refactor to state machine

scripts/states/fall.gd

@@ -0,0 +1,22 @@
+extends State
+
+func process_physics(delta: float) -> State:
+	if not multiplayer.is_server():
+		return
+
+	var target_velocity = Vector3(0, subject.velocity.y, 0)
+	subject.velocity = subject.velocity.move_toward(target_velocity, subject.air_deceleration * delta)
+	subject.velocity += Main.gravity_velocity
+	subject.move_and_slide()
+
+	if subject.is_on_floor():
+		var input_direction = %Input.direction
+		if input_direction.length() < 0.05:
+			return %Idle
+
+		if %Input.walking:
+			return %Walk
+
+		return %Run
+
+	return