Merge pull request #35 from oberbichler/fix/ds

Fix ds
oberbichler · Mar 31, 2020 · 3470574 · 3470574
2 parents 54e4460 + b6bf141
commit 3470574
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Showing 4 changed files with 30 additions and 6 deletions.
diff --git a/Bowerbird/CurveOnSurface/CurveOnSurface.cs b/Bowerbird/CurveOnSurface/CurveOnSurface.cs
@@ -239,5 +239,22 @@ public IOrientableCurve Morph(SpaceMorph xmorph)
             xmorph.Morph(surface);
             return Create(surface, Curve);
         }
+
+        public double Ds(double t)
+        {
+            var uv = Curve.DerivativeAt(t, 2);
+            var u = uv[0].X;
+            var v = uv[0].Y;
+            var u1 = uv[1].X;
+            var v1 = uv[1].Y;
+
+            Surface.Evaluate(u, v, 1, out var _, out var xyz);
+            var s10 = xyz[0];
+            var s01 = xyz[1];
+
+            var x1 = u1 * s10 + v1 * s01;
+
+            return x1.Length;
+        }
     }
 }
diff --git a/Bowerbird/CurveOnSurface/IOrientableCurve.cs b/Bowerbird/CurveOnSurface/IOrientableCurve.cs
@@ -10,6 +10,8 @@ public interface IOrientableCurve
 
         Vector3d TangentAt(double t);
 
+        double Ds(double t);
+
         Vector3d NormalAt(double t);
 
         Vector3d BinormalAt(double t);

diff --git a/Bowerbird/CurveOnSurface/IntegrateComponent.cs b/Bowerbird/CurveOnSurface/IntegrateComponent.cs
@@ -39,11 +39,11 @@ Func<double, double> Evaluate(IOrientableCurve curve, bool squared)
                 switch (ValueType)
                 {
                     case ValueTypes.NormalCurvature:
-                        return o => curve.NormalCurvatureAt(o).Length;
+                        return o => curve.NormalCurvatureAt(o).Length * curve.Ds(o);
                     case ValueTypes.GeodesicCurvature:
-                        return o => curve.GeodesicCurvatureAt(o).Length;
+                        return o => curve.GeodesicCurvatureAt(o).Length * curve.Ds(o);
                     case ValueTypes.GeodesicTorsion:
-                        return o => curve.GeodesicTorsionAt(o).Length;
+                        return o => curve.GeodesicTorsionAt(o).Length * curve.Ds(o);
                     default:
                         throw new Exception();
                 }
@@ -53,11 +53,11 @@ Func<double, double> Evaluate(IOrientableCurve curve, bool squared)
                 switch (ValueType)
                 {
                     case ValueTypes.NormalCurvature:
-                        return o => curve.NormalCurvatureAt(o).SquareLength;
+                        return o => curve.NormalCurvatureAt(o).SquareLength * curve.Ds(o);
                     case ValueTypes.GeodesicCurvature:
-                        return o => curve.GeodesicCurvatureAt(o).SquareLength;
+                        return o => curve.GeodesicCurvatureAt(o).SquareLength * curve.Ds(o);
                     case ValueTypes.GeodesicTorsion:
-                        return o => curve.GeodesicTorsionAt(o).SquareLength;
+                        return o => curve.GeodesicTorsionAt(o).SquareLength * curve.Ds(o);
                     default:
                         throw new Exception();
                 }

diff --git a/Bowerbird/CurveOnSurface/ZeroTwistingCurve.cs b/Bowerbird/CurveOnSurface/ZeroTwistingCurve.cs
@@ -190,5 +190,10 @@ public IOrientableCurve Morph(SpaceMorph xmorph)
             xmorph.Morph(curve);
             return Create(curve);
         }
+
+        public double Ds(double t)
+        {
+            return Curve.DerivativeAt(t, 1)[1].Length;
+        }
     }
 }