70 lines
2.1 KiB
GDScript
70 lines
2.1 KiB
GDScript
@icon("res://resources/icons/fsm.png")
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extends Node
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class_name FiniteStateMachine
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var states : Dictionary = {}
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var current_state : State
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@export var initial_state : State
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#NOTE This is a generic finite_state_machine, it handles all states, changes to this code will affect
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# everything that uses a state machine!
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func _ready():
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for child in get_children():
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if child is State:
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states[child.name.to_lower()] = child
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child.state_transition.connect(change_state)
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if initial_state:
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initial_state.enter()
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current_state = initial_state
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# Call the current states update function
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func _process(delta):
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if current_state:
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current_state.update(delta)
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func _physics_process(delta):
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if current_state:
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current_state.physics_update(delta)
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# Use force_change_state cautiously, it immediately switches to a state regardless of any transitions.
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# This is used to force us into a 'death state' when killed
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func force_change_state(new_state : String):
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var newState = states.get(new_state.to_lower())
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if !newState:
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print(new_state + " does not exist in the dictionary of states")
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return
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if current_state == newState:
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print("State is same, aborting")
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return
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# NOTE Calling exit like so: (current_state.Exit()) may cause warnings when flushing queries, like when the enemy is being removed after death.
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# call_deferred is safe and prevents this from occuring. We get the Exit function from the state as a callable and then call it in a thread-safe manner
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if current_state:
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var exit_callable = Callable(current_state, "exit")
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exit_callable.call_deferred()
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newState.enter()
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current_state = newState
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func change_state(source_state : State, new_state_name : String):
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if source_state != current_state:
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#print("Invalid change_state trying from: " + source_state.name + " but currently in: " + current_state.name)
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#This typically only happens when trying to switch from death state following a force_change
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return
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var new_state = states.get(new_state_name.to_lower())
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if !new_state:
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print("New state is empty")
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return
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if current_state:
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current_state.exit()
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new_state.enter()
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current_state = new_state
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