Contour Engine v3

WIP still, but promising.

Author: philstopford

Common/clipper/Clipper.Helper.cs

@@ -1,3 +1,5 @@
+using System;
+
 namespace Clipper2Lib;
 
 public static class Helper
@@ -45,4 +47,25 @@ public static PathsD initedPathsD(int count)
 
         return ret;
     }
+    
+    public static bool PointsEqual(PointD a, PointD b)
+    {
+        return Math.Abs(a.x - b.x) < 1e-9 && Math.Abs(a.y - b.y) < 1e-9;
+    }
+
+    public static PointD Add(PointD a, PointD b) => new PointD(a.x + b.x, a.y + b.y);
+    public static PointD Minus(PointD a, PointD b) => new PointD(a.x - b.x, a.y - b.y);
+    public static PointD Mult(PointD a, double s) => new PointD(a.x * s, a.y * s);
+    public static double Length(PointD p) => Math.Sqrt(p.x * p.x + p.y * p.y);
+    public static PointD Mul(PointD a, double s) => new PointD(a.x * s, a.y * s);
+
+    public static PointD Neg(PointD a) => new PointD(-a.x, -a.y);
+    public static double Dot(PointD a, PointD b) => a.x * b.x + a.y * b.y;
+    public static PointD Mid(PointD a, PointD b) => new PointD((a.x + b.x) / 2.0, (a.y + b.y) / 2.0);
+
+    public static PointD Normalized(PointD p)
+    {
+        double len = Length(p);
+        return len > 0 ? new PointD(p.x / len, p.y / len) : new PointD(0, 0);
+    }    
 }