refactor: extract Intersect from Helper

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest.Core/Geometry/Arc.cs

@@ -465,7 +465,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Arc arc)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, arc, out pts);
+            return Intersect.Intersects(this, arc, out pts);
         }
 
         /// <summary>
@@ -476,7 +476,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Arc arc, out List<Vector> pts)
         {
-            return Helper.Intersects(this, arc, out pts); ;
+            return Intersect.Intersects(this, arc, out pts); ;
         }
 
         /// <summary>
@@ -487,7 +487,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Circle circle)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, circle, out pts);
+            return Intersect.Intersects(this, circle, out pts);
         }
 
         /// <summary>
@@ -498,7 +498,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Circle circle, out List<Vector> pts)
         {
-            return Helper.Intersects(this, circle, out pts);
+            return Intersect.Intersects(this, circle, out pts);
         }
 
         /// <summary>
@@ -509,7 +509,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Line line)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, line, out pts);
+            return Intersect.Intersects(this, line, out pts);
         }
 
         /// <summary>
@@ -520,7 +520,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Line line, out List<Vector> pts)
         {
-            return Helper.Intersects(this, line, out pts);
+            return Intersect.Intersects(this, line, out pts);
         }
 
         /// <summary>
@@ -531,7 +531,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Polygon polygon)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -542,7 +542,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Polygon polygon, out List<Vector> pts)
         {
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -553,7 +553,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Shape shape)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>
@@ -564,7 +564,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Shape shape, out List<Vector> pts)
         {
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>

OpenNest.Core/Geometry/Circle.cs

@@ -320,7 +320,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Arc arc)
         {
             List<Vector> pts;
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -331,7 +331,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Arc arc, out List<Vector> pts)
         {
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -353,7 +353,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Circle circle, out List<Vector> pts)
         {
-            return Helper.Intersects(this, circle, out pts);
+            return Intersect.Intersects(this, circle, out pts);
         }
 
         /// <summary>
@@ -364,7 +364,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Line line)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, line, out pts);
+            return Intersect.Intersects(this, line, out pts);
         }
 
         /// <summary>
@@ -375,7 +375,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Line line, out List<Vector> pts)
         {
-            return Helper.Intersects(this, line, out pts);
+            return Intersect.Intersects(this, line, out pts);
         }
 
         /// <summary>
@@ -386,7 +386,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Polygon polygon)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -397,7 +397,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Polygon polygon, out List<Vector> pts)
         {
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -408,7 +408,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Shape shape)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>
@@ -419,7 +419,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Shape shape, out List<Vector> pts)
         {
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>

OpenNest.Core/Geometry/Intersect.cs

@@ -0,0 +1,373 @@
+using System.Collections.Generic;
+using System.Linq;
+using OpenNest.Math;
+
+namespace OpenNest.Geometry
+{
+    public static class Intersect
+    {
+        internal static bool Intersects(Arc arc1, Arc arc2, out List<Vector> pts)
+        {
+            var c1 = new Circle(arc1.Center, arc1.Radius);
+            var c2 = new Circle(arc2.Center, arc2.Radius);
+
+            if (!Intersects(c1, c2, out pts))
+            {
+                pts = new List<Vector>();
+                return false;
+            }
+
+            pts = pts.Where(pt =>
+                Angle.IsBetweenRad(arc1.Center.AngleTo(pt), arc1.StartAngle, arc1.EndAngle, arc1.IsReversed) &&
+                Angle.IsBetweenRad(arc2.Center.AngleTo(pt), arc2.StartAngle, arc2.EndAngle, arc2.IsReversed))
+                .ToList();
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Arc arc, Circle circle, out List<Vector> pts)
+        {
+            var c1 = new Circle(arc.Center, arc.Radius);
+
+            if (!Intersects(c1, circle, out pts))
+            {
+                pts = new List<Vector>();
+                return false;
+            }
+
+            pts = pts.Where(pt => Angle.IsBetweenRad(
+                arc.Center.AngleTo(pt),
+                arc.StartAngle,
+                arc.EndAngle,
+                arc.IsReversed)).ToList();
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Arc arc, Line line, out List<Vector> pts)
+        {
+            var c1 = new Circle(arc.Center, arc.Radius);
+
+            if (!Intersects(c1, line, out pts))
+            {
+                pts = new List<Vector>();
+                return false;
+            }
+
+            pts = pts.Where(pt => Angle.IsBetweenRad(
+                arc.Center.AngleTo(pt),
+                arc.StartAngle,
+                arc.EndAngle,
+                arc.IsReversed)).ToList();
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Arc arc, Shape shape, out List<Vector> pts)
+        {
+            var pts2 = new List<Vector>();
+
+            foreach (var geo in shape.Entities)
+            {
+                List<Vector> pts3;
+                geo.Intersects(arc, out pts3);
+                pts2.AddRange(pts3);
+            }
+
+            pts = pts2.Where(pt => Angle.IsBetweenRad(
+                arc.Center.AngleTo(pt),
+                arc.StartAngle,
+                arc.EndAngle,
+                arc.IsReversed)).ToList();
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Arc arc, Polygon polygon, out List<Vector> pts)
+        {
+            var pts2 = new List<Vector>();
+            var lines = polygon.ToLines();
+
+            foreach (var line in lines)
+            {
+                List<Vector> pts3;
+                Intersects(arc, line, out pts3);
+                pts2.AddRange(pts3);
+            }
+
+            pts = pts2.Where(pt => Angle.IsBetweenRad(
+                arc.Center.AngleTo(pt),
+                arc.StartAngle,
+                arc.EndAngle,
+                arc.IsReversed)).ToList();
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Circle circle1, Circle circle2, out List<Vector> pts)
+        {
+            var distance = circle1.Center.DistanceTo(circle2.Center);
+
+            // check if circles are too far apart
+            if (distance > circle1.Radius + circle2.Radius)
+            {
+                pts = new List<Vector>();
+                return false;
+            }
+
+            // check if one circle contains the other
+            if (distance < System.Math.Abs(circle1.Radius - circle2.Radius))
+            {
+                pts = new List<Vector>();
+                return false;
+            }
+
+            var d = circle2.Center - circle1.Center;
+            var a = (circle1.Radius * circle1.Radius - circle2.Radius * circle2.Radius + distance * distance) / (2.0 * distance);
+            var h = System.Math.Sqrt(circle1.Radius * circle1.Radius - a * a);
+
+            var pt = new Vector(
+                circle1.Center.X + (a * d.X) / distance,
+                circle1.Center.Y + (a * d.Y) / distance);
+
+            var i1 = new Vector(
+                pt.X + (h * d.Y) / distance,
+                pt.Y - (h * d.X) / distance);
+
+            var i2 = new Vector(
+                pt.X - (h * d.Y) / distance,
+                pt.Y + (h * d.X) / distance);
+
+            pts = i1 != i2 ? new List<Vector> { i1, i2 } : new List<Vector> { i1 };
+
+            return true;
+        }
+
+        internal static bool Intersects(Circle circle, Line line, out List<Vector> pts)
+        {
+            var d1 = line.EndPoint - line.StartPoint;
+            var d2 = line.StartPoint - circle.Center;
+
+            var a = d1.X * d1.X + d1.Y * d1.Y;
+            var b = (d1.X * d2.X + d1.Y * d2.Y) * 2;
+            var c = (d2.X * d2.X + d2.Y * d2.Y) - circle.Radius * circle.Radius;
+
+            var det = b * b - 4 * a * c;
+
+            if ((a <= Tolerance.Epsilon) || (det < 0))
+            {
+                pts = new List<Vector>();
+                return false;
+            }
+
+            double t;
+            pts = new List<Vector>();
+
+            if (det.IsEqualTo(0))
+            {
+                t = -b / (2 * a);
+                var pt1 = new Vector(line.StartPoint.X + t * d1.X, line.StartPoint.Y + t * d1.Y);
+
+                if (line.BoundingBox.Contains(pt1))
+                    pts.Add(pt1);
+
+                return true;
+            }
+
+            t = (-b + System.Math.Sqrt(det)) / (2 * a);
+            var pt2 = new Vector(line.StartPoint.X + t * d1.X, line.StartPoint.Y + t * d1.Y);
+
+            if (line.BoundingBox.Contains(pt2))
+                pts.Add(pt2);
+
+            t = (-b - System.Math.Sqrt(det)) / (2 * a);
+            var pt3 = new Vector(line.StartPoint.X + t * d1.X, line.StartPoint.Y + t * d1.Y);
+
+            if (line.BoundingBox.Contains(pt3))
+                pts.Add(pt3);
+
+            return true;
+        }
+
+        internal static bool Intersects(Circle circle, Shape shape, out List<Vector> pts)
+        {
+            pts = new List<Vector>();
+
+            foreach (var geo in shape.Entities)
+            {
+                List<Vector> pts3;
+                geo.Intersects(circle, out pts3);
+                pts.AddRange(pts3);
+            }
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Circle circle, Polygon polygon, out List<Vector> pts)
+        {
+            pts = new List<Vector>();
+            var lines = polygon.ToLines();
+
+            foreach (var line in lines)
+            {
+                List<Vector> pts3;
+                Intersects(circle, line, out pts3);
+                pts.AddRange(pts3);
+            }
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Line line1, Line line2, out Vector pt)
+        {
+            var a1 = line1.EndPoint.Y - line1.StartPoint.Y;
+            var b1 = line1.StartPoint.X - line1.EndPoint.X;
+            var c1 = a1 * line1.StartPoint.X + b1 * line1.StartPoint.Y;
+
+            var a2 = line2.EndPoint.Y - line2.StartPoint.Y;
+            var b2 = line2.StartPoint.X - line2.EndPoint.X;
+            var c2 = a2 * line2.StartPoint.X + b2 * line2.StartPoint.Y;
+
+            var d = a1 * b2 - a2 * b1;
+
+            if (d.IsEqualTo(0.0))
+            {
+                pt = Vector.Zero;
+                return false;
+            }
+
+            var x = (b2 * c1 - b1 * c2) / d;
+            var y = (a1 * c2 - a2 * c1) / d;
+
+            pt = new Vector(x, y);
+            return line1.BoundingBox.Contains(pt) && line2.BoundingBox.Contains(pt);
+        }
+
+        internal static bool Intersects(Line line, Shape shape, out List<Vector> pts)
+        {
+            pts = new List<Vector>();
+
+            foreach (var geo in shape.Entities)
+            {
+                List<Vector> pts3;
+                geo.Intersects(line, out pts3);
+                pts.AddRange(pts3);
+            }
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Line line, Polygon polygon, out List<Vector> pts)
+        {
+            pts = new List<Vector>();
+            var lines = polygon.ToLines();
+
+            foreach (var line2 in lines)
+            {
+                Vector pt;
+
+                if (Intersects(line, line2, out pt))
+                    pts.Add(pt);
+            }
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Shape shape1, Shape shape2, out List<Vector> pts)
+        {
+            pts = new List<Vector>();
+
+            for (int i = 0; i < shape1.Entities.Count; i++)
+            {
+                var geo1 = shape1.Entities[i];
+
+                for (int j = 0; j < shape2.Entities.Count; j++)
+                {
+                    List<Vector> pts2;
+                    bool success = false;
+
+                    var geo2 = shape2.Entities[j];
+
+                    switch (geo2.Type)
+                    {
+                        case EntityType.Arc:
+                            success = geo1.Intersects((Arc)geo2, out pts2);
+                            break;
+
+                        case EntityType.Circle:
+                            success = geo1.Intersects((Circle)geo2, out pts2);
+                            break;
+
+                        case EntityType.Line:
+                            success = geo1.Intersects((Line)geo2, out pts2);
+                            break;
+
+                        case EntityType.Shape:
+                            success = geo1.Intersects((Shape)geo2, out pts2);
+                            break;
+
+                        case EntityType.Polygon:
+                            success = geo1.Intersects((Polygon)geo2, out pts2);
+                            break;
+
+                        default:
+                            continue;
+                    }
+
+                    if (success)
+                        pts.AddRange(pts2);
+                }
+            }
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Shape shape, Polygon polygon, out List<Vector> pts)
+        {
+            pts = new List<Vector>();
+
+            var lines = polygon.ToLines();
+
+            for (int i = 0; i < shape.Entities.Count; i++)
+            {
+                var geo = shape.Entities[i];
+
+                for (int j = 0; j < lines.Count; j++)
+                {
+                    var line = lines[j];
+
+                    List<Vector> pts2;
+
+                    if (geo.Intersects(line, out pts2))
+                        pts.AddRange(pts2);
+                }
+            }
+
+            return pts.Count > 0;
+        }
+
+        internal static bool Intersects(Polygon polygon1, Polygon polygon2, out List<Vector> pts)
+        {
+            pts = new List<Vector>();
+
+            var lines1 = polygon1.ToLines();
+            var lines2 = polygon2.ToLines();
+
+            for (int i = 0; i < lines1.Count; i++)
+            {
+                var line1 = lines1[i];
+
+                for (int j = 0; j < lines2.Count; j++)
+                {
+                    var line2 = lines2[j];
+                    Vector pt;
+
+                    if (Intersects(line1, line2, out pt))
+                        pts.Add(pt);
+                }
+            }
+
+            return pts.Count > 0;
+        }
+    }
+}

OpenNest.Core/Geometry/Line.cs

@@ -456,7 +456,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Arc arc)
         {
             List<Vector> pts;
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -467,7 +467,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Arc arc, out List<Vector> pts)
         {
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -478,7 +478,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Circle circle)
         {
             List<Vector> pts;
-            return Helper.Intersects(circle, this, out pts);
+            return Intersect.Intersects(circle, this, out pts);
         }
 
         /// <summary>
@@ -489,7 +489,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Circle circle, out List<Vector> pts)
         {
-            return Helper.Intersects(circle, this, out pts);
+            return Intersect.Intersects(circle, this, out pts);
         }
 
         /// <summary>
@@ -512,7 +512,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Line line, out List<Vector> pts)
         {
             Vector pt;
-            var success = Helper.Intersects(this, line, out pt);
+            var success = Intersect.Intersects(this, line, out pt);
             pts = new List<Vector>(new[] { pt });
             return success;
         }
@@ -525,7 +525,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Polygon polygon)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -536,7 +536,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Polygon polygon, out List<Vector> pts)
         {
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -547,7 +547,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Shape shape)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>
@@ -558,7 +558,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Shape shape, out List<Vector> pts)
         {
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>

OpenNest.Core/Geometry/Polygon.cs

@@ -364,7 +364,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Arc arc)
         {
             List<Vector> pts;
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -375,7 +375,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Arc arc, out List<Vector> pts)
         {
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -386,7 +386,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Circle circle)
         {
             List<Vector> pts;
-            return Helper.Intersects(circle, this, out pts);
+            return Intersect.Intersects(circle, this, out pts);
         }
 
         /// <summary>
@@ -397,7 +397,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Circle circle, out List<Vector> pts)
         {
-            return Helper.Intersects(circle, this, out pts);
+            return Intersect.Intersects(circle, this, out pts);
         }
 
         /// <summary>
@@ -408,7 +408,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Line line)
         {
             List<Vector> pts;
-            return Helper.Intersects(line, this, out pts);
+            return Intersect.Intersects(line, this, out pts);
         }
 
         /// <summary>
@@ -419,7 +419,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Line line, out List<Vector> pts)
         {
-            return Helper.Intersects(line, this, out pts);
+            return Intersect.Intersects(line, this, out pts);
         }
 
         /// <summary>
@@ -430,7 +430,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Polygon polygon)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -441,7 +441,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Polygon polygon, out List<Vector> pts)
         {
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -452,7 +452,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Shape shape)
         {
             List<Vector> pts;
-            return Helper.Intersects(shape, this, out pts);
+            return Intersect.Intersects(shape, this, out pts);
         }
 
         /// <summary>
@@ -463,7 +463,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Shape shape, out List<Vector> pts)
         {
-            return Helper.Intersects(shape, this, out pts);
+            return Intersect.Intersects(shape, this, out pts);
         }
 
         /// <summary>

OpenNest.Core/Geometry/Shape.cs

@@ -534,7 +534,7 @@ namespace OpenNest.Geometry
         {
             Vector intersection;
 
-            if (Helper.Intersects(offsetLine, lastOffsetLine, out intersection))
+            if (Intersect.Intersects(offsetLine, lastOffsetLine, out intersection))
             {
                 offsetLine.StartPoint = intersection;
                 lastOffsetLine.EndPoint = intersection;
@@ -577,7 +577,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Arc arc)
         {
             List<Vector> pts;
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -588,7 +588,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Arc arc, out List<Vector> pts)
         {
-            return Helper.Intersects(arc, this, out pts);
+            return Intersect.Intersects(arc, this, out pts);
         }
 
         /// <summary>
@@ -599,7 +599,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Circle circle)
         {
             List<Vector> pts;
-            return Helper.Intersects(circle, this, out pts);
+            return Intersect.Intersects(circle, this, out pts);
         }
 
         /// <summary>
@@ -610,7 +610,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Circle circle, out List<Vector> pts)
         {
-            return Helper.Intersects(circle, this, out pts);
+            return Intersect.Intersects(circle, this, out pts);
         }
 
         /// <summary>
@@ -621,7 +621,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Line line)
         {
             List<Vector> pts;
-            return Helper.Intersects(line, this, out pts);
+            return Intersect.Intersects(line, this, out pts);
         }
 
         /// <summary>
@@ -632,7 +632,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Line line, out List<Vector> pts)
         {
-            return Helper.Intersects(line, this, out pts);
+            return Intersect.Intersects(line, this, out pts);
         }
 
         /// <summary>
@@ -643,7 +643,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Polygon polygon)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -654,7 +654,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Polygon polygon, out List<Vector> pts)
         {
-            return Helper.Intersects(this, polygon, out pts);
+            return Intersect.Intersects(this, polygon, out pts);
         }
 
         /// <summary>
@@ -665,7 +665,7 @@ namespace OpenNest.Geometry
         public override bool Intersects(Shape shape)
         {
             List<Vector> pts;
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>
@@ -676,7 +676,7 @@ namespace OpenNest.Geometry
         /// <returns></returns>
         public override bool Intersects(Shape shape, out List<Vector> pts)
         {
-            return Helper.Intersects(this, shape, out pts);
+            return Intersect.Intersects(this, shape, out pts);
         }
 
         /// <summary>

OpenNest.Core/Helper.cs

@@ -11,370 +11,6 @@ namespace OpenNest
 {
     public static class Helper
     {
-        internal static bool Intersects(Arc arc1, Arc arc2, out List<Vector> pts)
-        {
-            var c1 = new Circle(arc1.Center, arc1.Radius);
-            var c2 = new Circle(arc2.Center, arc2.Radius);
-
-            if (!Intersects(c1, c2, out pts))
-            {
-                pts = new List<Vector>();
-                return false;
-            }
-
-            pts = pts.Where(pt =>
-                Angle.IsBetweenRad(arc1.Center.AngleTo(pt), arc1.StartAngle, arc1.EndAngle, arc1.IsReversed) &&
-                Angle.IsBetweenRad(arc2.Center.AngleTo(pt), arc2.StartAngle, arc2.EndAngle, arc2.IsReversed))
-                .ToList();
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Arc arc, Circle circle, out List<Vector> pts)
-        {
-            var c1 = new Circle(arc.Center, arc.Radius);
-
-            if (!Intersects(c1, circle, out pts))
-            {
-                pts = new List<Vector>();
-                return false;
-            }
-
-            pts = pts.Where(pt => Angle.IsBetweenRad(
-                arc.Center.AngleTo(pt),
-                arc.StartAngle,
-                arc.EndAngle,
-                arc.IsReversed)).ToList();
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Arc arc, Line line, out List<Vector> pts)
-        {
-            var c1 = new Circle(arc.Center, arc.Radius);
-
-            if (!Intersects(c1, line, out pts))
-            {
-                pts = new List<Vector>();
-                return false;
-            }
-
-            pts = pts.Where(pt => Angle.IsBetweenRad(
-                arc.Center.AngleTo(pt),
-                arc.StartAngle,
-                arc.EndAngle,
-                arc.IsReversed)).ToList();
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Arc arc, Shape shape, out List<Vector> pts)
-        {
-            var pts2 = new List<Vector>();
-
-            foreach (var geo in shape.Entities)
-            {
-                List<Vector> pts3;
-                geo.Intersects(arc, out pts3);
-                pts2.AddRange(pts3);
-            }
-
-            pts = pts2.Where(pt => Angle.IsBetweenRad(
-                arc.Center.AngleTo(pt),
-                arc.StartAngle,
-                arc.EndAngle,
-                arc.IsReversed)).ToList();
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Arc arc, Polygon polygon, out List<Vector> pts)
-        {
-            var pts2 = new List<Vector>();
-            var lines = polygon.ToLines();
-
-            foreach (var line in lines)
-            {
-                List<Vector> pts3;
-                Intersects(arc, line, out pts3);
-                pts2.AddRange(pts3);
-            }
-
-            pts = pts2.Where(pt => Angle.IsBetweenRad(
-                arc.Center.AngleTo(pt),
-                arc.StartAngle,
-                arc.EndAngle,
-                arc.IsReversed)).ToList();
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Circle circle1, Circle circle2, out List<Vector> pts)
-        {
-            var distance = circle1.Center.DistanceTo(circle2.Center);
-
-            // check if circles are too far apart
-            if (distance > circle1.Radius + circle2.Radius)
-            {
-                pts = new List<Vector>();
-                return false;
-            }
-
-            // check if one circle contains the other
-            if (distance < System.Math.Abs(circle1.Radius - circle2.Radius))
-            {
-                pts = new List<Vector>();
-                return false;
-            }
-
-            var d = circle2.Center - circle1.Center;
-            var a = (circle1.Radius * circle1.Radius - circle2.Radius * circle2.Radius + distance * distance) / (2.0 * distance);
-            var h = System.Math.Sqrt(circle1.Radius * circle1.Radius - a * a);
-
-            var pt = new Vector(
-                circle1.Center.X + (a * d.X) / distance,
-                circle1.Center.Y + (a * d.Y) / distance);
-
-            var i1 = new Vector(
-                pt.X + (h * d.Y) / distance,
-                pt.Y - (h * d.X) / distance);
-
-            var i2 = new Vector(
-                pt.X - (h * d.Y) / distance,
-                pt.Y + (h * d.X) / distance);
-
-            pts = i1 != i2 ? new List<Vector> { i1, i2 } : new List<Vector> { i1 };
-
-            return true;
-        }
-
-        internal static bool Intersects(Circle circle, Line line, out List<Vector> pts)
-        {
-            var d1 = line.EndPoint - line.StartPoint;
-            var d2 = line.StartPoint - circle.Center;
-
-            var a = d1.X * d1.X + d1.Y * d1.Y;
-            var b = (d1.X * d2.X + d1.Y * d2.Y) * 2;
-            var c = (d2.X * d2.X + d2.Y * d2.Y) - circle.Radius * circle.Radius;
-
-            var det = b * b - 4 * a * c;
-
-            if ((a <= Tolerance.Epsilon) || (det < 0))
-            {
-                pts = new List<Vector>();
-                return false;
-            }
-
-            double t;
-            pts = new List<Vector>();
-
-            if (det.IsEqualTo(0))
-            {
-                t = -b / (2 * a);
-                var pt1 = new Vector(line.StartPoint.X + t * d1.X, line.StartPoint.Y + t * d1.Y);
-
-                if (line.BoundingBox.Contains(pt1))
-                    pts.Add(pt1);
-
-                return true;
-            }
-
-            t = (-b + System.Math.Sqrt(det)) / (2 * a);
-            var pt2 = new Vector(line.StartPoint.X + t * d1.X, line.StartPoint.Y + t * d1.Y);
-
-            if (line.BoundingBox.Contains(pt2))
-                pts.Add(pt2);
-
-            t = (-b - System.Math.Sqrt(det)) / (2 * a);
-            var pt3 = new Vector(line.StartPoint.X + t * d1.X, line.StartPoint.Y + t * d1.Y);
-
-            if (line.BoundingBox.Contains(pt3))
-                pts.Add(pt3);
-
-            return true;
-        }
-
-        internal static bool Intersects(Circle circle, Shape shape, out List<Vector> pts)
-        {
-            pts = new List<Vector>();
-
-            foreach (var geo in shape.Entities)
-            {
-                List<Vector> pts3;
-                geo.Intersects(circle, out pts3);
-                pts.AddRange(pts3);
-            }
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Circle circle, Polygon polygon, out List<Vector> pts)
-        {
-            pts = new List<Vector>();
-            var lines = polygon.ToLines();
-
-            foreach (var line in lines)
-            {
-                List<Vector> pts3;
-                Intersects(circle, line, out pts3);
-                pts.AddRange(pts3);
-            }
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Line line1, Line line2, out Vector pt)
-        {
-            var a1 = line1.EndPoint.Y - line1.StartPoint.Y;
-            var b1 = line1.StartPoint.X - line1.EndPoint.X;
-            var c1 = a1 * line1.StartPoint.X + b1 * line1.StartPoint.Y;
-
-            var a2 = line2.EndPoint.Y - line2.StartPoint.Y;
-            var b2 = line2.StartPoint.X - line2.EndPoint.X;
-            var c2 = a2 * line2.StartPoint.X + b2 * line2.StartPoint.Y;
-
-            var d = a1 * b2 - a2 * b1;
-
-            if (d.IsEqualTo(0.0))
-            {
-                pt = Vector.Zero;
-                return false;
-            }
-
-            var x = (b2 * c1 - b1 * c2) / d;
-            var y = (a1 * c2 - a2 * c1) / d;
-
-            pt = new Vector(x, y);
-            return line1.BoundingBox.Contains(pt) && line2.BoundingBox.Contains(pt);
-        }
-
-        internal static bool Intersects(Line line, Shape shape, out List<Vector> pts)
-        {
-            pts = new List<Vector>();
-
-            foreach (var geo in shape.Entities)
-            {
-                List<Vector> pts3;
-                geo.Intersects(line, out pts3);
-                pts.AddRange(pts3);
-            }
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Line line, Polygon polygon, out List<Vector> pts)
-        {
-            pts = new List<Vector>();
-            var lines = polygon.ToLines();
-
-            foreach (var line2 in lines)
-            {
-                Vector pt;
-
-                if (Intersects(line, line2, out pt))
-                    pts.Add(pt);
-            }
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Shape shape1, Shape shape2, out List<Vector> pts)
-        {
-            pts = new List<Vector>();
-
-            for (int i = 0; i < shape1.Entities.Count; i++)
-            {
-                var geo1 = shape1.Entities[i];
-
-                for (int j = 0; j < shape2.Entities.Count; j++)
-                {
-                    List<Vector> pts2;
-                    bool success = false;
-
-                    var geo2 = shape2.Entities[j];
-
-                    switch (geo2.Type)
-                    {
-                        case EntityType.Arc:
-                            success = geo1.Intersects((Arc)geo2, out pts2);
-                            break;
-
-                        case EntityType.Circle:
-                            success = geo1.Intersects((Circle)geo2, out pts2);
-                            break;
-
-                        case EntityType.Line:
-                            success = geo1.Intersects((Line)geo2, out pts2);
-                            break;
-
-                        case EntityType.Shape:
-                            success = geo1.Intersects((Shape)geo2, out pts2);
-                            break;
-
-                        case EntityType.Polygon:
-                            success = geo1.Intersects((Polygon)geo2, out pts2);
-                            break;
-
-                        default:
-                            continue;
-                    }
-
-                    if (success)
-                        pts.AddRange(pts2);
-                }
-            }
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Shape shape, Polygon polygon, out List<Vector> pts)
-        {
-            pts = new List<Vector>();
-
-            var lines = polygon.ToLines();
-
-            for (int i = 0; i < shape.Entities.Count; i++)
-            {
-                var geo = shape.Entities[i];
-
-                for (int j = 0; j < lines.Count; j++)
-                {
-                    var line = lines[j];
-
-                    List<Vector> pts2;
-
-                    if (geo.Intersects(line, out pts2))
-                        pts.AddRange(pts2);
-                }
-            }
-
-            return pts.Count > 0;
-        }
-
-        internal static bool Intersects(Polygon polygon1, Polygon polygon2, out List<Vector> pts)
-        {
-            pts = new List<Vector>();
-
-            var lines1 = polygon1.ToLines();
-            var lines2 = polygon2.ToLines();
-
-            for (int i = 0; i < lines1.Count; i++)
-            {
-                var line1 = lines1[i];
-
-                for (int j = 0; j < lines2.Count; j++)
-                {
-                    var line2 = lines2[j];
-                    Vector pt;
-
-                    if (Intersects(line1, line2, out pt))
-                        pts.Add(pt);
-                }
-            }
-
-            return pts.Count > 0;
-        }
-
         public static List<Line> GetPartLines(Part part, double chordTolerance = 0.001)
         {
             var entities = ConvertProgram.ToGeometry(part.Program);