feat: add BestFitFinder orchestrator with hull edge angle strategies

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

OpenNest.Engine/BestFit/BestFitFinder.cs

@@ -0,0 +1,179 @@
+using System.Collections.Generic;
+using System.Linq;
+using OpenNest.Converters;
+using OpenNest.Engine.BestFit.Tiling;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.Engine.BestFit
+{
+    public class BestFitFinder
+    {
+        private readonly PairEvaluator _evaluator;
+        private readonly BestFitFilter _filter;
+
+        public BestFitFinder(double maxPlateWidth, double maxPlateHeight)
+        {
+            _evaluator = new PairEvaluator();
+            _filter = new BestFitFilter
+            {
+                MaxPlateWidth = maxPlateWidth,
+                MaxPlateHeight = maxPlateHeight
+            };
+        }
+
+        public List<BestFitResult> FindBestFits(
+            Drawing drawing,
+            double spacing = 0.25,
+            double stepSize = 0.25,
+            BestFitSortField sortBy = BestFitSortField.Area)
+        {
+            var strategies = BuildStrategies(drawing);
+
+            var allCandidates = new List<PairCandidate>();
+
+            foreach (var strategy in strategies)
+                allCandidates.AddRange(strategy.GenerateCandidates(drawing, spacing, stepSize));
+
+            var results = allCandidates.Select(c => _evaluator.Evaluate(c)).ToList();
+
+            _filter.Apply(results);
+
+            results = SortResults(results, sortBy);
+
+            for (var i = 0; i < results.Count; i++)
+                results[i].Candidate.TestNumber = i;
+
+            return results;
+        }
+
+        public List<TileResult> FindAndTile(
+            Drawing drawing, Plate plate,
+            double spacing = 0.25, double stepSize = 0.25, int topN = 10)
+        {
+            var bestFits = FindBestFits(drawing, spacing, stepSize);
+            var tileEvaluator = new TileEvaluator();
+
+            return bestFits
+                .Where(r => r.Keep)
+                .Take(topN)
+                .Select(r => tileEvaluator.Evaluate(r, plate))
+                .OrderByDescending(t => t.PartsNested)
+                .ThenByDescending(t => t.Utilization)
+                .ToList();
+        }
+
+        private List<IBestFitStrategy> BuildStrategies(Drawing drawing)
+        {
+            var angles = GetRotationAngles(drawing);
+            var strategies = new List<IBestFitStrategy>();
+            var type = 1;
+
+            foreach (var angle in angles)
+            {
+                var desc = string.Format("{0:F1} deg rotated, offset slide", Angle.ToDegrees(angle));
+                strategies.Add(new RotationSlideStrategy(angle, type++, desc));
+            }
+
+            return strategies;
+        }
+
+        private List<double> GetRotationAngles(Drawing drawing)
+        {
+            var angles = new List<double>
+            {
+                0,
+                Angle.HalfPI,
+                System.Math.PI,
+                Angle.HalfPI * 3
+            };
+
+            var hullAngles = GetHullEdgeAngles(drawing);
+
+            foreach (var hullAngle in hullAngles)
+            {
+                AddUniqueAngle(angles, hullAngle);
+                AddUniqueAngle(angles, Angle.NormalizeRad(hullAngle + System.Math.PI));
+            }
+
+            return angles;
+        }
+
+        private List<double> GetHullEdgeAngles(Drawing drawing)
+        {
+            var entities = ConvertProgram.ToGeometry(drawing.Program)
+                .Where(e => e.Layer != SpecialLayers.Rapid);
+            var shapes = Helper.GetShapes(entities);
+
+            var points = new List<Vector>();
+
+            foreach (var shape in shapes)
+            {
+                var polygon = shape.ToPolygonWithTolerance(0.1);
+                points.AddRange(polygon.Vertices);
+            }
+
+            if (points.Count < 3)
+                return new List<double>();
+
+            var hull = ConvexHull.Compute(points);
+            var vertices = hull.Vertices;
+            var n = hull.IsClosed() ? vertices.Count - 1 : vertices.Count;
+            var hullAngles = new List<double>();
+
+            for (var i = 0; i < n; i++)
+            {
+                var next = (i + 1) % n;
+                var dx = vertices[next].X - vertices[i].X;
+                var dy = vertices[next].Y - vertices[i].Y;
+
+                if (dx * dx + dy * dy < Tolerance.Epsilon)
+                    continue;
+
+                var angle = Angle.NormalizeRad(System.Math.Atan2(dy, dx));
+                AddUniqueAngle(hullAngles, angle);
+            }
+
+            return hullAngles;
+        }
+
+        private static void AddUniqueAngle(List<double> angles, double angle)
+        {
+            angle = Angle.NormalizeRad(angle);
+
+            foreach (var existing in angles)
+            {
+                if (existing.IsEqualTo(angle))
+                    return;
+            }
+
+            angles.Add(angle);
+        }
+
+        private List<BestFitResult> SortResults(List<BestFitResult> results, BestFitSortField sortBy)
+        {
+            switch (sortBy)
+            {
+                case BestFitSortField.Area:
+                    return results.OrderBy(r => r.RotatedArea).ToList();
+                case BestFitSortField.LongestSide:
+                    return results.OrderBy(r => r.LongestSide).ToList();
+                case BestFitSortField.ShortestSide:
+                    return results.OrderBy(r => r.ShortestSide).ToList();
+                case BestFitSortField.Type:
+                    return results.OrderBy(r => r.Candidate.StrategyType)
+                        .ThenBy(r => r.Candidate.TestNumber).ToList();
+                case BestFitSortField.OriginalSequence:
+                    return results.OrderBy(r => r.Candidate.TestNumber).ToList();
+                case BestFitSortField.Keep:
+                    return results.OrderByDescending(r => r.Keep)
+                        .ThenBy(r => r.RotatedArea).ToList();
+                case BestFitSortField.WhyKeepDrop:
+                    return results.OrderBy(r => r.Reason)
+                        .ThenBy(r => r.RotatedArea).ToList();
+                default:
+                    return results;
+            }
+        }
+    }
+}

OpenNest.Engine/OpenNest.Engine.csproj

@@ -42,6 +42,7 @@
     <Compile Include="BestFit\IBestFitStrategy.cs" />
     <Compile Include="BestFit\PairEvaluator.cs" />
     <Compile Include="BestFit\BestFitFilter.cs" />
+    <Compile Include="BestFit\BestFitFinder.cs" />
     <Compile Include="BestFit\RotationSlideStrategy.cs" />
     <Compile Include="BestFit\Tiling\TileResult.cs" />
     <Compile Include="BestFit\Tiling\TileEvaluator.cs" />