public DrawingData DrawRadial()
{
DrawingData data = InitDrawingData();
TreeBorders borders = DrawSubtree(rootId, data, data.Height[rootId] + 1);
double maxWidth = 0.0;
double left = 0.0;
double right = 0.0;
for (int i = 0; i <= data.Height[rootId]; i++)
{
left += borders[i, BorderSide.Left];
right += borders[i, BorderSide.Right];
maxWidth = Math.Max(maxWidth, right - left);
}
maxWidth += 1.0; // 1 unit space.
double scale = 360.0 / maxWidth;
CalculateAbsuluteValues(data, scale, true);
return(data);
}
public DrawingData DrawLayered()
{
DrawingData data = InitDrawingData();
DrawSubtree(rootId, data, data.Height[rootId] + 1);
CalculateAbsuluteValues(data, 1.0, false);
return(data);
}
private DrawingData InitDrawingData()
{
// Preprocessing
int size = forest.Size;
DrawingData data = new DrawingData(size, rootId, isDummyRoot);
Stack <int> vStack = new Stack <int>(size);
vStack.Push(rootId);
data.Depth[rootId] = 0;
while (vStack.Count > 0)
{
int vId = vStack.Peek();
int pId = forest.GetParent(vId);
int[] neighs = forest[vId];
int maxHeight = -1;
bool maxFound = true;
foreach (int nId in neighs)
{
if (nId == pId)
{
continue;
}
data.Depth[nId] = data.Depth[vId] + 1;
int nH = data.Height[nId];
if (nH == -1)
{
vStack.Push(nId);
maxFound = false;
}
else
{
maxHeight = Math.Max(nH, maxHeight);
}
}
if (maxFound)
{
data.Height[vId] = maxHeight + 1;
vStack.Pop();
}
} // while -- calculates height and depth for each vertex.
return(data);
}
private void Preprocess()
{
hypertree.TransformToDual();
// Generate and "draw" underlying tree.
joinForest = hypertree.GetJoinTree();
drawer = new RootedDrawing(joinForest);
data = drawer.DrawRadial();
// Computes colouring and max colour.
colouring = hypertree.GetVertexColouring();
hypertree.TransformToDual();
maxCol = 0;
for (int i = 0; i < colouring.Length; i++)
{
maxCol = Math.Max(colouring[i], maxCol);
}
// Counting sort to sort edges by their colour.
edgeByColour = new int[colouring.Length];
int[] colCounter = new int[maxCol + 1];
for (int i = 0; i < colouring.Length; i++)
{
colCounter[colouring[i]]++;
}
for (int i = 1; i < colCounter.Length; i++)
{
colCounter[i] += colCounter[i - 1];
}
for (int i = colouring.Length - 1; i >= 0; i--)
{
int col = colouring[i];
colCounter[col]--;
int ind = colCounter[col];
edgeByColour[ind] = i;
}
// End of counting sort.
Array.Reverse(edgeByColour);
edges = new List <int> [hypertree.NoOfEdges];
for (int i = 0; i < edges.Length; i++)
{
edges[i] = new List <int>(Math.Max(hypertree.GetCardinality(i) * 2 - 2, 0));
}
// Use a DFS to determine the tree-edges of each hyperedge.
// The search starts at the root.
// Each time the search reaces a vertex v, it checks for all edges e containing v, if e is already activated.
// If e is already activated, the tree-edge from v to its parent is part of the edge.
bool[] activeEdges = new bool[hypertree.NoOfEdges];
Stack <int> verStack = new Stack <int>();
Stack <int> parStack = new Stack <int>();
int[] rootIds = joinForest.GetRoots();
foreach (int rId in rootIds)
{
verStack.Push(rId);
parStack.Push(-1);
while (verStack.Count > 0)
{
int vId = verStack.Pop();
int pId = parStack.Pop();
int[] edgeIds = hypertree.GetEdges(vId);
foreach (int eId in edgeIds)
{
if (activeEdges[eId])
{
edges[eId].Add(pId);
edges[eId].Add(vId);
}
activeEdges[eId] = true;
}
int[] neighs = joinForest[vId];
foreach (int nId in neighs)
{
if (nId == pId)
{
continue;
}
verStack.Push(nId);
parStack.Push(vId);
}
}
}
// Now, data contains the radial coordinates of each vertex,
// edges contains the list of tree-edges of each hyperedge,
// colouring contains the colours of each hyperedge,
// and edgeByColur has the edges ordered by their colour.
}
private void CalculateAbsuluteValues(DrawingData data, double scale, bool radial)
{
Stack <int> vStack = new Stack <int>(forest.Size);
Stack <double> sStack = new Stack <double>(forest.Size);
vStack.Push(rootId);
sStack.Push(scale);
while (vStack.Count > 0)
{
double maxScale = sStack.Pop();
int vId = vStack.Pop();
int pId = forest.GetParent(vId);
double xShift = data.XShift[vId];
int[] neighs = forest[vId];
data.XShift[vId] = (pId >= 0 ? data.XShift[pId] : 0) + xShift * maxScale;
if (radial)
{
double minX = 0.0;
double maxX = 0.0;
foreach (int nId in neighs)
{
if (nId == pId)
{
continue;
}
minX = Math.Min(minX, data.XShift[nId]);
maxX = Math.Max(maxX, data.XShift[nId]);
}
double difX = maxX - minX;
if (difX > 0 && data.Depth[vId] > 0)
{
double rad = (double)data.Depth[vId];
double maxDif = 2 * Math.Acos(rad / (rad + 1.0));
maxDif *= (180 / Math.PI);
maxScale = Math.Min(maxScale, maxDif / difX);
}
}
foreach (int nId in neighs)
{
if (nId == pId)
{
continue;
}
vStack.Push(nId);
sStack.Push(maxScale);
}
data.MinX = Math.Min(data.MinX, data.XShift[vId]);
data.MaxX = Math.Max(data.MaxX, data.XShift[vId]);
}
}
private TreeBorders DrawSubtree(int vId, DrawingData data, int borderCap)
{
TreeBorders borders;
if (data.Height[vId] == 0)
{
borders = new TreeBorders(borderCap);
borders.Add(0.0, 0.0);
return(borders);
}
int maxHeigtIndex = -1;
int maxHeigtId = -1;
int maxHeigt = -1;
int pId = forest.GetParent(vId);
int[] neighs = forest[vId];
for (int i = 0; i < neighs.Length; i++)
{
int nId = neighs[i];
if (nId == pId)
{
continue;
}
if (data.Height[nId] > maxHeigt)
{
maxHeigtIndex = i;
maxHeigtId = nId;
maxHeigt = data.Height[nId];
}
}
// Draw largest subtree with full capacity for borders.
borders = DrawSubtree(maxHeigtId, data, borderCap);
// Draw trees left of largest subtree.
for (int i = maxHeigtIndex - 1; i >= 0; i--)
{
int leftId = neighs[i];
int leftHeight = data.Height[leftId];
int hDif = maxHeigt - leftHeight;
if (leftId == pId)
{
continue;
}
TreeBorders leftBorders = DrawSubtree(leftId, data, leftHeight + 1);
// The distance the left tree is moved.
// Because it will move to the left, shiftDist will become negative.
double shiftDist = 0.0;
double totalLeftShift = 0.0;
double totalMaxShift = 0.0;
for (int h = 0; h <= leftHeight; h++)
{
totalLeftShift += leftBorders[h, BorderSide.Right];
totalMaxShift += borders[h, BorderSide.Left];
double dist = totalMaxShift - totalLeftShift;
shiftDist = Math.Min(shiftDist, dist);
}
// Have 1 unit space between both trees.
shiftDist -= 1.0;
// Move tree.
data.XShift[leftId] = shiftDist;
borders[0, BorderSide.Left] = shiftDist;
totalLeftShift = shiftDist;
for (int h = 1; h <= leftHeight; h++)
{
double localShift = leftBorders[h, BorderSide.Left];
totalLeftShift += localShift;
borders[h, BorderSide.Left] = localShift;
}
if (leftHeight < maxHeigt)
{
totalMaxShift += borders[leftHeight + 1, BorderSide.Left];
borders[leftHeight + 1, BorderSide.Left] = totalMaxShift - totalLeftShift;
}
}
// Draw trees right of largest subtree.
for (int i = maxHeigtIndex + 1; i < neighs.Length; i++)
{
int rightId = neighs[i];
int rightHeight = data.Height[rightId];
int hDif = maxHeigt - rightHeight;
if (rightId == pId)
{
continue;
}
TreeBorders rightBorders = DrawSubtree(rightId, data, rightHeight + 1);
// The distance the right tree is moved.
// Because it will move to the right, shiftDist will become positive.
double shiftDist = 0.0;
double totalRightShift = 0.0;
double totalMaxShift = 0.0;
for (int h = 0; h <= rightHeight; h++)
{
totalRightShift += rightBorders[h, BorderSide.Left];
totalMaxShift += borders[h, BorderSide.Right];
double dist = totalMaxShift - totalRightShift;
shiftDist = Math.Max(shiftDist, dist);
}
// Have 1 unit space between both trees.
shiftDist += 1.0;
// Move tree.
data.XShift[rightId] = shiftDist;
borders[0, BorderSide.Right] = shiftDist;
totalRightShift = shiftDist;
for (int h = 1; h <= rightHeight; h++)
{
double localShift = rightBorders[h, BorderSide.Right];
totalRightShift += localShift;
borders[h, BorderSide.Right] = localShift;
}
if (rightHeight < maxHeigt)
{
totalMaxShift += borders[rightHeight + 1, BorderSide.Right];
borders[rightHeight + 1, BorderSide.Right] = totalMaxShift - totalRightShift;
}
}
// Move trees such that center is 0.
double xShift = -(borders[0, BorderSide.Right] + borders[0, BorderSide.Left]) / 2.0;
borders[0, BorderSide.Right] += xShift;
borders[0, BorderSide.Left] += xShift;
for (int i = 0; i < neighs.Length; i++)
{
int nId = neighs[i];
if (nId == pId)
{
continue;
}
data.XShift[nId] += xShift;
}
borders.Add(0.0, 0.0);
return(borders);
}
