0029321: Improve performance of the 3D offset algorithm for the planar cases

Disable additional intersection of the splits of offset faces implemented in method BRepOffset_MakeOffset::Intersection3D() for the mode "Complete" and join type "Intersection".
This method is insufficient, as it does not allow to detect the tangential faces, necessary for this mode.
Intersection is performed in the method BuildShellsCompleteInter() developed for this mode.

diff --git a/src/BRepOffset/BRepOffset_MakeOffset.cxx b/src/BRepOffset/BRepOffset_MakeOffset.cxx
index 94996734fa8c8d2dd55b5b25cfa7d9f858b9a532..8ce2fc03122f2506438842c461861a49b7d388bc 100644 (file)
--- a/src/BRepOffset/BRepOffset_MakeOffset.cxx
+++ b/src/BRepOffset/BRepOffset_MakeOffset.cxx
@@ -112,6 +112,7 @@
 #include <BRepBuilderAPI_Sewing.hxx>
 #include <Geom_Line.hxx>
 #include <NCollection_Vector.hxx>
+#include <NCollection_IncAllocator.hxx>
 //
 #include <BOPAlgo_MakerVolume.hxx>
 #include <BOPTools_AlgoTools.hxx>
@@ -254,7 +255,6 @@ static
 
 static
   Standard_Boolean BuildShellsCompleteInter(const BOPCol_ListOfShape& theLF,
-                                            const BOPCol_IndexedDataMapOfShapeListOfShape& theOrigins,
                                             BRepAlgo_Image& theImage,
                                             TopoDS_Shape& theShells);
 
@@ -2282,6 +2282,19 @@ void BRepOffset_MakeOffset::Intersection3D(BRepOffset_Inter3d& Inter)
     Clock.Start();  
   }
 #endif
+
+  // In the Complete Intersection mode, implemented currently for planar
+  // solids only, there is no need to intersect the faces here.
+  // This intersection will be performed in the method BuildShellsCompleteInter
+  // where the special treatment is applied to produced faces.
+  //
+  // Make sure to match the parameters in which the method
+  // BuildShellsCompleteInter is called.
+  if (myInter && (myJoin == GeomAbs_Intersection) && myIsPlanar &&
+      !myThickening && myFaces.IsEmpty() && IsSolid(myShape))
+    return;
+
+
   TopTools_ListOfShape OffsetFaces;  // list of faces // created.
   MakeList (OffsetFaces,myInitOffsetFace,myFaces);
 
@@ -2920,8 +2933,7 @@ void BRepOffset_MakeOffset::MakeShells ()
   }
 #endif
   //
-  TopTools_IndexedDataMapOfShapeListOfShape anOrigins;
-  //
+  // Prepare list of splits of the offset faces to make the shells
   BOPCol_ListOfShape aLSF;
   const TopTools_ListOfShape& R = myImageOffset.Roots();
   TopTools_ListIteratorOfListOfShape it(R);
@@ -2935,12 +2947,6 @@ void BRepOffset_MakeOffset::MakeShells ()
     for (; it2.More(); it2.Next()) {
       const TopoDS_Shape& aFIm = it2.Value();
       aLSF.Append(aFIm);
-      //
-      TopTools_ListOfShape *pLOr = anOrigins.ChangeSeek(aFIm);
-      if (!pLOr) {
-        pLOr = &anOrigins(anOrigins.Add(aFIm, TopTools_ListOfShape()));
-      }
-      pLOr->Append(aF);
     }
   }
   //
@@ -2968,7 +2974,7 @@ void BRepOffset_MakeOffset::MakeShells ()
       IsSolid(myShape) && myIsPlanar) {
     //
     TopoDS_Shape aShells;
-    bDone = BuildShellsCompleteInter(aLSF, anOrigins, myImageOffset, aShells);
+    bDone = BuildShellsCompleteInter(aLSF, myImageOffset, aShells);
     if (bDone) {
       myOffsetShape = aShells;
     }
@@ -4075,7 +4081,6 @@ void GetEnlargedFaces(const TopoDS_Shape& theShape,
 //           rebuilt using only outer faces.
 //=======================================================================
 Standard_Boolean BuildShellsCompleteInter(const BOPCol_ListOfShape& theLF,
-                                          const BOPCol_IndexedDataMapOfShapeListOfShape& theOrigins,
                                           BRepAlgo_Image& theImage,
                                           TopoDS_Shape& theShells)
 {
@@ -4099,11 +4104,47 @@ Standard_Boolean BuildShellsCompleteInter(const BOPCol_ListOfShape& theLF,
     // result is the alone solid, nothing to do
     return GetSubShapes(aResult1, TopAbs_SHELL, theShells);
   }
-  //
-  // it is necessary to rebuild the solids, avoiding internal faces
-  //
-  // map faces to solids
-  TopTools_IndexedDataMapOfShapeListOfShape aDMFS;
+
+  // Allocators for effective memory allocations
+  // Global allocator for the long-living containers
+  Handle(NCollection_IncAllocator) anAllocGlob = new NCollection_IncAllocator;
+  // Local allocator for the local containers
+  Handle(NCollection_IncAllocator) anAllocLoc = new NCollection_IncAllocator;
+
+  // Since the <theImage> object does not support multiple ancestors,
+  // prepare local copy of the origins, which will be used to resolve
+  // non-manifold solids produced by Maker Volume algorithm by comparison
+  // of the normal directions of the split faces with their origins.
+  TopTools_DataMapOfShapeListOfShape anOrigins(1, anAllocGlob);
+  TopTools_ListIteratorOfListOfShape aItLR(theImage.Roots());
+  for (; aItLR.More(); aItLR.Next())
+  {
+    const TopoDS_Shape& aFR = aItLR.Value();
+
+    // Reset the local allocator
+    anAllocLoc->Reset();
+    // Find the last splits of the root face, including the ones
+    // created during MakeVolume operation
+    TopTools_ListOfShape aLFIm(anAllocLoc);
+    theImage.LastImage(aFR, aLFIm);
+
+    TopTools_ListIteratorOfListOfShape aItLFIm(aLFIm);
+    for (; aItLFIm.More(); aItLFIm.Next())
+    {
+      const TopoDS_Shape& aFIm = aItLFIm.Value();
+      TopTools_ListOfShape *pLFOr = anOrigins.ChangeSeek(aFIm);
+      if (!pLFOr) {
+        pLFOr = anOrigins.Bound(aFIm, TopTools_ListOfShape(anAllocGlob));
+      }
+      pLFOr->Append(aFR);
+    }
+  }
+
+  // Reset the local allocator
+  anAllocLoc->Reset();
+  // It is necessary to rebuild the solids, avoiding internal faces
+  // Map faces to solids
+  TopTools_IndexedDataMapOfShapeListOfShape aDMFS(1, anAllocLoc);
   TopExp::MapShapesAndAncestors(aResult1, TopAbs_FACE, TopAbs_SOLID, aDMFS);
   //
   Standard_Integer i, aNb = aDMFS.Extent();
@@ -4114,18 +4155,18 @@ Standard_Boolean BuildShellsCompleteInter(const BOPCol_ListOfShape& theLF,
   }
   //
   // get faces attached to only one solid
-  BOPCol_ListOfShape aLF2;
+  BOPCol_ListOfShape aLF(anAllocLoc);
   for (i = 1; i <= aNb; ++i) {
     const TopTools_ListOfShape& aLS = aDMFS(i);
     if (aLS.Extent() == 1) {
       const TopoDS_Shape& aF = aDMFS.FindKey(i);
-      aLF2.Append(aF);
+      aLF.Append(aF);
     }
   }
   //
   // make solids from the new list
   BOPAlgo_MakerVolume aMV2;
-  aMV2.SetArguments(aLF2);
+  aMV2.SetArguments(aLF);
   // no need to intersect this time
   aMV2.SetIntersect(Standard_False);
   aMV2.SetAvoidInternalShapes(Standard_True);
@@ -4146,24 +4187,30 @@ Standard_Boolean BuildShellsCompleteInter(const BOPCol_ListOfShape& theLF,
     return bDone;
   }
   //
-  // the result is non-manifold - resolve it comparing normals
+  aLF.Clear();
+  aDMFS.Clear();
+  anAllocLoc->Reset();
+
+  // the result is non-manifold - resolve it comparing normal
   // directions of the offset faces and original faces
-  BOPCol_ListOfShape aLF3;
-  for (; aExp.More(); aExp.Next()) {
+  for (; aExp.More(); aExp.Next())
+  {
     const TopoDS_Face& aF = TopoDS::Face(aExp.Current());
-    //
-    // check orientation
-    if (!theOrigins.Contains(aF)) {
-      aLF3.Append(aF);
+    const TopTools_ListOfShape* pLFOr = anOrigins.Seek(aF);
+    if (!pLFOr)
+    {
+      Standard_ASSERT_INVOKE("BRepOffset_MakeOffset::BuildShellsCompleteInterSplit(): "
+                             "Origins map does not contain the split face");
       continue;
     }
-    //
-    const TopTools_ListOfShape& aLFOr = theOrigins.FindFromKey(aF);
-    TopTools_ListIteratorOfListOfShape aItLF(aLFOr);
-    for (; aItLF.More(); aItLF.Next()) {
-      const TopoDS_Face& aFOr = TopoDS::Face(aItLF.Value());
-      if (BRepOffset_Tool::CheckPlanesNormals(aF, aFOr)) {
-        aLF3.Append(aF);
+    // Check orientation
+    TopTools_ListIteratorOfListOfShape aItLOr(*pLFOr);
+    for (; aItLOr.More(); aItLOr.Next())
+    {
+      const TopoDS_Face& aFOr = TopoDS::Face(aItLOr.Value());
+      if (BRepOffset_Tool::CheckPlanesNormals(aF, aFOr))
+      {
+        aLF.Append(aF);
         break;
       }
     }
@@ -4171,7 +4218,7 @@ Standard_Boolean BuildShellsCompleteInter(const BOPCol_ListOfShape& theLF,
   //
   // make solid from most outer faces with correct normal direction
   BOPAlgo_MakerVolume aMV3;
-  aMV3.SetArguments(aLF3);
+  aMV3.SetArguments(aLF);
   aMV3.SetIntersect(Standard_False);
   aMV3.SetAvoidInternalShapes(Standard_True);
   aMV3.Perform();