// The function front scans the frontier of nodePtr. It returns the keys
// of the leaves found in the frontier of nodePtr in a SListPure.
// These keys include keys of direction indicators detected in the frontier.
//
// CAREFUL: Funktion marks all full nodes for destruction.
// Only to be used in connection with replaceRoot.
//
void EmbedPQTree::front(
PQNode<edge,indInfo*,bool>* nodePtr,
SListPure<PQBasicKey<edge,indInfo*,bool>*> &keys)
{
Stack<PQNode<edge,indInfo*,bool>*> S;
S.push(nodePtr);
while (!S.empty())
{
PQNode<edge,indInfo*,bool> *checkNode = S.pop();
if (checkNode->type() == PQNodeRoot::leaf)
keys.pushBack((PQBasicKey<edge,indInfo*,bool>*) checkNode->getKey());
else
{
PQNode<edge,indInfo*,bool>* firstSon = 0;
if (checkNode->type() == PQNodeRoot::PNode)
{
firstSon = checkNode->referenceChild();
}
else if (checkNode->type() == PQNodeRoot::QNode)
{
firstSon = checkNode->getEndmost(RIGHT);
// By this, we make sure that we start on the left side
// since the left endmost child will be on top of the stack
}
if (firstSon->status() == INDICATOR)
{
keys.pushBack((PQBasicKey<edge,indInfo*,bool>*) firstSon->getNodeInfo());
m_pertinentNodes->pushBack(firstSon);
destroyNode(firstSon);
}
else
S.push(firstSon);
PQNode<edge,indInfo*,bool> *nextSon = firstSon->getNextSib(0);
PQNode<edge,indInfo*,bool> *oldSib = firstSon;
while (nextSon && nextSon != firstSon)
{
if (nextSon->status() == INDICATOR)
{
// Direction indicators point with their left sibling pointer
// in the direction of their sequence. If an indicator is scanned
// from the opposite direction, coming from its right sibling
// the corresponding sequence must be reversed.
if (oldSib == nextSon->getSib(LEFT)) //Direction changed
nextSon->getNodeInfo()->userStructInfo()->changeDir = true;
keys.pushBack((PQBasicKey<edge,indInfo*,bool>*) nextSon->getNodeInfo());
m_pertinentNodes->pushBack(nextSon);
}
else
S.push(nextSon);
PQNode<edge,indInfo*,bool> *holdSib = nextSon->getNextSib(oldSib);
oldSib = nextSon;
nextSon = holdSib;
}
}
}
}
void EmbedPQTree::ReplacePartialRoot(
SListPure<PlanarLeafKey<indInfo*>*> &leafKeys,
SListPure<PQBasicKey<edge,indInfo*,bool>*> &frontier,
node v)
{
m_pertinentRoot->childCount(m_pertinentRoot->childCount() + 1 -
fullChildren(m_pertinentRoot)->size());
PQNode<edge,indInfo*,bool> *predNode = 0; // dummy
PQNode<edge,indInfo*,bool> *beginSequence = 0; // marks begin consecuitve seqeunce
PQNode<edge,indInfo*,bool> *endSequence = 0; // marks end consecutive sequence
PQNode<edge,indInfo*,bool> *beginInd = 0; // initially, marks direct sibling indicator
// next to beginSequence not contained
// in consectuive sequence
// Get beginning and end of sequence.
while (fullChildren(m_pertinentRoot)->size())
{
PQNode<edge,indInfo*,bool> *currentNode = fullChildren(m_pertinentRoot)->popFrontRet();
if (!clientSibLeft(currentNode) ||
clientSibLeft(currentNode)->status() == EMPTY)
{
if (!beginSequence)
{
beginSequence = currentNode;
predNode = clientSibLeft(currentNode);
beginInd =PQTree<edge,indInfo*,bool>::clientSibLeft(currentNode);
}
else
endSequence = currentNode;
}
else if (!clientSibRight(currentNode) ||
clientSibRight(currentNode)->status() == EMPTY )
{
if (!beginSequence)
{
beginSequence = currentNode;
predNode = clientSibRight(currentNode);
beginInd =PQTree<edge,indInfo*,bool>::clientSibRight(currentNode);
}
else
endSequence = currentNode;
}
}
SListPure<PQBasicKey<edge,indInfo*,bool>*> partialFrontier;
// Now scan the sequence of full nodes. Remove all of them but the last.
// Call ReplaceFullRoot on the last one.
// For every full node get its frontier. Scan intermediate indicators.
PQNode<edge,indInfo*,bool> *currentNode = beginSequence;
while (currentNode != endSequence)
{
PQNode<edge,indInfo*,bool>* nextNode =
clientNextSib(currentNode,predNode);
front(currentNode,partialFrontier);
frontier.conc(partialFrontier);
PQNode<edge,indInfo*,bool>* currentInd = PQTree<edge,indInfo*,bool>::
clientNextSib(currentNode,beginInd);
// Scan for intermediate direction indicators.
while (currentInd != nextNode)
{
PQNode<edge,indInfo*,bool> *nextInd = PQTree<edge,indInfo*,bool>::
clientNextSib(currentInd,currentNode);
if (currentNode == currentInd->getSib(RIGHT)) //Direction changed
currentInd->getNodeInfo()->userStructInfo()->changeDir = true;
frontier.pushBack((PQBasicKey<edge,indInfo*,bool>*)
currentInd->getNodeInfo());
removeChildFromSiblings(currentInd);
m_pertinentNodes->pushBack(currentInd);
currentInd = nextInd;
}
removeChildFromSiblings(currentNode);
currentNode = nextNode;
}
currentNode->parent(m_pertinentRoot);
m_pertinentRoot = currentNode;
ReplaceFullRoot(leafKeys,partialFrontier,v,true,beginInd);
frontier.conc(partialFrontier);
}