From: ifv <ifv@opencascade.com>
Date: Fri, 2 Mar 2018 13:59:08 +0000 (+0300)
Subject: 0029535: Modeling Algorithms - BRepExtrema_DistShapeShape returns only one solution... 
X-Git-Tag: V7_3_0_beta~57
X-Git-Url: http://git.dev.opencascade.org/gitweb/?a=commitdiff_plain;h=56c5a5979ed3f13128a584354128defd39da3681;p=occt-copy.git

0029535: Modeling Algorithms - BRepExtrema_DistShapeShape returns only one solution but the wires have two intersections

The subdivision of long curve is added in algorithm GenExtCC, if length of curves are too different.
Test case added
---

diff --git a/src/Extrema/Extrema_GenExtCC.gxx b/src/Extrema/Extrema_GenExtCC.gxx
index 10e497d2e2..fec566c2a9 100644
--- a/src/Extrema/Extrema_GenExtCC.gxx
+++ b/src/Extrema/Extrema_GenExtCC.gxx
@@ -26,6 +26,7 @@
 #include <Precision.hxx>
 #include <NCollection_Vector.hxx>
 #include <NCollection_CellFilter.hxx>
+#include <GCPnts_AbscissaPoint.hxx>
 
 // Comparator, used in std::sort.
 static Standard_Boolean comp(const gp_XY& theA,
@@ -47,6 +48,57 @@ static Standard_Boolean comp(const gp_XY& theA,
   return Standard_False;
 }
 
+static void ChangeIntervals(Handle(TColStd_HArray1OfReal)& theInts, const Standard_Integer theNbInts)
+{
+  Standard_Integer aNbInts = theInts->Length() - 1;
+  Standard_Integer aNbAdd = theNbInts - aNbInts;
+  Handle(TColStd_HArray1OfReal) aNewInts = new TColStd_HArray1OfReal(1, theNbInts + 1);
+  Standard_Integer aNbLast = theInts->Length();
+  Standard_Integer i;
+  if (aNbInts == 1)
+  {
+    aNewInts->SetValue(1, theInts->First());
+    aNewInts->SetValue(theNbInts + 1, theInts->Last());
+    Standard_Real dt = (theInts->Last() - theInts->First()) / theNbInts;
+    Standard_Real t = theInts->First() + dt;
+    for (i = 2; i <= theNbInts; ++i, t += dt)
+    {
+      aNewInts->SetValue(i, t);
+    }
+    theInts = aNewInts;
+    return;
+  }
+  //
+  for (i = 1; i <= aNbLast; ++i)
+  {
+    aNewInts->SetValue(i, theInts->Value(i));
+  }
+  //
+  while (aNbAdd > 0)
+  {
+    Standard_Real anLIntMax = -1.;
+    Standard_Integer aMaxInd = -1;
+    for (i = 1; i < aNbLast; ++i)
+    {
+      Standard_Real anL = aNewInts->Value(i + 1) - aNewInts->Value(i);
+      if (anL > anLIntMax)
+      {
+        anLIntMax = anL;
+        aMaxInd = i;
+      }
+    }
+
+    Standard_Real t = (aNewInts->Value(aMaxInd + 1) + aNewInts->Value(aMaxInd)) / 2.;
+    for (i = aNbLast; i > aMaxInd; --i)
+    {
+      aNewInts->SetValue(i + 1, aNewInts->Value(i));
+    }
+    aNbLast++;
+    aNbAdd--;
+    aNewInts->SetValue(aMaxInd + 1, t);
+  }
+  theInts = aNewInts;
+}
 class Extrema_CCPointsInspector : public NCollection_CellFilter_InspectorXY
 {
 public:
@@ -229,10 +281,65 @@ void Extrema_GenExtCC::Perform()
     aNbInter[1] = C2.NbIntervals(aContinuity);
   }
 
-  TColStd_Array1OfReal anIntervals1(1, aNbInter[0] + 1);
-  TColStd_Array1OfReal anIntervals2(1, aNbInter[1] + 1);
-  C1.Intervals(anIntervals1, aContinuity);
-  C2.Intervals(anIntervals2, aContinuity);
+  Standard_Real anL[2];
+  Standard_Integer indmax = -1, indmin = -1;
+  const Standard_Real mult = 20.;
+  if (!(Precision::IsInfinite(C1.FirstParameter()) || Precision::IsInfinite(C1.LastParameter()) ||
+        Precision::IsInfinite(C2.FirstParameter()) || Precision::IsInfinite(C2.LastParameter())))
+  {
+    anL[0] = GCPnts_AbscissaPoint::Length(C1);
+    anL[1] = GCPnts_AbscissaPoint::Length(C2);
+    if (anL[0] / aNbInter[0] > mult * anL[1] / aNbInter[1])
+    {
+      indmax = 0;
+      indmin = 1;
+    }
+    else if (anL[1] / aNbInter[1] > mult * anL[0] / aNbInter[0])
+    {
+      indmax = 1;
+      indmin = 0;
+    }
+  }
+  Standard_Integer aNbIntOpt = 0;
+  if (indmax >= 0)
+  {
+    aNbIntOpt = RealToInt(anL[indmax] * aNbInter[indmin] / anL[indmin] / (mult / 4.))  + 1;
+    if (aNbIntOpt > 100 || aNbIntOpt < aNbInter[indmax])
+    {
+      indmax = -1;
+    }
+    else
+    {
+      if (aNbIntOpt * aNbInter[indmin] > 100)
+      {
+        aNbIntOpt = 100 / aNbInter[indmin];
+        if (aNbIntOpt < aNbInter[indmax])
+        {
+          indmax = -1;
+        }
+      }
+    }
+  }
+
+  Handle(TColStd_HArray1OfReal) anIntervals1 = new TColStd_HArray1OfReal(1, aNbInter[0] + 1);
+  Handle(TColStd_HArray1OfReal) anIntervals2 = new TColStd_HArray1OfReal(1, aNbInter[1] + 1);
+  C1.Intervals(anIntervals1->ChangeArray1(), aContinuity);
+  C2.Intervals(anIntervals2->ChangeArray1(), aContinuity);
+  if (indmax >= 0)
+  {
+    if (indmax == 0)
+    {
+      //Change anIntervals1
+      ChangeIntervals(anIntervals1, aNbIntOpt);
+      aNbInter[0] = anIntervals1->Length() - 1;
+    }
+    else
+    {
+      //Change anIntervals2;
+      ChangeIntervals(anIntervals2, aNbIntOpt);
+      aNbInter[1] = anIntervals2->Length() - 1;
+    }
+  }
 
   // Lipchitz constant computation.
   const Standard_Real aMaxLC = 10000.;
@@ -286,8 +393,8 @@ void Extrema_GenExtCC::Perform()
   aFinder.SetFunctionalMinimalValue(0.0); // Best distance cannot be lower than 0.0.
 
   // Size computed to have cell index inside of int32 value.
-  const Standard_Real aCellSize = Max(Max(anIntervals1.Last() - anIntervals1.First(),
-                                      anIntervals2.Last() - anIntervals2.First())
+  const Standard_Real aCellSize = Max(Max(anIntervals1->Last() - anIntervals1->First(),
+                                      anIntervals2->Last() - anIntervals2->First())
                                       * Precision::PConfusion() / (2.0 * Sqrt(2.0)),
                                       Precision::PConfusion());
   Extrema_CCPointsInspector anInspector(aCellSize);
@@ -303,10 +410,10 @@ void Extrema_GenExtCC::Perform()
   {
     for(j = 1; j <= aNbInter[1]; j++)
     {
-      aFirstBorderInterval(1) = anIntervals1(i);
-      aFirstBorderInterval(2) = anIntervals2(j); 
-      aSecondBorderInterval(1) = anIntervals1(i + 1);
-      aSecondBorderInterval(2) = anIntervals2(j + 1);
+      aFirstBorderInterval(1) = anIntervals1->Value(i);
+      aFirstBorderInterval(2) = anIntervals2->Value(j); 
+      aSecondBorderInterval(1) = anIntervals1->Value(i + 1);
+      aSecondBorderInterval(2) = anIntervals2->Value(j + 1);
 
       aFinder.SetLocalParams(aFirstBorderInterval, aSecondBorderInterval);
       aFinder.Perform(GetSingleSolutionFlag());
diff --git a/tests/bugs/modalg_7/bug29535 b/tests/bugs/modalg_7/bug29535
new file mode 100644
index 0000000000..2c401a1255
--- /dev/null
+++ b/tests/bugs/modalg_7/bug29535
@@ -0,0 +1,20 @@
+puts "========"
+puts "OCC29535"
+puts "========"
+puts ""
+#################################################
+# [Regression] BRepExtrema_DistShapeShape returns only one solution but the wires have two intersections .
+#################################################
+
+restore [locate_data_file bug29535_shapes.brep] s
+explode s
+distmini res s_1 s_2
+
+
+if { ([isdraw res] && [isdraw res2]) } {
+  checknbshapes res -vertex 1 -edge 0
+  checknbshapes res2 -vertex 1 -edge 0
+} else { puts "Error : result of distmini is wrong" }
+
+
+