From 50269d84374eca691ea6fffc341bc3dae2397185 Mon Sep 17 00:00:00 2001
From: ifv <ifv@opencascade.com>
Date: Tue, 12 Oct 2021 09:09:24 +0300
Subject: [PATCH] 0032607: Modeling Algorithms - BOPAlgo_BOP returns incomplete
 result

IntPatch/IntPatch_ImpPrmIntersection.cxx - decreasing step for some conditions
---
 src/IntPatch/IntPatch_ImpPrmIntersection.cxx | 90 +++++++++++++++++++-
 1 file changed, 89 insertions(+), 1 deletion(-)

diff --git a/src/IntPatch/IntPatch_ImpPrmIntersection.cxx b/src/IntPatch/IntPatch_ImpPrmIntersection.cxx
index ac89bbbcbb..672913e9ee 100644
--- a/src/IntPatch/IntPatch_ImpPrmIntersection.cxx
+++ b/src/IntPatch/IntPatch_ImpPrmIntersection.cxx
@@ -78,6 +78,9 @@ static
                               const Standard_Real theToler3D,
                               const Standard_Real theToler2D,
                               const Standard_Real thePeriod);
+static
+Standard_Real GetLocalStep(const Handle(Adaptor3d_HSurface)& theSurf,
+  const Standard_Real theStep);
 
 //=======================================================================
 //function : IsSeamOrPole
@@ -451,6 +454,82 @@ void Recadre(const Standard_Boolean ,
   }
   pt.SetParameters(U1,V1,U2,V2);
 }
+//=======================================================================
+//function : GetLocalStep
+//purpose  : 
+//=======================================================================
+Standard_Real GetLocalStep(const Handle(Adaptor3d_HSurface)& theSurf,
+  const Standard_Real theStep)
+{
+  Standard_Real aLocalStep = theStep;
+  if (theSurf->UContinuity() > GeomAbs_C0 && theSurf->VContinuity() > GeomAbs_C0)
+  {
+    GeomAbs_SurfaceType aSType = theSurf->GetType();
+
+    if (aSType == GeomAbs_BezierSurface || aSType == GeomAbs_BSplineSurface)
+    {
+      Standard_Real aMinRes = Precision::Infinite();
+      Standard_Integer aMaxDeg = 0;
+      const Standard_Real aLimRes = 1.e-10;
+
+      aMinRes = Min(theSurf->UResolution(Precision::Confusion()),
+        theSurf->VResolution(Precision::Confusion()));
+      aMaxDeg = Max(theSurf->UDegree(), theSurf->VDegree());
+      if (aMinRes < aLimRes && aMaxDeg > 3)
+      {
+        aLocalStep = 0.0001;
+      }
+    }
+  }
+  if (theSurf->UContinuity() == GeomAbs_C0)
+  {
+    Standard_Integer aNbInt = theSurf->NbUIntervals(GeomAbs_C1);
+    if (aNbInt > 1)
+    {
+      TColStd_Array1OfReal anInts(1, aNbInt + 1);
+      theSurf->UIntervals(anInts, GeomAbs_C1);
+      Standard_Integer i;
+      Standard_Real aMinInt = Precision::Infinite();
+      for (i = 1; i <= aNbInt; ++i)
+      {
+        aMinInt = Min(aMinInt, anInts(i + 1) - anInts(i));
+      }
+
+      aMinInt /= theSurf->LastUParameter() - theSurf->FirstUParameter();
+      if (aMinInt < 0.002)
+      {
+        aLocalStep = 0.0001;
+      }
+    }
+
+  }
+
+  if (theSurf->VContinuity() == GeomAbs_C0)
+  {
+    Standard_Integer aNbInt = theSurf->NbVIntervals(GeomAbs_C1);
+    if (aNbInt > 1)
+    {
+      TColStd_Array1OfReal anInts(1, aNbInt + 1);
+      theSurf->VIntervals(anInts, GeomAbs_C1);
+      Standard_Integer i;
+      Standard_Real aMinInt = Precision::Infinite();
+      for (i = 1; i <= aNbInt; ++i)
+      {
+        aMinInt = Min(aMinInt, anInts(i + 1) - anInts(i));
+      }
+
+      aMinInt /= theSurf->LastVParameter() - theSurf->FirstVParameter();
+      if (aMinInt < 0.002)
+      {
+        aLocalStep = 0.0001;
+      }
+    }
+  }
+
+  aLocalStep = Min(theStep, aLocalStep);
+  return aLocalStep;
+}
+
 
 //=======================================================================
 //function : Perform
@@ -556,7 +635,16 @@ void IntPatch_ImpPrmIntersection::Perform (const Handle(Adaptor3d_HSurface)& Sur
     }
     break;
   }
+
   //
+  Standard_Real aLocalPas = Pas;
+  if (reversed)
+    aLocalPas = GetLocalStep(Surf1, Pas);
+  else
+    aLocalPas = GetLocalStep(Surf2, Pas);
+
+  //
+
   Func.SetImplicitSurface(Quad);
   Func.Set(IntSurf_QuadricTool::Tolerance(Quad));
   AFunc.SetQuadric(Quad);
@@ -658,7 +746,7 @@ void IntPatch_ImpPrmIntersection::Perform (const Handle(Adaptor3d_HSurface)& Sur
   NbPointDep=seqpdep.Length();
   //
   if (NbPointDep || NbPointIns) {
-    IntPatch_TheIWalking iwalk(TolTang,Fleche,Pas);
+    IntPatch_TheIWalking iwalk(TolTang,Fleche, aLocalPas);
     if (!reversed) {
       iwalk.Perform(seqpdep,seqpins,Func,Surf2);
     }