Fix best-fit viewer bounds for angled pairs

OpenNest.Engine/BestFit/BestFitResult.cs

@@ -1,6 +1,9 @@
+using OpenNest.Engine;
+using OpenNest.Converters;
 using OpenNest.Geometry;
 using OpenNest.Math;
 using System.Collections.Generic;
+using System.Linq;
 
 namespace OpenNest.Engine.BestFit
 {
@@ -54,6 +57,68 @@ namespace OpenNest.Engine.BestFit
 
             return new List<Part> { part1, part2 };
         }
+
+        public List<Part> BuildCanonicalParts()
+        {
+            return NormalizeToCutOrigin(BuildParts(Candidate.Drawing));
+        }
+
+        public List<Part> BuildSourceParts(Drawing drawing)
+        {
+            var parts = BuildCanonicalParts();
+            var sourceAngle = drawing?.Source?.Angle ?? 0.0;
+
+            for (var i = 0; i < parts.Count; i++)
+            {
+                var p = parts[i];
+                var rebound = Part.CreateAtOrigin(drawing, p.Rotation);
+                var delta = p.BoundingBox.Location - rebound.BoundingBox.Location;
+                rebound.Offset(delta);
+                rebound.UpdateBounds();
+                parts[i] = rebound;
+            }
+
+            return NormalizeToCutOrigin(CanonicalFrame.FromCanonical(parts, sourceAngle));
+        }
+
+        public Box GetCutBounds(List<Part> parts)
+        {
+            return GetCutBoundingBox(parts);
+        }
+
+        private static List<Part> NormalizeToCutOrigin(List<Part> parts)
+        {
+            if (parts == null || parts.Count == 0)
+                return parts;
+
+            var bounds = GetCutBoundingBox(parts);
+            var offset = new Vector(-bounds.Left, -bounds.Bottom);
+
+            foreach (var part in parts)
+                part.Offset(offset);
+
+            return parts;
+        }
+
+        private static Box GetCutBoundingBox(List<Part> parts)
+        {
+            var entities = new List<IBoundable>();
+
+            foreach (var part in parts)
+            {
+                var partEntities = ConvertProgram.ToGeometry(part.Program)
+                    .Where(e => e.Layer != SpecialLayers.Rapid)
+                    .ToList();
+
+                foreach (var entity in partEntities)
+                {
+                    entity.Offset(part.Location);
+                    entities.Add(entity);
+                }
+            }
+
+            return entities.GetBoundingBox();
+        }
     }
 
     public enum BestFitSortField

OpenNest.Tests/BestFit/BestFitResultFrameTests.cs

@@ -0,0 +1,72 @@
+using OpenNest.Engine;
+using OpenNest.Engine.BestFit;
+using OpenNest.Geometry;
+using OpenNest.Math;
+using OpenNest.Shapes;
+
+namespace OpenNest.Tests.BestFit;
+
+public class BestFitResultFrameTests
+{
+    [Fact]
+    public void BuildCanonicalParts_NonAxisAlignedPairNormalizesActualBounds()
+    {
+        var drawing = new TShape { Width = 10, Height = 8 }.GetDrawing();
+        var canonical = CanonicalFrame.AsCanonicalCopy(drawing);
+
+        var result = EvaluateOffsetPair(canonical, new Vector(40, 30));
+
+        Assert.True(IsNonAxisAligned(result.OptimalRotation),
+            $"Expected a non-axis-aligned result, got {Angle.ToDegrees(result.OptimalRotation):F2} degrees.");
+
+        var parts = result.BuildCanonicalParts();
+        var bounds = result.GetCutBounds(parts);
+
+        Assert.Equal(0, bounds.Left, 3);
+        Assert.Equal(0, bounds.Bottom, 3);
+        Assert.Equal(result.BoundingWidth, bounds.Length, 2);
+        Assert.Equal(result.BoundingHeight, bounds.Width, 2);
+    }
+
+    [Fact]
+    public void BuildSourceParts_RebindsCanonicalResultToRotatedSourceDrawing()
+    {
+        var drawing = new TShape { Width = 10, Height = 8 }.GetDrawing();
+        drawing.Program.Rotate(Angle.ToRadians(30), drawing.Program.BoundingBox().Center);
+        drawing.RecomputeCanonicalAngle();
+
+        var canonical = CanonicalFrame.AsCanonicalCopy(drawing);
+        var result = EvaluateOffsetPair(canonical, new Vector(40, 30));
+
+        var parts = result.BuildSourceParts(drawing);
+        var bounds = result.GetCutBounds(parts);
+
+        Assert.All(parts, p => Assert.Same(drawing, p.BaseDrawing));
+        Assert.Equal(0, bounds.Left, 3);
+        Assert.Equal(0, bounds.Bottom, 3);
+        Assert.False(parts[0].Intersects(parts[1], out _));
+    }
+
+    private static BestFitResult EvaluateOffsetPair(Drawing drawing, Vector offset)
+    {
+        var candidate = new PairCandidate
+        {
+            Drawing = drawing,
+            Part1Rotation = 0,
+            Part2Rotation = System.Math.PI,
+            Part2Offset = offset,
+            Spacing = 0.25
+        };
+
+        return new PairEvaluator().Evaluate(candidate);
+    }
+
+    private static bool IsNonAxisAligned(double angle)
+    {
+        var normalized = Angle.NormalizeRad(angle);
+        var nearestQuadrant = Angle.HalfPI * System.Math.Round(normalized / Angle.HalfPI);
+        var delta = System.Math.Abs(normalized - nearestQuadrant);
+        delta = System.Math.Min(delta, Angle.HalfPI - delta);
+        return delta > Angle.ToRadians(1);
+    }
+}

OpenNest/Forms/BestFitViewerForm.cs

@@ -45,6 +45,7 @@ namespace OpenNest.Forms
 
         public BestFitResult SelectedResult { get; private set; }
         public Drawing SelectedDrawing => activeDrawing;
+        public List<Part> SelectedParts { get; private set; }
 
         public BestFitViewerForm(DrawingCollection drawings, Plate plate, Units units = Units.Inches)
         {
@@ -318,12 +319,12 @@ namespace OpenNest.Forms
             var cell = new BestFitCell(colorScheme);
             cell.PartColor = partColor;
             cell.Dock = DockStyle.Fill;
+
+            var parts = result.BuildCanonicalParts();
             cell.Plate.Size = new Geometry.Size(
                 result.BoundingHeight,
                 result.BoundingWidth);
 
-            var parts = result.BuildParts(drawing);
-
             foreach (var part in parts)
                 cell.Plate.Parts.Add(part);
 
@@ -332,6 +333,7 @@ namespace OpenNest.Forms
             cell.DoubleClick += (sender, e) =>
             {
                 SelectedResult = result;
+                SelectedParts = result.BuildSourceParts(drawing);
                 DialogResult = DialogResult.OK;
                 Close();
             };

OpenNest/Forms/MainForm.cs

@@ -686,7 +686,8 @@ namespace OpenNest.Forms
             {
                 if (form.ShowDialog(this) == DialogResult.OK && form.SelectedResult != null)
                 {
-                    var parts = form.SelectedResult.BuildParts(form.SelectedDrawing);
+                    var parts = form.SelectedParts
+                        ?? form.SelectedResult.BuildSourceParts(form.SelectedDrawing);
                     activeForm.PlateView.SetAction(typeof(ActionClone), parts);
                 }
             }