wtf/MathExtras.h

   1 /*
   2  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef WTF_MathExtras_h
  27 #define WTF_MathExtras_h
  28
  29 #include <float.h>
  30 #include <math.h>
  31 #include <stdlib.h>
  32
  33 #if OS(SOLARIS)
  34 #include <ieeefp.h>
  35 #endif
  36
  37 #if OS(OPENBSD)
  38 #include <sys/types.h>
  39 #include <machine/ieee.h>
  40 #endif
  41
  42 #if COMPILER(MSVC)
  43 #if OS(WINCE)
  44 #include <stdlib.h>
  45 #endif
  46 #include <limits>
  47 #endif
  48
  49 #ifndef M_PI
  50 const double piDouble = 3.14159265358979323846;
  51 const float piFloat = 3.14159265358979323846f;
  52 #else
  53 const double piDouble = M_PI;
  54 const float piFloat = static_cast<float>(M_PI);
  55 #endif
  56
  57 #ifndef M_PI_4
  58 const double piOverFourDouble = 0.785398163397448309616;
  59 const float piOverFourFloat = 0.785398163397448309616f;
  60 #else
  61 const double piOverFourDouble = M_PI_4;
  62 const float piOverFourFloat = static_cast<float>(M_PI_4);
  63 #endif
  64
  65 #if OS(DARWIN)
  66
  67 // Work around a bug in the Mac OS X libc where ceil(-0.1) return +0.
  68 inline double wtf_ceil(double x) { return copysign(ceil(x), x); }
  69
  70 #define ceil(x) wtf_ceil(x)
  71
  72 #endif
  73
  74 #if OS(SOLARIS)
  75
  76 #ifndef isfinite
  77 inline bool isfinite(double x) { return finite(x) && !isnand(x); }
  78 #endif
  79 #ifndef isinf
  80 inline bool isinf(double x) { return !finite(x) && !isnand(x); }
  81 #endif
  82 #ifndef signbit
  83 inline bool signbit(double x) { return x < 0.0; } // FIXME: Wrong for negative 0.
  84 #endif
  85
  86 #endif
  87
  88 #if OS(OPENBSD)
  89
  90 #ifndef isfinite
  91 inline bool isfinite(double x) { return finite(x); }
  92 #endif
  93 #ifndef signbit
  94 inline bool signbit(double x) { struct ieee_double *p = (struct ieee_double *)&x; return p->dbl_sign; }
  95 #endif
  96
  97 #endif
  98
  99 #if COMPILER(MSVC) || COMPILER(RVCT)
 100
 101 inline long long llround(double num) { return static_cast<long long>(num > 0 ? num + 0.5 : ceil(num - 0.5)); }
 102 inline long long llroundf(float num) { return static_cast<long long>(num > 0 ? num + 0.5f : ceil(num - 0.5f)); }
 103 inline long lround(double num) { return static_cast<long>(num > 0 ? num + 0.5 : ceil(num - 0.5)); }
 104 inline long lroundf(float num) { return static_cast<long>(num > 0 ? num + 0.5f : ceilf(num - 0.5f)); }
 105 inline double round(double num) { return num > 0 ? floor(num + 0.5) : ceil(num - 0.5); }
 106 inline float roundf(float num) { return num > 0 ? floorf(num + 0.5f) : ceilf(num - 0.5f); }
 107 inline double trunc(double num) { return num > 0 ? floor(num) : ceil(num); }
 108
 109 #endif
 110
 111 #if COMPILER(MSVC)
 112
 113 inline bool isinf(double num) { return !_finite(num) && !_isnan(num); }
 114 inline bool isnan(double num) { return !!_isnan(num); }
 115 inline bool signbit(double num) { return _copysign(1.0, num) < 0; }
 116
 117 inline double nextafter(double x, double y) { return _nextafter(x, y); }
 118 inline float nextafterf(float x, float y) { return x > y ? x - FLT_EPSILON : x + FLT_EPSILON; }
 119
 120 inline double copysign(double x, double y) { return _copysign(x, y); }
 121 inline int isfinite(double x) { return _finite(x); }
 122
 123 // Work around a bug in Win, where atan2(+-infinity, +-infinity) yields NaN instead of specific values.
 124 inline double wtf_atan2(double x, double y)
 125 {
 126     double posInf = std::numeric_limits<double>::infinity();
 127     double negInf = -std::numeric_limits<double>::infinity();
 128     double nan = std::numeric_limits<double>::quiet_NaN();
 129
 130     double result = nan;
 131
 132     if (x == posInf && y == posInf)
 133         result = piOverFourDouble;
 134     else if (x == posInf && y == negInf)
 135         result = 3 * piOverFourDouble;
 136     else if (x == negInf && y == posInf)
 137         result = -piOverFourDouble;
 138     else if (x == negInf && y == negInf)
 139         result = -3 * piOverFourDouble;
 140     else
 141         result = ::atan2(x, y);
 142
 143     return result;
 144 }
 145
 146 // Work around a bug in the Microsoft CRT, where fmod(x, +-infinity) yields NaN instead of x.
 147 inline double wtf_fmod(double x, double y) { return (!isinf(x) && isinf(y)) ? x : fmod(x, y); }
 148
 149 // Work around a bug in the Microsoft CRT, where pow(NaN, 0) yields NaN instead of 1.
 150 inline double wtf_pow(double x, double y) { return y == 0 ? 1 : pow(x, y); }
 151
 152 #define atan2(x, y) wtf_atan2(x, y)
 153 #define fmod(x, y) wtf_fmod(x, y)
 154 #define pow(x, y) wtf_pow(x, y)
 155
 156 #endif // COMPILER(MSVC)
 157
 158 inline double deg2rad(double d)  { return d * piDouble / 180.0; }
 159 inline double rad2deg(double r)  { return r * 180.0 / piDouble; }
 160 inline double deg2grad(double d) { return d * 400.0 / 360.0; }
 161 inline double grad2deg(double g) { return g * 360.0 / 400.0; }
 162 inline double turn2deg(double t) { return t * 360.0; }
 163 inline double deg2turn(double d) { return d / 360.0; }
 164 inline double rad2grad(double r) { return r * 200.0 / piDouble; }
 165 inline double grad2rad(double g) { return g * piDouble / 200.0; }
 166
 167 inline float deg2rad(float d)  { return d * piFloat / 180.0f; }
 168 inline float rad2deg(float r)  { return r * 180.0f / piFloat; }
 169 inline float deg2grad(float d) { return d * 400.0f / 360.0f; }
 170 inline float grad2deg(float g) { return g * 360.0f / 400.0f; }
 171 inline float turn2deg(float t) { return t * 360.0f; }
 172 inline float deg2turn(float d) { return d / 360.0f; }
 173 inline float rad2grad(float r) { return r * 200.0f / piFloat; }
 174 inline float grad2rad(float g) { return g * piFloat / 200.0f; }
 175
 176 #endif // #ifndef WTF_MathExtras_h