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/macros.h"
  35 #include "util/u_math.h"
  36 #include "imports.h"
  37
  38
  39 /**
  40  * \name Integer / float conversion for colors, normals, etc.
  41  */
  42 /*@{*/
  43
  44 /** Convert GLubyte in [0,255] to GLfloat in [0.0,1.0] */
  45 extern GLfloat _mesa_ubyte_to_float_color_tab[256];
  46 #define UBYTE_TO_FLOAT(u) _mesa_ubyte_to_float_color_tab[(unsigned int)(u)]
  47
  48 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
  49 #define FLOAT_TO_UBYTE(X)   ((GLubyte) (GLint) ((X) * 255.0F))
  50
  51
  52 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
  53 #define BYTE_TO_FLOAT(B)    ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
  54
  55 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
  56 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
  57
  58
  59 /** Convert GLbyte to GLfloat while preserving zero */
  60 #define BYTE_TO_FLOATZ(B)   ((B) == 0 ? 0.0F : BYTE_TO_FLOAT(B))
  61
  62
  63 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0], texture/fb data */
  64 #define BYTE_TO_FLOAT_TEX(B)    ((B) == -128 ? -1.0F : (B) * (1.0F/127.0F))
  65
  66 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127], texture/fb data */
  67 #define FLOAT_TO_BYTE_TEX(X)    CLAMP( (GLint) (127.0F * (X)), -128, 127 )
  68
  69 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
  70 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
  71
  72 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
  73 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0F))
  74
  75
  76 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
  77 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
  78
  79 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767] */
  80 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
  81
  82 /** Convert GLshort to GLfloat while preserving zero */
  83 #define SHORT_TO_FLOATZ(S)   ((S) == 0 ? 0.0F : SHORT_TO_FLOAT(S))
  84
  85
  86 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0], texture/fb data */
  87 #define SHORT_TO_FLOAT_TEX(S)    ((S) == -32768 ? -1.0F : (S) * (1.0F/32767.0F))
  88
  89 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767], texture/fb data */
  90 #define FLOAT_TO_SHORT_TEX(X)    ( (GLint) (32767.0F * (X)) )
  91
  92
  93 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
  94 #define UINT_TO_FLOAT(U)    ((GLfloat) ((U) * (1.0F / 4294967295.0)))
  95
  96 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
  97 #define FLOAT_TO_UINT(X)    ((GLuint) ((X) * 4294967295.0))
  98
  99
 100 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
 101 #define INT_TO_FLOAT(I)     ((GLfloat) ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0)))
 102
 103 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
 104 /* causes overflow:
 105 #define FLOAT_TO_INT(X)     ( (((GLint) (4294967294.0 * (X))) - 1) / 2 )
 106 */
 107 /* a close approximation: */
 108 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
 109
 110 /** Convert GLfloat in [-1.0,1.0] to GLint64 in [-(1<<63),(1 << 63) -1] */
 111 #define FLOAT_TO_INT64(X)     ( (GLint64) (9223372036854775807.0 * (double)(X)) )
 112
 113
 114 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0], texture/fb data */
 115 #define INT_TO_FLOAT_TEX(I)    ((I) == -2147483648 ? -1.0F : (I) * (1.0F/2147483647.0))
 116
 117 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647], texture/fb data */
 118 #define FLOAT_TO_INT_TEX(X)    ( (GLint) (2147483647.0 * (X)) )
 119
 120
 121 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
 122 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
 123 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))
 124 #define INT_TO_UBYTE(i)    ((GLubyte) ((i) < 0 ? 0 : (GLubyte) ((i) >> 23)))
 125 #define UINT_TO_UBYTE(i)   ((GLubyte) ((i) >> 24))
 126
 127
 128 #define BYTE_TO_USHORT(b)  ((b) < 0 ? 0 : ((GLushort) (((b) * 65535) / 255)))
 129 #define UBYTE_TO_USHORT(b) (((GLushort) (b) << 8) | (GLushort) (b))
 130 #define SHORT_TO_USHORT(s) ((s) < 0 ? 0 : ((GLushort) (((s) * 65535 / 32767))))
 131 #define INT_TO_USHORT(i)   ((i) < 0 ? 0 : ((GLushort) ((i) >> 15)))
 132 #define UINT_TO_USHORT(i)  ((i) < 0 ? 0 : ((GLushort) ((i) >> 16)))
 133 #define UNCLAMPED_FLOAT_TO_USHORT(us, f)  \
 134         us = ( (GLushort) F_TO_I( CLAMP((f), 0.0F, 1.0F) * 65535.0F) )
 135 #define CLAMPED_FLOAT_TO_USHORT(us, f)  \
 136         us = ( (GLushort) F_TO_I( (f) * 65535.0F) )
 137
 138 #define UNCLAMPED_FLOAT_TO_SHORT(s, f)  \
 139         s = ( (GLshort) F_TO_I( CLAMP((f), -1.0F, 1.0F) * 32767.0F) )
 140
 141 /***
 142  *** UNCLAMPED_FLOAT_TO_UBYTE: clamp float to [0,1] and map to ubyte in [0,255]
 143  *** CLAMPED_FLOAT_TO_UBYTE: map float known to be in [0,1] to ubyte in [0,255]
 144  ***/
 145 #ifndef DEBUG
 146 /* This function/macro is sensitive to precision.  Test very carefully
 147  * if you change it!
 148  */
 149 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, FLT)                               \
 150         do {                                                            \
 151            fi_type __tmp;                                               \
 152            __tmp.f = (FLT);                                             \
 153            if (__tmp.i < 0)                                             \
 154               UB = (GLubyte) 0;                                         \
 155            else if (__tmp.i >= IEEE_ONE)                                \
 156               UB = (GLubyte) 255;                                       \
 157            else {                                                       \
 158               __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F;           \
 159               UB = (GLubyte) __tmp.i;                                   \
 160            }                                                            \
 161         } while (0)
 162 #define CLAMPED_FLOAT_TO_UBYTE(UB, FLT)                                 \
 163         do {                                                            \
 164            fi_type __tmp;                                               \
 165            __tmp.f = (FLT) * (255.0F/256.0F) + 32768.0F;                \
 166            UB = (GLubyte) __tmp.i;                                      \
 167         } while (0)
 168 #else
 169 #define UNCLAMPED_FLOAT_TO_UBYTE(ub, f) \
 170         ub = ((GLubyte) F_TO_I(CLAMP((f), 0.0F, 1.0F) * 255.0F))
 171 #define CLAMPED_FLOAT_TO_UBYTE(ub, f) \
 172         ub = ((GLubyte) F_TO_I((f) * 255.0F))
 173 #endif
 174
 175 static fi_type UINT_AS_UNION(GLuint u)
 176 {
 177    fi_type tmp;
 178    tmp.u = u;
 179    return tmp;
 180 }
 181
 182 static inline fi_type INT_AS_UNION(GLint i)
 183 {
 184    fi_type tmp;
 185    tmp.i = i;
 186    return tmp;
 187 }
 188
 189 static inline fi_type FLOAT_AS_UNION(GLfloat f)
 190 {
 191    fi_type tmp;
 192    tmp.f = f;
 193    return tmp;
 194 }
 195
 196 /**
 197  * Convert a floating point value to an unsigned fixed point value.
 198  *
 199  * \param frac_bits   The number of bits used to store the fractional part.
 200  */
 201 static inline uint32_t
 202 U_FIXED(float value, uint32_t frac_bits)
 203 {
 204    value *= (1 << frac_bits);
 205    return value < 0.0f ? 0 : (uint32_t) value;
 206 }
 207
 208 /**
 209  * Convert a floating point value to an signed fixed point value.
 210  *
 211  * \param frac_bits   The number of bits used to store the fractional part.
 212  */
 213 static inline int32_t
 214 S_FIXED(float value, uint32_t frac_bits)
 215 {
 216    return (int32_t) (value * (1 << frac_bits));
 217 }
 218 /*@}*/
 219
 220
 221 /** Stepping a GLfloat pointer by a byte stride */
 222 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
 223 /** Stepping a GLuint pointer by a byte stride */
 224 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
 225 /** Stepping a GLubyte[4] pointer by a byte stride */
 226 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
 227 /** Stepping a GLfloat[4] pointer by a byte stride */
 228 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
 229 /** Stepping a \p t pointer by a byte stride */
 230 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
 231
 232
 233 /**********************************************************************/
 234 /** \name 4-element vector operations */
 235 /*@{*/
 236
 237 /** Zero */
 238 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
 239
 240 /** Test for equality */
 241 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
 242               (a)[1] == (b)[1] &&   \
 243               (a)[2] == (b)[2] &&   \
 244               (a)[3] == (b)[3])
 245
 246 /** Test for equality (unsigned bytes) */
 247 static inline GLboolean
 248 TEST_EQ_4UBV(const GLubyte a[4], const GLubyte b[4])
 249 {
 250 #if defined(__i386__)
 251    return *((const GLuint *) a) == *((const GLuint *) b);
 252 #else
 253    return TEST_EQ_4V(a, b);
 254 #endif
 255 }
 256
 257
 258 /** Copy a 4-element vector */
 259 #define COPY_4V( DST, SRC )         \
 260 do {                                \
 261    (DST)[0] = (SRC)[0];             \
 262    (DST)[1] = (SRC)[1];             \
 263    (DST)[2] = (SRC)[2];             \
 264    (DST)[3] = (SRC)[3];             \
 265 } while (0)
 266
 267 /** Copy a 4-element unsigned byte vector */
 268 static inline void
 269 COPY_4UBV(GLubyte dst[4], const GLubyte src[4])
 270 {
 271 #if defined(__i386__)
 272    *((GLuint *) dst) = *((GLuint *) src);
 273 #else
 274    /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
 275    COPY_4V(dst, src);
 276 #endif
 277 }
 278
 279 /** Copy \p SZ elements into a 4-element vector */
 280 #define COPY_SZ_4V(DST, SZ, SRC)  \
 281 do {                              \
 282    switch (SZ) {                  \
 283    case 4: (DST)[3] = (SRC)[3];   \
 284    case 3: (DST)[2] = (SRC)[2];   \
 285    case 2: (DST)[1] = (SRC)[1];   \
 286    case 1: (DST)[0] = (SRC)[0];   \
 287    }                              \
 288 } while(0)
 289
 290 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
 291  * default values to the remaining */
 292 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
 293 do {                                 \
 294       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
 295       COPY_SZ_4V( DST, SZ, SRC );    \
 296 } while (0)
 297
 298 /** Subtraction */
 299 #define SUB_4V( DST, SRCA, SRCB )           \
 300 do {                                        \
 301       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 302       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 303       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
 304       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
 305 } while (0)
 306
 307 /** Addition */
 308 #define ADD_4V( DST, SRCA, SRCB )           \
 309 do {                                        \
 310       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 311       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 312       (DST)[2] = (SRCA)[2] + (SRCB)[2];     \
 313       (DST)[3] = (SRCA)[3] + (SRCB)[3];     \
 314 } while (0)
 315
 316 /** Element-wise multiplication */
 317 #define SCALE_4V( DST, SRCA, SRCB )         \
 318 do {                                        \
 319       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 320       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 321       (DST)[2] = (SRCA)[2] * (SRCB)[2];     \
 322       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
 323 } while (0)
 324
 325 /** In-place addition */
 326 #define ACC_4V( DST, SRC )          \
 327 do {                                \
 328       (DST)[0] += (SRC)[0];         \
 329       (DST)[1] += (SRC)[1];         \
 330       (DST)[2] += (SRC)[2];         \
 331       (DST)[3] += (SRC)[3];         \
 332 } while (0)
 333
 334 /** Element-wise multiplication and addition */
 335 #define ACC_SCALE_4V( 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       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
 341 } while (0)
 342
 343 /** In-place scalar multiplication and addition */
 344 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
 345 do {                                        \
 346       (DST)[0] += S * (SRCB)[0];            \
 347       (DST)[1] += S * (SRCB)[1];            \
 348       (DST)[2] += S * (SRCB)[2];            \
 349       (DST)[3] += S * (SRCB)[3];            \
 350 } while (0)
 351
 352 /** Scalar multiplication */
 353 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
 354 do {                                    \
 355       (DST)[0] = S * (SRCB)[0];         \
 356       (DST)[1] = S * (SRCB)[1];         \
 357       (DST)[2] = S * (SRCB)[2];         \
 358       (DST)[3] = S * (SRCB)[3];         \
 359 } while (0)
 360
 361 /** In-place scalar multiplication */
 362 #define SELF_SCALE_SCALAR_4V( DST, S ) \
 363 do {                                   \
 364       (DST)[0] *= S;                   \
 365       (DST)[1] *= S;                   \
 366       (DST)[2] *= S;                   \
 367       (DST)[3] *= S;                   \
 368 } while (0)
 369
 370 /*@}*/
 371
 372
 373 /**********************************************************************/
 374 /** \name 3-element vector operations*/
 375 /*@{*/
 376
 377 /** Zero */
 378 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
 379
 380 /** Test for equality */
 381 #define TEST_EQ_3V(a,b)  \
 382    ((a)[0] == (b)[0] &&  \
 383     (a)[1] == (b)[1] &&  \
 384     (a)[2] == (b)[2])
 385
 386 /** Copy a 3-element vector */
 387 #define COPY_3V( DST, SRC )         \
 388 do {                                \
 389    (DST)[0] = (SRC)[0];             \
 390    (DST)[1] = (SRC)[1];             \
 391    (DST)[2] = (SRC)[2];             \
 392 } while (0)
 393
 394 /** Copy a 3-element vector with cast */
 395 #define COPY_3V_CAST( DST, SRC, CAST )  \
 396 do {                                    \
 397    (DST)[0] = (CAST)(SRC)[0];           \
 398    (DST)[1] = (CAST)(SRC)[1];           \
 399    (DST)[2] = (CAST)(SRC)[2];           \
 400 } while (0)
 401
 402 /** Copy a 3-element float vector */
 403 #define COPY_3FV( DST, SRC )        \
 404 do {                                \
 405    const GLfloat *_tmp = (SRC);     \
 406    (DST)[0] = _tmp[0];              \
 407    (DST)[1] = _tmp[1];              \
 408    (DST)[2] = _tmp[2];              \
 409 } while (0)
 410
 411 /** Subtraction */
 412 #define SUB_3V( DST, SRCA, SRCB )        \
 413 do {                                     \
 414       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
 415       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
 416       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
 417 } while (0)
 418
 419 /** Addition */
 420 #define ADD_3V( DST, SRCA, SRCB )       \
 421 do {                                    \
 422       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
 423       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
 424       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
 425 } while (0)
 426
 427 /** In-place scalar multiplication */
 428 #define SCALE_3V( DST, SRCA, SRCB )     \
 429 do {                                    \
 430       (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
 431       (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
 432       (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
 433 } while (0)
 434
 435 /** In-place element-wise multiplication */
 436 #define SELF_SCALE_3V( DST, SRC )   \
 437 do {                                \
 438       (DST)[0] *= (SRC)[0];         \
 439       (DST)[1] *= (SRC)[1];         \
 440       (DST)[2] *= (SRC)[2];         \
 441 } while (0)
 442
 443 /** In-place addition */
 444 #define ACC_3V( DST, SRC )          \
 445 do {                                \
 446       (DST)[0] += (SRC)[0];         \
 447       (DST)[1] += (SRC)[1];         \
 448       (DST)[2] += (SRC)[2];         \
 449 } while (0)
 450
 451 /** Element-wise multiplication and addition */
 452 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
 453 do {                                        \
 454       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 455       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 456       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 457 } while (0)
 458
 459 /** Scalar multiplication */
 460 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
 461 do {                                    \
 462       (DST)[0] = S * (SRCB)[0];         \
 463       (DST)[1] = S * (SRCB)[1];         \
 464       (DST)[2] = S * (SRCB)[2];         \
 465 } while (0)
 466
 467 /** In-place scalar multiplication and addition */
 468 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
 469 do {                                        \
 470       (DST)[0] += S * (SRCB)[0];            \
 471       (DST)[1] += S * (SRCB)[1];            \
 472       (DST)[2] += S * (SRCB)[2];            \
 473 } while (0)
 474
 475 /** In-place scalar multiplication */
 476 #define SELF_SCALE_SCALAR_3V( DST, S ) \
 477 do {                                   \
 478       (DST)[0] *= S;                   \
 479       (DST)[1] *= S;                   \
 480       (DST)[2] *= S;                   \
 481 } while (0)
 482
 483 /** In-place scalar addition */
 484 #define ACC_SCALAR_3V( DST, S )     \
 485 do {                                \
 486       (DST)[0] += S;                \
 487       (DST)[1] += S;                \
 488       (DST)[2] += S;                \
 489 } while (0)
 490
 491 /** Assignment */
 492 #define ASSIGN_3V( V, V0, V1, V2 )  \
 493 do {                                \
 494     V[0] = V0;                      \
 495     V[1] = V1;                      \
 496     V[2] = V2;                      \
 497 } while(0)
 498
 499 /*@}*/
 500
 501
 502 /**********************************************************************/
 503 /** \name 2-element vector operations*/
 504 /*@{*/
 505
 506 /** Zero */
 507 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
 508
 509 /** Copy a 2-element vector */
 510 #define COPY_2V( DST, SRC )         \
 511 do {                        \
 512    (DST)[0] = (SRC)[0];             \
 513    (DST)[1] = (SRC)[1];             \
 514 } while (0)
 515
 516 /** Copy a 2-element vector with cast */
 517 #define COPY_2V_CAST( DST, SRC, CAST )      \
 518 do {                        \
 519    (DST)[0] = (CAST)(SRC)[0];           \
 520    (DST)[1] = (CAST)(SRC)[1];           \
 521 } while (0)
 522
 523 /** Copy a 2-element float vector */
 524 #define COPY_2FV( DST, SRC )            \
 525 do {                        \
 526    const GLfloat *_tmp = (SRC);         \
 527    (DST)[0] = _tmp[0];              \
 528    (DST)[1] = _tmp[1];              \
 529 } while (0)
 530
 531 /** Subtraction */
 532 #define SUB_2V( DST, SRCA, SRCB )       \
 533 do {                        \
 534       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 535       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 536 } while (0)
 537
 538 /** Addition */
 539 #define ADD_2V( DST, SRCA, SRCB )       \
 540 do {                        \
 541       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 542       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 543 } while (0)
 544
 545 /** In-place scalar multiplication */
 546 #define SCALE_2V( DST, SRCA, SRCB )     \
 547 do {                        \
 548       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 549       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 550 } while (0)
 551
 552 /** In-place addition */
 553 #define ACC_2V( DST, SRC )          \
 554 do {                        \
 555       (DST)[0] += (SRC)[0];         \
 556       (DST)[1] += (SRC)[1];         \
 557 } while (0)
 558
 559 /** Element-wise multiplication and addition */
 560 #define ACC_SCALE_2V( DST, SRCA, SRCB )     \
 561 do {                        \
 562       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 563       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 564 } while (0)
 565
 566 /** Scalar multiplication */
 567 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
 568 do {                        \
 569       (DST)[0] = S * (SRCB)[0];         \
 570       (DST)[1] = S * (SRCB)[1];         \
 571 } while (0)
 572
 573 /** In-place scalar multiplication and addition */
 574 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
 575 do {                        \
 576       (DST)[0] += S * (SRCB)[0];        \
 577       (DST)[1] += S * (SRCB)[1];        \
 578 } while (0)
 579
 580 /** In-place scalar multiplication */
 581 #define SELF_SCALE_SCALAR_2V( DST, S )      \
 582 do {                        \
 583       (DST)[0] *= S;                \
 584       (DST)[1] *= S;                \
 585 } while (0)
 586
 587 /** In-place scalar addition */
 588 #define ACC_SCALAR_2V( DST, S )         \
 589 do {                        \
 590       (DST)[0] += S;                \
 591       (DST)[1] += S;                \
 592 } while (0)
 593
 594 /** Assign scalers to short vectors */
 595 #define ASSIGN_2V( V, V0, V1 )  \
 596 do {                            \
 597     V[0] = V0;                  \
 598     V[1] = V1;                  \
 599 } while(0)
 600
 601 /*@}*/
 602
 603 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
 604  * default values to the remaining components.
 605  * The default values are chosen based on \p type.
 606  */
 607 static inline void
 608 COPY_CLEAN_4V_TYPE_AS_UNION(fi_type dst[4], int sz, const fi_type src[4],
 609                             GLenum type)
 610 {
 611    switch (type) {
 612    case GL_FLOAT:
 613       ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
 614                 FLOAT_AS_UNION(0), FLOAT_AS_UNION(1));
 615       break;
 616    case GL_INT:
 617       ASSIGN_4V(dst, INT_AS_UNION(0), INT_AS_UNION(0),
 618                 INT_AS_UNION(0), INT_AS_UNION(1));
 619       break;
 620    case GL_UNSIGNED_INT:
 621       ASSIGN_4V(dst, UINT_AS_UNION(0), UINT_AS_UNION(0),
 622                 UINT_AS_UNION(0), UINT_AS_UNION(1));
 623       break;
 624    default:
 625       ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
 626                 FLOAT_AS_UNION(0), FLOAT_AS_UNION(1)); /* silence warnings */
 627       assert(!"Unexpected type in COPY_CLEAN_4V_TYPE_AS_UNION macro");
 628    }
 629    COPY_SZ_4V(dst, sz, src);
 630 }
 631
 632 /** \name Linear interpolation functions */
 633 /*@{*/
 634
 635 static inline GLfloat
 636 LINTERP(GLfloat t, GLfloat out, GLfloat in)
 637 {
 638    return out + t * (in - out);
 639 }
 640
 641 static inline void
 642 INTERP_3F(GLfloat t, GLfloat dst[3], const GLfloat out[3], const GLfloat in[3])
 643 {
 644    dst[0] = LINTERP( t, out[0], in[0] );
 645    dst[1] = LINTERP( t, out[1], in[1] );
 646    dst[2] = LINTERP( t, out[2], in[2] );
 647 }
 648
 649 static inline void
 650 INTERP_4F(GLfloat t, GLfloat dst[4], const GLfloat out[4], const GLfloat in[4])
 651 {
 652    dst[0] = LINTERP( t, out[0], in[0] );
 653    dst[1] = LINTERP( t, out[1], in[1] );
 654    dst[2] = LINTERP( t, out[2], in[2] );
 655    dst[3] = LINTERP( t, out[3], in[3] );
 656 }
 657
 658 /*@}*/
 659
 660
 661
 662 /** Clamp X to [MIN,MAX] */
 663 #define CLAMP( X, MIN, MAX )  ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
 664
 665 /** Minimum of two values: */
 666 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
 667
 668 /** Maximum of two values: */
 669 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
 670
 671 /** Minimum and maximum of three values: */
 672 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
 673 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
 674
 675 static inline unsigned
 676 minify(unsigned value, unsigned levels)
 677 {
 678     return MAX2(1, value >> levels);
 679 }
 680
 681 /**
 682  * Return true if the given value is a power of two.
 683  *
 684  * Note that this considers 0 a power of two.
 685  */
 686 static inline bool
 687 is_power_of_two(unsigned value)
 688 {
 689    return (value & (value - 1)) == 0;
 690 }
 691
 692 /**
 693  * Align a value up to an alignment value
 694  *
 695  * If \c value is not already aligned to the requested alignment value, it
 696  * will be rounded up.
 697  *
 698  * \param value  Value to be rounded
 699  * \param alignment  Alignment value to be used.  This must be a power of two.
 700  *
 701  * \sa ROUND_DOWN_TO()
 702  */
 703 #define ALIGN(value, alignment)  (((value) + (alignment) - 1) & ~((alignment) - 1))
 704
 705 /**
 706  * Align a value down to an alignment value
 707  *
 708  * If \c value is not already aligned to the requested alignment value, it
 709  * will be rounded down.
 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 ALIGN()
 715  */
 716 #define ROUND_DOWN_TO(value, alignment) ((value) & ~(alignment - 1))
 717
 718
 719 /** Cross product of two 3-element vectors */
 720 static inline void
 721 CROSS3(GLfloat n[3], const GLfloat u[3], const GLfloat v[3])
 722 {
 723    n[0] = u[1] * v[2] - u[2] * v[1];
 724    n[1] = u[2] * v[0] - u[0] * v[2];
 725    n[2] = u[0] * v[1] - u[1] * v[0];
 726 }
 727
 728
 729 /** Dot product of two 2-element vectors */
 730 static inline GLfloat
 731 DOT2(const GLfloat a[2], const GLfloat b[2])
 732 {
 733    return a[0] * b[0] + a[1] * b[1];
 734 }
 735
 736 static inline GLfloat
 737 DOT3(const GLfloat a[3], const GLfloat b[3])
 738 {
 739    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 740 }
 741
 742 static inline GLfloat
 743 DOT4(const GLfloat a[4], const GLfloat b[4])
 744 {
 745    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
 746 }
 747
 748
 749 static inline GLfloat
 750 LEN_SQUARED_3FV(const GLfloat v[3])
 751 {
 752    return DOT3(v, v);
 753 }
 754
 755 static inline GLfloat
 756 LEN_SQUARED_2FV(const GLfloat v[2])
 757 {
 758    return DOT2(v, v);
 759 }
 760
 761
 762 static inline GLfloat
 763 LEN_3FV(const GLfloat v[3])
 764 {
 765    return sqrtf(LEN_SQUARED_3FV(v));
 766 }
 767
 768 static inline GLfloat
 769 LEN_2FV(const GLfloat v[2])
 770 {
 771    return sqrtf(LEN_SQUARED_2FV(v));
 772 }
 773
 774
 775 /* Normalize a 3-element vector to unit length. */
 776 static inline void
 777 NORMALIZE_3FV(GLfloat v[3])
 778 {
 779    GLfloat len = (GLfloat) LEN_SQUARED_3FV(v);
 780    if (len) {
 781       len = 1.0f / sqrtf(len);
 782       v[0] *= len;
 783       v[1] *= len;
 784       v[2] *= len;
 785    }
 786 }
 787
 788
 789 /** Test two floats have opposite signs */
 790 static inline GLboolean
 791 DIFFERENT_SIGNS(GLfloat x, GLfloat y)
 792 {
 793 #ifdef _MSC_VER
 794 #pragma warning( push )
 795 #pragma warning( disable : 6334 ) /* sizeof operator applied to an expression with an operator may yield unexpected results */
 796 #endif
 797    return signbit(x) != signbit(y);
 798 #ifdef _MSC_VER
 799 #pragma warning( pop )
 800 #endif
 801 }
 802
 803
 804 /** casts to silence warnings with some compilers */
 805 #define ENUM_TO_INT(E)     ((GLint)(E))
 806 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
 807 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
 808 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
 809
 810
 811 /* Stringify */
 812 #define STRINGIFY(x) #x
 813
 814 #endif