public static Node ConstructTree(List <BoundingBox3D> zupboxes)
{
// select min and max from zupboxes for x and y
var bbox3d = BoundingBoxCalculator.GetBoundingBox(zupboxes);
var bbox = bbox3d.ToBoundingBox();
double maxTileSize = 2000.0;
var featuresPerTile = 50;
var xrange = (int)Math.Ceiling(bbox3d.ExtentX() / maxTileSize);
var yrange = (int)Math.Ceiling(bbox3d.ExtentY() / maxTileSize);
var tree = new Node();
for (var x = 0; x < xrange; x++)
{
for (var y = 0; y < yrange; y++)
{
var tileextent = B3dmTile.GetExtent(bbox, maxTileSize, x, y);
var features = new List <Feature>();
// loop through all zupboxes
for (var t = 0; t < zupboxes.Count; t++)
{
var isinside = tileextent.Inside(zupboxes[t].GetCenter());
if (isinside)
{
var f = new Feature()
{
Id = t, BoundingBox3D = zupboxes[t]
};
features.Add(f);
}
}
if (features.Count == 0)
{
continue;
}
var node = new Node();
if (features.Count > featuresPerTile)
{
node.Features = features.Take(featuresPerTile).ToList();
var new_features = features.GetRange(featuresPerTile, features.Count - featuresPerTile).ToList();
var new_x = x * 2;
var new_y = y * 2;
var new_maxTileSize = maxTileSize / 2;
Divide(tileextent, new_features, new_x, new_y, new_maxTileSize, featuresPerTile, node);
}
else
{
node.Features = features;
}
tree.Children.Add(node);
}
}
return(tree);
}
private static void Divide(BoundingBox extent, List <Feature> features, int XOffset, int YOffset, double TileSize, int FeaturesPerTile, Node parent)
{
for (var i = 0; i < 2; i++)
{
for (var j = 0; j < 2; j++)
{
var tileextent = B3dmTile.GetExtent(extent, TileSize, i, j);
var insideFeatures = new List <Feature>();
foreach (var f in features)
{
var center = f.BoundingBox3D.GetCenter();
var isinside = tileextent.Inside(center);
if (isinside)
{
var new_f = new Feature()
{
Id = f.Id, BoundingBox3D = f.BoundingBox3D
};
insideFeatures.Add(new_f);
}
}
if (insideFeatures.Count == 0)
{
continue;
}
var node = new Node();
if (insideFeatures.Count > FeaturesPerTile)
{
node.Features = insideFeatures.Take(FeaturesPerTile).ToList();
var new_features = insideFeatures.GetRange(FeaturesPerTile, insideFeatures.Count - FeaturesPerTile).ToList();
var new_x = (XOffset + i) * 2;
var new_y = (YOffset + j) * 2;
var new_maxTileSize = TileSize / 2;
Divide(tileextent, new_features, new_x, new_y, new_maxTileSize, FeaturesPerTile, node);
}
else
{
node.Features = insideFeatures;
}
parent.Children.Add(node);
}
}
}