bool ContractionHierarchiesClient::unpackEdge( const NodeIterator source, const NodeIterator target, bool forward, QVector< Node >* pathNodes, QVector< Edge >* pathEdges ) {
EdgeIterator shortestEdge;
unsigned distance = std::numeric_limits< unsigned >::max();
for ( EdgeIterator edge = m_graph.edges( source ); edge.hasEdgesLeft(); ) {
m_graph.unpackNextEdge( &edge );
if ( edge.target() != target )
continue;
if ( forward && !edge.forward() )
continue;
if ( !forward && !edge.backward() )
continue;
if ( edge.distance() > distance )
continue;
distance = edge.distance();
shortestEdge = edge;
}
if ( shortestEdge.unpacked() ) {
m_graph.path( shortestEdge, pathNodes, pathEdges, forward );
return true;
}
if ( !shortestEdge.shortcut() ) {
pathEdges->push_back( shortestEdge.description() );
if ( forward )
pathNodes->push_back( m_graph.node( target ).coordinate );
else
pathNodes->push_back( m_graph.node( source ).coordinate );
return true;
}
const NodeIterator middle = shortestEdge.middle();
if ( forward ) {
unpackEdge( middle, source, false, pathNodes, pathEdges );
unpackEdge( middle, target, true, pathNodes, pathEdges );
return true;
} else {
unpackEdge( middle, target, false, pathNodes, pathEdges );
unpackEdge( middle, source, true, pathNodes, pathEdges );
return true;
}
}
bool ContractionHierarchiesClient::GetRoute( double* distance, QVector< Node>* pathNodes, QVector< Edge >* pathEdges, const IGPSLookup::Result& source, const IGPSLookup::Result& target )
{
assert( distance != NULL );
m_heapForward->Clear();
m_heapBackward->Clear();
*distance = computeRoute( source, target, pathNodes, pathEdges );
if ( *distance == std::numeric_limits< int >::max() )
return false;
// is it shorter to drive along the edge?
if ( target.source == source.source && target.target == source.target && source.edgeID == target.edgeID ) {
EdgeIterator targetEdge = m_graph.findEdge( target.source, target.target, target.edgeID );
double onEdgeDistance = fabs( target.percentage - source.percentage ) * targetEdge.distance();
if ( onEdgeDistance < *distance ) {
if ( ( targetEdge.forward() && targetEdge.backward() ) || source.percentage < target.percentage ) {
if ( pathNodes != NULL && pathEdges != NULL )
{
pathNodes->clear();
pathEdges->clear();
pathNodes->push_back( source.nearestPoint );
QVector< Node > tempNodes;
if ( targetEdge.unpacked() )
m_graph.path( targetEdge, &tempNodes, pathEdges, target.target == targetEdge.target() );
else
pathEdges->push_back( targetEdge.description() );
if ( target.previousWayCoordinates < source.previousWayCoordinates ) {
for ( unsigned pathID = target.previousWayCoordinates; pathID < source.previousWayCoordinates; pathID++ )
pathNodes->push_back( tempNodes[pathID - 1] );
std::reverse( pathNodes->begin() + 1, pathNodes->end() );
} else {
for ( unsigned pathID = source.previousWayCoordinates; pathID < target.previousWayCoordinates; pathID++ )
pathNodes->push_back( tempNodes[pathID - 1] );
}
pathNodes->push_back( target.nearestPoint );
pathEdges->front().length = pathNodes->size() - 1;
}
*distance = onEdgeDistance;
}
}
}
*distance /= 10;
return true;
}
int ContractionHierarchiesClient::computeRoute( const IGPSLookup::Result& source, const IGPSLookup::Result& target, QVector< Node>* pathNodes, QVector< Edge >* pathEdges ) {
EdgeIterator sourceEdge = m_graph.findEdge( source.source, source.target, source.edgeID );
unsigned sourceWeight = sourceEdge.distance();
EdgeIterator targetEdge = m_graph.findEdge( target.source, target.target, target.edgeID );
unsigned targetWeight = targetEdge.distance();
//insert source into heap
m_heapForward->Insert( source.target, sourceWeight - sourceWeight * source.percentage, source.target );
if ( sourceEdge.backward() && sourceEdge.forward() && source.target != source.source )
m_heapForward->Insert( source.source, sourceWeight * source.percentage, source.source );
//insert target into heap
m_heapBackward->Insert( target.source, targetWeight * target.percentage, target.source );
if ( targetEdge.backward() && targetEdge.forward() && target.target != target.source )
m_heapBackward->Insert( target.target, targetWeight - targetWeight * target.percentage, target.target );
int targetDistance = std::numeric_limits< int >::max();
NodeIterator middle = ( NodeIterator ) 0;
AllowForwardEdge forward;
AllowBackwardEdge backward;
while ( m_heapForward->Size() + m_heapBackward->Size() > 0 ) {
if ( m_heapForward->Size() > 0 )
computeStep( m_heapForward, m_heapBackward, forward, backward, &middle, &targetDistance );
if ( m_heapBackward->Size() > 0 )
computeStep( m_heapBackward, m_heapForward, backward, forward, &middle, &targetDistance );
}
if ( targetDistance == std::numeric_limits< int >::max() )
return std::numeric_limits< int >::max();
// abort early if the path description is not requested
if ( pathNodes == NULL || pathEdges == NULL )
return targetDistance;
std::stack< NodeIterator > stack;
NodeIterator pathNode = middle;
while ( true ) {
NodeIterator parent = m_heapForward->GetData( pathNode ).parent;
stack.push( pathNode );
if ( parent == pathNode )
break;
pathNode = parent;
}
pathNodes->push_back( source.nearestPoint );
bool reverseSourceDescription = pathNode != source.target;
if ( source.source == source.target && sourceEdge.backward() && sourceEdge.forward() && source.percentage < 0.5 )
reverseSourceDescription = !reverseSourceDescription;
if ( sourceEdge.unpacked() ) {
bool unpackSourceForward = source.target != sourceEdge.target() ? reverseSourceDescription : !reverseSourceDescription;
m_graph.path( sourceEdge, pathNodes, pathEdges, unpackSourceForward );
if ( reverseSourceDescription ) {
pathNodes->remove( 1, pathNodes->size() - 1 - source.previousWayCoordinates );
} else {
pathNodes->remove( 1, source.previousWayCoordinates - 1 );
}
} else {
pathNodes->push_back( m_graph.node( pathNode ) );
pathEdges->push_back( sourceEdge.description() );
}
pathEdges->front().length = pathNodes->size() - 1;
pathEdges->front().seconds *= reverseSourceDescription ? source.percentage : 1 - source.percentage;
while ( stack.size() > 1 ) {
const NodeIterator node = stack.top();
stack.pop();
unpackEdge( node, stack.top(), true, pathNodes, pathEdges );
}
pathNode = middle;
while ( true ) {
NodeIterator parent = m_heapBackward->GetData( pathNode ).parent;
if ( parent == pathNode )
break;
unpackEdge( parent, pathNode, false, pathNodes, pathEdges );
pathNode = parent;
}
int begin = pathNodes->size();
bool reverseTargetDescription = pathNode != target.source;
if ( target.source == target.target && targetEdge.backward() && targetEdge.forward() && target.percentage > 0.5 )
reverseTargetDescription = !reverseTargetDescription;
if ( targetEdge.unpacked() ) {
bool unpackTargetForward = target.target != targetEdge.target() ? reverseTargetDescription : !reverseTargetDescription;
m_graph.path( targetEdge, pathNodes, pathEdges, unpackTargetForward );
if ( reverseTargetDescription ) {
pathNodes->resize( pathNodes->size() - target.previousWayCoordinates );
} else {
pathNodes->resize( begin + target.previousWayCoordinates - 1 );
}
} else {
pathEdges->push_back( targetEdge.description() );
}
pathNodes->push_back( target.nearestPoint );
pathEdges->back().length = pathNodes->size() - begin;
pathEdges->back().seconds *= reverseTargetDescription ? 1 - target.percentage : target.percentage;
return targetDistance;
}
void ContractionHierarchiesClient::computeStep( Heap* heapForward, Heap* heapBackward, const EdgeAllowed& edgeAllowed, const StallEdgeAllowed& stallEdgeAllowed, NodeIterator* middle, int* targetDistance ) {
const NodeIterator node = heapForward->DeleteMin();
const int distance = heapForward->GetKey( node );
if ( heapForward->GetData( node ).stalled )
return;
if ( heapBackward->WasInserted( node ) && !heapBackward->GetData( node ).stalled ) {
const int newDistance = heapBackward->GetKey( node ) + distance;
if ( newDistance < *targetDistance ) {
*middle = node;
*targetDistance = newDistance;
}
}
if ( distance > *targetDistance ) {
heapForward->DeleteAll();
return;
}
for ( EdgeIterator edge = m_graph.edges( node ); edge.hasEdgesLeft(); ) {
m_graph.unpackNextEdge( &edge );
const NodeIterator to = edge.target();
const int edgeWeight = edge.distance();
assert( edgeWeight > 0 );
const int toDistance = distance + edgeWeight;
if ( stallEdgeAllowed( edge.forward(), edge.backward() ) && heapForward->WasInserted( to ) ) {
const int shorterDistance = heapForward->GetKey( to ) + edgeWeight;
if ( shorterDistance < distance ) {
//perform a bfs starting at node
//only insert nodes when a sub-optimal path can be proven
//insert node into the stall queue
heapForward->GetKey( node ) = shorterDistance;
heapForward->GetData( node ).stalled = true;
m_stallQueue.push( node );
while ( !m_stallQueue.empty() ) {
//get node from the queue
const NodeIterator stallNode = m_stallQueue.front();
m_stallQueue.pop();
const int stallDistance = heapForward->GetKey( stallNode );
//iterate over outgoing edges
for ( EdgeIterator stallEdge = m_graph.edges( stallNode ); stallEdge.hasEdgesLeft(); ) {
m_graph.unpackNextEdge( &stallEdge );
//is edge outgoing/reached/stalled?
if ( !edgeAllowed( stallEdge.forward(), stallEdge.backward() ) )
continue;
const NodeIterator stallTo = stallEdge.target();
if ( !heapForward->WasInserted( stallTo ) )
continue;
if ( heapForward->GetData( stallTo ).stalled == true )
continue;
const int stallToDistance = stallDistance + stallEdge.distance();
//sub-optimal path found -> insert stallTo
if ( stallToDistance < heapForward->GetKey( stallTo ) ) {
if ( heapForward->WasRemoved( stallTo ) )
heapForward->GetKey( stallTo ) = stallToDistance;
else
heapForward->DecreaseKey( stallTo, stallToDistance );
m_stallQueue.push( stallTo );
heapForward->GetData( stallTo ).stalled = true;
}
}
}
break;
}
}
if ( edgeAllowed( edge.forward(), edge.backward() ) ) {
//New Node discovered -> Add to Heap + Node Info Storage
if ( !heapForward->WasInserted( to ) )
heapForward->Insert( to, toDistance, node );
//Found a shorter Path -> Update distance
else if ( toDistance <= heapForward->GetKey( to ) ) {
heapForward->DecreaseKey( to, toDistance );
//new parent + unstall
heapForward->GetData( to ).parent = node;
heapForward->GetData( to ).stalled = false;
}
}
}
}
