ft (Wip): FSM behaviour prey

evolve-die-repeat/shared/npc/prey2D.gd

@@ -1,6 +1,10 @@
 extends NPC2D
 class_name AbstractPrey2D
 
+enum States {IDLE, FORAGING, FLEEING}
+var state = States.IDLE
+
+
 # Called when the node enters the scene tree for the first time.
 func _ready() -> void:
 	pass # Replace with function body.

evolve-die-repeat/shared/npc/spawn_manager_2d.gd

@@ -1,11 +1,10 @@
 extends Node
 class_name SpawnManager2D
 
-#var scene = preload("res://molecular/nucleotide_prey.tscn")
 @export var scene: PackedScene
 @export var minCount = 1
 @export var maxCount = 2
-@export var spawnRange: Rect2
+@export var spawnRange: Rect2 = Rect2(0, 0, 0, 0)
 var _currentCount = 0
 
 

evolve-die-repeat/shared/state.gd

@@ -0,0 +1,24 @@
+class_name State extends Node
+
+# Emits on state completion
+signal finished(next_state_path: String, data: Dictionary)
+
+# Called by StateMachine on unhandled input
+func handle_input(_event: InputEvent) -> void:
+	pass
+
+# Main update loop
+func update(_delta: float) -> void:
+	pass
+
+# Physics update loop
+func physics_update(_delta: float) -> void:
+	pass
+
+# Called by StateMachine on state change. Data contains arbitrary data to initialize state.
+func enter(previous_state_path: String, data := {}) -> void:
+	pass
+
+# Called by StateMachine before state change. Should be used for cleanup.
+func exit() -> void:
+	pass

evolve-die-repeat/shared/state.gd.uid

@@ -0,0 +1 @@
+uid://co2xp7gauamql

evolve-die-repeat/shared/state_machine.gd

@@ -0,0 +1,39 @@
+class_name StateMachine extends Node
+
+@export var initial_state: State = null
+
+# use first child as 'active' state
+@onready var state: State = (func get_initial_state() -> State:
+	return initial_state if initial_state != null else get_child(0)
+).call()
+
+# Connect states on ready, then wait.
+func _ready() -> void:
+	for node: State in find_children("*", "State"):
+		node.finished.connect(_transition_to_next_state)
+
+	await owner.ready
+	state.enter("")
+
+#  pass unhandled input to state.
+func _unhandled_input(event: InputEvent) -> void:
+	state.handle_input(event)
+
+# Pass process tick to state.
+func _process(delta: float) -> void:
+	state.update(delta)
+
+# Pass physics tick to state.
+func _physics_process(delta: float) -> void:
+	state.physics_update(delta)
+
+# Transition to next state
+func _transition_to_next_state(target_path: String, data: Dictionary = {}) -> void:
+	if not has_node(target_path):
+		printerr(owner.name + ": Trying to transition to state " + target_path + ", which does not exist.")
+		return
+
+	var previous_state_path := state.name
+	state.exit()
+	state = get_node(target_path)
+	state.enter(previous_state_path, data)

evolve-die-repeat/shared/state_machine.gd.uid

@@ -0,0 +1 @@
+uid://ck7k8ht54snsy