public static VpNode Near(VpNode root, Rgb target)
{
long bestQDist = uint.MaxValue;
VpNode bestCandidat = null;
int i=0;
var candidats = new Stack<VpNode>();
candidats.Push(root);
while (candidats.Count > 0)
{
i++;
var node = candidats.Pop();
long dist = node.Value.QDist(target);
if(!node.IsLeaf)
dist = dist + node.Radius;
Check.Assert(dist >= 0);
if (dist <= bestQDist) // = чтобы добраться до листьев
{
bestQDist = dist;
bestCandidat = node;
}
dist = node.Value.QDist(target);
if (node.Outsade != null && !(dist < node.Radius - bestQDist))
candidats.Push(node.Outsade);
if (node.Insade != null && !(dist > bestQDist + node.Radius))
candidats.Push(node.Insade);
}
//Console.WriteLine(i);
Check.Assert(bestCandidat.IsLeaf, "Узел не лист");
return bestCandidat;
}
public static void Remove(VpNode node)
{
Check.Assert(node.IsLeaf, "Узел не лист");
var parent = node.Parent;
if (parent == null)
return;
if (parent.Insade == node)
{
var anotherNode = parent.Outsade;
parent.Insade = anotherNode.Insade;
parent.Outsade = anotherNode.Outsade;
parent.IsLeaf = anotherNode.IsLeaf;
parent.Value = anotherNode.Value;
parent.Radius = anotherNode.Radius;
if (parent.Insade != null)
parent.Insade.Parent = parent;
if (parent.Outsade != null)
parent.Outsade.Parent = parent;
return;
}
if (parent.Outsade == node)
{
var anotherNode = parent.Insade;
parent.Insade = anotherNode.Insade;
parent.Outsade = anotherNode.Outsade;
parent.IsLeaf = anotherNode.IsLeaf;
parent.Value = anotherNode.Value;
parent.Radius = anotherNode.Radius;
if (parent.Insade != null)
parent.Insade.Parent = parent;
if (parent.Outsade != null)
parent.Outsade.Parent = parent;
return;
}
throw new Exception("Не правильный родитель");
}
public static VpNode CreateTree(Rgb[] colors)
{
var root = new VpNode();
var candidats = new Stack<Tuple<VpNode, Rgb[]>>();
candidats.Push(Tuple.Create(root, colors));
while (candidats.Count > 0)
{
var candidat = candidats.Pop();
var node = candidat.Item1;
var allColors = candidat.Item2;
var color = allColors[0];
if (allColors.Length == 1)
{
node.Value = color;
node.IsLeaf = true;
continue;
}
var sorted = allColors.OrderBy(x => color.QDist(x)).ToArray();
var medianIndex = (sorted.Length - 1) / 2; //2 - 0, 3 - 1, 4 - 1, 5 - 2
var inside = new VpNode { Parent = node };
var insideColors = new Rgb[medianIndex + 1];
Array.Copy(sorted, insideColors, medianIndex + 1);
candidats.Push(Tuple.Create(inside, insideColors));
var outside = new VpNode { Parent = node };
var outsideColors = new Rgb[sorted.Length - (medianIndex + 1)];
Array.Copy(sorted, medianIndex + 1, outsideColors, 0, sorted.Length - (medianIndex + 1));
candidats.Push(Tuple.Create(outside, outsideColors));
node.Value = color;
node.Radius = sorted[medianIndex].QDist(color);
node.Insade = inside;
node.Outsade = outside;
}
return root;
}
