using System;

namespace Psychlops
{

	public static class Math
	{
		public static readonly double PI = 3.14159265, E = 2.718281828459045, LOG2E = 1.44269504088896340736;
		public static Random random_generator;
		static Math()
		{
			random_generator = new Random();
		}

		public static double max(double val1, double val2)
		{
			return val1 > val2 ? val1 : val2;
		}
		public static double min(double val1, double val2)
		{
			return val1 < val2 ? val1 : val2;
		}
		public static void shuffle<X>(X[] array, int n)
		{
			int a;
			X tmp;
			for(int i = 1; i < n; i++){
				a = random(i + 1);
				tmp = array[i];
				array[i] = array[a];
				array[a] = tmp;
			}
		}


		public static double mod(double lhs, double rhs)
		{
			return lhs - System.Math.Floor(lhs/rhs)*rhs;
		}
		public static double abs(double x)
		{
			return System.Math.Abs(x);
		}
		public static double sin(double x)
		{
			return System.Math.Sin(x);
		}
		public static double cos(double x)
		{
			return System.Math.Cos(x);
		}
		public static double tan(double x)
		{
			return System.Math.Tan(x);
		}
		public static double sqrt(double x)
		{
			return System.Math.Sqrt(x);
		}
		public static double exp(double x)
		{
			return System.Math.Exp(x);
		}
		public static double log(double x)
		{
			return System.Math.Log(x);
		}
		public static double log2(double val)
		{
			return log(val) * LOG2E;
		}
		/*public static int round(double val)
		{
			double integer_part, particle = modf(val, &integer_part);
			return ((particle < 0.5 | (particle == 0.5 && (int)integer_part % 2 == 0)) ? (int)integer_part : (int)integer_part + 1);
		}*/

		public static double radius(double x, double y)
		{
			return System.Math.Sqrt(x * x + y * y);
		}

		public static double random()
		{
			return (random_generator.NextDouble());
		}
		public static int random(int x)
		{
			return (int)((random_generator.NextDouble()) * x);
		}
		public static double random(double x)
		{
			return (random_generator.NextDouble()) * x;
		}
		public static double random(double x, double y)
		{
			return (random_generator.NextDouble()) * (y-x) + x;
		}


		public static double gaussian(double x, double sigma)
		{
			return exp(- (x*x) / (2*sigma*sigma));
		}
	}

}