bool MyGraphicsView::isPointVisible(QPointF p)
{
QPointF corner1, corner2, corner3, corner4;
getFourViewportCornersInSceneCoordinates(&corner1, &corner2, &corner3, &corner4);
QLineF boundary1(corner1, corner2);
QLineF boundary2(corner2, corner3);
QLineF boundary3(corner3, corner4);
QLineF boundary4(corner4, corner1);
return !(differentSidesOfLine(p, corner3, boundary1) || differentSidesOfLine(p, corner4, boundary2) ||
differentSidesOfLine(p, corner1, boundary3) || differentSidesOfLine(p, corner2, boundary4));
}
//This function assumes that the line does intersect with the viewport
//boundary - i.e. one end of the line is in the viewport and one is not.
QPointF MyGraphicsView::findIntersectionWithViewportBoundary(QLineF line)
{
QPointF c1, c2, c3, c4;
getFourViewportCornersInSceneCoordinates(&c1, &c2, &c3, &c4);
QLineF boundary1(c1, c2);
QLineF boundary2(c2, c3);
QLineF boundary3(c3, c4);
QLineF boundary4(c4, c1);
QPointF intersection;
if (line.intersect(boundary1, &intersection) == QLineF::BoundedIntersection)
return intersection;
if (line.intersect(boundary2, &intersection) == QLineF::BoundedIntersection)
return intersection;
if (line.intersect(boundary3, &intersection) == QLineF::BoundedIntersection)
return intersection;
if (line.intersect(boundary4, &intersection) == QLineF::BoundedIntersection)
return intersection;
//The code should not get here, as the line should intersect with one of
//the boundaries.
return intersection;
}
// implements our version of gal combine
// compute a matching between blocks (greedily)
// extend to partition
// apply our refinements and tabu search
void gal_combine::perform_gal_combine( PartitionConfig & config, graph_access & G) {
//first greedily compute a matching of the partitions
std::vector< std::unordered_map<PartitionID, unsigned> > counters(config.k);
forall_nodes(G, node) {
//boundary_pair bp;
if(counters[G.getPartitionIndex(node)].find(G.getSecondPartitionIndex(node)) != counters[G.getPartitionIndex(node)].end()) {
counters[G.getPartitionIndex(node)][G.getSecondPartitionIndex(node)] += 1;
} else {
counters[G.getPartitionIndex(node)][G.getSecondPartitionIndex(node)] = 1;
}
} endfor
std::vector< PartitionID > permutation(config.k);
for( unsigned i = 0; i < permutation.size(); i++) {
permutation[i] = i;
}
random_functions::permutate_vector_good_small(permutation);
std::vector<bool> rhs_matched(config.k, false);
std::vector<PartitionID> bipartite_matching(config.k);
for( unsigned i = 0; i < permutation.size(); i++) {
PartitionID cur_partition = permutation[i];
PartitionID best_unassigned = config.k;
NodeWeight best_value = 0;
for( std::unordered_map<PartitionID, unsigned>::iterator it = counters[cur_partition].begin();
it != counters[cur_partition].end(); ++it) {
if( rhs_matched[it->first] == false && it->second > best_value ) {
best_unassigned = it->first;
best_value = it->second;
}
}
bipartite_matching[cur_partition] = best_unassigned;
if( best_unassigned != config.k ) {
rhs_matched[best_unassigned] = true;
}
}
std::vector<bool> blocked_vertices(G.number_of_nodes(), false);
forall_nodes(G, node) {
if( bipartite_matching[G.getPartitionIndex(node)] == G.getSecondPartitionIndex(node) ){
blocked_vertices[node] = true;
} else {
// we will reassign this vertex since the partitions do not agree on it
G.setPartitionIndex(node, config.k);
}
} endfor
construct_partition cp;
cp.construct_starting_from_partition( config, G );
refinement* refine = new mixed_refinement();
double real_epsilon = config.imbalance/100.0;
double epsilon = random_functions::nextDouble(real_epsilon+0.005,real_epsilon+config.kabaE_internal_bal);
PartitionConfig copy = config;
copy.upper_bound_partition = (1+epsilon)*ceil(config.largest_graph_weight/(double)config.k);
complete_boundary boundary(&G);
boundary.build();
tabu_search ts;
ts.perform_refinement( copy, G, boundary);
//now obtain the quotient graph
complete_boundary boundary2(&G);
boundary2.build();
copy = config;
copy.upper_bound_partition = (1+epsilon)*ceil(config.largest_graph_weight/(double)config.k);
refine->perform_refinement( copy, G, boundary2);
copy = config;
cycle_refinement cr;
cr.perform_refinement(config, G, boundary2);
delete refine;
}
