/// <summary>
/// Gets the possible action branches that arrive at the goals required state.
/// </summary>
/// <param name="goal"></param>
/// <returns></returns>
List <GoapNode> GetGoalTree(GoapGoal goal)
{
List <GoapNode> EndNodes = new List <GoapNode>();
GoapNode RootNode = new GoapNode(null, 0, goal.RequiredWorldState, null);
// check if the world state already matches this goal.
if (TestGoalStateAgainstWorldState(goal))
{
return(new List <GoapNode>());
}
List <GoapAction> ImmedeateActions = GetGoalActions(goal);
foreach (GoapAction action in ImmedeateActions)
{
// test each immediate action's pre-requisite states against the world states.
if (TestActionAgainstWorldState(action))
{
EndNodes.Add(new GoapNode(RootNode, RootNode.CumulativeCost + action.Cost, action.SatisfiesStates, action));
}
else
{
// recurse through this action's state requirements until it either matches the world state or has no prerequisites.
EndNodes.AddRange(GetActionTree(action, new GoapNode(RootNode, RootNode.CumulativeCost + action.Cost, action.SatisfiesStates, action)));
}
}
return(EndNodes);
}
public GoapNode(GoapNode parent, float cumulativeCost, List <GoapState> satisfiedStates, GoapAction action)
{
Parent = parent;
CumulativeCost = cumulativeCost;
SatisfiedStates = satisfiedStates;
Action = action;
}
// takes the node path that is passed in and turns it into a queue of actions.
Queue <GoapAction> ProccessNodeListIntoQueue(GoapNode StartNode)
{
Queue <GoapAction> ReturnQueue = new Queue <GoapAction>();
GoapNode tempNode = StartNode;
while (tempNode.Parent != null)
{
ReturnQueue.Enqueue(tempNode.Action);
tempNode = tempNode.Parent;
}
return(ReturnQueue);
}
List <GoapNode> GetActionTree(GoapAction action, GoapNode RootNode)
{
List <GoapNode> returnList = new List <GoapNode>();
List <GoapAction> ChildActions = PreCursorActions(action);
// if this action has pre-requisite requirements that are not fulfilled, then find the actions that satisfy the required worls states.
if (ChildActions.Count > 0)
{
foreach (GoapAction ChildAction in ChildActions)
{
returnList.AddRange(GetActionTree(ChildAction, new GoapNode(RootNode, RootNode.CumulativeCost + action.Cost, action.SatisfiesStates, action)));
}
}
else
{
// otherwise if the action has no pre-requisite states return this action.
if (action.RequiredStates.Count == 0)
{
returnList.Add(new GoapNode(RootNode, RootNode.CumulativeCost + action.Cost, action.SatisfiesStates, action));
}
}
return(returnList);
}