Initial Commit

2DGAMELIB/_2DGAMELIB/Vec.cs

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+using System;
+
+namespace _2DGAMELIB;
+
+public static class Vec
+{
+
+	public static void Add(ref Vector2D v1, ref Vector2D v2, out Vector2D r)
+	{
+		r.X = v1.X + v2.X;
+		r.Y = v1.Y + v2.Y;
+	}
+
+	public static void Subtract(ref Vector2D v1, ref Vector2D v2, out Vector2D r)
+	{
+		r.X = v1.X - v2.X;
+		r.Y = v1.Y - v2.Y;
+	}
+
+	public static double DistanceSquared(this Vector2D v1, Vector2D v2)
+	{
+		double num = v1.X - v2.X;
+		double num2 = v1.Y - v2.Y;
+		return num * num + num2 * num2;
+	}
+
+	public static void Dot(ref Vector2D v1, ref Vector2D v2, out double r)
+	{
+		r = v1.X * v2.X + v1.Y * v2.Y;
+	}
+
+	public static double Cross(ref Vector2D v1, ref Vector2D v2)
+	{
+		return v1.X * v2.Y - v1.Y * v2.X;
+	}
+
+	public static Vector2D newNormalize(this Vector2D vector)
+	{
+		vector.Normalize();
+		return vector;
+	}
+
+	public static double Angle(ref Vector2D v1, ref Vector2D v2)
+	{
+		Dot(ref v1, ref v2, out var r);
+		r /= v1.Length() * v2.Length();
+		if (r > 1.0)
+		{
+			r = 1.0;
+		}
+		else if (r < -1.0)
+		{
+			r = -1.0;
+		}
+		return System.Math.Acos(r);
+	}
+
+	public static double Angle02π(this Vector2D v1, Vector2D v2)
+	{
+		double num = Angle(ref v1, ref v2);
+		if (Cross(ref v1, ref v2) < 0.0)
+		{
+			num = System.Math.PI * 2.0 - num;
+		}
+		return num;
+	}
+}