ILSpy/EleCho.WpfSuite/MathHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;
using System.Windows;

namespace EleCho.WpfSuite
{
	internal static class MathHelper
	{
		internal const double DBL_EPSILON = 2.2204460492503131e-016;

		public static bool AreClose(double value1, double value2) =>
			// ReSharper disable once CompareOfFloatsByEqualityOperator
			value1 == value2 || IsVerySmall(value1 - value2);

		public static double Lerp(double x, double y, double alpha) => x * (1.0 - alpha) + y * alpha;

		public static bool IsVerySmall(double value) => Math.Abs(value) < 1E-06;

		public static bool IsZero(double value) => Math.Abs(value) < 10.0 * DBL_EPSILON;

		public static bool IsFiniteDouble(double x) => !double.IsInfinity(x) && !double.IsNaN(x);

		public static double DoubleFromMantissaAndExponent(double x, int exp) => x * Math.Pow(2.0, exp);

		public static bool GreaterThan(double value1, double value2) => value1 > value2 && !AreClose(value1, value2);

		public static bool GreaterThanOrClose(double value1, double value2)
		{
			if (value1 <= value2)
			{
				return AreClose(value1, value2);
			}
			return true;
		}

		public static double Hypotenuse(double x, double y) => Math.Sqrt(x * x + y * y);

		public static bool LessThan(double value1, double value2) => value1 < value2 && !AreClose(value1, value2);

		public static bool LessThanOrClose(double value1, double value2)
		{
			if (value1 >= value2)
			{
				return AreClose(value1, value2);
			}
			return true;
		}

		public static double EnsureRange(double value, double? min, double? max)
		{
			if (min.HasValue && value < min.Value)
			{
				return min.Value;
			}
			if (max.HasValue && value > max.Value)
			{
				return max.Value;
			}
			return value;
		}

		public static double SafeDivide(double lhs, double rhs, double fallback)
		{
			if (!IsVerySmall(rhs))
			{
				return lhs / rhs;
			}
			return fallback;
		}
	}
}