gd,refacto: added state chart addon and namespace cleanup

godot_state_charts_examples/platformer/checkpoint/checkpoint.gd

@@ -0,0 +1,36 @@
+extends Node2D
+
+## emitted when this checkpoint is clicked with the mouse
+signal clicked(checkpoint:Node2D)
+
+## emitted when this checkpoint is activated
+signal activated(checkpoint:Node2D)
+
+## emitted when this checkpoint is deactivated
+signal deactivated(checkpoint:Node2D)
+
+@onready var _state_chart:StateChart = get_node("StateChart")
+
+
+func _on_area_2d_input_event(_viewport:Node, event:InputEvent, _shape_idx:int):
+	# if event was left mouse button up, emit clicked signal
+	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_LEFT and event.is_pressed() == false:
+		# print("Checkpoint clicked")
+		clicked.emit(self)
+
+
+func _on_area_2d_body_entered(body:Node2D):
+	if body.is_in_group("player"):
+		_state_chart.send_event("player_entered")
+
+
+func _on_area_2d_body_exited(body:Node2D):
+	if body.is_in_group("player"):
+		_state_chart.send_event("player_exited")
+		
+		
+func emit_activated():
+	activated.emit(self)
+	
+func emit_deactivated():
+	deactivated.emit(self)