ddnet/src/base/math.h

/* (c) Magnus Auvinen. See licence.txt in the root of the distribution for more information. */
/* If you are missing that file, acquire a complete release at teeworlds.com.                */
#ifndef BASE_MATH_H
#define BASE_MATH_H

#include <math.h>
#include <stdlib.h>

template <typename T>
constexpr inline T clamp(T val, T min, T max)
{
	return val < min ? min : (val > max ? max : val);
}

constexpr inline float sign(float f)
{
	return f<0.0f?-1.0f:1.0f;
}

constexpr inline int round_to_int(float f)
{
	return f > 0 ? (int)(f + 0.5f) : (int)(f - 0.5f);
}

constexpr inline int round_truncate(float f)
{
	return (int)f;
}

inline int round_ceil(float f)
{
	return (int)ceilf(f);
}

template<typename T, typename TB>
constexpr inline T mix(const T a, const T b, TB amount)
{
	return a + (b-a)*amount;
}

inline float frandom() { return rand()/(float)(RAND_MAX); }

// float to fixed
constexpr inline int f2fx(float v) { return (int)(v*(float)(1<<10)); }
constexpr inline float fx2f(int v) { return v*(1.0f/(1<<10)); }

inline int gcd(int a, int b)
{
	while(b != 0)
	{
		int c = a % b;
		a = b;
		b = c;
	}
	return a;
}

class fxp
{
	int value;
public:
	void set(int v) { value = v; }
	int get() const { return value; }
	fxp &operator = (int v) { value = v<<10; return *this; }
	fxp &operator = (float v) { value = (int)(v*(float)(1<<10)); return *this; }
	operator float() const { return value/(float)(1<<10); }
};

constexpr float pi = 3.1415926535897932384626433f;

template <typename T> constexpr inline T minimum(T a, T b) { return a<b?a:b; }
template <typename T> constexpr inline T minimum(T a, T b, T c) { return minimum(minimum(a, b), c); }
template <typename T> constexpr inline T maximum(T a, T b) { return a>b?a:b; }
template <typename T> constexpr inline T maximum(T a, T b, T c) { return maximum(maximum(a, b), c); }
template <typename T> constexpr inline T absolute(T a) { return a<T(0)?-a:a; }

template <typename T> constexpr inline T in_range(T a, T lower, T upper) { return lower <= a && a <= upper; }
template <typename T> constexpr inline T in_range(T a, T upper) { return in_range(a, 0, upper); }

#endif // BASE_MATH_H