source: cpp/common/nonstd_math.h @ 1117

Last change on this file since 1117 was 1053, checked in by Maciej Komosinski, 4 years ago

Implemented missing ffs(int) for Windows compilers

  • Property svn:eol-style set to native
File size: 3.5 KB
Line 
1// This file is a part of Framsticks SDK.  http://www.framsticks.com/
2// Copyright (C) 1999-2020  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> //w vc2008 dzia³a³o tu <cmath>, ale w vc2010 juz nie bo "coœ" (jakiœ inny .h stl'a?) includuje wczeœniej <cmath> bez _USE_MATH_DEFINES, a <cmath> includuje <math.h> (ale tylko raz bo ma "include guards" jak kazdy .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 //m.in. __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 void rndSetSeed(unsigned int seed) { rndGetInstance().setSeed(seed); }
28inline unsigned int rndRandomizeSeed() { return rndGetInstance().randomize(); }
29
30
31
32// precision==-1 for full precision, or positive values for the number of digits to print past the decimal point.
33// Allocated buffer with bufferlen=30 is OK.
34// Returns the number of chars actually used (not including the ending 0).
35int doubleToString(double x, int precision, char *buffer, int bufferlen);
36
37#include <string>
38std::string doubleToString(double x, int precision);
39double round(const double x, const int precision);
40
41
42
43
44
45//floating point specific numbers
46#include "stdlib.h"
47
48#ifdef __BORLANDC__
49        #include <float.h>
50        #define isnan(x) _isnan(x) //http://stackoverflow.com/questions/570669/checking-if-a-double-or-float-is-nan-in-c
51        #define finite(x) _finite(x)
52#endif
53
54#ifdef LINUX
55  #define _isnan(a) isnan(a)
56#endif
57
58#ifdef IPHONE
59        #define finite(x) (!isinf(x))
60  #define _isnan(a) isnan(a)
61#endif
62
63
64#if defined SHP
65 //#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 szczêœcie jest w³asna (byle by by³a, bo i tak zak³adamy ze assert ktore przeciez dziala tylko w trybie debug nie jest potrzebne na bada) implementacja w "bada-assert.cpp"
66 #define isnan(x) false //isnan() sie nie linkuje
67 #define finite(x) true //j.w.
68 //#include <cstdlib> //RAND_MAX defined incorrectly
69 //#ifdef BADA_SIMULATOR //...but only in simulator libs
70 // #undef RAND_MAX
71 // #define RAND_MAX 32768 //...this is the actual value used by rand()
72 //#endif
73#endif
74
75//handling floating point exceptions
76void fpExceptInit(); //call once, before ...Enable/Disable
77void fpExceptEnable();
78void fpExceptDisable();
79
80// 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
81template <typename Value, typename Linear> Value universal_lerp(Value a,Value b,Linear t) {return a*(1-t)+b*t;}
82
83template <typename T> T linearTransform(T value, T min_in, T max_in, T min_out, T max_out)
84{
85        return min_out + (value-min_in)*(max_out-min_out)/(max_in-min_in);
86}
87
88//in C++20, related: https://en.cppreference.com/w/cpp/numeric/countl_zero
89#ifdef _WIN32 //visual studio is missing ffs()
90static inline unsigned ffs(int x)
91{
92        if (x == 0) return 0u;
93        unsigned r = 1;
94        while ((x & 1) == 0)
95                x >>= 1, ++r;
96        return r;
97}
98#endif
99
100
101#endif
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