internal Node(Treemap <T> map, T value, float length)
{
_map = map;
Value = value;
SplitVertical = false;
IsLeaf = true;
Length = length;
}
public static Treemap <T> Build(BoundingRectangle space, ITree <T> data)
{
//Create the output
var map = new Treemap <T>(space);
//Create root node with unspecified direction and length
var root = new Node <T>(map, data.Root.Value, -1);
map.Root = root;
//Create the map, this will initialize the direction of the root node
DivideNode(space, data.Root, root, new ArrayPool <float>(), map);
//Initialize the length of the root node
root.Length = Size(space, !root.SplitVertical);
return(map);
}
private static void DivideNode(BoundingRectangle space, INode <T> input, Node <T> output, ArrayPool <float> pool, Treemap <T> map)
{
//Recursion base case
if (input.Count == 0)
{
return;
}
var h = pool.Allocate(input.Count);
var v = pool.Allocate(input.Count);
//Take the split with the least bad aspect ratio
if (MeasureSizes(false, space, input, h) < MeasureSizes(true, space, input, v))
{
//Free the unused array
pool.Free(v);
SplitHorizontal(space, input, output, h, pool, map);
}
else
{
//Free the unused array
pool.Free(h);
SplitVertical(space, input, output, v, pool, map);
}
}
private static void SplitVertical(BoundingRectangle space, INode <T> input, Node <T> output, float[] sizes, ArrayPool <float> pool, Treemap <T> map)
{
output.SplitVertical = true;
ApplySplit(space, input, output, sizes, pool, map);
}
private static void ApplySplit(BoundingRectangle space, INode <T> input, Node <T> output, float[] sizes, ArrayPool <float> pool, Treemap <T> map)
{
//Create child nodes and add them to the parent
var index = 0;
foreach (var child in input)
{
output.Add(new Node <T>(map, child.Value, sizes[index++]));
}
//Now that we're done with the array, free it
pool.Free(sizes);
//Recursively subdivide each child
for (var i = 0; i < output.Count; i++)
{
var iNode = input[i];
var oNode = output[i];
//Calculate bounds for this node (the bounds are not in the right place, they are the right *size* which is the only thing we care about here)
var box = output.SplitVertical
? new BoundingRectangle(new Vector2(0, space.Min.Y), new Vector2(oNode.Length, space.Max.Y))
: new BoundingRectangle(new Vector2(space.Min.X, 0), new Vector2(space.Max.X, oNode.Length));
//Recursion
DivideNode(box, iNode, oNode, pool, map);
}
}
