MeshPtr MeshTools::timeSliceMesh(MeshPtr spaceTimeMesh, double t,
map<GlobalIndexType, GlobalIndexType> &sliceCellIDToSpaceTimeCellID, int H1OrderForSlice) {
MeshTopologyPtr meshTopo = spaceTimeMesh->getTopology();
set<IndexType> cellIDsToCheck = meshTopo->getRootCellIndices();
set<IndexType> activeCellIDsForTime;
set<IndexType> allActiveCellIDs = meshTopo->getActiveCellIndices();
int spaceDim = meshTopo->getSpaceDim() - 1; // # of true spatial dimensions
MeshTopologyPtr sliceTopo = Teuchos::rcp( new MeshTopology(spaceDim) );
set<IndexType> rootCellIDs = meshTopo->getRootCellIndices();
for (set<IndexType>::iterator rootCellIt = rootCellIDs.begin(); rootCellIt != rootCellIDs.end(); rootCellIt++) {
IndexType rootCellID = *rootCellIt;
FieldContainer<double> physicalNodes = spaceTimeMesh->physicalCellNodesForCell(rootCellID);
if (cellMatches(physicalNodes, t)) { // cell and some subset of its descendents should be included in slice mesh
vector< vector< double > > sliceNodes = timeSliceForCell(physicalNodes, t);
CellTopoPtrLegacy cellTopo = getBottomTopology(meshTopo, rootCellID);
CellPtr sliceCell = sliceTopo->addCell(cellTopo, sliceNodes);
sliceCellIDToSpaceTimeCellID[sliceCell->cellIndex()] = rootCellID;
}
}
MeshPtr sliceMesh = Teuchos::rcp( new Mesh(sliceTopo, spaceTimeMesh->bilinearForm(), H1OrderForSlice, spaceDim) );
// process refinements. For now, we assume isotropic refinements, which means that each refinement in spacetime induces a refinement in the spatial slice
set<IndexType> sliceCellIDsToCheckForRefinement = sliceTopo->getActiveCellIndices();
while (sliceCellIDsToCheckForRefinement.size() > 0) {
set<IndexType>::iterator cellIt = sliceCellIDsToCheckForRefinement.begin();
IndexType sliceCellID = *cellIt;
sliceCellIDsToCheckForRefinement.erase(cellIt);
CellPtr sliceCell = sliceTopo->getCell(sliceCellID);
CellPtr spaceTimeCell = meshTopo->getCell(sliceCellIDToSpaceTimeCellID[sliceCellID]);
if (spaceTimeCell->isParent()) {
set<GlobalIndexType> cellsToRefine;
cellsToRefine.insert(sliceCellID);
sliceMesh->hRefine(cellsToRefine, RefinementPattern::regularRefinementPattern(sliceCell->topology()->getKey()));
vector<IndexType> spaceTimeChildren = spaceTimeCell->getChildIndices();
for (int childOrdinal=0; childOrdinal<spaceTimeChildren.size(); childOrdinal++) {
IndexType childID = spaceTimeChildren[childOrdinal];
FieldContainer<double> childNodes = meshTopo->physicalCellNodesForCell(childID);
if (cellMatches(childNodes, t)) {
vector< vector<double> > childSlice = timeSliceForCell(childNodes, t);
CellPtr childSliceCell = sliceTopo->findCellWithVertices(childSlice);
sliceCellIDToSpaceTimeCellID[childSliceCell->cellIndex()] = childID;
sliceCellIDsToCheckForRefinement.insert(childSliceCell->cellIndex());
}
}
}
}
return sliceMesh;
}
CellTopoPtrLegacy getBottomTopology(MeshTopologyPtr meshTopo, IndexType cellID) {
int spaceDim = meshTopo->getSpaceDim() - 1;
// determine cell topology:
vector<IndexType> cellVertexIndices = meshTopo->getCell(cellID)->vertices();
set<IndexType> bottomVertexIndices;
int bottomNodeCount = cellVertexIndices.size() / 2;
for (int i=0; i<bottomNodeCount; i++) {
bottomVertexIndices.insert(cellVertexIndices[i]);
}
IndexType bottomEntityIndex = meshTopo->getEntityIndex(spaceDim, bottomVertexIndices);
unsigned bottomCellTopoKey = meshTopo->getEntityTopology(spaceDim, bottomEntityIndex).getKey();
CellTopoPtrLegacy cellTopo = CamelliaCellTools::cellTopoForKey(bottomCellTopoKey);
return cellTopo;
}
