// Find a good edge
forAll(singleEdges, edgeI)
{
SLList<label> pointChain;
bool blockHead = false;
bool blockTail = false;
if (!singleEdgeUsage[edgeI])
{
// found a new edge
singleEdgeUsage[edgeI] = true;
label newEdgeStart = singleEdges[edgeI].start();
label newEdgeEnd = singleEdges[edgeI].end();
pointChain.insert(newEdgeStart);
pointChain.append(newEdgeEnd);
# ifdef DEBUG_CHAIN
Info<< "found edge to start with: "
<< singleEdges[edgeI] << endl;
# endif
// Check if head or tail are blocked
forAll(cellPoints, pointI)
{
if (cellPoints[pointI] == newEdgeStart)
{
if (pointUsage[pointI] > 2)
{
# ifdef DEBUG_CHAIN
Info<< "start head blocked" << endl;
# endif
blockHead = true;
}
}
else if (cellPoints[pointI] == newEdgeEnd)
{
if (pointUsage[pointI] > 2)
{
# ifdef DEBUG_CHAIN
Info<< "start tail blocked" << endl;
# endif
blockTail = true;
}
}
}
bool stopSearching = false;
// Go through the unused edges and try to chain them up
do
{
stopSearching = false;
forAll(singleEdges, addEdgeI)
{
if (!singleEdgeUsage[addEdgeI])
{
// Grab start and end of the candidate
label addStart =
singleEdges[addEdgeI].start();
label addEnd =
singleEdges[addEdgeI].end();
# ifdef DEBUG_CHAIN
Info<< "Trying candidate "
<< singleEdges[addEdgeI] << endl;
# endif
// Try to add the edge onto the head
if (!blockHead)
{
if (pointChain.first() == addStart)
{
// Added at start mark as used
pointChain.insert(addEnd);
singleEdgeUsage[addEdgeI] = true;
}
else if (pointChain.first() == addEnd)
{
pointChain.insert(addStart);
singleEdgeUsage[addEdgeI] = true;
}
}
// Try the other end only if the first end
// did not add it
if (!blockTail && !singleEdgeUsage[addEdgeI])
{
if (pointChain.last() == addStart)
{
// Added at start mark as used
pointChain.append(addEnd);
singleEdgeUsage[addEdgeI] = true;
}
else if (pointChain.last() == addEnd)
{
pointChain.append(addStart);
singleEdgeUsage[addEdgeI] = true;
}
}
// check if the new head or tail are blocked
label curEdgeStart = pointChain.first();
label curEdgeEnd = pointChain.last();
# ifdef DEBUG_CHAIN
Info<< "curEdgeStart: " << curEdgeStart
<< " curEdgeEnd: " << curEdgeEnd << endl;
# endif
forAll(cellPoints, pointI)
{
if (cellPoints[pointI] == curEdgeStart)
{
if (pointUsage[pointI] > 2)
{
# ifdef DEBUG_CHAIN
Info<< "head blocked" << endl;
# endif
blockHead = true;
}
}
else if (cellPoints[pointI] == curEdgeEnd)
{
if (pointUsage[pointI] > 2)
{
# ifdef DEBUG_CHAIN
Info<< "tail blocked" << endl;
# endif
blockTail = true;
}
}
}
// Check if the loop is closed
if (curEdgeStart == curEdgeEnd)
{
# ifdef DEBUG_CHAIN
Info<< "closed loop" << endl;
# endif
pointChain.removeHead();
blockHead = true;
blockTail = true;
stopSearching = true;
}
# ifdef DEBUG_CHAIN
Info<< "current pointChain: " << pointChain
<< endl;
# endif
if (stopSearching) break;
}
}
} while (stopSearching);
}
void Foam::immersedBoundaryFvPatch::makeTriAddressing() const
{
if (debug)
{
InfoIn("void immersedBoundaryFvPatch::makeTriAddressing() const")
<< "creating tri addressing for immersed boundary " << name()
<< endl;
}
// It is an error to attempt to recalculate
// if the pointer is already set
if (cellsToTriAddrPtr_ || cellsToTriWeightsPtr_)
{
FatalErrorIn("immersedBoundaryFvPatch::makeTriAddressing() const")
<< "tri addressing already exist"
<< "for immersed boundary" << name()
<< abort(FatalError);
}
// Get reference to tri patch and hit faces
const triSurface& triPatch = ibPolyPatch_.ibMesh();
const vectorField& triCentres = triPatch.faceCentres();
const labelList& hf = hitFaces();
const vectorField& ibp = ibPoints();
// Create a markup field and mark all tris containing an ib point with its
// index
labelList hitTris(triPatch.size(), -1);
forAll (hf, hfI)
{
hitTris[hf[hfI]] = hfI;
}
// Allocate storage
cellsToTriAddrPtr_ = new labelListList(triPatch.size());
labelListList& addr = *cellsToTriAddrPtr_;
cellsToTriWeightsPtr_ = new scalarListList(triPatch.size());
scalarListList& w = *cellsToTriWeightsPtr_;
// Algorithm:
// For each tri face, check if it contains an IB point
// - if so, set the addressing to the index of IB point and weight to 1
// - if not, search the neighbouring faces of the visited faces until
// at least 3 IB points are found, or the neighbourhood is exhausted.
// When a sufficient number of points is found, calculate the weights
// using inverse distance weighting
// Get addressing from the triangular patch
const labelListList& pf = triPatch.pointFaces();
forAll (triPatch, triI)
{
if (hitTris[triI] > -1)
{
// Triangle contains IB point
addr[triI].setSize(1);
w[triI].setSize(1);
addr[triI] = hitTris[triI];
w[triI] = 1;
}
else
{
// No direct hit. Start a neighbourhood search
// Record already visited faces
labelHashSet visited;
// Collect new faces to visit
SLList<label> nextToVisit;
// Collect IB points for interpolation
labelHashSet ibPointsToUse;
// Initialise with the original tri
nextToVisit.insert(triI);
do
{
const label curTri = nextToVisit.removeHead();
// Discard tri if already visited
if (visited[curTri]) continue;
visited.insert(curTri);
const triFace& curTriPoints = triPatch[curTri];
// For all current points of face, pick up neighbouring faces
forAll (curTriPoints, tpI)
{
const labelList curNbrs = pf[curTriPoints[tpI]];
forAll (curNbrs, nbrI)
{
if (!visited.found(curNbrs[nbrI]))
{
// Found a face which is not visited. Add it to
// the list of faces to visit
nextToVisit.append(curNbrs[nbrI]);
if (hitTris[curNbrs[nbrI]] > -1)
{
// Found a neighbour with a hit: use this
// IB point
ibPointsToUse.insert(hitTris[curNbrs[nbrI]]);
}
}
}
}
} while
(
ibPointsToUse.size() < 3
&& !nextToVisit.empty()
);
// Found neighbourhood: collect addressing and weights
addr[triI] = ibPointsToUse.toc();
w[triI].setSize(addr[triI].size());
labelList& curAddr = addr[triI];
scalarList& curW = w[triI];
vector curTriCentre = triCentres[triI];
scalar sumW = 0;
forAll (curAddr, ibI)
{
curW[ibI] = 1/mag(curTriCentre - ibp[curAddr[ibI]]);
sumW += curW[ibI];
}
// Divide weights by sum distance
forAll (curW, ibI)
{
curW[ibI] /= sumW;
}
}
}
