add wagons

core/biome_generator/rails.gd

@@ -1,31 +1,60 @@
 extends Path3D
 
 @export_group("Train")
-@export var train_speed: float = 6.0
-@export var is_inmotion: bool = true
-@export var train_model: PackedScene 
+##train speed
+@export var train_speed: float = 6.0	
+##if true the train is in motion
+@export var is_inmotion: bool = true	
+##the model for the locomotive
+@export var train_model: PackedScene 	
+##array of wagon scenes
+@export var wagon_pool: Resource		
+##if true the number of wagons is random from 1 to wagon_count
+@export var wagon_random_number: bool = true	
+##if wagon_random_number = true is used as max wagons
+@export_range(0, 32, 1, "or_greater") var wagon_count: int = 3 
+##the distance between two wagons
+@export var wagon_gap: float = 0.4 
+##the scale to calculate the distance of the bounds
+@export_range(0.1, 2.0, 0.05, "or_greater") var wagon_spacing_scale: float = 0.5 
+##override spacing using this value
+@export var wagon_spacing_override: float = 0.0
+##distance of the rail axes	
 @export var axes_distance: float = 3.0 
-@export var rail_distance: float = 1.2 
+##discance between rails
+@export var rail_distance: float = 1.2
+##current camera 
 @export var cameras: Node3D 
+##swing of the train during the ran
 @export_range(0.0, 1.0) var basic_swing: float = 0.1 
 
 @export_group("Rails Bulding")
+##distance between sleepers of the rails
 @export var sleepers_distance: float = 1.0
+##nodel for the sleeper of the rail
 @export var sleepers_model: PackedScene 
 
 @export_group("Manual Controls")
+##max speed
 @export var speed_max: float = 15.0
-@export var speed_min: float = -5.0 
+##min speed
+@export var speed_min: float = -5.0
+##acceleration 
 @export var manual_acceleration: float = 5.0 
 
 @export_group("Train Stops")
+##if true the train stop the ran on stops
 @export var enable_stops: bool = true
+##time of stop
 @export var stop_time: float = 4.0 
-@export var brake_distance: float = 15.0 
+##distance when the train start to brake
+@export var brake_distance: float = 15.0
+##restart time 
 @export var restart_time: float = 3.0 
+##scene for fireworks
 @export var fireworks_scene: PackedScene 
-
-var fireworks_colors: Array[Color] = [
+##array of colors for fireworks
+@export var fireworks_colors: Array[Color] = [
 	Color(1.0, 0.2, 0.2), # Rosso vivo
 	Color(0.2, 1.0, 0.2), # Verde lime
 	Color(0.3, 0.5, 1.0), # Blu cielo
@@ -48,9 +77,14 @@ var stop_multiply: float = 1.0
 var is_restarting: bool = false
 var tween_restart: Tween
 var environment_config: EnvironmentConfig
+var wagon_instances: Array[Node3D] = []
+var wagon_progress_offsets: Array[float] = []
 
 func _ready() -> void:
+	randomize()
+	
 	_cache_environment_config()
+	
 	if curve != null and curve.get_baked_length() > 0:
 		build_rails()
 		build_train()
@@ -153,6 +187,8 @@ func _snap_train_to_progress() -> void:
 		cameras.global_position = center_position
 		cameras.global_basis = train_instance.global_basis
 
+	_snap_wagons_to_progress(total_length)
+
 func build_rails() -> void:
 	var mat_wood = StandardMaterial3D.new()
 	mat_wood.albedo_color = Color(0.35, 0.2, 0.1) 
@@ -323,6 +359,8 @@ func train_move(delta: float) -> void:
 		if cameras:
 			cameras.global_position = center_position
 			cameras.global_basis = train_instance.global_basis
+
+		_snap_wagons_to_progress(total_length)
 				
 		var real_speed = abs(train_speed * stop_multiply)
 		var speed_factor = clamp(real_speed / max(speed_max, 0.001), 0.0, 1.0)
@@ -401,6 +439,34 @@ func build_train() -> void:
 	else:
 		build_default_train()
 
+	var wagons = wagon_count
+	if wagon_random_number:
+		wagons = randi_range(1, wagon_count)
+	build_train_wagons(wagons)
+
+func build_train_wagons(wagon_number: int) -> void:
+	_clear_train_wagons()
+	if wagon_number <= 0 or wagon_pool == null or not "available_wagons" in wagon_pool:
+		return
+	if wagon_pool.available_wagons.is_empty():
+		return
+
+	for i in range(wagon_number):
+		var wagon_scene: PackedScene = wagon_pool.available_wagons.pick_random()
+		if wagon_scene == null:
+			continue
+
+		var wagon: Node3D = wagon_scene.instantiate() as Node3D
+		if wagon == null:
+			push_warning("Wagon scene root must be a Node3D.")
+			continue
+
+		add_child(wagon)
+		wagon_instances.append(wagon)
+
+	_update_wagon_progress_offsets()
+	_snap_wagons_to_progress()
+
 func build_default_train() -> void:
 	train_instance = Node3D.new()
 	add_child(train_instance)
@@ -435,3 +501,118 @@ func build_default_train() -> void:
 	stack.material_override = mat_body
 	stack.position = Vector3(0, 1.2, 1.0)
 	train_instance.add_child(stack)
+
+func _clear_train_wagons() -> void:
+	for wagon in wagon_instances:
+		if is_instance_valid(wagon):
+			wagon.queue_free()
+	wagon_instances.clear()
+	wagon_progress_offsets.clear()
+
+func _update_wagon_progress_offsets() -> void:
+	wagon_progress_offsets.clear()
+	if train_instance == null or wagon_instances.is_empty():
+		return
+
+	var train_length: float = _get_vehicle_length(train_instance)
+	var previous_length: float = train_length
+	var accumulated_distance: float = 0.0
+
+	for wagon in wagon_instances:
+		var wagon_length: float = _get_vehicle_length(wagon)
+		accumulated_distance += _get_wagon_spacing(previous_length, wagon_length)
+		wagon_progress_offsets.append(accumulated_distance)
+		previous_length = wagon_length
+
+func _get_wagon_spacing(previous_length: float, wagon_length: float) -> float:
+	if wagon_spacing_override > 0.0:
+		return wagon_spacing_override + wagon_gap
+
+	var detected_spacing: float = previous_length * 0.5 + wagon_length * 0.5
+	return detected_spacing * wagon_spacing_scale + wagon_gap
+
+func _snap_wagons_to_progress(total_length: float = 0.0) -> void:
+	if curve == null or wagon_instances.is_empty():
+		return
+
+	if total_length <= 0.0:
+		total_length = curve.get_baked_length()
+	if total_length <= 0.0:
+		return
+
+	var direction: float = 1.0
+	if train_speed < 0.0:
+		direction = -1.0
+
+	for i in range(wagon_instances.size()):
+		var wagon: Node3D = wagon_instances[i]
+		if not is_instance_valid(wagon):
+			continue
+
+		var wagon_offset: float = float(i + 1) * 7.0
+		if i < wagon_progress_offsets.size():
+			wagon_offset = wagon_progress_offsets[i]
+
+		var wagon_progress: float = train_progress - direction * wagon_offset
+		_snap_vehicle_to_progress(wagon, wagon_progress, total_length)
+
+func _snap_vehicle_to_progress(vehicle: Node3D, progress: float, total_length: float) -> void:
+	var vehicle_progress: float = wrapf(progress, 0.0, total_length)
+	var center_position: Vector3 = to_global(curve.sample_baked(vehicle_progress, true))
+	var prog_forward: float = wrapf(vehicle_progress + 2.0, 0.0, total_length)
+	var forward_position: Vector3 = to_global(curve.sample_baked(prog_forward, true))
+
+	vehicle.global_position = center_position
+	if center_position.distance_to(forward_position) > 0.01:
+		vehicle.look_at(forward_position, Vector3.UP)
+		vehicle.rotate_y(PI)
+
+func _get_vehicle_length(vehicle: Node3D) -> float:
+	var bounds: AABB = _get_node_local_bounds(vehicle, vehicle)
+	if bounds.size == Vector3.ZERO:
+		return 7.0
+
+	return maxf(bounds.size.z, 0.1)
+
+func _get_node_local_bounds(root: Node3D, node: Node) -> AABB:
+	var result: AABB = AABB()
+	var has_bounds: bool = false
+
+	var mesh_instance := node as MeshInstance3D
+	if mesh_instance != null and mesh_instance.mesh != null:
+		var mesh_bounds: AABB = mesh_instance.get_aabb()
+		var mesh_transform: Transform3D = root.global_transform.affine_inverse() * mesh_instance.global_transform
+		for corner in _get_aabb_corners(mesh_bounds):
+			var local_point: Vector3 = mesh_transform * corner
+			if has_bounds:
+				result = result.expand(local_point)
+			else:
+				result = AABB(local_point, Vector3.ZERO)
+				has_bounds = true
+
+	for child in node.get_children():
+		var child_bounds: AABB = _get_node_local_bounds(root, child)
+		if child_bounds.size == Vector3.ZERO:
+			continue
+
+		if has_bounds:
+			result = result.merge(child_bounds)
+		else:
+			result = child_bounds
+			has_bounds = true
+
+	return result
+
+func _get_aabb_corners(bounds: AABB) -> Array[Vector3]:
+	var start: Vector3 = bounds.position
+	var end: Vector3 = bounds.end
+	return [
+		Vector3(start.x, start.y, start.z),
+		Vector3(end.x, start.y, start.z),
+		Vector3(start.x, end.y, start.z),
+		Vector3(end.x, end.y, start.z),
+		Vector3(start.x, start.y, end.z),
+		Vector3(end.x, start.y, end.z),
+		Vector3(start.x, end.y, end.z),
+		Vector3(end.x, end.y, end.z),
+	]

core/biome_generator/wagon_pool.gd

@@ -0,0 +1,6 @@
+## Resource that lists the wagon scenes available for train composition.
+class_name WagonPool
+extends Resource
+
+@export var name: String = "New Wagon Pool"
+@export var available_wagons: Array[PackedScene] = []

core/biome_generator/wagon_pool.tres

@@ -0,0 +1,9 @@
+[gd_resource type="Resource" script_class="WagonPool" format=3 uid="uid://bjnytgwt8tmf4"]
+
+[ext_resource type="PackedScene" uid="uid://dvk3bytqn3m5s" path="res://tgcc/train/main_train.tscn" id="1_t6q5r"]
+[ext_resource type="Script" uid="uid://b6xk0gtn2pwa" path="res://core/biome_generator/wagon_pool.gd" id="2_x6bmc"]
+
+[resource]
+script = ExtResource("2_x6bmc")
+name = "Wagon Pool"
+available_wagons = Array[PackedScene]([ExtResource("1_t6q5r")])