1 files changed, 72 insertions, 0 deletions
diff --git a/src/entities/actors/snake/scripts/state_machine.gd b/src/entities/actors/snake/scripts/state_machine.gd
new file mode 100644
index 0000000..b63f272
--- /dev/null
+++ b/src/entities/actors/snake/scripts/state_machine.gd
@@ -0,0 +1,72 @@
+class_name StateMachine
+extends Node
+
+const DEBUG: bool = false
+
+var player: KinematicBody2D
+var state: Node
+var history: Array = []
+
+
+func _ready() -> void:
+	player = get_parent()
+	state = get_child(0)
+	_enter_state()
+
+
+func change_to(new_state: String) -> void:
+	history.append(state.name)
+	state = get_node(new_state)
+	_enter_state()
+
+
+func back() -> void:
+	if history.size() > 0:
+		state = get_node(history.pop_back())
+		_enter_state()
+
+
+func _enter_state() -> void:
+	if DEBUG:
+		print("Entering state %s" % state.name)
+	state.fsm = self
+	state.enter()
+
+
+# routing game loop functions
+func _process(delta: float) -> void:
+	if state.has_method("process"):
+		state.process(delta)
+
+
+func _physics_process(delta: float) -> void:
+	if Input.is_action_pressed("move_left"):
+		player.rotate_to(player.LEFT)
+	if Input.is_action_pressed("move_right"):
+		player.rotate_to(player.RIGHT)
+
+	# state specific code, move_and_slide is called here
+	if state.has_method("physics_process"):
+		state.physics_process(delta)
+
+	handle_slow_speeds()
+
+	player.handle_time_elapsed(delta)
+
+
+func slow_down_on_collisions(speed_backup: float):
+	if player.get_last_slide_collision():
+		Global.SNAKE_SPEED = player.velocity.length()
+	else:
+		Global.SNAKE_SPEED = speed_backup
+
+
+func handle_slow_speeds() -> void:
+	if Global.SNAKE_SPEED <= Global.SNAKE_SPEED_BACKUP / 4.0:
+		Global.SNAKE_SPEED = Global.SNAKE_SPEED_BACKUP
+		Event.emit_signal("game_over")
+
+
+func _input(event: InputEvent) -> void:
+	if state.has_method("input"):
+		state.input(event)