src/mesa/main/macros.h

   1 /**
   2  * \file macros.h
   3  * A collection of useful macros.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  * Version:  6.5.2
   9  *
  10  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  27  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28  */
  29
  30
  31 #ifndef MACROS_H
  32 #define MACROS_H
  33
  34 #include "imports.h"
  35
  36
  37 /**
  38  * \name Integer / float conversion for colors, normals, etc.
  39  */
  40 /*@{*/
  41
  42 /** Convert GLubyte in [0,255] to GLfloat in [0.0,1.0] */
  43 extern GLfloat _mesa_ubyte_to_float_color_tab[256];
  44 #define UBYTE_TO_FLOAT(u) _mesa_ubyte_to_float_color_tab[(unsigned int)(u)]
  45
  46 /** Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
  47 #define FLOAT_TO_UBYTE(X)   ((GLubyte) (GLint) ((X) * 255.0F))
  48
  49
  50 /** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
  51 #define BYTE_TO_FLOAT(B)    ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
  52
  53 /** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
  54 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
  55
  56
  57 /** Convert 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 #if defined(USE_IEEE) && !defined(DEBUG)
 144 #define IEEE_0996 0x3f7f0000    /* 0.996 or so */
 145 /* This function/macro is sensitive to precision.  Test very carefully
 146  * if you change it!
 147  */
 148 #define UNCLAMPED_FLOAT_TO_UBYTE(UB, F)                                 \
 149         do {                                                            \
 150            fi_type __tmp;                                               \
 151            __tmp.f = (F);                                               \
 152            if (__tmp.i < 0)                                             \
 153               UB = (GLubyte) 0;                                         \
 154            else if (__tmp.i >= IEEE_0996)                               \
 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, F)                                   \
 162         do {                                                            \
 163            fi_type __tmp;                                               \
 164            __tmp.f = (F) * (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 /*@}*/
 189
 190
 191 /** Stepping a GLfloat pointer by a byte stride */
 192 #define STRIDE_F(p, i)  (p = (GLfloat *)((GLubyte *)p + i))
 193 /** Stepping a GLuint pointer by a byte stride */
 194 #define STRIDE_UI(p, i)  (p = (GLuint *)((GLubyte *)p + i))
 195 /** Stepping a GLubyte[4] pointer by a byte stride */
 196 #define STRIDE_4UB(p, i)  (p = (GLubyte (*)[4])((GLubyte *)p + i))
 197 /** Stepping a GLfloat[4] pointer by a byte stride */
 198 #define STRIDE_4F(p, i)  (p = (GLfloat (*)[4])((GLubyte *)p + i))
 199 /** Stepping a \p t pointer by a byte stride */
 200 #define STRIDE_T(p, t, i)  (p = (t)((GLubyte *)p + i))
 201
 202
 203 /**********************************************************************/
 204 /** \name 4-element vector operations */
 205 /*@{*/
 206
 207 /** Zero */
 208 #define ZERO_4V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = (DST)[3] = 0
 209
 210 /** Test for equality */
 211 #define TEST_EQ_4V(a,b)  ((a)[0] == (b)[0] &&   \
 212               (a)[1] == (b)[1] &&   \
 213               (a)[2] == (b)[2] &&   \
 214               (a)[3] == (b)[3])
 215
 216 /** Test for equality (unsigned bytes) */
 217 static inline GLboolean
 218 TEST_EQ_4UBV(const GLubyte a[4], const GLubyte b[4])
 219 {
 220 #if defined(__i386__)
 221    return *((const GLuint *) a) == *((const GLuint *) b);
 222 #else
 223    return TEST_EQ_4V(a, b);
 224 #endif
 225 }
 226
 227
 228 /** Copy a 4-element vector */
 229 #define COPY_4V( DST, SRC )         \
 230 do {                                \
 231    (DST)[0] = (SRC)[0];             \
 232    (DST)[1] = (SRC)[1];             \
 233    (DST)[2] = (SRC)[2];             \
 234    (DST)[3] = (SRC)[3];             \
 235 } while (0)
 236
 237 /** Copy a 4-element unsigned byte vector */
 238 static inline void
 239 COPY_4UBV(GLubyte dst[4], const GLubyte src[4])
 240 {
 241 #if defined(__i386__)
 242    *((GLuint *) dst) = *((GLuint *) src);
 243 #else
 244    /* The GLuint cast might fail if DST or SRC are not dword-aligned (RISC) */
 245    COPY_4V(dst, src);
 246 #endif
 247 }
 248
 249 /** Copy a 4-element float vector */
 250 static inline void
 251 COPY_4FV(GLfloat dst[4], const GLfloat src[4])
 252 {
 253    /* memcpy seems to be most efficient */
 254    memcpy(dst, src, sizeof(GLfloat) * 4);
 255 }
 256
 257 /** Copy \p SZ elements into a 4-element vector */
 258 #define COPY_SZ_4V(DST, SZ, SRC)  \
 259 do {                              \
 260    switch (SZ) {                  \
 261    case 4: (DST)[3] = (SRC)[3];   \
 262    case 3: (DST)[2] = (SRC)[2];   \
 263    case 2: (DST)[1] = (SRC)[1];   \
 264    case 1: (DST)[0] = (SRC)[0];   \
 265    }                              \
 266 } while(0)
 267
 268 /** Copy \p SZ elements into a homegeneous (4-element) vector, giving
 269  * default values to the remaining */
 270 #define COPY_CLEAN_4V(DST, SZ, SRC)  \
 271 do {                                 \
 272       ASSIGN_4V( DST, 0, 0, 0, 1 );  \
 273       COPY_SZ_4V( DST, SZ, SRC );    \
 274 } while (0)
 275
 276 /** Subtraction */
 277 #define SUB_4V( DST, SRCA, SRCB )           \
 278 do {                                        \
 279       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 280       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 281       (DST)[2] = (SRCA)[2] - (SRCB)[2];     \
 282       (DST)[3] = (SRCA)[3] - (SRCB)[3];     \
 283 } while (0)
 284
 285 /** Addition */
 286 #define ADD_4V( DST, SRCA, SRCB )           \
 287 do {                                        \
 288       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 289       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 290       (DST)[2] = (SRCA)[2] + (SRCB)[2];     \
 291       (DST)[3] = (SRCA)[3] + (SRCB)[3];     \
 292 } while (0)
 293
 294 /** Element-wise multiplication */
 295 #define SCALE_4V( DST, SRCA, SRCB )         \
 296 do {                                        \
 297       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 298       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 299       (DST)[2] = (SRCA)[2] * (SRCB)[2];     \
 300       (DST)[3] = (SRCA)[3] * (SRCB)[3];     \
 301 } while (0)
 302
 303 /** In-place addition */
 304 #define ACC_4V( DST, SRC )          \
 305 do {                                \
 306       (DST)[0] += (SRC)[0];         \
 307       (DST)[1] += (SRC)[1];         \
 308       (DST)[2] += (SRC)[2];         \
 309       (DST)[3] += (SRC)[3];         \
 310 } while (0)
 311
 312 /** Element-wise multiplication and addition */
 313 #define ACC_SCALE_4V( DST, SRCA, SRCB )     \
 314 do {                                        \
 315       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 316       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 317       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 318       (DST)[3] += (SRCA)[3] * (SRCB)[3];    \
 319 } while (0)
 320
 321 /** In-place scalar multiplication and addition */
 322 #define ACC_SCALE_SCALAR_4V( DST, S, SRCB ) \
 323 do {                                        \
 324       (DST)[0] += S * (SRCB)[0];            \
 325       (DST)[1] += S * (SRCB)[1];            \
 326       (DST)[2] += S * (SRCB)[2];            \
 327       (DST)[3] += S * (SRCB)[3];            \
 328 } while (0)
 329
 330 /** Scalar multiplication */
 331 #define SCALE_SCALAR_4V( DST, S, SRCB ) \
 332 do {                                    \
 333       (DST)[0] = S * (SRCB)[0];         \
 334       (DST)[1] = S * (SRCB)[1];         \
 335       (DST)[2] = S * (SRCB)[2];         \
 336       (DST)[3] = S * (SRCB)[3];         \
 337 } while (0)
 338
 339 /** In-place scalar multiplication */
 340 #define SELF_SCALE_SCALAR_4V( DST, S ) \
 341 do {                                   \
 342       (DST)[0] *= S;                   \
 343       (DST)[1] *= S;                   \
 344       (DST)[2] *= S;                   \
 345       (DST)[3] *= S;                   \
 346 } while (0)
 347
 348 /** Assignment */
 349 #define ASSIGN_4V( V, V0, V1, V2, V3 )  \
 350 do {                                    \
 351     V[0] = V0;                          \
 352     V[1] = V1;                          \
 353     V[2] = V2;                          \
 354     V[3] = V3;                          \
 355 } while(0)
 356
 357 /*@}*/
 358
 359
 360 /**********************************************************************/
 361 /** \name 3-element vector operations*/
 362 /*@{*/
 363
 364 /** Zero */
 365 #define ZERO_3V( DST )  (DST)[0] = (DST)[1] = (DST)[2] = 0
 366
 367 /** Test for equality */
 368 #define TEST_EQ_3V(a,b)  \
 369    ((a)[0] == (b)[0] &&  \
 370     (a)[1] == (b)[1] &&  \
 371     (a)[2] == (b)[2])
 372
 373 /** Copy a 3-element vector */
 374 #define COPY_3V( DST, SRC )         \
 375 do {                                \
 376    (DST)[0] = (SRC)[0];             \
 377    (DST)[1] = (SRC)[1];             \
 378    (DST)[2] = (SRC)[2];             \
 379 } while (0)
 380
 381 /** Copy a 3-element vector with cast */
 382 #define COPY_3V_CAST( DST, SRC, CAST )  \
 383 do {                                    \
 384    (DST)[0] = (CAST)(SRC)[0];           \
 385    (DST)[1] = (CAST)(SRC)[1];           \
 386    (DST)[2] = (CAST)(SRC)[2];           \
 387 } while (0)
 388
 389 /** Copy a 3-element float vector */
 390 #define COPY_3FV( DST, SRC )        \
 391 do {                                \
 392    const GLfloat *_tmp = (SRC);     \
 393    (DST)[0] = _tmp[0];              \
 394    (DST)[1] = _tmp[1];              \
 395    (DST)[2] = _tmp[2];              \
 396 } while (0)
 397
 398 /** Subtraction */
 399 #define SUB_3V( DST, SRCA, SRCB )        \
 400 do {                                     \
 401       (DST)[0] = (SRCA)[0] - (SRCB)[0];  \
 402       (DST)[1] = (SRCA)[1] - (SRCB)[1];  \
 403       (DST)[2] = (SRCA)[2] - (SRCB)[2];  \
 404 } while (0)
 405
 406 /** Addition */
 407 #define ADD_3V( DST, SRCA, SRCB )       \
 408 do {                                    \
 409       (DST)[0] = (SRCA)[0] + (SRCB)[0]; \
 410       (DST)[1] = (SRCA)[1] + (SRCB)[1]; \
 411       (DST)[2] = (SRCA)[2] + (SRCB)[2]; \
 412 } while (0)
 413
 414 /** In-place scalar multiplication */
 415 #define SCALE_3V( DST, SRCA, SRCB )     \
 416 do {                                    \
 417       (DST)[0] = (SRCA)[0] * (SRCB)[0]; \
 418       (DST)[1] = (SRCA)[1] * (SRCB)[1]; \
 419       (DST)[2] = (SRCA)[2] * (SRCB)[2]; \
 420 } while (0)
 421
 422 /** In-place element-wise multiplication */
 423 #define SELF_SCALE_3V( DST, SRC )   \
 424 do {                                \
 425       (DST)[0] *= (SRC)[0];         \
 426       (DST)[1] *= (SRC)[1];         \
 427       (DST)[2] *= (SRC)[2];         \
 428 } while (0)
 429
 430 /** In-place addition */
 431 #define ACC_3V( DST, SRC )          \
 432 do {                                \
 433       (DST)[0] += (SRC)[0];         \
 434       (DST)[1] += (SRC)[1];         \
 435       (DST)[2] += (SRC)[2];         \
 436 } while (0)
 437
 438 /** Element-wise multiplication and addition */
 439 #define ACC_SCALE_3V( DST, SRCA, SRCB )     \
 440 do {                                        \
 441       (DST)[0] += (SRCA)[0] * (SRCB)[0];    \
 442       (DST)[1] += (SRCA)[1] * (SRCB)[1];    \
 443       (DST)[2] += (SRCA)[2] * (SRCB)[2];    \
 444 } while (0)
 445
 446 /** Scalar multiplication */
 447 #define SCALE_SCALAR_3V( DST, S, SRCB ) \
 448 do {                                    \
 449       (DST)[0] = S * (SRCB)[0];         \
 450       (DST)[1] = S * (SRCB)[1];         \
 451       (DST)[2] = S * (SRCB)[2];         \
 452 } while (0)
 453
 454 /** In-place scalar multiplication and addition */
 455 #define ACC_SCALE_SCALAR_3V( DST, S, SRCB ) \
 456 do {                                        \
 457       (DST)[0] += S * (SRCB)[0];            \
 458       (DST)[1] += S * (SRCB)[1];            \
 459       (DST)[2] += S * (SRCB)[2];            \
 460 } while (0)
 461
 462 /** In-place scalar multiplication */
 463 #define SELF_SCALE_SCALAR_3V( DST, S ) \
 464 do {                                   \
 465       (DST)[0] *= S;                   \
 466       (DST)[1] *= S;                   \
 467       (DST)[2] *= S;                   \
 468 } while (0)
 469
 470 /** In-place scalar addition */
 471 #define ACC_SCALAR_3V( DST, S )     \
 472 do {                                \
 473       (DST)[0] += S;                \
 474       (DST)[1] += S;                \
 475       (DST)[2] += S;                \
 476 } while (0)
 477
 478 /** Assignment */
 479 #define ASSIGN_3V( V, V0, V1, V2 )  \
 480 do {                                \
 481     V[0] = V0;                      \
 482     V[1] = V1;                      \
 483     V[2] = V2;                      \
 484 } while(0)
 485
 486 /*@}*/
 487
 488
 489 /**********************************************************************/
 490 /** \name 2-element vector operations*/
 491 /*@{*/
 492
 493 /** Zero */
 494 #define ZERO_2V( DST )  (DST)[0] = (DST)[1] = 0
 495
 496 /** Copy a 2-element vector */
 497 #define COPY_2V( DST, SRC )         \
 498 do {                        \
 499    (DST)[0] = (SRC)[0];             \
 500    (DST)[1] = (SRC)[1];             \
 501 } while (0)
 502
 503 /** Copy a 2-element vector with cast */
 504 #define COPY_2V_CAST( DST, SRC, CAST )      \
 505 do {                        \
 506    (DST)[0] = (CAST)(SRC)[0];           \
 507    (DST)[1] = (CAST)(SRC)[1];           \
 508 } while (0)
 509
 510 /** Copy a 2-element float vector */
 511 #define COPY_2FV( DST, SRC )            \
 512 do {                        \
 513    const GLfloat *_tmp = (SRC);         \
 514    (DST)[0] = _tmp[0];              \
 515    (DST)[1] = _tmp[1];              \
 516 } while (0)
 517
 518 /** Subtraction */
 519 #define SUB_2V( DST, SRCA, SRCB )       \
 520 do {                        \
 521       (DST)[0] = (SRCA)[0] - (SRCB)[0];     \
 522       (DST)[1] = (SRCA)[1] - (SRCB)[1];     \
 523 } while (0)
 524
 525 /** Addition */
 526 #define ADD_2V( DST, SRCA, SRCB )       \
 527 do {                        \
 528       (DST)[0] = (SRCA)[0] + (SRCB)[0];     \
 529       (DST)[1] = (SRCA)[1] + (SRCB)[1];     \
 530 } while (0)
 531
 532 /** In-place scalar multiplication */
 533 #define SCALE_2V( DST, SRCA, SRCB )     \
 534 do {                        \
 535       (DST)[0] = (SRCA)[0] * (SRCB)[0];     \
 536       (DST)[1] = (SRCA)[1] * (SRCB)[1];     \
 537 } while (0)
 538
 539 /** In-place addition */
 540 #define ACC_2V( DST, SRC )          \
 541 do {                        \
 542       (DST)[0] += (SRC)[0];         \
 543       (DST)[1] += (SRC)[1];         \
 544 } while (0)
 545
 546 /** Element-wise multiplication and addition */
 547 #define ACC_SCALE_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 /** Scalar multiplication */
 554 #define SCALE_SCALAR_2V( DST, S, SRCB )     \
 555 do {                        \
 556       (DST)[0] = S * (SRCB)[0];         \
 557       (DST)[1] = S * (SRCB)[1];         \
 558 } while (0)
 559
 560 /** In-place scalar multiplication and addition */
 561 #define ACC_SCALE_SCALAR_2V( DST, S, SRCB ) \
 562 do {                        \
 563       (DST)[0] += S * (SRCB)[0];        \
 564       (DST)[1] += S * (SRCB)[1];        \
 565 } while (0)
 566
 567 /** In-place scalar multiplication */
 568 #define SELF_SCALE_SCALAR_2V( DST, S )      \
 569 do {                        \
 570       (DST)[0] *= S;                \
 571       (DST)[1] *= S;                \
 572 } while (0)
 573
 574 /** In-place scalar addition */
 575 #define ACC_SCALAR_2V( DST, S )         \
 576 do {                        \
 577       (DST)[0] += S;                \
 578       (DST)[1] += S;                \
 579 } while (0)
 580
 581 /** Assign scalers to short vectors */
 582 #define ASSIGN_2V( V, V0, V1 )  \
 583 do {                            \
 584     V[0] = V0;                  \
 585     V[1] = V1;                  \
 586 } while(0)
 587
 588 /*@}*/
 589
 590 /** Copy \p sz elements into a homegeneous (4-element) vector, giving
 591  * default values to the remaining components.
 592  * The default values are chosen based on \p type.
 593  */
 594 static inline void
 595 COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst[4], int sz, const GLfloat src[4],
 596                             GLenum type)
 597 {
 598    switch (type) {
 599    case GL_FLOAT:
 600       ASSIGN_4V(dst, 0, 0, 0, 1);
 601       break;
 602    case GL_INT:
 603       ASSIGN_4V(dst, INT_AS_FLT(0), INT_AS_FLT(0),
 604                      INT_AS_FLT(0), INT_AS_FLT(1));
 605       break;
 606    case GL_UNSIGNED_INT:
 607       ASSIGN_4V(dst, UINT_AS_FLT(0), UINT_AS_FLT(0),
 608                      UINT_AS_FLT(0), UINT_AS_FLT(1));
 609       break;
 610    default:
 611       ASSERT(0);
 612    }
 613    COPY_SZ_4V(dst, sz, src);
 614 }
 615
 616 /** \name Linear interpolation functions */
 617 /*@{*/
 618
 619 static inline GLfloat
 620 LINTERP(GLfloat t, GLfloat out, GLfloat in)
 621 {
 622    return out + t * (in - out);
 623 }
 624
 625 static inline void
 626 INTERP_3F(GLfloat t, GLfloat dst[3], const GLfloat out[3], const GLfloat in[3])
 627 {
 628    dst[0] = LINTERP( t, out[0], in[0] );
 629    dst[1] = LINTERP( t, out[1], in[1] );
 630    dst[2] = LINTERP( t, out[2], in[2] );
 631 }
 632
 633 static inline void
 634 INTERP_4F(GLfloat t, GLfloat dst[4], const GLfloat out[4], const GLfloat in[4])
 635 {
 636    dst[0] = LINTERP( t, out[0], in[0] );
 637    dst[1] = LINTERP( t, out[1], in[1] );
 638    dst[2] = LINTERP( t, out[2], in[2] );
 639    dst[3] = LINTERP( t, out[3], in[3] );
 640 }
 641
 642 /*@}*/
 643
 644
 645
 646 /** Clamp X to [MIN,MAX] */
 647 #define CLAMP( X, MIN, MAX )  ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) )
 648
 649 /** Minimum of two values: */
 650 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
 651
 652 /** Maximum of two values: */
 653 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
 654
 655 /** Minimum and maximum of three values: */
 656 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
 657 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
 658
 659 static inline unsigned
 660 minify(unsigned value, unsigned levels)
 661 {
 662     return MAX2(1, value >> levels);
 663 }
 664
 665 /**
 666  * Align a value up to an alignment value
 667  *
 668  * If \c value is not already aligned to the requested alignment value, it
 669  * will be rounded up.
 670  *
 671  * \param value  Value to be rounded
 672  * \param alignment  Alignment value to be used.  This must be a power of two.
 673  *
 674  * \sa ROUND_DOWN_TO()
 675  */
 676 #define ALIGN(value, alignment)  (((value) + alignment - 1) & ~(alignment - 1))
 677
 678
 679
 680 /** Cross product of two 3-element vectors */
 681 static inline void
 682 CROSS3(GLfloat n[3], const GLfloat u[3], const GLfloat v[3])
 683 {
 684    n[0] = u[1] * v[2] - u[2] * v[1];
 685    n[1] = u[2] * v[0] - u[0] * v[2];
 686    n[2] = u[0] * v[1] - u[1] * v[0];
 687 }
 688
 689
 690 /** Dot product of two 2-element vectors */
 691 static inline GLfloat
 692 DOT2(const GLfloat a[2], const GLfloat b[2])
 693 {
 694    return a[0] * b[0] + a[1] * b[1];
 695 }
 696
 697 static inline GLfloat
 698 DOT3(const GLfloat a[3], const GLfloat b[3])
 699 {
 700    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 701 }
 702
 703 static inline GLfloat
 704 DOT4(const GLfloat a[4], const GLfloat b[4])
 705 {
 706    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
 707 }
 708
 709
 710 static inline GLfloat
 711 LEN_SQUARED_3FV(const GLfloat v[3])
 712 {
 713    return DOT3(v, v);
 714 }
 715
 716 static inline GLfloat
 717 LEN_SQUARED_2FV(const GLfloat v[2])
 718 {
 719    return DOT2(v, v);
 720 }
 721
 722
 723 static inline GLfloat
 724 LEN_3FV(const GLfloat v[3])
 725 {
 726    return sqrtf(LEN_SQUARED_3FV(v));
 727 }
 728
 729 static inline GLfloat
 730 LEN_2FV(const GLfloat v[2])
 731 {
 732    return sqrtf(LEN_SQUARED_2FV(v));
 733 }
 734
 735
 736 /* Normalize a 3-element vector to unit length. */
 737 static inline void
 738 NORMALIZE_3FV(GLfloat v[3])
 739 {
 740    GLfloat len = (GLfloat) LEN_SQUARED_3FV(v);
 741    if (len) {
 742       len = INV_SQRTF(len);
 743       v[0] *= len;
 744       v[1] *= len;
 745       v[2] *= len;
 746    }
 747 }
 748
 749
 750 /** Is float value negative? */
 751 static inline GLboolean
 752 IS_NEGATIVE(float x)
 753 {
 754    return signbit(x) != 0;
 755 }
 756
 757 /** Test two floats have opposite signs */
 758 static inline GLboolean
 759 DIFFERENT_SIGNS(GLfloat x, GLfloat y)
 760 {
 761    return signbit(x) != signbit(y);
 762 }
 763
 764
 765 /** Compute ceiling of integer quotient of A divided by B. */
 766 #define CEILING( A, B )  ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
 767
 768
 769 /** casts to silence warnings with some compilers */
 770 #define ENUM_TO_INT(E)     ((GLint)(E))
 771 #define ENUM_TO_FLOAT(E)   ((GLfloat)(GLint)(E))
 772 #define ENUM_TO_DOUBLE(E)  ((GLdouble)(GLint)(E))
 773 #define ENUM_TO_BOOLEAN(E) ((E) ? GL_TRUE : GL_FALSE)
 774
 775 /* Compute the size of an array */
 776 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
 777
 778
 779 #endif