source: cpp/common/nonstd_math.h @ 1298

Last change on this file since 1298 was 1298, checked in by Maciej Komosinski, 3 weeks ago

Introduced overloads for rndUint() with size_t and int arguments to avoid numerous type casts in sources

  • Property svn:eol-style set to native
File size: 5.1 KB
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1// This file is a part of Framsticks SDK.  http://www.framsticks.com/
2// Copyright (C) 1999-2024  Maciej Komosinski and Szymon Ulatowski.
3// See LICENSE.txt for details.
4
5#ifndef _NONSTD_MATH_H_
6#define _NONSTD_MATH_H_
7
8
9#ifdef _MSC_VER
10 #define _USE_MATH_DEFINES //after this is defined, the next #include <math.h> or <cmath> will define M_PI etc.
11 #include <math.h> //in vc2008, <cmath> worked here, but no longer in vc2010 because "something" (some other .h from stl?) earlier includes <cmath> without _USE_MATH_DEFINES, and <cmath> includes <math.h> (just once because it has "include guards" like any other .h)
12 #include <float.h>
13 //#define isnan(x) _isnan(x) //since 2014 we use std::isnan()
14 #define finite(x) _finite(x)
15#else //e.g. __BORLANDC__
16 #include <math.h>
17#endif
18
19
20
21//random number generator:
22#include "random.h"
23RandomGenerator &rndGetInstance();
24
25inline double rndDouble(double limit_exclusive) { return rndGetInstance().getDouble() * limit_exclusive; }
26inline unsigned int rndUint(unsigned int limit_exclusive) { return (unsigned int)(rndGetInstance().getDouble() * limit_exclusive); } //returns random from 0..limit_exclusive-1
27inline unsigned int rndUint(size_t limit_exclusive) {return rndUint((unsigned int)limit_exclusive);} //just an overload with size_t argument
28unsigned int rndUint(int limit_exclusive); //just an overload with int argument
29inline void rndSetSeed(unsigned int seed) { rndGetInstance().setSeed(seed); }
30inline unsigned int rndRandomizeSeed() { return rndGetInstance().randomize(); }
31
32
33
34// precision==-1 for full precision, or positive values for the number of digits to print past the decimal point.
35// Allocated buffer with bufferlen=30 is OK.
36// Returns the number of chars actually used (not including the ending 0).
37int doubleToString(double x, int precision, char *buffer, int bufferlen);
38
39#include <string>
40std::string doubleToString(double x, int precision);
41double round(const double x, const int precision);
42static inline void clipNegativeZeroIfNeeded(double& value, const double range_low)
43{
44        if (value == 0.0 && range_low == 0.0) // if we have range_low==0.0 and we get value==-0.0 (which is ==0.0)
45                value = 0.0; //turn -0.0 to 0.0 so that it does not look like exceeding the allowed range (even though -0.0==0.0). This code unnecessarily also "overwrites" value==0.0 with 0.0, but it is faster and simpler than additionally checking std::signbit(value) just to distinguish -0.0 from 0.0.
46        //these conditions are not intended for range_low==-0.0, as we assume nobody would define allowed ranges using -0.0.
47}
48
49
50
51
52
53//floating point specific numbers
54#include "stdlib.h"
55
56#ifdef __BORLANDC__
57        #include <float.h>
58        #define isnan(x) _isnan(x) //http://stackoverflow.com/questions/570669/checking-if-a-double-or-float-is-nan-in-c
59        #define finite(x) _finite(x)
60#endif
61
62#ifdef LINUX
63  #define _isnan(a) isnan(a)
64#endif
65
66#ifdef IPHONE
67        #define finite(x) (!isinf(x))
68  #define _isnan(a) isnan(a)
69#endif
70
71
72#if defined SHP
73 //#define __assert_func(a,b,c,d) 0 //Currently, we are sorry to inform you that assert() is not yet supported. We have considered your request for internal discussion. Na szcz�cie jest w�asna (byle by by�a, bo i tak zak�adamy ze assert ktore przeciez dziala tylko w trybie debug nie jest potrzebne na bada) implementacja w "bada-assert.cpp"
74 #define isnan(x) false //isnan() sie nie linkuje
75 #define finite(x) true //j.w.
76 //#include <cstdlib> //RAND_MAX defined incorrectly
77 //#ifdef BADA_SIMULATOR //...but only in simulator libs
78 // #undef RAND_MAX
79 // #define RAND_MAX 32768 //...this is the actual value used by rand()
80 //#endif
81#endif
82
83#if defined LINUX || defined TIZEN || defined __ANDROID__
84#include <fenv.h>
85#endif
86
87namespace fpExcept
88{
89//handling floating point exceptions
90#if defined LINUX || defined TIZEN || defined __ANDROID__
91        //fenv.h values
92        static constexpr unsigned int FPEX_DIV0 = FE_DIVBYZERO;
93        static constexpr unsigned int FPEX_INVALID = FE_INVALID;
94        static constexpr unsigned int FPEX_OVERFLOW = FE_OVERFLOW;
95#elif defined IPHONE
96        // (not implemented but these constants are still needed)
97        static constexpr unsigned int FPEX_DIV0 = 0;
98        static constexpr unsigned int FPEX_INVALID = 0;
99        static constexpr unsigned int FPEX_OVERFLOW = 0;
100#else
101        //_control87() values
102        static constexpr unsigned int FPEX_DIV0 = EM_ZERODIVIDE;
103        static constexpr unsigned int FPEX_INVALID = EM_INVALID;
104        static constexpr unsigned int FPEX_OVERFLOW = EM_OVERFLOW;
105#endif
106        extern int wanted_exceptions;
107       
108        void init(); //call once, before ...Enable/Disable
109        void enable();
110        void disable();
111};
112
113// std::lerp can be used since C++20 (and has some guaranteed properties probably better than this basic formula) but apparently it is not a template
114template <typename Value, typename Linear> Value universal_lerp(Value a,Value b,Linear t) {return a*(1-t)+b*t;}
115
116template <typename T> T linearTransform(T value, T min_in, T max_in, T min_out, T max_out)
117{
118        return min_out + (value-min_in)*(max_out-min_out)/(max_in-min_in);
119}
120
121//in C++20, related: https://en.cppreference.com/w/cpp/numeric/countl_zero
122#ifdef _WIN32 //visual studio is missing ffs()
123static inline unsigned ffs(int x)
124{
125        if (x == 0) return 0u;
126        unsigned r = 1;
127        while ((x & 1) == 0)
128                x >>= 1, ++r;
129        return r;
130}
131#endif
132
133
134#endif
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