fix(engine): make canonical-frame fills orientation-invariant

Part.Rotation is cumulative, so rebinding canonical parts with CreateAtOrigin(original, p.Rotation) double-counted the drawing's own rotation, and FromCanonical rotated each part about its Location, which moved it off its slot and out of the work area. Add CanonicalFrame.RebindToOriginal (rotation = part - original program rotation, footprint aligned to the canonical part) and use it in the three places that duplicated the old logic. The MBR only fixes the frame modulo 90 degrees and nest results are not 90-degree symmetric (an L gave 56/43/42/42 parts by orientation). CanonicalAngle.Compute now picks one of the four orientations from the centroid offset; symmetric shapes keep the MBR orientation. Fixes the three NestInvarianceTests. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-21 11:07:44 -04:00
parent 2a855139d2
commit a764a70e52
7 changed files with 221 additions and 68 deletions
@@ -96,6 +96,61 @@ public class CanonicalAngleTests
        var d = new Drawing("empty", new OpenNest.CNC.Program());
        Assert.Equal(0.0, CanonicalAngle.Compute(d), precision: 6);
    }
+
+    private static Drawing MakeL(double rotation)
+    {
+        var pgm = new OpenNest.CNC.Program();
+        pgm.Codes.Add(new RapidMove(new Vector(0, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(100, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(100, 20)));
+        pgm.Codes.Add(new LinearMove(new Vector(50, 20)));
+        pgm.Codes.Add(new LinearMove(new Vector(50, 50)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 50)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 0)));
+        if (!OpenNest.Math.Tolerance.IsEqualTo(rotation, 0))
+            pgm.Rotate(rotation, pgm.BoundingBox().Center);
+        return new Drawing("L", pgm);
+    }
+
+    // Canonical outline, translated to its own corner, as sorted rounded vertices.
+    private static string Signature(Drawing drawing)
+    {
+        var canonical = CanonicalFrame.AsCanonicalCopy(drawing);
+        var entities = ConvertProgram
+            .ToGeometry(canonical.Program)
+            .Where(e => e.Layer != SpecialLayers.Rapid);
+        var vertices = ShapeBuilder
+            .GetShapes(entities)
+            .OrderByDescending(s => s.Area())
+            .First()
+            .ToPolygonWithTolerance(0.1)
+            .Vertices.ToList();
+        var minX = vertices.Min(v => v.X);
+        var minY = vertices.Min(v => v.Y);
+        return string.Join(
+            ";",
+            vertices
+                .Select(v =>
+                    $"{System.Math.Round(v.X - minX, 2):F2},{System.Math.Round(v.Y - minY, 2):F2}"
+                )
+                .Distinct()
+                .OrderBy(x => x)
+        );
+    }
+
+    [Theory]
+    [InlineData(0.3)]
+    [InlineData(0.8)]
+    [InlineData(1.2)]
+    public void AsymmetricShape_CanonicalOrientationIsIndependentOfQuarterTurns(double offset)
+    {
+        // The MBR fixes the frame only modulo 90 degrees; an L-shape must still land in one
+        // deterministic orientation however it was imported.
+        var baseline = Signature(MakeL(offset));
+
+        for (var turns = 1; turns < 4; turns++)
+            Assert.Equal(baseline, Signature(MakeL(offset + turns * System.Math.PI / 2)));
+    }
 }

 public class DrawingCanonicalAngleWiringTests