1 /*
2 * Copyright (C) 2006, 2007, 2008, 2009, 2010 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 <cmath>
30 #include <float.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.
wtf_ceil(double x)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
isfinite(double x)77 inline bool isfinite(double x) { return finite(x) && !isnand(x); }
78 #endif
79 #ifndef isinf
isinf(double x)80 inline bool isinf(double x) { return !finite(x) && !isnand(x); }
81 #endif
82 #ifndef signbit
signbit(double x)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
isfinite(double x)91 inline bool isfinite(double x) { return finite(x); }
92 #endif
93 #ifndef signbit
signbit(double x)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 // We must not do 'num + 0.5' or 'num - 0.5' because they can cause precision loss.
round(double num)102 static double round(double num)
103 {
104 double integer = ceil(num);
105 if (num > 0)
106 return integer - num > 0.5 ? integer - 1.0 : integer;
107 return integer - num >= 0.5 ? integer - 1.0 : integer;
108 }
roundf(float num)109 static float roundf(float num)
110 {
111 float integer = ceilf(num);
112 if (num > 0)
113 return integer - num > 0.5f ? integer - 1.0f : integer;
114 return integer - num >= 0.5f ? integer - 1.0f : integer;
115 }
llround(double num)116 inline long long llround(double num) { return static_cast<long long>(round(num)); }
llroundf(float num)117 inline long long llroundf(float num) { return static_cast<long long>(roundf(num)); }
lround(double num)118 inline long lround(double num) { return static_cast<long>(round(num)); }
lroundf(float num)119 inline long lroundf(float num) { return static_cast<long>(roundf(num)); }
trunc(double num)120 inline double trunc(double num) { return num > 0 ? floor(num) : ceil(num); }
121
122 #endif
123
124 #if COMPILER(MSVC)
125
isinf(double num)126 inline bool isinf(double num) { return !_finite(num) && !_isnan(num); }
isnan(double num)127 inline bool isnan(double num) { return !!_isnan(num); }
signbit(double num)128 inline bool signbit(double num) { return _copysign(1.0, num) < 0; }
129
nextafter(double x,double y)130 inline double nextafter(double x, double y) { return _nextafter(x, y); }
nextafterf(float x,float y)131 inline float nextafterf(float x, float y) { return x > y ? x - FLT_EPSILON : x + FLT_EPSILON; }
132
copysign(double x,double y)133 inline double copysign(double x, double y) { return _copysign(x, y); }
isfinite(double x)134 inline int isfinite(double x) { return _finite(x); }
135
136 // Work around a bug in Win, where atan2(+-infinity, +-infinity) yields NaN instead of specific values.
wtf_atan2(double x,double y)137 inline double wtf_atan2(double x, double y)
138 {
139 double posInf = std::numeric_limits<double>::infinity();
140 double negInf = -std::numeric_limits<double>::infinity();
141 double nan = std::numeric_limits<double>::quiet_NaN();
142
143 double result = nan;
144
145 if (x == posInf && y == posInf)
146 result = piOverFourDouble;
147 else if (x == posInf && y == negInf)
148 result = 3 * piOverFourDouble;
149 else if (x == negInf && y == posInf)
150 result = -piOverFourDouble;
151 else if (x == negInf && y == negInf)
152 result = -3 * piOverFourDouble;
153 else
154 result = ::atan2(x, y);
155
156 return result;
157 }
158
159 // Work around a bug in the Microsoft CRT, where fmod(x, +-infinity) yields NaN instead of x.
wtf_fmod(double x,double y)160 inline double wtf_fmod(double x, double y) { return (!isinf(x) && isinf(y)) ? x : fmod(x, y); }
161
162 // Work around a bug in the Microsoft CRT, where pow(NaN, 0) yields NaN instead of 1.
wtf_pow(double x,double y)163 inline double wtf_pow(double x, double y) { return y == 0 ? 1 : pow(x, y); }
164
165 #define atan2(x, y) wtf_atan2(x, y)
166 #define fmod(x, y) wtf_fmod(x, y)
167 #define pow(x, y) wtf_pow(x, y)
168
169 #endif // COMPILER(MSVC)
170
deg2rad(double d)171 inline double deg2rad(double d) { return d * piDouble / 180.0; }
rad2deg(double r)172 inline double rad2deg(double r) { return r * 180.0 / piDouble; }
deg2grad(double d)173 inline double deg2grad(double d) { return d * 400.0 / 360.0; }
grad2deg(double g)174 inline double grad2deg(double g) { return g * 360.0 / 400.0; }
turn2deg(double t)175 inline double turn2deg(double t) { return t * 360.0; }
deg2turn(double d)176 inline double deg2turn(double d) { return d / 360.0; }
rad2grad(double r)177 inline double rad2grad(double r) { return r * 200.0 / piDouble; }
grad2rad(double g)178 inline double grad2rad(double g) { return g * piDouble / 200.0; }
179
deg2rad(float d)180 inline float deg2rad(float d) { return d * piFloat / 180.0f; }
rad2deg(float r)181 inline float rad2deg(float r) { return r * 180.0f / piFloat; }
deg2grad(float d)182 inline float deg2grad(float d) { return d * 400.0f / 360.0f; }
grad2deg(float g)183 inline float grad2deg(float g) { return g * 360.0f / 400.0f; }
turn2deg(float t)184 inline float turn2deg(float t) { return t * 360.0f; }
deg2turn(float d)185 inline float deg2turn(float d) { return d / 360.0f; }
rad2grad(float r)186 inline float rad2grad(float r) { return r * 200.0f / piFloat; }
grad2rad(float g)187 inline float grad2rad(float g) { return g * piFloat / 200.0f; }
188
189 // ANDROID
190 // TODO: Upstream to webkit.org
191 #if !COMPILER(MSVC) && !COMPILER(RVCT) && !COMPILER(WINSCW)
192 using std::isfinite;
193 using std::isinf;
194 using std::isnan;
195 using std::signbit;
196 #endif
197
198 #endif // #ifndef WTF_MathExtras_h
199