src/mesa/main/imports.c

   1 /**
   2  * \file imports.c
   3  * Standard C library function wrappers.
   4  *
   5  * Imports are services which the device driver or window system or
   6  * operating system provides to the core renderer.  The core renderer (Mesa)
   7  * will call these functions in order to do memory allocation, simple I/O,
   8  * etc.
   9  *
  10  * Some drivers will want to override/replace this file with something
  11  * specialized, but that'll be rare.
  12  *
  13  * Eventually, I want to move roll the glheader.h file into this.
  14  *
  15  * \todo Functions still needed:
  16  * - scanf
  17  * - qsort
  18  * - rand and RAND_MAX
  19  */
  20
  21 /*
  22  * Mesa 3-D graphics library
  23  * Version:  7.1
  24  *
  25  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
  26  *
  27  * Permission is hereby granted, free of charge, to any person obtaining a
  28  * copy of this software and associated documentation files (the "Software"),
  29  * to deal in the Software without restriction, including without limitation
  30  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  31  * and/or sell copies of the Software, and to permit persons to whom the
  32  * Software is furnished to do so, subject to the following conditions:
  33  *
  34  * The above copyright notice and this permission notice shall be included
  35  * in all copies or substantial portions of the Software.
  36  *
  37  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  38  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  39  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  40  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  41  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  42  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  43  */
  44
  45
  46
  47 #include "imports.h"
  48 #include "context.h"
  49 #include "version.h"
  50
  51 #ifdef _GNU_SOURCE
  52 #include <locale.h>
  53 #ifdef __APPLE__
  54 #include <xlocale.h>
  55 #endif
  56 #endif
  57
  58
  59 #define MAXSTRING 4000  /* for vsnprintf() */
  60
  61 #ifdef WIN32
  62 #define vsnprintf _vsnprintf
  63 #elif defined(__IBMC__) || defined(__IBMCPP__) || ( defined(__VMS) && __CRTL_VER < 70312000 )
  64 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list arg);
  65 #ifdef __VMS
  66 #include "vsnprintf.c"
  67 #endif
  68 #endif
  69
  70 /**********************************************************************/
  71 /** \name Memory */
  72 /*@{*/
  73
  74 /** Wrapper around malloc() */
  75 void *
  76 _mesa_malloc(size_t bytes)
  77 {
  78    return malloc(bytes);
  79 }
  80
  81 /** Wrapper around calloc() */
  82 void *
  83 _mesa_calloc(size_t bytes)
  84 {
  85    return calloc(1, bytes);
  86 }
  87
  88 /** Wrapper around free() */
  89 void
  90 _mesa_free(void *ptr)
  91 {
  92    free(ptr);
  93 }
  94
  95 /**
  96  * Allocate aligned memory.
  97  *
  98  * \param bytes number of bytes to allocate.
  99  * \param alignment alignment (must be greater than zero).
 100  *
 101  * Allocates extra memory to accommodate rounding up the address for
 102  * alignment and to record the real malloc address.
 103  *
 104  * \sa _mesa_align_free().
 105  */
 106 void *
 107 _mesa_align_malloc(size_t bytes, unsigned long alignment)
 108 {
 109 #if defined(HAVE_POSIX_MEMALIGN)
 110    void *mem;
 111    int err = posix_memalign(& mem, alignment, bytes);
 112    (void) err;
 113    return mem;
 114 #elif defined(_WIN32) && defined(_MSC_VER)
 115    return _aligned_malloc(bytes, alignment);
 116 #else
 117    uintptr_t ptr, buf;
 118
 119    ASSERT( alignment > 0 );
 120
 121    ptr = (uintptr_t) _mesa_malloc(bytes + alignment + sizeof(void *));
 122    if (!ptr)
 123       return NULL;
 124
 125    buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
 126    *(uintptr_t *)(buf - sizeof(void *)) = ptr;
 127
 128 #ifdef DEBUG
 129    /* mark the non-aligned area */
 130    while ( ptr < buf - sizeof(void *) ) {
 131       *(unsigned long *)ptr = 0xcdcdcdcd;
 132       ptr += sizeof(unsigned long);
 133    }
 134 #endif
 135
 136    return (void *) buf;
 137 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 138 }
 139
 140 /**
 141  * Same as _mesa_align_malloc(), but using _mesa_calloc() instead of
 142  * _mesa_malloc()
 143  */
 144 void *
 145 _mesa_align_calloc(size_t bytes, unsigned long alignment)
 146 {
 147 #if defined(HAVE_POSIX_MEMALIGN)
 148    void *mem;
 149
 150    mem = _mesa_align_malloc(bytes, alignment);
 151    if (mem != NULL) {
 152       (void) memset(mem, 0, bytes);
 153    }
 154
 155    return mem;
 156 #elif defined(_WIN32) && defined(_MSC_VER)
 157    void *mem;
 158
 159    mem = _aligned_malloc(bytes, alignment);
 160    if (mem != NULL) {
 161       (void) memset(mem, 0, bytes);
 162    }
 163
 164    return mem;
 165 #else
 166    uintptr_t ptr, buf;
 167
 168    ASSERT( alignment > 0 );
 169
 170    ptr = (uintptr_t) _mesa_calloc(bytes + alignment + sizeof(void *));
 171    if (!ptr)
 172       return NULL;
 173
 174    buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
 175    *(uintptr_t *)(buf - sizeof(void *)) = ptr;
 176
 177 #ifdef DEBUG
 178    /* mark the non-aligned area */
 179    while ( ptr < buf - sizeof(void *) ) {
 180       *(unsigned long *)ptr = 0xcdcdcdcd;
 181       ptr += sizeof(unsigned long);
 182    }
 183 #endif
 184
 185    return (void *)buf;
 186 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 187 }
 188
 189 /**
 190  * Free memory which was allocated with either _mesa_align_malloc()
 191  * or _mesa_align_calloc().
 192  * \param ptr pointer to the memory to be freed.
 193  * The actual address to free is stored in the word immediately before the
 194  * address the client sees.
 195  */
 196 void
 197 _mesa_align_free(void *ptr)
 198 {
 199 #if defined(HAVE_POSIX_MEMALIGN)
 200    free(ptr);
 201 #elif defined(_WIN32) && defined(_MSC_VER)
 202    _aligned_free(ptr);
 203 #else
 204    void **cubbyHole = (void **) ((char *) ptr - sizeof(void *));
 205    void *realAddr = *cubbyHole;
 206    _mesa_free(realAddr);
 207 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 208 }
 209
 210 /**
 211  * Reallocate memory, with alignment.
 212  */
 213 void *
 214 _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
 215                     unsigned long alignment)
 216 {
 217 #if defined(_WIN32) && defined(_MSC_VER)
 218    (void) oldSize;
 219    return _aligned_realloc(oldBuffer, newSize, alignment);
 220 #else
 221    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 222    void *newBuf = _mesa_align_malloc(newSize, alignment);
 223    if (newBuf && oldBuffer && copySize > 0) {
 224       memcpy(newBuf, oldBuffer, copySize);
 225    }
 226    if (oldBuffer)
 227       _mesa_align_free(oldBuffer);
 228    return newBuf;
 229 #endif
 230 }
 231
 232
 233
 234 /** Reallocate memory */
 235 void *
 236 _mesa_realloc(void *oldBuffer, size_t oldSize, size_t newSize)
 237 {
 238    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 239    void *newBuffer = _mesa_malloc(newSize);
 240    if (newBuffer && oldBuffer && copySize > 0)
 241       memcpy(newBuffer, oldBuffer, copySize);
 242    if (oldBuffer)
 243       _mesa_free(oldBuffer);
 244    return newBuffer;
 245 }
 246
 247 /** Wrapper around memset() */
 248 void
 249 _mesa_memset( void *dst, int val, size_t n )
 250 {
 251 #if defined(SUNOS4)
 252    memset( (char *) dst, (int) val, (int) n );
 253 #else
 254    memset(dst, val, n);
 255 #endif
 256 }
 257
 258 /**
 259  * Fill memory with a constant 16bit word.
 260  * \param dst destination pointer.
 261  * \param val value.
 262  * \param n number of words.
 263  */
 264 void
 265 _mesa_memset16( unsigned short *dst, unsigned short val, size_t n )
 266 {
 267    while (n-- > 0)
 268       *dst++ = val;
 269 }
 270
 271 /** Wrapper around either memset() or bzero() */
 272 void
 273 _mesa_bzero( void *dst, size_t n )
 274 {
 275 #if defined(__FreeBSD__)
 276    bzero( dst, n );
 277 #else
 278    memset( dst, 0, n );
 279 #endif
 280 }
 281
 282 /** Wrapper around memcmp() */
 283 int
 284 _mesa_memcmp( const void *s1, const void *s2, size_t n )
 285 {
 286 #if defined(SUNOS4)
 287    return memcmp( (char *) s1, (char *) s2, (int) n );
 288 #else
 289    return memcmp(s1, s2, n);
 290 #endif
 291 }
 292
 293 /*@}*/
 294
 295
 296 /**********************************************************************/
 297 /** \name Math */
 298 /*@{*/
 299
 300 /** Wrapper around sin() */
 301 double
 302 _mesa_sin(double a)
 303 {
 304    return sin(a);
 305 }
 306
 307 /** Single precision wrapper around sin() */
 308 float
 309 _mesa_sinf(float a)
 310 {
 311    return (float) sin((double) a);
 312 }
 313
 314 /** Wrapper around cos() */
 315 double
 316 _mesa_cos(double a)
 317 {
 318    return cos(a);
 319 }
 320
 321 /** Single precision wrapper around asin() */
 322 float
 323 _mesa_asinf(float x)
 324 {
 325    return (float) asin((double) x);
 326 }
 327
 328 /** Single precision wrapper around atan() */
 329 float
 330 _mesa_atanf(float x)
 331 {
 332    return (float) atan((double) x);
 333 }
 334
 335 /** Wrapper around sqrt() */
 336 double
 337 _mesa_sqrtd(double x)
 338 {
 339    return sqrt(x);
 340 }
 341
 342
 343 /*
 344  * A High Speed, Low Precision Square Root
 345  * by Paul Lalonde and Robert Dawson
 346  * from "Graphics Gems", Academic Press, 1990
 347  *
 348  * SPARC implementation of a fast square root by table
 349  * lookup.
 350  * SPARC floating point format is as follows:
 351  *
 352  * BIT 31       30      23      22      0
 353  *     sign     exponent        mantissa
 354  */
 355 static short sqrttab[0x100];    /* declare table of square roots */
 356
 357 void
 358 _mesa_init_sqrt_table(void)
 359 {
 360 #if defined(USE_IEEE) && !defined(DEBUG)
 361    unsigned short i;
 362    fi_type fi;     /* to access the bits of a float in  C quickly  */
 363                    /* we use a union defined in glheader.h         */
 364
 365    for(i=0; i<= 0x7f; i++) {
 366       fi.i = 0;
 367
 368       /*
 369        * Build a float with the bit pattern i as mantissa
 370        * and an exponent of 0, stored as 127
 371        */
 372
 373       fi.i = (i << 16) | (127 << 23);
 374       fi.f = _mesa_sqrtd(fi.f);
 375
 376       /*
 377        * Take the square root then strip the first 7 bits of
 378        * the mantissa into the table
 379        */
 380
 381       sqrttab[i] = (fi.i & 0x7fffff) >> 16;
 382
 383       /*
 384        * Repeat the process, this time with an exponent of
 385        * 1, stored as 128
 386        */
 387
 388       fi.i = 0;
 389       fi.i = (i << 16) | (128 << 23);
 390       fi.f = sqrt(fi.f);
 391       sqrttab[i+0x80] = (fi.i & 0x7fffff) >> 16;
 392    }
 393 #else
 394    (void) sqrttab;  /* silence compiler warnings */
 395 #endif /*HAVE_FAST_MATH*/
 396 }
 397
 398
 399 /**
 400  * Single precision square root.
 401  */
 402 float
 403 _mesa_sqrtf( float x )
 404 {
 405 #if defined(USE_IEEE) && !defined(DEBUG)
 406    fi_type num;
 407                                 /* to access the bits of a float in C
 408                                  * we use a union from glheader.h     */
 409
 410    short e;                     /* the exponent */
 411    if (x == 0.0F) return 0.0F;  /* check for square root of 0 */
 412    num.f = x;
 413    e = (num.i >> 23) - 127;     /* get the exponent - on a SPARC the */
 414                                 /* exponent is stored with 127 added */
 415    num.i &= 0x7fffff;           /* leave only the mantissa */
 416    if (e & 0x01) num.i |= 0x800000;
 417                                 /* the exponent is odd so we have to */
 418                                 /* look it up in the second half of  */
 419                                 /* the lookup table, so we set the   */
 420                                 /* high bit                                */
 421    e >>= 1;                     /* divide the exponent by two */
 422                                 /* note that in C the shift */
 423                                 /* operators are sign preserving */
 424                                 /* for signed operands */
 425    /* Do the table lookup, based on the quaternary mantissa,
 426     * then reconstruct the result back into a float
 427     */
 428    num.i = ((sqrttab[num.i >> 16]) << 16) | ((e + 127) << 23);
 429
 430    return num.f;
 431 #else
 432    return (float) _mesa_sqrtd((double) x);
 433 #endif
 434 }
 435
 436
 437 /**
 438  inv_sqrt - A single precision 1/sqrt routine for IEEE format floats.
 439  written by Josh Vanderhoof, based on newsgroup posts by James Van Buskirk
 440  and Vesa Karvonen.
 441 */
 442 float
 443 _mesa_inv_sqrtf(float n)
 444 {
 445 #if defined(USE_IEEE) && !defined(DEBUG)
 446         float r0, x0, y0;
 447         float r1, x1, y1;
 448         float r2, x2, y2;
 449 #if 0 /* not used, see below -BP */
 450         float r3, x3, y3;
 451 #endif
 452         fi_type u;
 453         unsigned int magic;
 454
 455         /*
 456          Exponent part of the magic number -
 457
 458          We want to:
 459          1. subtract the bias from the exponent,
 460          2. negate it
 461          3. divide by two (rounding towards -inf)
 462          4. add the bias back
 463
 464          Which is the same as subtracting the exponent from 381 and dividing
 465          by 2.
 466
 467          floor(-(x - 127) / 2) + 127 = floor((381 - x) / 2)
 468         */
 469
 470         magic = 381 << 23;
 471
 472         /*
 473          Significand part of magic number -
 474
 475          With the current magic number, "(magic - u.i) >> 1" will give you:
 476
 477          for 1 <= u.f <= 2: 1.25 - u.f / 4
 478          for 2 <= u.f <= 4: 1.00 - u.f / 8
 479
 480          This isn't a bad approximation of 1/sqrt.  The maximum difference from
 481          1/sqrt will be around .06.  After three Newton-Raphson iterations, the
 482          maximum difference is less than 4.5e-8.  (Which is actually close
 483          enough to make the following bias academic...)
 484
 485          To get a better approximation you can add a bias to the magic
 486          number.  For example, if you subtract 1/2 of the maximum difference in
 487          the first approximation (.03), you will get the following function:
 488
 489          for 1 <= u.f <= 2:    1.22 - u.f / 4
 490          for 2 <= u.f <= 3.76: 0.97 - u.f / 8
 491          for 3.76 <= u.f <= 4: 0.72 - u.f / 16
 492          (The 3.76 to 4 range is where the result is < .5.)
 493
 494          This is the closest possible initial approximation, but with a maximum
 495          error of 8e-11 after three NR iterations, it is still not perfect.  If
 496          you subtract 0.0332281 instead of .03, the maximum error will be
 497          2.5e-11 after three NR iterations, which should be about as close as
 498          is possible.
 499
 500          for 1 <= u.f <= 2:    1.2167719 - u.f / 4
 501          for 2 <= u.f <= 3.73: 0.9667719 - u.f / 8
 502          for 3.73 <= u.f <= 4: 0.7167719 - u.f / 16
 503
 504         */
 505
 506         magic -= (int)(0.0332281 * (1 << 25));
 507
 508         u.f = n;
 509         u.i = (magic - u.i) >> 1;
 510
 511         /*
 512          Instead of Newton-Raphson, we use Goldschmidt's algorithm, which
 513          allows more parallelism.  From what I understand, the parallelism
 514          comes at the cost of less precision, because it lets error
 515          accumulate across iterations.
 516         */
 517         x0 = 1.0f;
 518         y0 = 0.5f * n;
 519         r0 = u.f;
 520
 521         x1 = x0 * r0;
 522         y1 = y0 * r0 * r0;
 523         r1 = 1.5f - y1;
 524
 525         x2 = x1 * r1;
 526         y2 = y1 * r1 * r1;
 527         r2 = 1.5f - y2;
 528
 529 #if 1
 530         return x2 * r2;  /* we can stop here, and be conformant -BP */
 531 #else
 532         x3 = x2 * r2;
 533         y3 = y2 * r2 * r2;
 534         r3 = 1.5f - y3;
 535
 536         return x3 * r3;
 537 #endif
 538 #else
 539         return (float) (1.0 / sqrt(n));
 540 #endif
 541 }
 542
 543
 544 /** Wrapper around pow() */
 545 double
 546 _mesa_pow(double x, double y)
 547 {
 548    return pow(x, y);
 549 }
 550
 551
 552 /**
 553  * Find the first bit set in a word.
 554  */
 555 int
 556 _mesa_ffs(int32_t i)
 557 {
 558 #if (defined(_WIN32) ) || defined(__IBMC__) || defined(__IBMCPP__)
 559    register int bit = 0;
 560    if (i != 0) {
 561       if ((i & 0xffff) == 0) {
 562          bit += 16;
 563          i >>= 16;
 564       }
 565       if ((i & 0xff) == 0) {
 566          bit += 8;
 567          i >>= 8;
 568       }
 569       if ((i & 0xf) == 0) {
 570          bit += 4;
 571          i >>= 4;
 572       }
 573       while ((i & 1) == 0) {
 574          bit++;
 575          i >>= 1;
 576       }
 577       bit++;
 578    }
 579    return bit;
 580 #else
 581    return ffs(i);
 582 #endif
 583 }
 584
 585
 586 /**
 587  * Find position of first bit set in given value.
 588  * XXX Warning: this function can only be used on 64-bit systems!
 589  * \return  position of least-significant bit set, starting at 1, return zero
 590  *          if no bits set.
 591  */
 592 int
 593 _mesa_ffsll(int64_t val)
 594 {
 595 #ifdef ffsll
 596    return ffsll(val);
 597 #else
 598    int bit;
 599
 600    assert(sizeof(val) == 8);
 601
 602    bit = _mesa_ffs((int32_t)val);
 603    if (bit != 0)
 604       return bit;
 605
 606    bit = _mesa_ffs((int32_t)(val >> 32));
 607    if (bit != 0)
 608       return 32 + bit;
 609
 610    return 0;
 611 #endif
 612 }
 613
 614
 615 /**
 616  * Return number of bits set in given GLuint.
 617  */
 618 unsigned int
 619 _mesa_bitcount(unsigned int n)
 620 {
 621 #if defined(__GNUC__)
 622    return __builtin_popcount(n);
 623 #else
 624    unsigned int bits;
 625    for (bits = 0; n > 0; n = n >> 1) {
 626       bits += (n & 1);
 627    }
 628    return bits;
 629 #endif
 630 }
 631
 632
 633 /**
 634  * Convert a 4-byte float to a 2-byte half float.
 635  * Based on code from:
 636  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 637  */
 638 GLhalfARB
 639 _mesa_float_to_half(float val)
 640 {
 641    const fi_type fi = {val};
 642    const int flt_m = fi.i & 0x7fffff;
 643    const int flt_e = (fi.i >> 23) & 0xff;
 644    const int flt_s = (fi.i >> 31) & 0x1;
 645    int s, e, m = 0;
 646    GLhalfARB result;
 647
 648    /* sign bit */
 649    s = flt_s;
 650
 651    /* handle special cases */
 652    if ((flt_e == 0) && (flt_m == 0)) {
 653       /* zero */
 654       /* m = 0; - already set */
 655       e = 0;
 656    }
 657    else if ((flt_e == 0) && (flt_m != 0)) {
 658       /* denorm -- denorm float maps to 0 half */
 659       /* m = 0; - already set */
 660       e = 0;
 661    }
 662    else if ((flt_e == 0xff) && (flt_m == 0)) {
 663       /* infinity */
 664       /* m = 0; - already set */
 665       e = 31;
 666    }
 667    else if ((flt_e == 0xff) && (flt_m != 0)) {
 668       /* NaN */
 669       m = 1;
 670       e = 31;
 671    }
 672    else {
 673       /* regular number */
 674       const int new_exp = flt_e - 127;
 675       if (new_exp < -24) {
 676          /* this maps to 0 */
 677          /* m = 0; - already set */
 678          e = 0;
 679       }
 680       else if (new_exp < -14) {
 681          /* this maps to a denorm */
 682          unsigned int exp_val = (unsigned int) (-14 - new_exp); /* 2^-exp_val*/
 683          e = 0;
 684          switch (exp_val) {
 685             case 0:
 686                _mesa_warning(NULL,
 687                    "float_to_half: logical error in denorm creation!\n");
 688                /* m = 0; - already set */
 689                break;
 690             case 1: m = 512 + (flt_m >> 14); break;
 691             case 2: m = 256 + (flt_m >> 15); break;
 692             case 3: m = 128 + (flt_m >> 16); break;
 693             case 4: m = 64 + (flt_m >> 17); break;
 694             case 5: m = 32 + (flt_m >> 18); break;
 695             case 6: m = 16 + (flt_m >> 19); break;
 696             case 7: m = 8 + (flt_m >> 20); break;
 697             case 8: m = 4 + (flt_m >> 21); break;
 698             case 9: m = 2 + (flt_m >> 22); break;
 699             case 10: m = 1; break;
 700          }
 701       }
 702       else if (new_exp > 15) {
 703          /* map this value to infinity */
 704          /* m = 0; - already set */
 705          e = 31;
 706       }
 707       else {
 708          /* regular */
 709          e = new_exp + 15;
 710          m = flt_m >> 13;
 711       }
 712    }
 713
 714    result = (s << 15) | (e << 10) | m;
 715    return result;
 716 }
 717
 718
 719 /**
 720  * Convert a 2-byte half float to a 4-byte float.
 721  * Based on code from:
 722  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 723  */
 724 float
 725 _mesa_half_to_float(GLhalfARB val)
 726 {
 727    /* XXX could also use a 64K-entry lookup table */
 728    const int m = val & 0x3ff;
 729    const int e = (val >> 10) & 0x1f;
 730    const int s = (val >> 15) & 0x1;
 731    int flt_m, flt_e, flt_s;
 732    fi_type fi;
 733    float result;
 734
 735    /* sign bit */
 736    flt_s = s;
 737
 738    /* handle special cases */
 739    if ((e == 0) && (m == 0)) {
 740       /* zero */
 741       flt_m = 0;
 742       flt_e = 0;
 743    }
 744    else if ((e == 0) && (m != 0)) {
 745       /* denorm -- denorm half will fit in non-denorm single */
 746       const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */
 747       float mantissa = ((float) (m)) / 1024.0f;
 748       float sign = s ? -1.0f : 1.0f;
 749       return sign * mantissa * half_denorm;
 750    }
 751    else if ((e == 31) && (m == 0)) {
 752       /* infinity */
 753       flt_e = 0xff;
 754       flt_m = 0;
 755    }
 756    else if ((e == 31) && (m != 0)) {
 757       /* NaN */
 758       flt_e = 0xff;
 759       flt_m = 1;
 760    }
 761    else {
 762       /* regular */
 763       flt_e = e + 112;
 764       flt_m = m << 13;
 765    }
 766
 767    fi.i = (flt_s << 31) | (flt_e << 23) | flt_m;
 768    result = fi.f;
 769    return result;
 770 }
 771
 772 /*@}*/
 773
 774
 775 /**********************************************************************/
 776 /** \name Sort & Search */
 777 /*@{*/
 778
 779 /**
 780  * Wrapper for bsearch().
 781  */
 782 void *
 783 _mesa_bsearch( const void *key, const void *base, size_t nmemb, size_t size,
 784                int (*compar)(const void *, const void *) )
 785 {
 786 #if defined(_WIN32_WCE)
 787    void *mid;
 788    int cmp;
 789    while (nmemb) {
 790       nmemb >>= 1;
 791       mid = (char *)base + nmemb * size;
 792       cmp = (*compar)(key, mid);
 793       if (cmp == 0)
 794          return mid;
 795       if (cmp > 0) {
 796          base = (char *)mid + size;
 797          --nmemb;
 798       }
 799    }
 800    return NULL;
 801 #else
 802    return bsearch(key, base, nmemb, size, compar);
 803 #endif
 804 }
 805
 806 /*@}*/
 807
 808
 809 /**********************************************************************/
 810 /** \name Environment vars */
 811 /*@{*/
 812
 813 /**
 814  * Wrapper for getenv().
 815  */
 816 char *
 817 _mesa_getenv( const char *var )
 818 {
 819 #if defined(_XBOX) || defined(_WIN32_WCE)
 820    return NULL;
 821 #else
 822    return getenv(var);
 823 #endif
 824 }
 825
 826 /*@}*/
 827
 828
 829 /**********************************************************************/
 830 /** \name String */
 831 /*@{*/
 832
 833 /**
 834  * Implemented using _mesa_malloc() and strcpy.
 835  * Note that NULL is handled accordingly.
 836  */
 837 char *
 838 _mesa_strdup( const char *s )
 839 {
 840    if (s) {
 841       size_t l = strlen(s);
 842       char *s2 = (char *) _mesa_malloc(l + 1);
 843       if (s2)
 844          strcpy(s2, s);
 845       return s2;
 846    }
 847    else {
 848       return NULL;
 849    }
 850 }
 851
 852 /** Wrapper around strtod() */
 853 double
 854 _mesa_strtod( const char *s, char **end )
 855 {
 856 #ifdef _GNU_SOURCE
 857    static locale_t loc = NULL;
 858    if (!loc) {
 859       loc = newlocale(LC_CTYPE_MASK, "C", NULL);
 860    }
 861    return strtod_l(s, end, loc);
 862 #else
 863    return strtod(s, end);
 864 #endif
 865 }
 866
 867 /** Compute simple checksum/hash for a string */
 868 unsigned int
 869 _mesa_str_checksum(const char *str)
 870 {
 871    /* This could probably be much better */
 872    unsigned int sum, i;
 873    const char *c;
 874    sum = i = 1;
 875    for (c = str; *c; c++, i++)
 876       sum += *c * (i % 100);
 877    return sum + i;
 878 }
 879
 880
 881 /*@}*/
 882
 883
 884 /**********************************************************************/
 885 /** \name I/O */
 886 /*@{*/
 887
 888 /** Wrapper around vsprintf() */
 889 int
 890 _mesa_sprintf( char *str, const char *fmt, ... )
 891 {
 892    int r;
 893    va_list args;
 894    va_start( args, fmt );
 895    r = vsprintf( str, fmt, args );
 896    va_end( args );
 897    return r;
 898 }
 899
 900 /** Wrapper around vsnprintf() */
 901 int
 902 _mesa_snprintf( char *str, size_t size, const char *fmt, ... )
 903 {
 904    int r;
 905    va_list args;
 906    va_start( args, fmt );
 907    r = vsnprintf( str, size, fmt, args );
 908    va_end( args );
 909    return r;
 910 }
 911
 912 /** Wrapper around printf(), using vsprintf() for the formatting. */
 913 void
 914 _mesa_printf( const char *fmtString, ... )
 915 {
 916    va_list args;
 917    va_start( args, fmtString );
 918    vfprintf(stderr, fmtString, args);
 919    va_end( args );
 920 }
 921
 922 /** Wrapper around fprintf(), using vsprintf() for the formatting. */
 923 void
 924 _mesa_fprintf( FILE *f, const char *fmtString, ... )
 925 {
 926    char s[MAXSTRING];
 927    va_list args;
 928    va_start( args, fmtString );
 929    vsnprintf(s, MAXSTRING, fmtString, args);
 930    va_end( args );
 931    fprintf(f, "%s", s);
 932 }
 933
 934
 935 /** Wrapper around vsprintf() */
 936 int
 937 _mesa_vsprintf( char *str, const char *fmt, va_list args )
 938 {
 939    return vsprintf( str, fmt, args );
 940 }
 941
 942 /*@}*/
 943
 944
 945 /**********************************************************************/
 946 /** \name Diagnostics */
 947 /*@{*/
 948
 949 static void
 950 output_if_debug(const char *prefixString, const char *outputString,
 951                 GLboolean newline)
 952 {
 953    static int debug = -1;
 954
 955    /* Check the MESA_DEBUG environment variable if it hasn't
 956     * been checked yet.  We only have to check it once...
 957     */
 958    if (debug == -1) {
 959       char *env = _mesa_getenv("MESA_DEBUG");
 960
 961       /* In a debug build, we print warning messages *unless*
 962        * MESA_DEBUG is 0.  In a non-debug build, we don't
 963        * print warning messages *unless* MESA_DEBUG is
 964        * set *to any value*.
 965        */
 966 #ifdef DEBUG
 967       debug = (env != NULL && atoi(env) == 0) ? 0 : 1;
 968 #else
 969       debug = (env != NULL) ? 1 : 0;
 970 #endif
 971    }
 972
 973    /* Now only print the string if we're required to do so. */
 974    if (debug) {
 975       fprintf(stderr, "%s: %s", prefixString, outputString);
 976       if (newline)
 977          fprintf(stderr, "\n");
 978
 979 #if defined(_WIN32) && !defined(_WIN32_WCE)
 980       /* stderr from windows applications without console is not usually
 981        * visible, so communicate with the debugger instead */
 982       {
 983          char buf[4096];
 984          _mesa_snprintf(buf, sizeof(buf), "%s: %s%s", prefixString, outputString, newline ? "\n" : "");
 985          OutputDebugStringA(buf);
 986       }
 987 #endif
 988    }
 989 }
 990
 991
 992 /**
 993  * Return string version of GL error code.
 994  */
 995 static const char *
 996 error_string( GLenum error )
 997 {
 998    switch (error) {
 999    case GL_NO_ERROR:
1000       return "GL_NO_ERROR";
1001    case GL_INVALID_VALUE:
1002       return "GL_INVALID_VALUE";
1003    case GL_INVALID_ENUM:
1004       return "GL_INVALID_ENUM";
1005    case GL_INVALID_OPERATION:
1006       return "GL_INVALID_OPERATION";
1007    case GL_STACK_OVERFLOW:
1008       return "GL_STACK_OVERFLOW";
1009    case GL_STACK_UNDERFLOW:
1010       return "GL_STACK_UNDERFLOW";
1011    case GL_OUT_OF_MEMORY:
1012       return "GL_OUT_OF_MEMORY";
1013    case GL_TABLE_TOO_LARGE:
1014       return "GL_TABLE_TOO_LARGE";
1015    case GL_INVALID_FRAMEBUFFER_OPERATION_EXT:
1016       return "GL_INVALID_FRAMEBUFFER_OPERATION";
1017    default:
1018       return "unknown";
1019    }
1020 }
1021
1022
1023 /**
1024  * When a new type of error is recorded, print a message describing
1025  * previous errors which were accumulated.
1026  */
1027 static void
1028 flush_delayed_errors( GLcontext *ctx )
1029 {
1030    char s[MAXSTRING];
1031
1032    if (ctx->ErrorDebugCount) {
1033       _mesa_snprintf(s, MAXSTRING, "%d similar %s errors",
1034                      ctx->ErrorDebugCount,
1035                      error_string(ctx->ErrorValue));
1036
1037       output_if_debug("Mesa", s, GL_TRUE);
1038
1039       ctx->ErrorDebugCount = 0;
1040    }
1041 }
1042
1043
1044 /**
1045  * Report a warning (a recoverable error condition) to stderr if
1046  * either DEBUG is defined or the MESA_DEBUG env var is set.
1047  *
1048  * \param ctx GL context.
1049  * \param fmtString printf()-like format string.
1050  */
1051 void
1052 _mesa_warning( GLcontext *ctx, const char *fmtString, ... )
1053 {
1054    char str[MAXSTRING];
1055    va_list args;
1056    va_start( args, fmtString );
1057    (void) vsnprintf( str, MAXSTRING, fmtString, args );
1058    va_end( args );
1059
1060    if (ctx)
1061       flush_delayed_errors( ctx );
1062
1063    output_if_debug("Mesa warning", str, GL_TRUE);
1064 }
1065
1066
1067 /**
1068  * Report an internal implementation problem.
1069  * Prints the message to stderr via fprintf().
1070  *
1071  * \param ctx GL context.
1072  * \param fmtString problem description string.
1073  */
1074 void
1075 _mesa_problem( const GLcontext *ctx, const char *fmtString, ... )
1076 {
1077    va_list args;
1078    char str[MAXSTRING];
1079    (void) ctx;
1080
1081    va_start( args, fmtString );
1082    vsnprintf( str, MAXSTRING, fmtString, args );
1083    va_end( args );
1084
1085    fprintf(stderr, "Mesa %s implementation error: %s\n", MESA_VERSION_STRING, str);
1086    fprintf(stderr, "Please report at bugzilla.freedesktop.org\n");
1087 }
1088
1089
1090 /**
1091  * Record an OpenGL state error.  These usually occur when the user
1092  * passes invalid parameters to a GL function.
1093  *
1094  * If debugging is enabled (either at compile-time via the DEBUG macro, or
1095  * run-time via the MESA_DEBUG environment variable), report the error with
1096  * _mesa_debug().
1097  *
1098  * \param ctx the GL context.
1099  * \param error the error value.
1100  * \param fmtString printf() style format string, followed by optional args
1101  */
1102 void
1103 _mesa_error( GLcontext *ctx, GLenum error, const char *fmtString, ... )
1104 {
1105    static GLint debug = -1;
1106
1107    /* Check debug environment variable only once:
1108     */
1109    if (debug == -1) {
1110       const char *debugEnv = _mesa_getenv("MESA_DEBUG");
1111
1112 #ifdef DEBUG
1113       if (debugEnv && strstr(debugEnv, "silent"))
1114          debug = GL_FALSE;
1115       else
1116          debug = GL_TRUE;
1117 #else
1118       if (debugEnv)
1119          debug = GL_TRUE;
1120       else
1121          debug = GL_FALSE;
1122 #endif
1123    }
1124
1125    if (debug) {
1126       if (ctx->ErrorValue == error &&
1127           ctx->ErrorDebugFmtString == fmtString) {
1128          ctx->ErrorDebugCount++;
1129       }
1130       else {
1131          char s[MAXSTRING], s2[MAXSTRING];
1132          va_list args;
1133
1134          flush_delayed_errors( ctx );
1135
1136          va_start(args, fmtString);
1137          vsnprintf(s, MAXSTRING, fmtString, args);
1138          va_end(args);
1139
1140          _mesa_snprintf(s2, MAXSTRING, "%s in %s", error_string(error), s);
1141          output_if_debug("Mesa: User error", s2, GL_TRUE);
1142
1143          ctx->ErrorDebugFmtString = fmtString;
1144          ctx->ErrorDebugCount = 0;
1145       }
1146    }
1147
1148    _mesa_record_error(ctx, error);
1149 }
1150
1151
1152 /**
1153  * Report debug information.  Print error message to stderr via fprintf().
1154  * No-op if DEBUG mode not enabled.
1155  *
1156  * \param ctx GL context.
1157  * \param fmtString printf()-style format string, followed by optional args.
1158  */
1159 void
1160 _mesa_debug( const GLcontext *ctx, const char *fmtString, ... )
1161 {
1162 #ifdef DEBUG
1163    char s[MAXSTRING];
1164    va_list args;
1165    va_start(args, fmtString);
1166    vsnprintf(s, MAXSTRING, fmtString, args);
1167    va_end(args);
1168    output_if_debug("Mesa", s, GL_FALSE);
1169 #endif /* DEBUG */
1170    (void) ctx;
1171    (void) fmtString;
1172 }
1173
1174 /*@}*/