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  *
   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 "util/u_math.h"
  35 #include "imports.h"
  36
  37
  38 /**
  39  * \name Integer / float conversion for colors, normals, etc.
  40  */
  41 /*@{*/
  42
  43 /** Convert GLubyte in [0,255] to GLfloat in [0.0,1.0] */
  44 extern GLfloat _mesa_ubyte_to_float_color_tab[256];
  45 #define UBYTE_TO_FLOAT(u) _mesa_ubyte_to_float_color_tab[(unsigned int)(u)]
  46
  47 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
  48 #define FLOAT_TO_UBYTE(X)   ((GLubyte) (GLint) ((X) * 255.0F))
  49
  50
  51 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
  52 #define BYTE_TO_FLOAT(B)    ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
  53
  54 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
  55 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
  56
  57
  58 /** Convert GLbyte to GLfloat while preserving zero */
  59 #define BYTE_TO_FLOATZ(B)   ((B) == 0 ? 0.0F : BYTE_TO_FLOAT(B))
  60
  61
  62 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0], texture/fb data */
  63 #define BYTE_TO_FLOAT_TEX(B)    ((B) == -128 ? -1.0F : (B) * (1.0F/127.0F))
  64
  65 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127], texture/fb data */
  66 #define FLOAT_TO_BYTE_TEX(X)    CLAMP( (GLint) (127.0F * (X)), -128, 127 )
  67
  68 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
  69 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
  70
  71 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
  72 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0F))
  73
  74
  75 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
  76 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
  77
  78 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767] */
  79 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
  80
  81 /** Convert GLshort to GLfloat while preserving zero */
  82 #define SHORT_TO_FLOATZ(S)   ((S) == 0 ? 0.0F : SHORT_TO_FLOAT(S))
  83
  84
  85 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0], texture/fb data */
  86 #define SHORT_TO_FLOAT_TEX(S)    ((S) == -32768 ? -1.0F : (S) * (1.0F/32767.0F))
  87
  88 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767], texture/fb data */
  89 #define FLOAT_TO_SHORT_TEX(X)    ( (GLint) (32767.0F * (X)) )
  90
  91
  92 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
  93 #define UINT_TO_FLOAT(U)    ((GLfloat) ((U) * (1.0F / 4294967295.0)))
  94
  95 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
  96 #define FLOAT_TO_UINT(X)    ((GLuint) ((X) * 4294967295.0))
  97
  98
  99 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
 100 #define INT_TO_FLOAT(I)     ((GLfloat) ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0)))
 101
 102 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
 103 /* causes overflow:
 104 #define FLOAT_TO_INT(X)     ( (((GLint) (4294967294.0 * (X))) - 1) / 2 )
 105 */
 106 /* a close approximation: */
 107 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
 108
 109 /** Convert GLfloat in [-1.0,1.0] to GLint64 in [-(1<<63),(1 << 63) -1] */
 110 #define FLOAT_TO_INT64(X)     ( (GLint64) (9223372036854775807.0 * (double)(X)) )
 111
 112
 113 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0], texture/fb data */
 114 #define INT_TO_FLOAT_TEX(I)    ((I) == -2147483648 ? -1.0F : (I) * (1.0F/2147483647.0))
 115
 116 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647], texture/fb data */
 117 #define FLOAT_TO_INT_TEX(X)    ( (GLint) (2147483647.0 * (X)) )
 118
 119
 120 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
 121 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
 122 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))
 123 #define INT_TO_UBYTE(i)    ((GLubyte) ((i) < 0 ? 0 : (GLubyte) ((i) >> 23)))
 124 #define UINT_TO_UBYTE(i)   ((GLubyte) ((i) >> 24))
 125
 126
 127 #define BYTE_TO_USHORT(b)  ((b) < 0 ? 0 : ((GLushort) (((b) * 65535) / 255)))
 128 #define UBYTE_TO_USHORT(b) (((GLushort) (b) << 8) | (GLushort) (b))
 129 #define SHORT_TO_USHORT(s) ((s) < 0 ? 0 : ((GLushort) (((s) * 65535 / 32767))))
 130 #define INT_TO_USHORT(i)   ((i) < 0 ? 0 : ((GLushort) ((i) >> 15)))
 131 #define UINT_TO_USHORT(i)  ((i) < 0 ? 0 : ((GLushort) ((i) >> 16)))
 132 #define UNCLAMPED_FLOAT_TO_USHORT(us, f)  \
 133         us = ( (GLushort) F_TO_I( CLAMP((f), 0.0F, 1.0F) * 65535.0F) )
 134 #define CLAMPED_FLOAT_TO_USHORT(us, f)  \
 135         us = ( (GLushort) F_TO_I( (f) * 65535.0F) )
 136
 137 #define UNCLAMPED_FLOAT_TO_SHORT(s, f)  \
 138         s = ( (GLshort) F_TO_I( CLAMP((f), -1.0F, 1.0F) * 32767.0F) )
 139
 140 /***
 141  *** UNCLAMPED_FLOAT_TO_UBYTE: clamp float to [0,1] and map to ubyte in [0,255]
 142  *** CLAMPED_FLOAT_TO_UBYTE: map float known to be in [0,1] to ubyte in [0,255]
 143  ***/
 144 #ifndef DEBUG
 145 /* This function/macro is sensitive to precision.  Test very carefully
 146  * if you change it!
 147  */
 148 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, FLT)                               \
 149         do {                                                            \
 150            fi_type __tmp;                                               \
 151            __tmp.f = (FLT);                                             \
 152            if (__tmp.i < 0)                                             \
 153               UB = (GLubyte) 0;                                         \
 154            else if (__tmp.i >= IEEE_ONE)                                \
 155               UB = (GLubyte) 255;                                       \
 156            else {                                                       \
 157               __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F;           \
 158               UB = (GLubyte) __tmp.i;                                   \
 159            }                                                            \
 160         } while (0)
 161 #define CLAMPED_FLOAT_TO_UBYTE(UB, FLT)                                 \
 162         do {                                                            \
 163            fi_type __tmp;                                               \
 164            __tmp.f = (FLT) * (255.0F/256.0F) + 32768.0F;                \
 165            UB = (GLubyte) __tmp.i;                                      \
 166         } while (0)
 167 #else
 168 #define UNCLAMPED_FLOAT_TO_UBYTE(ub, f) \
 169         ub = ((GLubyte) F_TO_I(CLAMP((f), 0.0F, 1.0F) * 255.0F))
 170 #define CLAMPED_FLOAT_TO_UBYTE(ub, f) \
 171         ub = ((GLubyte) F_TO_I((f) * 255.0F))
 172 #endif
 173
 174 static inline GLfloat INT_AS_FLT(GLint i)
 175 {
 176    fi_type tmp;
 177    tmp.i = i;
 178    return tmp.f;
 179 }
 180
 181 static inline GLfloat UINT_AS_FLT(GLuint u)
 182 {
 183    fi_type tmp;
 184    tmp.u = u;
 185    return tmp.f;
 186 }
 187
 188 static inline unsigned FLT_AS_UINT(float f)
 189 {
 190    fi_type tmp;
 191    tmp.f = f;
 192    return tmp.u;
 193 }
 194
 195 /**
 196  * Convert a floating point value to an unsigned fixed point value.
 197  *
 198  * \param frac_bits   The number of bits used to store the fractional part.
 199  */
 200 static inline uint32_t
 201 U_FIXED(float value, uint32_t frac_bits)
 202 {
 203    value *= (1 << frac_bits);
 204    return value < 0.0f ? 0 : (uint32_t) value;
 205 }
 206
 207 /**
 208  * Convert a floating point value to an signed fixed point value.
 209  *
 210  * \param frac_bits   The number of bits used to store the fractional part.
 211  */
 212 static inline int32_t
 213 S_FIXED(float value, uint32_t frac_bits)
 214 {
 215    return (int32_t) (value * (1 << frac_bits));
 216 }
 217 /*@}*/
 218
 219
 220 /** Stepping a GLfloat pointer by a byte stride */
 221 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
 222 /** Stepping a GLuint pointer by a byte stride */
 223 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
 224 /** Stepping a GLubyte[4] pointer by a byte stride */
 225 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
 226 /** Stepping a GLfloat[4] pointer by a byte stride */
 227 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
 228 /** Stepping a \p t pointer by a byte stride */
 229 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
 230
 231
 232 /**********************************************************************/
 233 /** \name 4-element vector operations */
 234 /*@{*/
 235
 236 /** Zero */
 237 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
 238
 239 /** Test for equality */
 240 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
 241               (a)[1] == (b)[1] &&   \
 242               (a)[2] == (b)[2] &&   \
 243               (a)[3] == (b)[3])
 244
 245 /** Test for equality (unsigned bytes) */
 246 static inline GLboolean
 247 TEST_EQ_4UBV(const GLubyte a[4], const GLubyte b[4])
 248 {
 249 #if defined(__i386__)
 250    return *((const GLuint *) a) == *((const GLuint *) b);
 251 #else
 252    return TEST_EQ_4V(a, b);
 253 #endif
 254 }
 255
 256
 257 /** Copy a 4-element vector */
 258 #define COPY_4V( DST, SRC )         \
 259 do {                                \
 260    (DST)[0] = (SRC)[0];             \
 261    (DST)[1] = (SRC)[1];             \
 262    (DST)[2] = (SRC)[2];             \
 263    (DST)[3] = (SRC)[3];             \
 264 } while (0)
 265
 266 /** Copy a 4-element unsigned byte vector */
 267 static inline void
 268 COPY_4UBV(GLubyte dst[4], const GLubyte src[4])
 269 {
 270 #if defined(__i386__)
 271    *((GLuint *) dst) = *((GLuint *) src);
 272 #else
 273    /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
 274    COPY_4V(dst, src);
 275 #endif
 276 }
 277
 278 /** Copy \p SZ elements into a 4-element vector */
 279 #define COPY_SZ_4V(DST, SZ, SRC)  \
 280 do {                              \
 281    switch (SZ) {                  \
 282    case 4: (DST)[3] = (SRC)[3];   \
 283    case 3: (DST)[2] = (SRC)[2];   \
 284    case 2: (DST)[1] = (SRC)[1];   \
 285    case 1: (DST)[0] = (SRC)[0];   \
 286    }                              \
 287 } while(0)
 288
 289 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
 290  * default values to the remaining */
 291 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
 292 do {                                 \
 293       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
 294       COPY_SZ_4V( DST, SZ, SRC );    \
 295 } while (0)
 296
 297 /** Subtraction */
 298 #define SUB_4V( DST, SRCA, SRCB )           \
 299 do {                                        \
 300       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 301       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 302       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
 303       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
 304 } while (0)
 305
 306 /** Addition */
 307 #define ADD_4V( DST, SRCA, SRCB )           \
 308 do {                                        \
 309       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 310       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 311       (DST)[2] = (SRCA)[2] + (SRCB)[2];     \
 312       (DST)[3] = (SRCA)[3] + (SRCB)[3];     \
 313 } while (0)
 314
 315 /** Element-wise multiplication */
 316 #define SCALE_4V( DST, SRCA, SRCB )         \
 317 do {                                        \
 318       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 319       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 320       (DST)[2] = (SRCA)[2] * (SRCB)[2];     \
 321       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
 322 } while (0)
 323
 324 /** In-place addition */
 325 #define ACC_4V( DST, SRC )          \
 326 do {                                \
 327       (DST)[0] += (SRC)[0];         \
 328       (DST)[1] += (SRC)[1];         \
 329       (DST)[2] += (SRC)[2];         \
 330       (DST)[3] += (SRC)[3];         \
 331 } while (0)
 332
 333 /** Element-wise multiplication and addition */
 334 #define ACC_SCALE_4V( DST, SRCA, SRCB )     \
 335 do {                                        \
 336       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 337       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 338       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 339       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
 340 } while (0)
 341
 342 /** In-place scalar multiplication and addition */
 343 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
 344 do {                                        \
 345       (DST)[0] += S * (SRCB)[0];            \
 346       (DST)[1] += S * (SRCB)[1];            \
 347       (DST)[2] += S * (SRCB)[2];            \
 348       (DST)[3] += S * (SRCB)[3];            \
 349 } while (0)
 350
 351 /** Scalar multiplication */
 352 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
 353 do {                                    \
 354       (DST)[0] = S * (SRCB)[0];         \
 355       (DST)[1] = S * (SRCB)[1];         \
 356       (DST)[2] = S * (SRCB)[2];         \
 357       (DST)[3] = S * (SRCB)[3];         \
 358 } while (0)
 359
 360 /** In-place scalar multiplication */
 361 #define SELF_SCALE_SCALAR_4V( DST, S ) \
 362 do {                                   \
 363       (DST)[0] *= S;                   \
 364       (DST)[1] *= S;                   \
 365       (DST)[2] *= S;                   \
 366       (DST)[3] *= S;                   \
 367 } while (0)
 368
 369 /*@}*/
 370
 371
 372 /**********************************************************************/
 373 /** \name 3-element vector operations*/
 374 /*@{*/
 375
 376 /** Zero */
 377 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
 378
 379 /** Test for equality */
 380 #define TEST_EQ_3V(a,b)  \
 381    ((a)[0] == (b)[0] &&  \
 382     (a)[1] == (b)[1] &&  \
 383     (a)[2] == (b)[2])
 384
 385 /** Copy a 3-element vector */
 386 #define COPY_3V( DST, SRC )         \
 387 do {                                \
 388    (DST)[0] = (SRC)[0];             \
 389    (DST)[1] = (SRC)[1];             \
 390    (DST)[2] = (SRC)[2];             \
 391 } while (0)
 392
 393 /** Copy a 3-element vector with cast */
 394 #define COPY_3V_CAST( DST, SRC, CAST )  \
 395 do {                                    \
 396    (DST)[0] = (CAST)(SRC)[0];           \
 397    (DST)[1] = (CAST)(SRC)[1];           \
 398    (DST)[2] = (CAST)(SRC)[2];           \
 399 } while (0)
 400
 401 /** Copy a 3-element float vector */
 402 #define COPY_3FV( DST, SRC )        \
 403 do {                                \
 404    const GLfloat *_tmp = (SRC);     \
 405    (DST)[0] = _tmp[0];              \
 406    (DST)[1] = _tmp[1];              \
 407    (DST)[2] = _tmp[2];              \
 408 } while (0)
 409
 410 /** Subtraction */
 411 #define SUB_3V( DST, SRCA, SRCB )        \
 412 do {                                     \
 413       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
 414       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
 415       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
 416 } while (0)
 417
 418 /** Addition */
 419 #define ADD_3V( DST, SRCA, SRCB )       \
 420 do {                                    \
 421       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
 422       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
 423       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
 424 } while (0)
 425
 426 /** In-place scalar multiplication */
 427 #define SCALE_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 /** In-place element-wise multiplication */
 435 #define SELF_SCALE_3V( DST, SRC )   \
 436 do {                                \
 437       (DST)[0] *= (SRC)[0];         \
 438       (DST)[1] *= (SRC)[1];         \
 439       (DST)[2] *= (SRC)[2];         \
 440 } while (0)
 441
 442 /** In-place addition */
 443 #define ACC_3V( DST, SRC )          \
 444 do {                                \
 445       (DST)[0] += (SRC)[0];         \
 446       (DST)[1] += (SRC)[1];         \
 447       (DST)[2] += (SRC)[2];         \
 448 } while (0)
 449
 450 /** Element-wise multiplication and addition */
 451 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
 452 do {                                        \
 453       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 454       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 455       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 456 } while (0)
 457
 458 /** Scalar multiplication */
 459 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
 460 do {                                    \
 461       (DST)[0] = S * (SRCB)[0];         \
 462       (DST)[1] = S * (SRCB)[1];         \
 463       (DST)[2] = S * (SRCB)[2];         \
 464 } while (0)
 465
 466 /** In-place scalar multiplication and addition */
 467 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
 468 do {                                        \
 469       (DST)[0] += S * (SRCB)[0];            \
 470       (DST)[1] += S * (SRCB)[1];            \
 471       (DST)[2] += S * (SRCB)[2];            \
 472 } while (0)
 473
 474 /** In-place scalar multiplication */
 475 #define SELF_SCALE_SCALAR_3V( DST, S ) \
 476 do {                                   \
 477       (DST)[0] *= S;                   \
 478       (DST)[1] *= S;                   \
 479       (DST)[2] *= S;                   \
 480 } while (0)
 481
 482 /** In-place scalar addition */
 483 #define ACC_SCALAR_3V( DST, S )     \
 484 do {                                \
 485       (DST)[0] += S;                \
 486       (DST)[1] += S;                \
 487       (DST)[2] += S;                \
 488 } while (0)
 489
 490 /** Assignment */
 491 #define ASSIGN_3V( V, V0, V1, V2 )  \
 492 do {                                \
 493     V[0] = V0;                      \
 494     V[1] = V1;                      \
 495     V[2] = V2;                      \
 496 } while(0)
 497
 498 /*@}*/
 499
 500
 501 /**********************************************************************/
 502 /** \name 2-element vector operations*/
 503 /*@{*/
 504
 505 /** Zero */
 506 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
 507
 508 /** Copy a 2-element vector */
 509 #define COPY_2V( DST, SRC )         \
 510 do {                        \
 511    (DST)[0] = (SRC)[0];             \
 512    (DST)[1] = (SRC)[1];             \
 513 } while (0)
 514
 515 /** Copy a 2-element vector with cast */
 516 #define COPY_2V_CAST( DST, SRC, CAST )      \
 517 do {                        \
 518    (DST)[0] = (CAST)(SRC)[0];           \
 519    (DST)[1] = (CAST)(SRC)[1];           \
 520 } while (0)
 521
 522 /** Copy a 2-element float vector */
 523 #define COPY_2FV( DST, SRC )            \
 524 do {                        \
 525    const GLfloat *_tmp = (SRC);         \
 526    (DST)[0] = _tmp[0];              \
 527    (DST)[1] = _tmp[1];              \
 528 } while (0)
 529
 530 /** Subtraction */
 531 #define SUB_2V( DST, SRCA, SRCB )       \
 532 do {                        \
 533       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 534       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 535 } while (0)
 536
 537 /** Addition */
 538 #define ADD_2V( DST, SRCA, SRCB )       \
 539 do {                        \
 540       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 541       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 542 } while (0)
 543
 544 /** In-place scalar multiplication */
 545 #define SCALE_2V( DST, SRCA, SRCB )     \
 546 do {                        \
 547       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 548       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 549 } while (0)
 550
 551 /** In-place addition */
 552 #define ACC_2V( DST, SRC )          \
 553 do {                        \
 554       (DST)[0] += (SRC)[0];         \
 555       (DST)[1] += (SRC)[1];         \
 556 } while (0)
 557
 558 /** Element-wise multiplication and addition */
 559 #define ACC_SCALE_2V( DST, SRCA, SRCB )     \
 560 do {                        \
 561       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 562       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 563 } while (0)
 564
 565 /** Scalar multiplication */
 566 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
 567 do {                        \
 568       (DST)[0] = S * (SRCB)[0];         \
 569       (DST)[1] = S * (SRCB)[1];         \
 570 } while (0)
 571
 572 /** In-place scalar multiplication and addition */
 573 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
 574 do {                        \
 575       (DST)[0] += S * (SRCB)[0];        \
 576       (DST)[1] += S * (SRCB)[1];        \
 577 } while (0)
 578
 579 /** In-place scalar multiplication */
 580 #define SELF_SCALE_SCALAR_2V( DST, S )      \
 581 do {                        \
 582       (DST)[0] *= S;                \
 583       (DST)[1] *= S;                \
 584 } while (0)
 585
 586 /** In-place scalar addition */
 587 #define ACC_SCALAR_2V( DST, S )         \
 588 do {                        \
 589       (DST)[0] += S;                \
 590       (DST)[1] += S;                \
 591 } while (0)
 592
 593 /** Assign scalers to short vectors */
 594 #define ASSIGN_2V( V, V0, V1 )  \
 595 do {                            \
 596     V[0] = V0;                  \
 597     V[1] = V1;                  \
 598 } while(0)
 599
 600 /*@}*/
 601
 602 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
 603  * default values to the remaining components.
 604  * The default values are chosen based on \p type.
 605  */
 606 static inline void
 607 COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst[4], int sz, const GLfloat src[4],
 608                             GLenum type)
 609 {
 610    switch (type) {
 611    case GL_FLOAT:
 612       ASSIGN_4V(dst, 0, 0, 0, 1);
 613       break;
 614    case GL_INT:
 615       ASSIGN_4V(dst, INT_AS_FLT(0), INT_AS_FLT(0),
 616                      INT_AS_FLT(0), INT_AS_FLT(1));
 617       break;
 618    case GL_UNSIGNED_INT:
 619       ASSIGN_4V(dst, UINT_AS_FLT(0), UINT_AS_FLT(0),
 620                      UINT_AS_FLT(0), UINT_AS_FLT(1));
 621       break;
 622    default:
 623       ASSIGN_4V(dst, 0.0f, 0.0f, 0.0f, 1.0f); /* silence warnings */
 624       ASSERT(!"Unexpected type in COPY_CLEAN_4V_TYPE_AS_FLOAT macro");
 625    }
 626    COPY_SZ_4V(dst, sz, src);
 627 }
 628
 629 /** \name Linear interpolation functions */
 630 /*@{*/
 631
 632 static inline GLfloat
 633 LINTERP(GLfloat t, GLfloat out, GLfloat in)
 634 {
 635    return out + t * (in - out);
 636 }
 637
 638 static inline void
 639 INTERP_3F(GLfloat t, GLfloat dst[3], const GLfloat out[3], const GLfloat in[3])
 640 {
 641    dst[0] = LINTERP( t, out[0], in[0] );
 642    dst[1] = LINTERP( t, out[1], in[1] );
 643    dst[2] = LINTERP( t, out[2], in[2] );
 644 }
 645
 646 static inline void
 647 INTERP_4F(GLfloat t, GLfloat dst[4], const GLfloat out[4], const GLfloat in[4])
 648 {
 649    dst[0] = LINTERP( t, out[0], in[0] );
 650    dst[1] = LINTERP( t, out[1], in[1] );
 651    dst[2] = LINTERP( t, out[2], in[2] );
 652    dst[3] = LINTERP( t, out[3], in[3] );
 653 }
 654
 655 /*@}*/
 656
 657
 658
 659 /** Clamp X to [MIN,MAX] */
 660 #define CLAMP( X, MIN, MAX )  ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
 661
 662 /** Minimum of two values: */
 663 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
 664
 665 /** Maximum of two values: */
 666 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
 667
 668 /** Minimum and maximum of three values: */
 669 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
 670 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
 671
 672 static inline unsigned
 673 minify(unsigned value, unsigned levels)
 674 {
 675     return MAX2(1, value >> levels);
 676 }
 677
 678 /**
 679  * Return true if the given value is a power of two.
 680  *
 681  * Note that this considers 0 a power of two.
 682  */
 683 static inline bool
 684 is_power_of_two(unsigned value)
 685 {
 686    return (value & (value - 1)) == 0;
 687 }
 688
 689 /**
 690  * Align a value up to an alignment value
 691  *
 692  * If \c value is not already aligned to the requested alignment value, it
 693  * will be rounded up.
 694  *
 695  * \param value  Value to be rounded
 696  * \param alignment  Alignment value to be used.  This must be a power of two.
 697  *
 698  * \sa ROUND_DOWN_TO()
 699  */
 700 #define ALIGN(value, alignment)  (((value) + (alignment) - 1) & ~((alignment) - 1))
 701
 702 /**
 703  * Align a value down to an alignment value
 704  *
 705  * If \c value is not already aligned to the requested alignment value, it
 706  * will be rounded down.
 707  *
 708  * \param value  Value to be rounded
 709  * \param alignment  Alignment value to be used.  This must be a power of two.
 710  *
 711  * \sa ALIGN()
 712  */
 713 #define ROUND_DOWN_TO(value, alignment) ((value) & ~(alignment - 1))
 714
 715
 716 /** Cross product of two 3-element vectors */
 717 static inline void
 718 CROSS3(GLfloat n[3], const GLfloat u[3], const GLfloat v[3])
 719 {
 720    n[0] = u[1] * v[2] - u[2] * v[1];
 721    n[1] = u[2] * v[0] - u[0] * v[2];
 722    n[2] = u[0] * v[1] - u[1] * v[0];
 723 }
 724
 725
 726 /** Dot product of two 2-element vectors */
 727 static inline GLfloat
 728 DOT2(const GLfloat a[2], const GLfloat b[2])
 729 {
 730    return a[0] * b[0] + a[1] * b[1];
 731 }
 732
 733 static inline GLfloat
 734 DOT3(const GLfloat a[3], const GLfloat b[3])
 735 {
 736    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 737 }
 738
 739 static inline GLfloat
 740 DOT4(const GLfloat a[4], const GLfloat b[4])
 741 {
 742    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
 743 }
 744
 745
 746 static inline GLfloat
 747 LEN_SQUARED_3FV(const GLfloat v[3])
 748 {
 749    return DOT3(v, v);
 750 }
 751
 752 static inline GLfloat
 753 LEN_SQUARED_2FV(const GLfloat v[2])
 754 {
 755    return DOT2(v, v);
 756 }
 757
 758
 759 static inline GLfloat
 760 LEN_3FV(const GLfloat v[3])
 761 {
 762    return sqrtf(LEN_SQUARED_3FV(v));
 763 }
 764
 765 static inline GLfloat
 766 LEN_2FV(const GLfloat v[2])
 767 {
 768    return sqrtf(LEN_SQUARED_2FV(v));
 769 }
 770
 771
 772 /* Normalize a 3-element vector to unit length. */
 773 static inline void
 774 NORMALIZE_3FV(GLfloat v[3])
 775 {
 776    GLfloat len = (GLfloat) LEN_SQUARED_3FV(v);
 777    if (len) {
 778       len = INV_SQRTF(len);
 779       v[0] *= len;
 780       v[1] *= len;
 781       v[2] *= len;
 782    }
 783 }
 784
 785
 786 /** Test two floats have opposite signs */
 787 static inline GLboolean
 788 DIFFERENT_SIGNS(GLfloat x, GLfloat y)
 789 {
 790    return signbit(x) != signbit(y);
 791 }
 792
 793
 794 /** Compute ceiling of integer quotient of A divided by B. */
 795 #define DIV_ROUND_UP( A, B )  ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
 796
 797
 798 /** casts to silence warnings with some compilers */
 799 #define ENUM_TO_INT(E)     ((GLint)(E))
 800 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
 801 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
 802 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
 803
 804 /* Compute the size of an array */
 805 #ifndef ARRAY_SIZE
 806 #  define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
 807 #endif
 808
 809 /* Stringify */
 810 #define STRINGIFY(x) #x
 811
 812 #endif