0ad/source/maths/MathUtil.h

#ifndef MATH_UTIL_H
#define MATH_UTIL_H

#ifndef PI
#define PI							3.14159265358979323846f
#endif

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#ifndef M_PI_2
#define M_PI_2 1.57079632679489661923
#endif

#define DEGTORAD(a)					((a) * (PI/180.0f))
#define RADTODEG(a)					((a) * (180.0f/PI))
#define SQR(x)						((x) * (x))
#define MAX3(a,b,c)					( MAX (MAX(a,b), c) )
#define ABS(a)						((a > 0) ? (a) : (-a))

template <typename T>
T Interpolate( T& a, T& b, float l )
{
	return( a + ( b - a ) * l );
}

template <typename T>
inline T clamp(T value, T min, T max)
{
	if (value<=min) return min;
	else if (value>=max) return max;
	else return value;
}

static inline int RoundUpToPowerOf2(int x)
{
	if ((x & (x-1))==0) return x;
	int d=x;
	while (d & (d-1)) {
		d&=(d-1);
	}
	return d<<1;
}

inline float sgn(float a)
{
    if (a > 0.0f) return 1.0f;
    if (a < 0.0f) return -1.0f;
    return 0.0f;
}

#endif