Trying to understand this difference in behavior for legacy

Author: philstopford

UnitTests/LegacyHelper.cs

@@ -0,0 +1,66 @@
+using Clipper2Lib;
+using geoWrangler;
+using shapeEngine;
+
+namespace UnitTests;
+using System;
+using System.Reflection;
+
+// Paste this into your test project (same assembly as ShapeLibrary) and call InvokeLegacyFromTest.
+// Requires the project's PathD, ShapeLibrary, GeoWrangler and Clipper types to be in scope.
+
+public static class LegacyReflectionHelper
+{
+    /// <summary>
+    /// Invokes the private legacy_processCorners_actual method on an existing ShapeLibrary instance.
+    /// Returns the produced PathD and its signed area (as returned by Clipper.Area).
+    /// </summary>
+    public static (PathD path, double area) InvokeLegacy(
+        ShapeLibrary shapeLib,
+        bool previewMode,
+        bool cornerCheck,
+        int cornerSegments,
+        int optimizeCorners,
+        double resolution,
+        bool iCPA = false,
+        bool oCPA = false,
+        double iCV = 0.0,
+        double iCVariation_scalar = 0.0,
+        double oCV = 0.0,
+        double oCVariation_scalar = 0.0)
+    {
+        if (shapeLib == null) throw new ArgumentNullException(nameof(shapeLib));
+
+        var method = typeof(ShapeLibrary).GetMethod(
+            "legacy_processCorners_actual",
+            BindingFlags.NonPublic | BindingFlags.Instance);
+
+        if (method == null)
+            throw new InvalidOperationException("legacy_processCorners_actual method not found on ShapeLibrary");
+
+        object[] args = new object[]
+        {
+            previewMode,
+            cornerCheck,
+            cornerSegments,
+            optimizeCorners,
+            resolution,
+            iCPA,
+            oCPA,
+            iCV,
+            iCVariation_scalar,
+            oCV,
+            oCVariation_scalar
+        };
+
+        // If the private method throws, TargetInvocationException will be raised — let it bubble so the test can see the cause.
+        var result = method.Invoke(shapeLib, args) as PathD ?? new PathD();
+
+        // Optionally remove duplicate points before area measurement to match other tests:
+        var clean = GeoWrangler.removeDuplicates(result);
+
+        double area = Clipper.Area(clean);
+
+        return (clean, area);
+    }
+}

UnitTests/ShapeEngineTests.cs

@@ -1597,15 +1597,27 @@ public static void customOrthoOuterRoundingTest()
         shape.setShape(shapeSettings.getInt(ShapeSettings.properties_i.shapeIndex), customShape);
         // Check the shape settings are in the shape.
         Assert.That(shape.shapeIndex, Is.EqualTo((int)ShapeLibrary.shapeNames_all.GEOCORE));
-        PathD out_ = shape.processCorners(false, false, 90, 1, .5);
+        PathD out_ = shape.processCorners(false, false, 90, 1, .01);
         SvgWriter svgSrc = new SvgWriter();
         SvgUtils.AddSolution(svgSrc, new() { out_ }, true);
         SvgUtils.SaveToFile(svgSrc, root_loc + "customortho_outer.svg", FillRule.NonZero, 800, 800, 10);
         // Corners can have duplicate points.
         PathD clean = GeoWrangler.removeDuplicates(out_);
-        Assert.That(clean.Count, Is.EqualTo(115));
+        // Assert.That(clean.Count, Is.EqualTo(115));
         // Check expected area
-        // double area = Clipper.Area(out_);
+        double area = Clipper.Area(out_);
+        // Call the private legacy routine directly
+        var (legacyPath, legacyArea) = LegacyReflectionHelper.InvokeLegacy(
+            shape,
+            previewMode: false,
+            cornerCheck: false,
+            cornerSegments: 90,
+            optimizeCorners: 0,    // optimization off
+            resolution: 0.01,
+            iCPA: false,
+            oCPA: false,
+            iCV: 0, iCVariation_scalar: 0, oCV: 0, oCVariation_scalar: 0
+        );
         // Assert.That(Math.Abs(-(Math.PI * 10 * 10) - area), Is.LessThanOrEqualTo(0.15));
         RectD bounds = Clipper.GetBounds(clean);
         Assert.That(bounds.Width, Is.GreaterThanOrEqualTo(19.99));