/// <summary>
/// This method places new states inside the FSM,
/// or prints an ERROR message if the state was already inside the List.
/// First state added is also the initial state.
/// </summary>
public void AddState(DCFSMState s)
{
// Check for Null reference before deleting
if (s == null)
{
Debug.LogError("FSM ERROR: Null reference is not allowed");
}
// First State inserted is also the Initial state,
// the state the machine is in when the simulation begins
if (states.Count == 0)
{
states.Add(s.ID, s);
currentState = s;
currentStateID = s.ID;
return;
}
// Add the state to the List if it's not inside it
if (states.ContainsKey(s.ID))
{
Debug.LogError("FSM ERROR: Impossible to add state " + s.ID.ToString() +
" because state has already been added");
return;
}
states.Add(s.ID, s);
}
public void BackToPreviousState()
{
if (mStateStack.Count > 1)
{
var top = mStateStack.Pop();
top.DoBeforeLeaving();
var previous = mStateStack.Pop();
currentStateID = previous.ID;
currentState = previous;
previous.DoBeforeEntering();
}
}
/// <summary>
/// This method tries to change the state the FSM is in based on
/// the current state and the transition passed. If current state
/// doesn't have a target state for the transition passed,
/// an ERROR message is printed.
/// </summary>
public void PerformTransition(int trans)
{
// Check for NullTransition before changing the current state
if (trans == DCFSMState.common_none_trans)
{
Debug.LogError("FSM ERROR: NullTransition is not allowed for a real transition");
return;
}
// Check if the currentState has the transition passed as argument
var id = currentState.GetOutputState(trans);
if (id == DCFSMState.common_none_state)
{
Debug.LogError("FSM ERROR: State " + currentStateID.ToString() + " does not have a target state " +
" for transition " + trans.ToString());
return;
}
// Update the currentStateID and currentState
currentStateID = id;
if (states.TryGetValue(id, out var state))
{
// Do the post processing of the state before setting the new one
currentState.DoBeforeLeaving();
currentState = state;
//如果栈里面已经有这个状态，删除这个状态
Toolkit.RemoveFromStack(mStateStack, currentState);
//加到状态栈
mStateStack.Push(currentState);
// Reset the state to its desired condition before it can reason or act
currentState.DoBeforeEntering();
}
}
