1/* Copyright Statement:
2 *
3 * (C) 2021-2024  Cubios Inc. All rights reserved.
4 */
5 
6#ifndef WASMLIBS_CPP_MATH_H_
7#define WASMLIBS_CPP_MATH_H_
8 
9#include <math.h>
10 
11#ifndef LN_2
12#define LN_2 0.693147180559945f
13#endif
14 
15#ifndef PI
16#define PI (3.141592653589f)
17#endif
18 
19#ifndef PI_2
20#define PI_2 (6.28318530718f)
21#endif
22 
23#ifndef TINY
24#define TINY (0.0000001)
25#endif
26 
27#define n_max(a,b)      (((a) > (b)) ? (a) : (b))
28#define n_min(a,b)      (((a) < (b)) ? (a) : (b))
29#define n_abs(a)        (((a)<0.0f) ? (-(a)) : (a))
30#define n_sgn(a)        (((a)<0.0f) ? (-1) : (1))
31#define n_deg2rad(d)    (((d)*PI)/180.0f)
32#define n_rad2deg(r)    (((r)*180.0f)/PI)
33#define n_sin(x) (float(sin(x)))
34#define n_cos(x) (float(cos(x)))
35#define n_tan(x) (float(tan(x)))
36#define n_atan(x) (float(atan(x)))
37 
38 
39namespace Cubios 
40{
41    namespace Math
42    {
43 
44    //log2() function.
45static inline float log2(float f) 
46{ 
47    return logf(f) / LN_2; 
48}
49 
50//Integer clamping.
51static inline int iclamp(int val, int minVal, int maxVal)
52{
53    if (val < minVal)      return minVal;
54    else if (val > maxVal) return maxVal;
55    else return val;
56}
57 
58 //  acos with value clamping.
59static inline float acos(float x)
60{
61    if(x >  1.0f) x =  1.0f;
62    if(x < -1.0f) x = -1.0f;
63    return (float)acos(x);
64}
65 
66//asin with value clamping.
67static inline float asin(float x)
68{
69    if(x >  1.0f) x =  1.0f;
70    if(x < -1.0f) x = -1.0f;
71    return (float)asin(x);
72}
73 
74//Safe sqrt.
75static inline float sqrt(float x)
76{
77    if (x<0.0f) x=(float)0.0f;
78    return (float) sqrt(x);
79}
80 
81//A fuzzy floating point equality check
82static inline bool fequal(float f0, float f1, float tol) 
83{
84    float f = f0-f1;
85    if ((f>(-tol)) && (f<tol)) return true;
86    else                       return false;
87}
88 
89//A fuzzy floating point less-then check.
90static inline bool fless(float f0, float f1, float tol) 
91{
92    if ((f0-f1)<tol) return true;
93    else             return false;
94}
95 
96//A fuzzy floating point greater-then check.
97static inline bool fgreater(float f0, float f1, float tol) 
98{
99    if ((f0-f1)>tol) return true;
100    else             return false;
101}
102 
103/**
104    fast float to int conversion (always truncates)
105    see http://www.stereopsis.com/FPU.html for a discussion.
106    NOTE: this works only on little endian machines.
107*/
108static inline long ftol(float val)
109{
110    double v = double(val) + (68719476736.0*1.5);
111    return ((long*)&v)[0] >> 16;
112}
113 
114 
115//Smooth a new value towards an old value using a change value.
116static inline float smooth(float newVal, float curVal, float maxChange)
117{
118    float diff = newVal - curVal;
119    if (fabs(diff) > maxChange)
120    {
121        if (diff > 0.0f)
122        {
123            curVal += maxChange;
124            if (curVal > newVal)
125            {
126                curVal = newVal;
127            }
128        }
129        else if (diff < 0.0f)
130        {
131            curVal -= maxChange;
132            if (curVal < newVal)
133            {
134                curVal = newVal;
135            }
136        }
137    }
138    else
139    {
140        curVal = newVal;
141    }
142    return curVal;
143}
144 
145 
146//Clamp a value against lower und upper boundary.
147static inline float clamp(float val, float lower, float upper)
148{
149    if (val < lower)      return lower;
150    else if (val > upper) return upper;
151    else                  return val;
152}
153 
154//Saturate a value (clamps between 0.0f and 1.0f)
155static inline float saturate(float val)
156{
157    if (val < 0.0f)      return 0.0f;
158    else if (val > 1.0f) return 1.0f;
159    else return val;
160}
161 
162static unsigned long seed = 0;
163 
164//Return a pseudo random number between 0 and 1.
165static inline float rand2()
166{
167    return float(rand()) / float(RAND_MAX);
168}
169 
170 
171// Geteral randomizer
172static inline unsigned long rand()
173{
174  seed = (1664525L*seed + 1013904223L) & 0xffffffff;
175  return seed;
176}
177 
178 
179// Gets randomizer seed
180static inline unsigned long  randGetSeed()
181{
182  return seed;
183}
184 
185// Initializes randomizer's seed
186static inline void randSetSeed (unsigned long s)
187{
188  seed = s;
189}
190 
191// Returns random int in range of [0,n]
192static inline int randInt (int n)
193{
194  double a = double(n) / 4294967296.0;
195  return (int) (double(rand()) * a);
196}
197 
198// Returns random float in [0,1]
199static inline float randReal()
200{
201  return ((float) rand()) / ((float) 0xffffffff);
202}
203 
204//Linearly interpolate between 2 values: ret = x + l * (y - x)
205static inline float lerp(float x, float y, float l)
206{
207    return x + l * (y - x);
208}
209 
210    }
211 
212}
213#endif /* WASMLIBS_CPP_MATH_H_ */
214