add train control game

scripts/train_movement.gd

@@ -0,0 +1,31 @@
+extends MeshInstance3D
+
+signal speed_changed(new_speed: float)
+
+@export_group("Train")
+@export var base_speed: float = 15.0
+@export var max_speed: float = 50.0
+@export var min_speed: float = 3.0
+@export var acceleration: float = 12.0
+
+var current_speed: float = 15.0
+
+func _ready() -> void:
+	current_speed = base_speed
+
+
+func _process(delta: float) -> void:
+	_handle_input(delta)
+
+
+func _handle_input(delta: float) -> void:
+	if Input.is_action_pressed("speed_up"):
+		current_speed = min(current_speed + acceleration * delta, max_speed)
+		speed_changed.emit(current_speed)
+	elif Input.is_action_pressed("speed_down"):
+		current_speed = max(current_speed - acceleration * delta, min_speed)
+		speed_changed.emit(current_speed)
+
+
+func get_speed() -> float:
+	return current_speed