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 "util/rounding.h"
  37 #include "util/imports.h"
  38 #include "main/glheader.h"
  39
  40
  41 /**
  42  * \name Integer / float conversion for colors, normals, etc.
  43  */
  44 /*@{*/
  45
  46 /** Convert GLubyte in [0,255] to GLfloat in [0.0,1.0] */
  47 extern GLfloat _mesa_ubyte_to_float_color_tab[256];
  48 #define UBYTE_TO_FLOAT(u) _mesa_ubyte_to_float_color_tab[(unsigned int)(u)]
  49
  50 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
  51 #define FLOAT_TO_UBYTE(X)   ((GLubyte) (GLint) ((X) * 255.0F))
  52
  53
  54 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
  55 #define BYTE_TO_FLOAT(B)    ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
  56
  57 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
  58 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
  59
  60
  61 /** Convert GLbyte to GLfloat while preserving zero */
  62 #define BYTE_TO_FLOATZ(B)   ((B) == 0 ? 0.0F : BYTE_TO_FLOAT(B))
  63
  64
  65 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0], texture/fb data */
  66 #define BYTE_TO_FLOAT_TEX(B)    ((B) == -128 ? -1.0F : (B) * (1.0F/127.0F))
  67
  68 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127], texture/fb data */
  69 #define FLOAT_TO_BYTE_TEX(X)    CLAMP( (GLint) (127.0F * (X)), -128, 127 )
  70
  71 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
  72 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
  73
  74 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
  75 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0F))
  76
  77
  78 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
  79 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
  80
  81 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767] */
  82 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
  83
  84 /** Convert GLshort to GLfloat while preserving zero */
  85 #define SHORT_TO_FLOATZ(S)   ((S) == 0 ? 0.0F : SHORT_TO_FLOAT(S))
  86
  87
  88 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0], texture/fb data */
  89 #define SHORT_TO_FLOAT_TEX(S)    ((S) == -32768 ? -1.0F : (S) * (1.0F/32767.0F))
  90
  91 /** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767], texture/fb data */
  92 #define FLOAT_TO_SHORT_TEX(X)    ( (GLint) (32767.0F * (X)) )
  93
  94
  95 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
  96 #define UINT_TO_FLOAT(U)    ((GLfloat) ((U) * (1.0F / 4294967295.0)))
  97
  98 /** Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
  99 #define FLOAT_TO_UINT(X)    ((GLuint) ((X) * 4294967295.0))
 100
 101
 102 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
 103 #define INT_TO_FLOAT(I)     ((GLfloat) ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0)))
 104
 105 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
 106 /* causes overflow:
 107 #define FLOAT_TO_INT(X)     ( (((GLint) (4294967294.0 * (X))) - 1) / 2 )
 108 */
 109 /* a close approximation: */
 110 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
 111
 112 /** Convert GLfloat in [-1.0,1.0] to GLint64 in [-(1<<63),(1 << 63) -1] */
 113 #define FLOAT_TO_INT64(X)     ( (GLint64) (9223372036854775807.0 * (double)(X)) )
 114
 115
 116 /** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0], texture/fb data */
 117 #define INT_TO_FLOAT_TEX(I)    ((I) == -2147483648 ? -1.0F : (I) * (1.0F/2147483647.0))
 118
 119 /** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647], texture/fb data */
 120 #define FLOAT_TO_INT_TEX(X)    ( (GLint) (2147483647.0 * (X)) )
 121
 122
 123 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
 124 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
 125 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))
 126 #define INT_TO_UBYTE(i)    ((GLubyte) ((i) < 0 ? 0 : (GLubyte) ((i) >> 23)))
 127 #define UINT_TO_UBYTE(i)   ((GLubyte) ((i) >> 24))
 128
 129
 130 #define BYTE_TO_USHORT(b)  ((b) < 0 ? 0 : ((GLushort) (((b) * 65535) / 255)))
 131 #define UBYTE_TO_USHORT(b) (((GLushort) (b) << 8) | (GLushort) (b))
 132 #define SHORT_TO_USHORT(s) ((s) < 0 ? 0 : ((GLushort) (((s) * 65535 / 32767))))
 133 #define INT_TO_USHORT(i)   ((i) < 0 ? 0 : ((GLushort) ((i) >> 15)))
 134 #define UINT_TO_USHORT(i)  ((i) < 0 ? 0 : ((GLushort) ((i) >> 16)))
 135 #define UNCLAMPED_FLOAT_TO_USHORT(us, f)  \
 136         us = ( (GLushort) _mesa_lroundevenf( CLAMP((f), 0.0F, 1.0F) * 65535.0F) )
 137 #define CLAMPED_FLOAT_TO_USHORT(us, f)  \
 138         us = ( (GLushort) _mesa_lroundevenf( (f) * 65535.0F) )
 139
 140 #define UNCLAMPED_FLOAT_TO_SHORT(s, f)  \
 141         s = ( (GLshort) _mesa_lroundevenf( CLAMP((f), -1.0F, 1.0F) * 32767.0F) )
 142
 143 /***
 144  *** UNCLAMPED_FLOAT_TO_UBYTE: clamp float to [0,1] and map to ubyte in [0,255]
 145  *** CLAMPED_FLOAT_TO_UBYTE: map float known to be in [0,1] to ubyte in [0,255]
 146  ***/
 147 #ifndef DEBUG
 148 /* This function/macro is sensitive to precision.  Test very carefully
 149  * if you change it!
 150  */
 151 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, FLT)                               \
 152         do {                                                            \
 153            fi_type __tmp;                                               \
 154            __tmp.f = (FLT);                                             \
 155            if (__tmp.i < 0)                                             \
 156               UB = (GLubyte) 0;                                         \
 157            else if (__tmp.i >= IEEE_ONE)                                \
 158               UB = (GLubyte) 255;                                       \
 159            else {                                                       \
 160               __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F;           \
 161               UB = (GLubyte) __tmp.i;                                   \
 162            }                                                            \
 163         } while (0)
 164 #define CLAMPED_FLOAT_TO_UBYTE(UB, FLT)                                 \
 165         do {                                                            \
 166            fi_type __tmp;                                               \
 167            __tmp.f = (FLT) * (255.0F/256.0F) + 32768.0F;                \
 168            UB = (GLubyte) __tmp.i;                                      \
 169         } while (0)
 170 #else
 171 #define UNCLAMPED_FLOAT_TO_UBYTE(ub, f) \
 172         ub = ((GLubyte) _mesa_lroundevenf(CLAMP((f), 0.0F, 1.0F) * 255.0F))
 173 #define CLAMPED_FLOAT_TO_UBYTE(ub, f) \
 174         ub = ((GLubyte) _mesa_lroundevenf((f) * 255.0F))
 175 #endif
 176
 177 static fi_type UINT_AS_UNION(GLuint u)
 178 {
 179    fi_type tmp;
 180    tmp.u = u;
 181    return tmp;
 182 }
 183
 184 static inline fi_type INT_AS_UNION(GLint i)
 185 {
 186    fi_type tmp;
 187    tmp.i = i;
 188    return tmp;
 189 }
 190
 191 static inline fi_type FLOAT_AS_UNION(GLfloat f)
 192 {
 193    fi_type tmp;
 194    tmp.f = f;
 195    return tmp;
 196 }
 197
 198 static inline uint64_t DOUBLE_AS_UINT64(double d)
 199 {
 200    union {
 201       double d;
 202       uint64_t u64;
 203    } tmp;
 204    tmp.d = d;
 205    return tmp.u64;
 206 }
 207
 208 static inline double UINT64_AS_DOUBLE(uint64_t u)
 209 {
 210    union {
 211       double d;
 212       uint64_t u64;
 213    } tmp;
 214    tmp.u64 = u;
 215    return tmp.d;
 216 }
 217
 218 /* First sign-extend x, then return uint32_t. */
 219 #define INT_AS_UINT(x) ((uint32_t)((int32_t)(x)))
 220 #define FLOAT_AS_UINT(x) (FLOAT_AS_UNION(x).u)
 221
 222 /**
 223  * Convert a floating point value to an unsigned fixed point value.
 224  *
 225  * \param frac_bits   The number of bits used to store the fractional part.
 226  */
 227 static inline uint32_t
 228 U_FIXED(float value, uint32_t frac_bits)
 229 {
 230    value *= (1 << frac_bits);
 231    return value < 0.0f ? 0 : (uint32_t) value;
 232 }
 233
 234 /**
 235  * Convert a floating point value to an signed fixed point value.
 236  *
 237  * \param frac_bits   The number of bits used to store the fractional part.
 238  */
 239 static inline int32_t
 240 S_FIXED(float value, uint32_t frac_bits)
 241 {
 242    return (int32_t) (value * (1 << frac_bits));
 243 }
 244 /*@}*/
 245
 246
 247 /** Stepping a GLfloat pointer by a byte stride */
 248 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
 249 /** Stepping a GLuint pointer by a byte stride */
 250 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
 251 /** Stepping a GLubyte[4] pointer by a byte stride */
 252 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
 253 /** Stepping a GLfloat[4] pointer by a byte stride */
 254 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
 255 /** Stepping a \p t pointer by a byte stride */
 256 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
 257
 258
 259 /**********************************************************************/
 260 /** \name 4-element vector operations */
 261 /*@{*/
 262
 263 /** Zero */
 264 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
 265
 266 /** Test for equality */
 267 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
 268               (a)[1] == (b)[1] &&   \
 269               (a)[2] == (b)[2] &&   \
 270               (a)[3] == (b)[3])
 271
 272 /** Test for equality (unsigned bytes) */
 273 static inline GLboolean
 274 TEST_EQ_4UBV(const GLubyte a[4], const GLubyte b[4])
 275 {
 276 #if defined(__i386__)
 277    return *((const GLuint *) a) == *((const GLuint *) b);
 278 #else
 279    return TEST_EQ_4V(a, b);
 280 #endif
 281 }
 282
 283
 284 /** Copy a 4-element vector */
 285 #define COPY_4V( DST, SRC )         \
 286 do {                                \
 287    (DST)[0] = (SRC)[0];             \
 288    (DST)[1] = (SRC)[1];             \
 289    (DST)[2] = (SRC)[2];             \
 290    (DST)[3] = (SRC)[3];             \
 291 } while (0)
 292
 293 /** Copy a 4-element unsigned byte vector */
 294 static inline void
 295 COPY_4UBV(GLubyte dst[4], const GLubyte src[4])
 296 {
 297 #if defined(__i386__)
 298    *((GLuint *) dst) = *((GLuint *) src);
 299 #else
 300    /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
 301    COPY_4V(dst, src);
 302 #endif
 303 }
 304
 305 /** Copy \p SZ elements into a 4-element vector */
 306 #define COPY_SZ_4V(DST, SZ, SRC)  \
 307 do {                              \
 308    switch (SZ) {                  \
 309    case 4: (DST)[3] = (SRC)[3];   \
 310    case 3: (DST)[2] = (SRC)[2];   \
 311    case 2: (DST)[1] = (SRC)[1];   \
 312    case 1: (DST)[0] = (SRC)[0];   \
 313    }                              \
 314 } while(0)
 315
 316 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
 317  * default values to the remaining */
 318 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
 319 do {                                 \
 320       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
 321       COPY_SZ_4V( DST, SZ, SRC );    \
 322 } while (0)
 323
 324 /** Subtraction */
 325 #define SUB_4V( DST, SRCA, SRCB )           \
 326 do {                                        \
 327       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 328       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 329       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
 330       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
 331 } while (0)
 332
 333 /** Addition */
 334 #define ADD_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 /** Element-wise multiplication */
 343 #define SCALE_4V( 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       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
 349 } while (0)
 350
 351 /** In-place addition */
 352 #define ACC_4V( DST, SRC )          \
 353 do {                                \
 354       (DST)[0] += (SRC)[0];         \
 355       (DST)[1] += (SRC)[1];         \
 356       (DST)[2] += (SRC)[2];         \
 357       (DST)[3] += (SRC)[3];         \
 358 } while (0)
 359
 360 /** Element-wise multiplication and addition */
 361 #define ACC_SCALE_4V( DST, SRCA, SRCB )     \
 362 do {                                        \
 363       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 364       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 365       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 366       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
 367 } while (0)
 368
 369 /** In-place scalar multiplication and addition */
 370 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
 371 do {                                        \
 372       (DST)[0] += S * (SRCB)[0];            \
 373       (DST)[1] += S * (SRCB)[1];            \
 374       (DST)[2] += S * (SRCB)[2];            \
 375       (DST)[3] += S * (SRCB)[3];            \
 376 } while (0)
 377
 378 /** Scalar multiplication */
 379 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
 380 do {                                    \
 381       (DST)[0] = S * (SRCB)[0];         \
 382       (DST)[1] = S * (SRCB)[1];         \
 383       (DST)[2] = S * (SRCB)[2];         \
 384       (DST)[3] = S * (SRCB)[3];         \
 385 } while (0)
 386
 387 /** In-place scalar multiplication */
 388 #define SELF_SCALE_SCALAR_4V( DST, S ) \
 389 do {                                   \
 390       (DST)[0] *= S;                   \
 391       (DST)[1] *= S;                   \
 392       (DST)[2] *= S;                   \
 393       (DST)[3] *= S;                   \
 394 } while (0)
 395
 396 /*@}*/
 397
 398
 399 /**********************************************************************/
 400 /** \name 3-element vector operations*/
 401 /*@{*/
 402
 403 /** Zero */
 404 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
 405
 406 /** Test for equality */
 407 #define TEST_EQ_3V(a,b)  \
 408    ((a)[0] == (b)[0] &&  \
 409     (a)[1] == (b)[1] &&  \
 410     (a)[2] == (b)[2])
 411
 412 /** Copy a 3-element vector */
 413 #define COPY_3V( DST, SRC )         \
 414 do {                                \
 415    (DST)[0] = (SRC)[0];             \
 416    (DST)[1] = (SRC)[1];             \
 417    (DST)[2] = (SRC)[2];             \
 418 } while (0)
 419
 420 /** Copy a 3-element vector with cast */
 421 #define COPY_3V_CAST( DST, SRC, CAST )  \
 422 do {                                    \
 423    (DST)[0] = (CAST)(SRC)[0];           \
 424    (DST)[1] = (CAST)(SRC)[1];           \
 425    (DST)[2] = (CAST)(SRC)[2];           \
 426 } while (0)
 427
 428 /** Copy a 3-element float vector */
 429 #define COPY_3FV( DST, SRC )        \
 430 do {                                \
 431    const GLfloat *_tmp = (SRC);     \
 432    (DST)[0] = _tmp[0];              \
 433    (DST)[1] = _tmp[1];              \
 434    (DST)[2] = _tmp[2];              \
 435 } while (0)
 436
 437 /** Subtraction */
 438 #define SUB_3V( DST, SRCA, SRCB )        \
 439 do {                                     \
 440       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
 441       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
 442       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
 443 } while (0)
 444
 445 /** Addition */
 446 #define ADD_3V( DST, SRCA, SRCB )       \
 447 do {                                    \
 448       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
 449       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
 450       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
 451 } while (0)
 452
 453 /** In-place scalar multiplication */
 454 #define SCALE_3V( DST, SRCA, SRCB )     \
 455 do {                                    \
 456       (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
 457       (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
 458       (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
 459 } while (0)
 460
 461 /** In-place element-wise multiplication */
 462 #define SELF_SCALE_3V( DST, SRC )   \
 463 do {                                \
 464       (DST)[0] *= (SRC)[0];         \
 465       (DST)[1] *= (SRC)[1];         \
 466       (DST)[2] *= (SRC)[2];         \
 467 } while (0)
 468
 469 /** In-place addition */
 470 #define ACC_3V( DST, SRC )          \
 471 do {                                \
 472       (DST)[0] += (SRC)[0];         \
 473       (DST)[1] += (SRC)[1];         \
 474       (DST)[2] += (SRC)[2];         \
 475 } while (0)
 476
 477 /** Element-wise multiplication and addition */
 478 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
 479 do {                                        \
 480       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 481       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 482       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 483 } while (0)
 484
 485 /** Scalar multiplication */
 486 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
 487 do {                                    \
 488       (DST)[0] = S * (SRCB)[0];         \
 489       (DST)[1] = S * (SRCB)[1];         \
 490       (DST)[2] = S * (SRCB)[2];         \
 491 } while (0)
 492
 493 /** In-place scalar multiplication and addition */
 494 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
 495 do {                                        \
 496       (DST)[0] += S * (SRCB)[0];            \
 497       (DST)[1] += S * (SRCB)[1];            \
 498       (DST)[2] += S * (SRCB)[2];            \
 499 } while (0)
 500
 501 /** In-place scalar multiplication */
 502 #define SELF_SCALE_SCALAR_3V( DST, S ) \
 503 do {                                   \
 504       (DST)[0] *= S;                   \
 505       (DST)[1] *= S;                   \
 506       (DST)[2] *= S;                   \
 507 } while (0)
 508
 509 /** In-place scalar addition */
 510 #define ACC_SCALAR_3V( DST, S )     \
 511 do {                                \
 512       (DST)[0] += S;                \
 513       (DST)[1] += S;                \
 514       (DST)[2] += S;                \
 515 } while (0)
 516
 517 /** Assignment */
 518 #define ASSIGN_3V( V, V0, V1, V2 )  \
 519 do {                                \
 520     V[0] = V0;                      \
 521     V[1] = V1;                      \
 522     V[2] = V2;                      \
 523 } while(0)
 524
 525 /*@}*/
 526
 527
 528 /**********************************************************************/
 529 /** \name 2-element vector operations*/
 530 /*@{*/
 531
 532 /** Zero */
 533 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
 534
 535 /** Copy a 2-element vector */
 536 #define COPY_2V( DST, SRC )         \
 537 do {                        \
 538    (DST)[0] = (SRC)[0];             \
 539    (DST)[1] = (SRC)[1];             \
 540 } while (0)
 541
 542 /** Copy a 2-element vector with cast */
 543 #define COPY_2V_CAST( DST, SRC, CAST )      \
 544 do {                        \
 545    (DST)[0] = (CAST)(SRC)[0];           \
 546    (DST)[1] = (CAST)(SRC)[1];           \
 547 } while (0)
 548
 549 /** Copy a 2-element float vector */
 550 #define COPY_2FV( DST, SRC )            \
 551 do {                        \
 552    const GLfloat *_tmp = (SRC);         \
 553    (DST)[0] = _tmp[0];              \
 554    (DST)[1] = _tmp[1];              \
 555 } while (0)
 556
 557 /** Subtraction */
 558 #define SUB_2V( DST, SRCA, SRCB )       \
 559 do {                        \
 560       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 561       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 562 } while (0)
 563
 564 /** Addition */
 565 #define ADD_2V( DST, SRCA, SRCB )       \
 566 do {                        \
 567       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 568       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 569 } while (0)
 570
 571 /** In-place scalar multiplication */
 572 #define SCALE_2V( DST, SRCA, SRCB )     \
 573 do {                        \
 574       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 575       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 576 } while (0)
 577
 578 /** In-place addition */
 579 #define ACC_2V( DST, SRC )          \
 580 do {                        \
 581       (DST)[0] += (SRC)[0];         \
 582       (DST)[1] += (SRC)[1];         \
 583 } while (0)
 584
 585 /** Element-wise multiplication and addition */
 586 #define ACC_SCALE_2V( DST, SRCA, SRCB )     \
 587 do {                        \
 588       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 589       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 590 } while (0)
 591
 592 /** Scalar multiplication */
 593 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
 594 do {                        \
 595       (DST)[0] = S * (SRCB)[0];         \
 596       (DST)[1] = S * (SRCB)[1];         \
 597 } while (0)
 598
 599 /** In-place scalar multiplication and addition */
 600 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
 601 do {                        \
 602       (DST)[0] += S * (SRCB)[0];        \
 603       (DST)[1] += S * (SRCB)[1];        \
 604 } while (0)
 605
 606 /** In-place scalar multiplication */
 607 #define SELF_SCALE_SCALAR_2V( DST, S )      \
 608 do {                        \
 609       (DST)[0] *= S;                \
 610       (DST)[1] *= S;                \
 611 } while (0)
 612
 613 /** In-place scalar addition */
 614 #define ACC_SCALAR_2V( DST, S )         \
 615 do {                        \
 616       (DST)[0] += S;                \
 617       (DST)[1] += S;                \
 618 } while (0)
 619
 620 /** Assign scalers to short vectors */
 621 #define ASSIGN_2V( V, V0, V1 )  \
 622 do {                            \
 623     V[0] = V0;                  \
 624     V[1] = V1;                  \
 625 } while(0)
 626
 627 /*@}*/
 628
 629 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
 630  * default values to the remaining components.
 631  * The default values are chosen based on \p type.
 632  */
 633 static inline void
 634 COPY_CLEAN_4V_TYPE_AS_UNION(fi_type dst[4], int sz, const fi_type src[4],
 635                             GLenum type)
 636 {
 637    switch (type) {
 638    case GL_FLOAT:
 639       ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
 640                 FLOAT_AS_UNION(0), FLOAT_AS_UNION(1));
 641       break;
 642    case GL_INT:
 643       ASSIGN_4V(dst, INT_AS_UNION(0), INT_AS_UNION(0),
 644                 INT_AS_UNION(0), INT_AS_UNION(1));
 645       break;
 646    case GL_UNSIGNED_INT:
 647       ASSIGN_4V(dst, UINT_AS_UNION(0), UINT_AS_UNION(0),
 648                 UINT_AS_UNION(0), UINT_AS_UNION(1));
 649       break;
 650    default:
 651       ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
 652                 FLOAT_AS_UNION(0), FLOAT_AS_UNION(1)); /* silence warnings */
 653       assert(!"Unexpected type in COPY_CLEAN_4V_TYPE_AS_UNION macro");
 654    }
 655    COPY_SZ_4V(dst, sz, src);
 656 }
 657
 658 /** \name Linear interpolation functions */
 659 /*@{*/
 660
 661 static inline GLfloat
 662 LINTERP(GLfloat t, GLfloat out, GLfloat in)
 663 {
 664    return out + t * (in - out);
 665 }
 666
 667 static inline void
 668 INTERP_3F(GLfloat t, GLfloat dst[3], const GLfloat out[3], const GLfloat in[3])
 669 {
 670    dst[0] = LINTERP( t, out[0], in[0] );
 671    dst[1] = LINTERP( t, out[1], in[1] );
 672    dst[2] = LINTERP( t, out[2], in[2] );
 673 }
 674
 675 static inline void
 676 INTERP_4F(GLfloat t, GLfloat dst[4], const GLfloat out[4], const GLfloat in[4])
 677 {
 678    dst[0] = LINTERP( t, out[0], in[0] );
 679    dst[1] = LINTERP( t, out[1], in[1] );
 680    dst[2] = LINTERP( t, out[2], in[2] );
 681    dst[3] = LINTERP( t, out[3], in[3] );
 682 }
 683
 684 /*@}*/
 685
 686
 687
 688 static inline unsigned
 689 minify(unsigned value, unsigned levels)
 690 {
 691     return MAX2(1, value >> levels);
 692 }
 693
 694
 695 /** Cross product of two 3-element vectors */
 696 static inline void
 697 CROSS3(GLfloat n[3], const GLfloat u[3], const GLfloat v[3])
 698 {
 699    n[0] = u[1] * v[2] - u[2] * v[1];
 700    n[1] = u[2] * v[0] - u[0] * v[2];
 701    n[2] = u[0] * v[1] - u[1] * v[0];
 702 }
 703
 704
 705 /** Dot product of two 2-element vectors */
 706 static inline GLfloat
 707 DOT2(const GLfloat a[2], const GLfloat b[2])
 708 {
 709    return a[0] * b[0] + a[1] * b[1];
 710 }
 711
 712 static inline GLfloat
 713 DOT3(const GLfloat a[3], const GLfloat b[3])
 714 {
 715    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 716 }
 717
 718 static inline GLfloat
 719 DOT4(const GLfloat a[4], const GLfloat b[4])
 720 {
 721    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
 722 }
 723
 724
 725 static inline GLfloat
 726 LEN_SQUARED_3FV(const GLfloat v[3])
 727 {
 728    return DOT3(v, v);
 729 }
 730
 731 static inline GLfloat
 732 LEN_SQUARED_2FV(const GLfloat v[2])
 733 {
 734    return DOT2(v, v);
 735 }
 736
 737
 738 static inline GLfloat
 739 LEN_3FV(const GLfloat v[3])
 740 {
 741    return sqrtf(LEN_SQUARED_3FV(v));
 742 }
 743
 744 static inline GLfloat
 745 LEN_2FV(const GLfloat v[2])
 746 {
 747    return sqrtf(LEN_SQUARED_2FV(v));
 748 }
 749
 750
 751 /* Normalize a 3-element vector to unit length. */
 752 static inline void
 753 NORMALIZE_3FV(GLfloat v[3])
 754 {
 755    GLfloat len = (GLfloat) LEN_SQUARED_3FV(v);
 756    if (len) {
 757       len = 1.0f / sqrtf(len);
 758       v[0] *= len;
 759       v[1] *= len;
 760       v[2] *= len;
 761    }
 762 }
 763
 764
 765 /** Test two floats have opposite signs */
 766 static inline GLboolean
 767 DIFFERENT_SIGNS(GLfloat x, GLfloat y)
 768 {
 769 #ifdef _MSC_VER
 770 #pragma warning( push )
 771 #pragma warning( disable : 6334 ) /* sizeof operator applied to an expression with an operator may yield unexpected results */
 772 #endif
 773    return signbit(x) != signbit(y);
 774 #ifdef _MSC_VER
 775 #pragma warning( pop )
 776 #endif
 777 }
 778
 779
 780 /** casts to silence warnings with some compilers */
 781 #define ENUM_TO_INT(E)     ((GLint)(E))
 782 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
 783 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
 784 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
 785
 786
 787 /* Stringify */
 788 #define STRINGIFY(x) #x
 789
 790 #endif