// 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);
}
