feat: add BestFitFilter and TileEvaluator for pair filtering and tiling

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

OpenNest.Engine/BestFit/BestFitFilter.cs

@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+
+namespace OpenNest.Engine.BestFit
+{
+    public class BestFitFilter
+    {
+        public double MaxPlateWidth { get; set; }
+        public double MaxPlateHeight { get; set; }
+        public double MaxAspectRatio { get; set; } = 5.0;
+        public double MinUtilization { get; set; } = 0.3;
+
+        public void Apply(List<BestFitResult> results)
+        {
+            foreach (var result in results)
+            {
+                if (!result.Keep)
+                    continue;
+
+                if (result.ShortestSide > System.Math.Min(MaxPlateWidth, MaxPlateHeight))
+                {
+                    result.Keep = false;
+                    result.Reason = "Exceeds plate dimensions";
+                    continue;
+                }
+
+                var aspect = result.LongestSide / result.ShortestSide;
+
+                if (aspect > MaxAspectRatio)
+                {
+                    result.Keep = false;
+                    result.Reason = string.Format("Aspect ratio {0:F1} exceeds max {1}", aspect, MaxAspectRatio);
+                    continue;
+                }
+
+                if (result.Utilization < MinUtilization)
+                {
+                    result.Keep = false;
+                    result.Reason = string.Format("Utilization {0:P0} below minimum", result.Utilization);
+                    continue;
+                }
+
+                result.Reason = "Valid";
+            }
+        }
+    }
+}

OpenNest.Engine/BestFit/Tiling/TileEvaluator.cs

@@ -0,0 +1,62 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.Engine.BestFit.Tiling
+{
+    public class TileEvaluator
+    {
+        public TileResult Evaluate(BestFitResult bestFit, Plate plate)
+        {
+            var plateWidth = plate.Size.Width - plate.EdgeSpacing.Left - plate.EdgeSpacing.Right;
+            var plateHeight = plate.Size.Height - plate.EdgeSpacing.Top - plate.EdgeSpacing.Bottom;
+
+            var result1 = TryTile(bestFit, plateWidth, plateHeight, false);
+            var result2 = TryTile(bestFit, plateWidth, plateHeight, true);
+            return result1.PartsNested >= result2.PartsNested ? result1 : result2;
+        }
+
+        private TileResult TryTile(BestFitResult bestFit, double plateWidth, double plateHeight, bool rotatePair)
+        {
+            var pairWidth = rotatePair ? bestFit.BoundingHeight : bestFit.BoundingWidth;
+            var pairHeight = rotatePair ? bestFit.BoundingWidth : bestFit.BoundingHeight;
+            var spacing = bestFit.Candidate.Spacing;
+
+            var cols = (int)System.Math.Floor((plateWidth + spacing) / (pairWidth + spacing));
+            var rows = (int)System.Math.Floor((plateHeight + spacing) / (pairHeight + spacing));
+            var pairsNested = cols * rows;
+            var partsNested = pairsNested * 2;
+
+            var usedArea = partsNested * (bestFit.TrueArea / 2);
+            var plateArea = plateWidth * plateHeight;
+
+            var placements = new List<PairPlacement>();
+
+            for (var row = 0; row < rows; row++)
+            {
+                for (var col = 0; col < cols; col++)
+                {
+                    placements.Add(new PairPlacement
+                    {
+                        Position = new Vector(
+                            col * (pairWidth + spacing),
+                            row * (pairHeight + spacing)),
+                        PairRotation = rotatePair ? Angle.HalfPI : 0
+                    });
+                }
+            }
+
+            return new TileResult
+            {
+                BestFit = bestFit,
+                PairsNested = pairsNested,
+                PartsNested = partsNested,
+                Rows = rows,
+                Columns = cols,
+                Utilization = plateArea > 0 ? usedArea / plateArea : 0,
+                Placements = placements,
+                PairRotated = rotatePair
+            };
+        }
+    }
+}

OpenNest.Engine/BestFit/Tiling/TileResult.cs

@@ -0,0 +1,23 @@
+using System.Collections.Generic;
+using OpenNest.Geometry;
+
+namespace OpenNest.Engine.BestFit.Tiling
+{
+    public class TileResult
+    {
+        public BestFitResult BestFit { get; set; }
+        public int PairsNested { get; set; }
+        public int PartsNested { get; set; }
+        public int Rows { get; set; }
+        public int Columns { get; set; }
+        public double Utilization { get; set; }
+        public List<PairPlacement> Placements { get; set; }
+        public bool PairRotated { get; set; }
+    }
+
+    public class PairPlacement
+    {
+        public Vector Position { get; set; }
+        public double PairRotation { get; set; }
+    }
+}