ENH: cleanup treeData items (#2609)

Changes / Improvements

- more consistent subsetting, interface

  * Extend the use of subset and non-subset collections with uniform
    internal getters to ensure that the subset/non-subset versions
    are robustly handled.

  * operator[](label) and objectIndex(label) for standardized access
    to the underlying item, or the original index, regardless of
    subsetting or not.

  * centres() and centre(label) for representative point cloud
    information.

  * nDim() returns the object dimensionality (0: point, 1: line, etc)
    these can be used to determine how 'fat' each shape may be
    and whether bounds(labelList) may contribute any useful information.

  * bounds(labelList) to return the full bound box required for
    specific items. Eg, the overall bounds for various 3D cells.

- easier construction of non-caching versions. The bounding boxes are
  rarely cached, so simpler constructors without the caching bool
  are provided.

- expose findNearest (bound sphere) method to allow general use
  since this does not actually need a tree.

- static helpers

  The boxes() static methods can be used by callers that need to build
  their own treeBoundBoxList of common shapes (edge, face, cell)
  that are also available as treeData types.

  The bounds() static methods can be used by callers to determine the
  overall bound-box size prior to constructing an indexedOctree
  without writing ad hoc code inplace.

  Not implemented for treeDataPrimitivePatch since similiar
  functionality is available directly from the PrimitivePatch::box()
  method with less typing.

========
BREAKING: cellLabels(), faceLabels(), edgeLabel() access methods

- it was always unsafe to use the treeData xxxLabels() methods without
  subsetting elements. However, since the various classes
  (treeDataCell, treeDataEdge, etc) automatically provided
  an identity lookup, this problem was not apparent.

  Use objectIndex(label) to safely de-reference to the original index
  and operator[](index) to de-reference to the original object.

src/sampling/meshToMesh0/calculateMeshToMesh0Addressing.C

@@ -88,7 +88,7 @@ void Foam::meshToMesh0::calcAddressing()
         << "   bounding box (shifted) : " << shiftedBb << nl
         << "   typical dimension      : " << shiftedBb.avgDim() << endl;
 
-    indexedOctree<treeDataCell> oc
+    indexedOctree<treeDataCell> cellTree
     (
         treeDataCell(false, fromMesh_, polyMesh::CELL_TETS),
         shiftedBb,      // overall bounding box
@@ -99,7 +99,7 @@ void Foam::meshToMesh0::calcAddressing()
 
     if (debug)
     {
-        oc.print(Pout, false, 0);
+        cellTree.print(Pout, false, 0);
     }
 
     cellAddresses
@@ -108,7 +108,7 @@ void Foam::meshToMesh0::calcAddressing()
         toMesh_.cellCentres(),
         fromMesh_,
         boundaryCell,
-        oc
+        cellTree
     );
 
     forAll(toMesh_.boundaryMesh(), patchi)
@@ -125,7 +125,7 @@ void Foam::meshToMesh0::calcAddressing()
                 toPatch.faceCentres(),
                 fromMesh_,
                 boundaryCell,
-                oc
+                cellTree
             );
         }
         else if
@@ -160,7 +160,7 @@ void Foam::meshToMesh0::calcAddressing()
 
                 // Note: allow more levels than in meshSearch. Assume patch
                 // is not as big as all boundary faces
-                indexedOctree<treeDataFace> oc
+                indexedOctree<treeDataFace> faceTree
                 (
                     treeDataFace(false, fromPatch),
                     shiftedBb,  // overall search domain
@@ -178,7 +178,7 @@ void Foam::meshToMesh0::calcAddressing()
 
                 forAll(toPatch, toi)
                 {
-                    boundaryAddressing_[patchi][toi] = oc.findNearest
+                    boundaryAddressing_[patchi][toi] = faceTree.findNearest
                     (
                         centresToBoundary[toi],
                         distSqr
@@ -199,7 +199,7 @@ void Foam::meshToMesh0::cellAddresses
     const pointField& points,
     const fvMesh& fromMesh,
     const List<bool>& boundaryCell,
-    const indexedOctree<treeDataCell>& oc
+    const indexedOctree<treeDataCell>& cellTree
 ) const
 {
     // the implemented search method is a simple neighbour array search.
@@ -263,7 +263,7 @@ void Foam::meshToMesh0::cellAddresses
             // the octree search to find it.
             if (boundaryCell[curCell])
             {
-                cellAddressing_[toI] = oc.findInside(p);
+                cellAddressing_[toI] = cellTree.findInside(p);
 
                 if (cellAddressing_[toI] != -1)
                 {
@@ -320,7 +320,7 @@ void Foam::meshToMesh0::cellAddresses
                 if (!found)
                 {
                     // Still not found so use the octree
-                    cellAddressing_[toI] = oc.findInside(p);
+                    cellAddressing_[toI] = cellTree.findInside(p);
 
                     if (cellAddressing_[toI] != -1)
                     {

src/sampling/meshToMesh0/meshToMesh0.H

@@ -116,7 +116,7 @@ class meshToMesh0
             const pointField& points,
             const fvMesh& fromMesh,
             const List<bool>& boundaryCell,
-            const indexedOctree<treeDataCell>& oc
+            const indexedOctree<treeDataCell>& cellTree
         ) const;
 
         void calculateInverseDistanceWeights() const;

src/sampling/probes/patchProbes.C

@@ -107,14 +107,13 @@ void Foam::patchProbes::findElements(const fvMesh& mesh)
 
         forAll(probeLocations(), probei)
         {
+            const auto& treeData = boundaryTree.shapes();
             const point sample = probeLocations()[probei];
 
-            const scalar span = boundaryTree.bb().mag();
-
             pointIndexHit info = boundaryTree.findNearest
             (
                 sample,
-                Foam::sqr(span)
+                Foam::sqr(boundaryTree.bb().mag())
             );
 
             if (!info.hit())
@@ -122,7 +121,7 @@ void Foam::patchProbes::findElements(const fvMesh& mesh)
                 info = boundaryTree.findNearest(sample, Foam::sqr(GREAT));
             }
 
-            label facei = boundaryTree.shapes().faceLabels()[info.index()];
+            const label facei = treeData.objectIndex(info.index());
 
             const label patchi = bm.whichPatch(facei);
 

src/sampling/sampledSet/patchCloud/patchCloudSet.C

@@ -115,9 +115,11 @@ void Foam::patchCloudSet::calcSamples
 
     forAll(sampleCoords_, sampleI)
     {
+        const auto& treeData = patchTree.shapes();
         const point& sample = sampleCoords_[sampleI];
 
         pointIndexHit& nearInfo = nearest[sampleI].first();
+        auto& distSqrProc = nearest[sampleI].second();
 
         // Find the nearest locally
         if (patchFaces.size())
@@ -133,17 +135,18 @@ void Foam::patchCloudSet::calcSamples
         // Fill in the distance field and the processor field
         if (!nearInfo.hit())
         {
-            nearest[sampleI].second().first() = Foam::sqr(GREAT);
-            nearest[sampleI].second().second() = Pstream::myProcNo();
+            distSqrProc.first() = Foam::sqr(GREAT);
+            distSqrProc.second() = Pstream::myProcNo();
         }
         else
         {
             // Set nearest to mesh face label
-            nearInfo.setIndex(patchFaces[nearInfo.index()]);
+            const label objectIndex = treeData.objectIndex(nearInfo.index());
 
-            nearest[sampleI].second().first() =
-                nearInfo.point().distSqr(sample);
-            nearest[sampleI].second().second() = Pstream::myProcNo();
+            nearInfo.setIndex(objectIndex);
+
+            distSqrProc.first() = sample.distSqr(nearInfo.point());
+            distSqrProc.second() = Pstream::myProcNo();
         }
     }
 

src/sampling/sampledSet/patchSeed/patchSeedSet.C

@@ -136,9 +136,12 @@ void Foam::patchSeedSet::calcSamples
 
             forAll(selectedLocations_, sampleI)
             {
+                const auto& treeData = boundaryTree.shapes();
                 const point& sample = selectedLocations_[sampleI];
 
                 pointIndexHit& nearInfo = nearest[sampleI].first();
+                auto& distSqrProc = nearest[sampleI].second();
+
                 nearInfo = boundaryTree.findNearest
                 (
                     sample,
@@ -147,17 +150,15 @@ void Foam::patchSeedSet::calcSamples
 
                 if (!nearInfo.hit())
                 {
-                    nearest[sampleI].second().first() = Foam::sqr(GREAT);
-                    nearest[sampleI].second().second() =
-                        Pstream::myProcNo();
+                    distSqrProc.first() = Foam::sqr(GREAT);
+                    distSqrProc.second() = Pstream::myProcNo();
                 }
                 else
                 {
-                    point fc(pp[nearInfo.index()].centre(pp.points()));
-                    nearInfo.setPoint(fc);
-                    nearest[sampleI].second().first() = sample.magSqr(fc);
-                    nearest[sampleI].second().second() =
-                        Pstream::myProcNo();
+                    nearInfo.setPoint(treeData.centre(nearInfo.index()));
+
+                    distSqrProc.first() = sample.distSqr(nearInfo.point());
+                    distSqrProc.second() = Pstream::myProcNo();
                 }
             }
 

src/sampling/sampledSurface/sampledMeshedSurface/sampledMeshedSurface.C

@@ -159,7 +159,8 @@ bool Foam::sampledMeshedSurface::update(const meshSearch& meshSearcher)
     {
         // Search for nearest cell
 
-        const indexedOctree<treeDataCell>& cellTree = meshSearcher.cellTree();
+        const auto& cellTree = meshSearcher.cellTree();
+        const auto& treeData = cellTree.shapes();
 
         forAll(fc, facei)
         {
@@ -170,8 +171,10 @@ bool Foam::sampledMeshedSurface::update(const meshSearch& meshSearcher)
 
             if (info.hit())
             {
+                const label objectIndex = treeData.objectIndex(info.index());
+
                 near.first()  = info.point().distSqr(pt);
-                near.second() = globalCells.toGlobal(info.index());
+                near.second() = globalCells.toGlobal(objectIndex);
             }
         }
     }
@@ -180,6 +183,7 @@ bool Foam::sampledMeshedSurface::update(const meshSearch& meshSearcher)
         // Search for cell containing point
 
         const auto& cellTree = meshSearcher.cellTree();
+        const auto& treeData = cellTree.shapes();
 
         forAll(fc, facei)
         {
@@ -189,10 +193,13 @@ bool Foam::sampledMeshedSurface::update(const meshSearch& meshSearcher)
             if (cellTree.bb().contains(pt))
             {
                 const label index = cellTree.findInside(pt);
+
                 if (index != -1)
                 {
+                    const label objectIndex = treeData.objectIndex(index);
+
                     near.first()  = 0;
-                    near.second() = globalCells.toGlobal(index);
+                    near.second() = globalCells.toGlobal(objectIndex);
                 }
             }
         }
@@ -203,6 +210,7 @@ bool Foam::sampledMeshedSurface::update(const meshSearch& meshSearcher)
         // on all non-coupled boundary faces
 
         const auto& bndTree = meshSearcher.nonCoupledBoundaryTree();
+        const auto& treeData = bndTree.shapes();
 
         forAll(fc, facei)
         {
@@ -213,12 +221,10 @@ bool Foam::sampledMeshedSurface::update(const meshSearch& meshSearcher)
 
             if (info.hit())
             {
+                const label objectIndex = treeData.objectIndex(info.index());
+
                 near.first()  = info.point().distSqr(pt);
-                near.second() =
-                    globalCells.toGlobal
-                    (
-                        bndTree.shapes().faceLabels()[info.index()]
-                    );
+                near.second() = globalCells.toGlobal(objectIndex);
             }
         }
     }