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 <math.h>
  30 #include <stdlib.h>
  31
  32 #if PLATFORM(SOLARIS)
  33 #include <ieeefp.h>
  34 #endif
  35
  36 #if PLATFORM(OPENBSD)
  37 #include <sys/types.h>
  38 #include <machine/ieee.h>
  39 #endif
  40
  41 #if COMPILER(MSVC)
  42 #if PLATFORM(WIN_CE)
  43 #include <stdlib.h>
  44 #else
  45 #include <xmath.h>
  46 #endif
  47 #include <limits>
  48
  49 #if HAVE(FLOAT_H)
  50 #include <float.h>
  51 #endif
  52
  53 #endif
  54
  55 #ifndef M_PI
  56 const double piDouble = 3.14159265358979323846;
  57 const float piFloat = 3.14159265358979323846f;
  58 #else
  59 const double piDouble = M_PI;
  60 const float piFloat = static_cast<float>(M_PI);
  61 #endif
  62
  63 #ifndef M_PI_4
  64 const double piOverFourDouble = 0.785398163397448309616;
  65 const float piOverFourFloat = 0.785398163397448309616f;
  66 #else
  67 const double piOverFourDouble = M_PI_4;
  68 const float piOverFourFloat = static_cast<float>(M_PI_4);
  69 #endif
  70
  71 #if PLATFORM(DARWIN)
  72
  73 // Work around a bug in the Mac OS X libc where ceil(-0.1) return +0.
  74 inline double wtf_ceil(double x) { return copysign(ceil(x), x); }
  75
  76 #define ceil(x) wtf_ceil(x)
  77
  78 #endif
  79
  80 #if PLATFORM(SOLARIS)
  81
  82 #ifndef isfinite
  83 inline bool isfinite(double x) { return finite(x) && !isnand(x); }
  84 #endif
  85 #ifndef isinf
  86 inline bool isinf(double x) { return !finite(x) && !isnand(x); }
  87 #endif
  88 #ifndef signbit
  89 inline bool signbit(double x) { return x < 0.0; } // FIXME: Wrong for negative 0.
  90 #endif
  91
  92 #endif
  93
  94 #if PLATFORM(OPENBSD)
  95
  96 #ifndef isfinite
  97 inline bool isfinite(double x) { return finite(x); }
  98 #endif
  99 #ifndef signbit
 100 inline bool signbit(double x) { struct ieee_double *p = (struct ieee_double *)&x; return p->dbl_sign; }
 101 #endif
 102
 103 #endif
 104
 105 #if COMPILER(MSVC) || COMPILER(RVCT)
 106
 107 inline long lround(double num) { return static_cast<long>(num > 0 ? num + 0.5 : ceil(num - 0.5)); }
 108 inline long lroundf(float num) { return static_cast<long>(num > 0 ? num + 0.5f : ceilf(num - 0.5f)); }
 109 inline double round(double num) { return num > 0 ? floor(num + 0.5) : ceil(num - 0.5); }
 110 inline float roundf(float num) { return num > 0 ? floorf(num + 0.5f) : ceilf(num - 0.5f); }
 111 inline double trunc(double num) { return num > 0 ? floor(num) : ceil(num); }
 112
 113 #endif
 114
 115 #if COMPILER(MSVC)
 116
 117 inline bool isinf(double num) { return !_finite(num) && !_isnan(num); }
 118 inline bool isnan(double num) { return !!_isnan(num); }
 119 inline bool signbit(double num) { return _copysign(1.0, num) < 0; }
 120
 121 inline double nextafter(double x, double y) { return _nextafter(x, y); }
 122 inline float nextafterf(float x, float y) { return x > y ? x - FLT_EPSILON : x + FLT_EPSILON; }
 123
 124 inline double copysign(double x, double y) { return _copysign(x, y); }
 125 inline int isfinite(double x) { return _finite(x); }
 126
 127 // Work around a bug in Win, where atan2(+-infinity, +-infinity) yields NaN instead of specific values.
 128 inline double wtf_atan2(double x, double y)
 129 {
 130     double posInf = std::numeric_limits<double>::infinity();
 131     double negInf = -std::numeric_limits<double>::infinity();
 132     double nan = std::numeric_limits<double>::quiet_NaN();
 133
 134     double result = nan;
 135
 136     if (x == posInf && y == posInf)
 137         result = piOverFourDouble;
 138     else if (x == posInf && y == negInf)
 139         result = 3 * piOverFourDouble;
 140     else if (x == negInf && y == posInf)
 141         result = -piOverFourDouble;
 142     else if (x == negInf && y == negInf)
 143         result = -3 * piOverFourDouble;
 144     else
 145         result = ::atan2(x, y);
 146
 147     return result;
 148 }
 149
 150 // Work around a bug in the Microsoft CRT, where fmod(x, +-infinity) yields NaN instead of x.
 151 inline double wtf_fmod(double x, double y) { return (!isinf(x) && isinf(y)) ? x : fmod(x, y); }
 152
 153 // Work around a bug in the Microsoft CRT, where pow(NaN, 0) yields NaN instead of 1.
 154 inline double wtf_pow(double x, double y) { return y == 0 ? 1 : pow(x, y); }
 155
 156 #define atan2(x, y) wtf_atan2(x, y)
 157 #define fmod(x, y) wtf_fmod(x, y)
 158 #define pow(x, y) wtf_pow(x, y)
 159
 160 #endif // COMPILER(MSVC)
 161
 162 inline double deg2rad(double d)  { return d * piDouble / 180.0; }
 163 inline double rad2deg(double r)  { return r * 180.0 / piDouble; }
 164 inline double deg2grad(double d) { return d * 400.0 / 360.0; }
 165 inline double grad2deg(double g) { return g * 360.0 / 400.0; }
 166 inline double turn2deg(double t) { return t * 360.0; }
 167 inline double deg2turn(double d) { return d / 360.0; }
 168 inline double rad2grad(double r) { return r * 200.0 / piDouble; }
 169 inline double grad2rad(double g) { return g * piDouble / 200.0; }
 170
 171 inline float deg2rad(float d)  { return d * piFloat / 180.0f; }
 172 inline float rad2deg(float r)  { return r * 180.0f / piFloat; }
 173 inline float deg2grad(float d) { return d * 400.0f / 360.0f; }
 174 inline float grad2deg(float g) { return g * 360.0f / 400.0f; }
 175 inline float turn2deg(float t) { return t * 360.0f; }
 176 inline float deg2turn(float d) { return d / 360.0f; }
 177 inline float rad2grad(float r) { return r * 200.0f / piFloat; }
 178 inline float grad2rad(float g) { return g * piFloat / 200.0f; }
 179
 180 #endif // #ifndef WTF_MathExtras_h