public static List <Node> RetrieveNodesOfType(N_Root tree, Type nodeType)
{
Queue <Node> itQ = new Queue <Node>();
List <Node> found = new List <Node>();
itQ.Enqueue(tree.Child);
// Do a breadth-first search to retrieve all nodes of the given type.
while (itQ.Count > 0)
{
Node current = itQ.Dequeue();
// If the current node ís the same as the search type
// or a subclass of it, add it to found.
if (current.GetType().IsSubclassOf(nodeType) ||
current.GetType() == nodeType)
{
found.Add(current);
}
// If node is a composition or decorator, enqueue its child(ren).
if (current.GetType().IsSubclassOf(typeof(N_CompositionNode)))
{
N_CompositionNode comp = current as N_CompositionNode;
foreach (Node n in comp.GetChildren())
{
itQ.Enqueue(n);
}
}
else if (current.GetType().IsSubclassOf(typeof(N_Decorator)))
{
N_Decorator dec = current as N_Decorator;
itQ.Enqueue(dec.Child);
}
}
// Lastly, return the found children.
return(found);
}
// Return a list of all nodes that act as roots for a randomized subtree.
public static List <Node> RetrieveSubtreeNodes(N_Root tree)
{
Queue <Node> itQ = new Queue <Node>();
List <Node> found = new List <Node>();
itQ.Enqueue(tree.Child);
while (itQ.Count > 0)
{
Node current = itQ.Dequeue();
// If current node is flagged as subtree, add it to found
if (current.IsSubtree)
{
found.Add(current);
}
// If node is a composition or decorator, enqueue its child(ren).
if (current.GetType().IsSubclassOf(typeof(N_CompositionNode)))
{
N_CompositionNode comp = current as N_CompositionNode;
foreach (Node n in comp.GetChildren())
{
itQ.Enqueue(n);
}
}
else if (current.GetType().IsSubclassOf(typeof(N_Decorator)))
{
N_Decorator dec = current as N_Decorator;
itQ.Enqueue(dec.Child);
}
}
// Return all nodes found with the subtree flag
return(found);
}
// Assign random mutations to the given tree.
protected void Mutate(N_Root child)
{
// First, check if there'll be any mutation at all.
float random = UnityEngine.Random.Range(0.0f, 1.0f);
if (random < mutationRate)
{
List <Node> thresholds = TreeOperations.RetrieveNodesOfType(child, typeof(N_Threshold));
List <Node> probNodes = TreeOperations.RetrieveNodesOfType(child, typeof(N_ProbabilitySelector));
// Randomise between whether to change thresholds or probabilities
random = UnityEngine.Random.Range(0.0f, 1.0f);
// If no probnode exists, change condition if there are any instead
if ((random <= 0.25f && thresholds.Count > 0))
{
//Debug.Log("Changing threshold!");
// Get random index within range of list
int index = UnityEngine.Random.Range(0, thresholds.Count);
N_Threshold thresh = thresholds[index] as N_Threshold;
// Mutate threshold by random offset
int offset = UnityEngine.Random.Range(minThresholdOffset, maxTresholdOffset);
thresh.SetThreshold(thresh.Threshold + offset);
}
else if (random > 0.25f && random <= 0.5f && probNodes.Count > 0) // Adjust relative probabilities on a probability selector.
{
//Debug.Log("Changing prob!");
// Get random index within range of list
int index = UnityEngine.Random.Range(0, probNodes.Count);
N_ProbabilitySelector probSelect = probNodes[index] as N_ProbabilitySelector;
// Check so that the probablitySelector has any children.
if (probSelect.GetChildren().Count <= 0)
{
return;
}
// Calculate total probability and retrieve a relative offset based on it.
float totalProb = 0.0f;
foreach (Node n in probSelect.GetChildren())
{
totalProb += probSelect.GetProbabilityWeight(n);
}
float offset = totalProb * (relativeProbabilityMutation / 100.0f);
// Also, get a random sign to decide whether to substract or add offset
// and a random index for which child to be changed.
float randomSign = Mathf.Sign(UnityEngine.Random.Range(-1.0f, 1.0f));
int randomChildIndex = UnityEngine.Random.Range(0, probSelect.GetChildren().Count);
// Finally, offset the given childs probability by the random amount.
probSelect.OffsetProbabilityWeight(probSelect.GetChildren()[randomChildIndex]
, offset * randomSign);
}
else if (random > 0.5f && random <= 0.75f) // Change subtree
{
//Debug.Log("Changing subtree!");
List <Node> subtrees = TreeOperations.RetrieveSubtreeNodes(child);
int randomIndex = UnityEngine.Random.Range(0, subtrees.Count);
Node subtree = subtrees[randomIndex];
N_CompositionNode parentComp = subtree.Parent as N_CompositionNode;
// Get a random subtree index and replace its position in the tree with
// a new randomized subtree instead.
parentComp.ReplaceChild(subtree, RandomSubtree());
}
else if (random > 0.75f) // Change composition
{
//Debug.Log("Changing composition!");
List <Node> comps = TreeOperations.RetrieveNodesOfType(child, typeof(N_CompositionNode));
int randomIndex = UnityEngine.Random.Range(0, comps.Count);
N_CompositionNode replaceComp = comps[randomIndex] as N_CompositionNode;
// If parent is null, this comp is the initial comp.
if (replaceComp.Parent != null)
{
Node compParent = replaceComp.Parent;
List <Node> children = replaceComp.GetChildren();
// Attach old comps children to the new one.
N_CompositionNode newComp = RandomComp();
// Make sure to keep structure of subtrees
if (replaceComp.IsSubtree)
{
newComp.IsSubtree = true;
}
foreach (Node c in children)
{
c.Parent = newComp;
newComp.AddLast(c);
}
// Reattach parent to the new comp
if (compParent.GetType().IsSubclassOf(typeof(N_CompositionNode)))
{
N_CompositionNode compParent_comp = compParent as N_CompositionNode;
compParent_comp.ReplaceChild(replaceComp, newComp);
}
else if (compParent.GetType().IsSubclassOf(typeof(N_Decorator)))
{
N_Decorator compParent_dec = compParent as N_Decorator;
compParent_dec.Child = newComp;
}
}
}
}
}
