First commit.

Source/OpenNest.Core/ConvertGeometry.cs

@@ -0,0 +1,117 @@
+using System.Collections.Generic;
+using OpenNest.CNC;
+using OpenNest.Geometry;
+
+namespace OpenNest
+{
+    public static class ConvertGeometry
+    {
+        public static Program ToProgram(IList<Entity> geometry)
+        {
+            var shapes = Helper.GetShapes(geometry);
+
+            if (shapes.Count == 0)
+                return null;
+
+            var perimeter = shapes[0];
+            var area = perimeter.BoundingBox.Area();
+            var index = 0;
+
+            for (int i = 1; i < shapes.Count; ++i)
+            {
+                var program = shapes[i];
+                var area2 = program.BoundingBox.Area();
+                if (area2 > area)
+                {
+                    perimeter = program;
+                    area = area2;
+                    index = i;
+                }
+            }
+
+            shapes.RemoveAt(index);
+
+            var pgm = new Program();
+
+            foreach (var shape in shapes)
+            {
+                var subpgm = ToProgram(shape);
+                pgm.Merge(subpgm);
+            }
+
+            pgm.Merge(ToProgram(perimeter));
+            pgm.Mode = Mode.Incremental;
+
+            return pgm;
+        }
+
+        public static Program ToProgram(Shape shape)
+        {
+            var pgm = new Program();
+            var lastpt = new Vector();
+
+            for (int i = 0; i < shape.Entities.Count; i++)
+                lastpt = AddEntity(pgm, lastpt, shape.Entities[i]);
+
+            return pgm;
+        }
+
+        private static Vector AddEntity(Program pgm, Vector lastpt, Entity geo)
+        {
+            switch (geo.Type)
+            {
+                case EntityType.Arc:
+                    lastpt = AddArc(pgm, lastpt, (Arc)geo);
+                    break;
+
+                case EntityType.Circle:
+                    lastpt = AddCircle(pgm, lastpt, (Circle)geo);
+                    break;
+
+                case EntityType.Line:
+                    lastpt = AddLine(pgm, lastpt, (Line)geo);
+                    break;
+            }
+
+            return lastpt;
+        }
+
+        private static Vector AddArc(Program pgm, Vector lastpt, Arc arc)
+        {
+            var startpt = arc.StartPoint();
+            var endpt = arc.EndPoint();
+
+            if (startpt != lastpt)
+                pgm.MoveTo(startpt);
+
+            lastpt = endpt;
+
+            pgm.ArcTo(endpt, arc.Center, arc.IsReversed ? RotationType.CW : RotationType.CCW);
+            return lastpt;
+        }
+
+        private static Vector AddCircle(Program pgm, Vector lastpt, Circle circle)
+        {
+            var startpt = new Vector(circle.Center.X + circle.Radius, circle.Center.Y);
+
+            if (startpt != lastpt)
+                pgm.MoveTo(startpt);
+
+            pgm.ArcTo(startpt, circle.Center, RotationType.CCW);
+
+            lastpt = startpt;
+            return lastpt;
+        }
+
+        private static Vector AddLine(Program pgm, Vector lastpt, Line line)
+        {
+            if (line.StartPoint != lastpt)
+                pgm.MoveTo(line.StartPoint);
+
+            pgm.LineTo(line.EndPoint);
+
+            lastpt = line.EndPoint;
+            return lastpt;
+        }
+    }
+}