// moves the meta info to a new position, uses RefEquals
public static void UpdateInSorted(this List <Pathfinding.NodeMetaInfo> nodes, Pathfinding.NodeMetaInfo newNode, float oldTotalCost)
{
float newTotalCost = newNode.totalCost;
newNode.totalCost = oldTotalCost;
int ind = nodes.FindIndexSorted(newNode);
newNode.totalCost = newTotalCost;
if (ind > 0 && newNode.totalCost < nodes[ind - 1].totalCost) // need to swap left (shift right)
{
while (ind > 0 && newNode.totalCost < nodes[ind - 1].totalCost)
{
nodes[ind] = nodes[ind - 1];
ind--;
}
nodes[ind] = newNode;
}
else if (ind < nodes.Count - 1 && newNode.totalCost > nodes[ind + 1].totalCost) // need to swap right (shift left)
{
while (ind < nodes.Count - 1 && newNode.totalCost > nodes[ind + 1].totalCost)
{
nodes[ind] = nodes[ind + 1];
ind++;
}
nodes[ind] = newNode;
}
}
// binary search for index of an element, uses RefEquals
public static int FindIndexSorted(this List <Pathfinding.NodeMetaInfo> nodes, Pathfinding.NodeMetaInfo node)
{
int left = 0, right = nodes.Count;
int index = -1;
while (right > left)
{
int center = (left + right) / 2;
if (nodes[center].totalCost == node.totalCost)
{
index = center;
break;
}
else if (nodes[center].totalCost < node.totalCost)
{
left = center + 1;
}
else
{
right = center;
}
}
if (index > -1)
{
// we found one of the occurances, now need to go through the range of em and check every one
// to the right
int i = index;
while (i < nodes.Count && nodes[i].totalCost == node.totalCost)
{
if (ReferenceEquals(nodes[i++], node))
{
return(i - 1);
}
}
// to the left
i = index - 1;
while (i >= 0 && nodes[i].totalCost == node.totalCost)
{
if (ReferenceEquals(nodes[i--], node))
{
return(i + 1);
}
}
}
return(index);
}
// assuming the array is sorted, insert a node retaining sorted order using binary search
public static void AddSorted(this List <Pathfinding.NodeMetaInfo> nodes, Pathfinding.NodeMetaInfo newNode)
{
int left = 0, right = nodes.Count;
while (right > left)
{
int center = (left + right) / 2;
if (nodes[center].totalCost <= newNode.totalCost)
{
left = center + 1;
}
else
{
right = center;
}
}
nodes.Insert(left, newNode);
}
// using binary search check for node, uses RefEquals
public static bool ContainsSorted(this List <Pathfinding.NodeMetaInfo> nodes, Pathfinding.NodeMetaInfo node)
{
return(nodes.FindIndexSorted(node) != -1);
}
