feat(engine): add CanonicalFrame helper for drawing-to-canonical rotation

2026-04-20 09:06:30 -04:00
parent 9a6b656e3c
commit 402af91af5
3 changed files with 169 additions and 0 deletions
@@ -0,0 +1,84 @@
+using OpenNest.CNC;
+using OpenNest.Engine;
+using OpenNest.Geometry;
+using OpenNest.Math;
+
+namespace OpenNest.Tests.Engine;
+
+public class CanonicalFrameTests
+{
+    private static Drawing MakeRect(double w, double h, double rotation)
+    {
+        var pgm = new OpenNest.CNC.Program();
+        pgm.Codes.Add(new RapidMove(new Vector(0, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(w, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(w, h)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, h)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 0)));
+        if (!Tolerance.IsEqualTo(rotation, 0))
+            pgm.Rotate(rotation, pgm.BoundingBox().Center);
+        return new Drawing("rect", pgm) { Source = new SourceInfo { Angle = -rotation } };
+    }
+
+    [Fact]
+    public void AsCanonicalCopy_AxisAlignsMbr()
+    {
+        var d = MakeRect(100, 50, 0.6);
+        var canonical = CanonicalFrame.AsCanonicalCopy(d);
+
+        var bb = canonical.Program.BoundingBox();
+        var longer = System.Math.Max(bb.Length, bb.Width);
+        var shorter = System.Math.Min(bb.Length, bb.Width);
+        Assert.InRange(longer, 100 - 0.1, 100 + 0.1);
+        Assert.InRange(shorter, 50 - 0.1, 50 + 0.1);
+        Assert.Equal(0.0, canonical.Source.Angle, precision: 6);
+    }
+
+    [Fact]
+    public void AsCanonicalCopy_DoesNotMutateSource()
+    {
+        var d = MakeRect(100, 50, 0.6);
+        var originalBbox = d.Program.BoundingBox();
+        var originalAngle = d.Source.Angle;
+
+        CanonicalFrame.AsCanonicalCopy(d);
+
+        var afterBbox = d.Program.BoundingBox();
+        Assert.Equal(originalBbox.Width, afterBbox.Width, precision: 6);
+        Assert.Equal(originalBbox.Length, afterBbox.Length, precision: 6);
+        Assert.Equal(originalAngle, d.Source.Angle, precision: 6);
+    }
+
+    [Fact]
+    public void FromCanonical_ComposesSourceAngleOntoRotation()
+    {
+        var d = MakeRect(100, 50, 0.0);
+        var part = new Part(d);
+        part.Rotate(0.2); // engine returned a canonical-frame part at R = 0.2
+
+        var placed = CanonicalFrame.FromCanonical(new List<Part> { part }, sourceAngle: -0.5);
+
+        // R' = R + sourceAngle = 0.2 + (-0.5) = -0.3
+        // Part.Rotation comes from Program.Rotation which is normalized to [0, 2PI),
+        // so compare after normalizing the expected value as well.
+        Assert.Single(placed);
+        Assert.Equal(Angle.NormalizeRad(-0.3), placed[0].Rotation, precision: 4);
+    }
+
+    [Fact]
+    public void RoundTrip_RestoresGeometry()
+    {
+        var d = MakeRect(100, 50, 0.4);
+        var canonical = CanonicalFrame.AsCanonicalCopy(d);
+
+        // Place a part at origin in the canonical frame.
+        var part = Part.CreateAtOrigin(canonical);
+        var canonicalBbox = part.BoundingBox;
+
+        var placed = CanonicalFrame.FromCanonical(new List<Part> { part }, d.Source.Angle);
+
+        var originalBbox = d.Program.BoundingBox();
+        Assert.Equal(originalBbox.Width, placed[0].BoundingBox.Width, precision: 2);
+        Assert.Equal(originalBbox.Length, placed[0].BoundingBox.Length, precision: 2);
+    }
+}