// sets the positions of the nodes in a largest face of G in the form
// of a regular k-gon. The corresponding nodes and their positions are
// stored in nodes and pos, respectively.
void TutteLayout::setFixedNodes(
const Graph &G,
List<node>& nodes,
List<DPoint>& pos,
double radius)
{
// compute faces of a copy of G
GraphCopy GC(G);
PlanarModule pm;
// compute a planar embedding if \a G is planar
if(pm.planarityTest(G)) pm.planarEmbed(GC);
CombinatorialEmbedding E(GC);
E.computeFaces();
// search for largest face
face maxFace = E.maximalFace();
// delete possible old entries in nodes and pos
nodes.clear();
pos.clear();
// set nodes and pos
NodeArray<bool> addMe(GC,true);
adjEntry adj;
List<node> maxNodes;
forall_face_adj(adj,maxFace) {
maxNodes.pushBack(adj->theNode());
}
void ExpandedGraph2::expand(node v, node vPred, node vSucc)
{
m_exp.clear();
while (!m_nodesG.empty())
m_GtoExp[m_nodesG.popBackRet()] = 0;
edge eInS = 0;
if (vPred != 0) {
eInS = m_BC.dynamicSPQRForest().virtualEdge(vPred,v);
m_eS = insertEdge(eInS->source(),eInS->target(),0);
}
edge eOutS = 0;
if (vSucc != 0) {
eOutS = m_BC.dynamicSPQRForest().virtualEdge(vSucc,v);
m_eT = insertEdge(eOutS->source(),eOutS->target(),0);
}
expandSkeleton(v, eInS, eOutS);
PlanarModule pm;
pm.planarEmbed(m_exp);
m_E.init(m_exp);
}
void PlanarDrawLayout::doCall(
const Graph &G,
adjEntry adjExternal,
GridLayout &gridLayout,
IPoint &boundingBox,
bool fixEmbedding)
{
// require to have a planar graph without multi-edges and self-loops;
// planarity is checked below
OGDF_ASSERT(isSimple(G) && isLoopFree(G));
// handle special case of graphs with less than 3 nodes
if(G.numberOfNodes() < 3)
{
node v1, v2;
switch(G.numberOfNodes())
{
case 0:
boundingBox = IPoint(0,0);
return;
case 1:
v1 = G.firstNode();
gridLayout.x(v1) = gridLayout.y(v1) = 0;
boundingBox = IPoint(0,0);
return;
case 2:
v1 = G.firstNode();
v2 = G.lastNode ();
gridLayout.x(v1) = gridLayout.y(v1) = gridLayout.y(v2) = 0;
gridLayout.x(v2) = 1;
boundingBox = IPoint(1,0);
return;
}
}
// we make a copy of G since we use planar biconnected augmentation
GraphCopySimple GC(G);
if(fixEmbedding) {
PlanarAugmentationFix augmenter;
augmenter.call(GC);
} else {
// augment graph planar biconnected
m_augmenter.get().call(GC);
// embed augmented graph
PlanarModule pm;
bool isPlanar = pm.planarEmbed(GC);
if(isPlanar == false)
OGDF_THROW_PARAM(PreconditionViolatedException, pvcPlanar);
}
// compute shelling order
m_computeOrder.get().baseRatio(m_baseRatio);
ShellingOrder order;
m_computeOrder.get().call(GC,order,adjExternal);
// compute grid coordinates for GC
NodeArray<int> x(GC), y(GC);
computeCoordinates(GC,order,x,y);
boundingBox.m_x = x[order(1,order.len(1))];
boundingBox.m_y = 0;
node v;
forall_nodes(v,GC)
if(y[v] > boundingBox.m_y) boundingBox.m_y = y[v];
// copy coordinates from GC to G
forall_nodes(v,G) {
node vCopy = GC.copy(v);
gridLayout.x(v) = x[vCopy];
gridLayout.y(v) = y[vCopy];
}
void planarTriconnectedGraph(Graph &G, int n, int m)
{
if (n < 4) n = 4;
if(n % 2) ++n; // need an even number
// start with K_4
completeGraph(G,4);
PlanarModule pm;
pm.planarEmbed(G);
// nodes[0],...,nodes[i-1] is array of all nodes
Array<node> nodes(n);
node v;
int i = 0;
forall_nodes(v,G)
nodes[i++] = v;
// create planar triconnected 3-graph
for(; i < n; )
{
// pick a random node
v = nodes[randomNumber(0,i-1)];
adjEntry adj2 = v->firstAdj();
int r = randomNumber(0,2);
switch(r) {
case 2: adj2 = adj2->succ(); // fall through to next case
case 1: adj2 = adj2->succ();
}
adjEntry adj1 = adj2->cyclicSucc();
nodes[i++] = G.splitNode(adj1,adj2);
r = randomNumber(0,1);
if(r == 0) {
adjEntry adj = adj1->twin();
G.newEdge(adj2,adj);
nodes[i++] = G.splitNode(adj,adj->cyclicSucc()->cyclicSucc());
} else {
adjEntry adj = adj1->cyclicSucc()->twin();
G.newEdge(adj2,adj,ogdf::before);
nodes[i++] = G.splitNode(adj->cyclicPred(),adj->cyclicSucc());
}
}
nodes.init();
Array<edge> edges(m);
CombinatorialEmbedding E(G);
Array<face> faces(2*n);
i = 0;
face f;
forall_faces(f,E) {
if(f->size() >= 4)
faces[i++] = f;
}
while(G.numberOfEdges() < m && i > 0)
{
int r = randomNumber(0,i-1);
f = faces[r];
faces[r] = faces[--i];
int p = randomNumber(0,f->size()-1);
int j = 0;
adjEntry adj, adj2;
for(adj = f->firstAdj(); j < p; adj = adj->faceCycleSucc(), ++j) ;
p = randomNumber(2, f->size()-2);
for(j = 0, adj2 = adj; j < p; adj2 = adj2->faceCycleSucc(), ++j) ;
edge e = E.splitFace(adj,adj2);
f = E.rightFace(e->adjSource());
if(f->size() >= 4) faces[i++] = f;
f = E.rightFace(e->adjTarget());
if(f->size() >= 4) faces[i++] = f;
}
}
void planarTriconnectedGraph(Graph &G, int n, double p1, double p2)
{
if (n < 4) n = 4;
// start with K_4
completeGraph(G,4);
PlanarModule pm;
pm.planarEmbed(G);
// nodes[0],...,nodes[i-1] is array of all nodes
Array<node> nodes(n);
node v;
int i = 0;
forall_nodes(v,G)
nodes[i++] = v;
for(; i < n; ++i)
{
// pick a random node
v = nodes[randomNumber(0,i-1)];
int m = v->degree();
int a1 = randomNumber(0,m-1);
int a2 = randomNumber(0,m-2);
int j;
adjEntry adj1, adj2;
for(adj1 = v->firstAdj(), j = 0; j < a1; adj1 = adj1->succ(), ++j) ;
for(adj2 = adj1->cyclicSucc(), j = 0; j < a2; adj2 = adj2->cyclicSucc(), ++j) ;
adjEntry adj_b1 = adj2->cyclicPred();
adjEntry adj_b2 = adj1->cyclicPred();
nodes[i] = G.splitNode(adj1, adj2);
if(adj1 == adj_b1)
G.newEdge(adj_b1, adj2->twin());
else if(adj2 == adj_b2)
G.newEdge(adj2, adj_b1->twin(), ogdf::before);
else {
double r = randomDouble(0.0,1.0);
if(r <= p1) {
int s = randomNumber(0,1);
if(s == 0)
G.newEdge(adj_b1, adj2->twin());
else
G.newEdge(adj2, adj_b1->twin(), ogdf::before);
}
}
double r = randomDouble(0.0,1.0);
if(r <= p2) {
int s = randomNumber(0,1);
if(s == 0)
G.newEdge(adj1, adj_b2->twin(), ogdf::before);
else
G.newEdge(adj_b2, adj1->twin());
}
}
}