /** Compute ceiling of integer quotient of A divided by B. */
 811 #define CEILING( A, B )  ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
 812
 813
 814 /** casts to silence warnings with some compilers */
 815 #define ENUM_TO_INT(E)     ((GLint)(E))
 816 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
 817 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
 818 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
 819
 820 /* Compute the size of an array */
 821 #ifndef ARRAY_SIZE
 822 #  define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
 823 #endif
 824
 825 /* Stringify */
 826 #define STRINGIFY(x) #x
 827
 828 #endif