add uniqueness property to chunk and manage it on biome generator

core/biome_generator/biome_generator.gd

@@ -7,6 +7,8 @@ const CHUNK_TYPE_CURVED_TRACK: int = 2
 const CHUNK_GENERATION_STEPS_PER_FRAME: int = 2
 const CHUNK_CLEANUP_STEPS_PER_FRAME: int = 4
 const LAMPPOST_WIRE_STEPS_PER_FRAME: int = 1
+
+const MAX_CHUNK_UNIQUENESS: int = 5
 const RAILWAY_SCENE_DIRECTORY: String = "res://tgcc/chunk/railway/scene"
 const RIVER_SIDE_ORDER: Array[String] = ["north", "est", "south", "west"]
 const RIVER_DIRECTIONS: Dictionary = {
@@ -48,7 +50,6 @@ var pending_generation_cells: Array[Vector2i] = []
 var pending_cleanup_cells: Array[Vector2i] = []
 var pending_wire_cells: Array[Vector2i] = []
 var pending_wire_lookup: Dictionary = {}
-var pending_radar_update: bool = false
 var rail_chunk_catalogue: Dictionary = {}
 
 var manual_biome: Biome = null
@@ -125,16 +126,12 @@ func _destroy_and_regenrate_world() -> void:
 		var train_pos = rail_path.train_instance.global_position
 		var current_pos = Vector2i(roundi(train_pos.x / chunk_size), roundi(train_pos.z / chunk_size))
 		_refresh_world(current_pos)
-		pending_radar_update = true
 
 func _process(_delta: float) -> void:
 	_drain_cleanup_queue()
 	_drain_generation_queue()
 	_drain_wire_queue()
 
-	if pending_radar_update:
-		pending_radar_update = false
-
 func _physics_process(_delta: float) -> void:
 	if rail_path == null or rail_path.train_instance == null: return
 		
@@ -146,7 +143,6 @@ func _physics_process(_delta: float) -> void:
 	if current_pos != last_pos_train:
 		last_pos_train = current_pos
 		_refresh_world(current_pos)
-		pending_radar_update = true
 
 func collect_all_chunkinfo(root: Node, list: Array[Node]) -> void:
 	if root == null: return
@@ -239,6 +235,7 @@ func _get_chunk_scene_metadata(scene: PackedScene) -> Dictionary:
 		"info_path": info_path,
 		"rotations": rotations,
 		"has_lamppost": "have_lamppost" in info_node and info_node.have_lamppost,
+		"uniqueness": _get_chunk_uniqueness_from_info(info_node),
 	}
 	preview_chunk.queue_free()
 	chunk_candidate_cache[key] = metadata
@@ -273,7 +270,6 @@ func _clear_pending_world_work() -> void:
 	pending_cleanup_cells.clear()
 	pending_wire_cells.clear()
 	pending_wire_lookup.clear()
-	pending_radar_update = false
 
 func _collect_replaceable_rail_chunks(root: Node, result: Array[Node3D]) -> void:
 	if root == null:
@@ -470,6 +466,54 @@ func _get_procedural_biome_name(value: float) -> String:
 	var index = clamp(int(normalized_value * biome_list.size()), 0, biome_list.size() - 1)
 	return biome_list[index].name
 
+func _get_chunk_uniqueness_from_info(info_node: Node) -> int:
+	if info_node != null and "uniqueness" in info_node:
+		return clampi(info_node.uniqueness, 0, MAX_CHUNK_UNIQUENESS)
+	return 0
+
+func _has_nearby_unique_chunk(grid_pos: Vector2i, uniqueness: int) -> bool:
+	if uniqueness <= 0:
+		return false
+
+	for nearby_pos in board.keys():
+		var nearby_uniqueness = int(board[nearby_pos].get("uniqueness", 0))
+		if nearby_uniqueness <= 0:
+			continue
+
+		var min_distance = maxi(uniqueness, nearby_uniqueness)
+		var dist_x = abs(nearby_pos.x - grid_pos.x)
+		var dist_z = abs(nearby_pos.y - grid_pos.y)
+		if dist_x <= min_distance and dist_z <= min_distance:
+			return true
+	return false
+
+func _get_uniqueness_pick_weight(uniqueness: int) -> float:
+	return 1.0 / pow(float(uniqueness + 1), 2.0)
+
+func _pick_weighted_candidate(candidates: Array) -> Dictionary:
+	var total_weight = 0.0
+	for candidate in candidates:
+		total_weight += candidate.weight
+
+	if total_weight <= 0.0:
+		return candidates.pick_random()
+
+	var target_weight = randf() * total_weight
+	var current_weight = 0.0
+	for candidate in candidates:
+		current_weight += candidate.weight
+		if current_weight >= target_weight:
+			return candidate
+	return candidates.back()
+
+func _pick_backup_scene(zone_catalogue: Array[PackedScene], grid_pos: Vector2i) -> PackedScene:
+	for scene in zone_catalogue:
+		var metadata = _get_chunk_scene_metadata(scene)
+		var uniqueness = int(metadata.get("uniqueness", 0))
+		if not _has_nearby_unique_chunk(grid_pos, uniqueness):
+			return scene
+	return zone_catalogue[0]
+
 func _register_cell_with_ray(grid_pos: Vector2i) -> bool:
 	if board.has(grid_pos): return true 
 	
@@ -517,6 +561,7 @@ func _register_cell_with_ray(grid_pos: Vector2i) -> bool:
 		var river_exit_found = {"north": false, "est": false, "south": false, "west": false}
 		var height_found = {"north": 0, "est": 0, "south": 0, "west": 0}
 		var have_lamppost = false
+		var uniqueness = 0
 		
 		#Get node info
 		if right_info_node != null:
@@ -530,6 +575,8 @@ func _register_cell_with_ray(grid_pos: Vector2i) -> bool:
 			if "have_lamppost" in right_info_node:
 				have_lamppost = right_info_node.have_lamppost
 
+			uniqueness = _get_chunk_uniqueness_from_info(right_info_node)
+
 		#Add piece to the grid
 		board[grid_pos] = {
 			"type": "obstacle", 
@@ -538,7 +585,8 @@ func _register_cell_with_ray(grid_pos: Vector2i) -> bool:
 			"heights": height_found, 
 			"node": root_chunk,  
 			"info": right_info_node,     
-			"have_lamppost": have_lamppost
+			"have_lamppost": have_lamppost,
+			"uniqueness": uniqueness
 		}
 		
 		if have_lamppost:
@@ -579,6 +627,9 @@ func _add_compatible_biome(grid_pos: Vector2i) -> void:
 			var u_conn = data["connections"]
 			var u_river_conn = data["river_connections"]
 			var u_height = data["heights"]
+			var uniqueness = int(metadata.get("uniqueness", 0))
+			if _has_nearby_unique_chunk(grid_pos, uniqueness):
+				continue
 			
 			var match_conn_n = (req_conn_north == -1) or ((req_conn_north == 1) == u_conn["north"])
 			var match_conn_e = (req_conn_est == -1)  or ((req_conn_est == 1) == u_conn["est"])
@@ -607,7 +658,14 @@ func _add_compatible_biome(grid_pos: Vector2i) -> void:
 				if req_height_south == -1 and u_height["south"] == height_target: score += 1
 				if req_height_west == -1 and u_height["west"] == height_target: score += 1
 				
-				valid_candidates.append({"scene": scene, "rotation": rot, "data": data, "score": score})
+				valid_candidates.append({
+					"scene": scene,
+					"rotation": rot,
+					"data": data,
+					"score": score,
+					"weight": _get_uniqueness_pick_weight(uniqueness),
+					"uniqueness": uniqueness
+				})
 		
 	if valid_candidates.size() > 0:
 		var max_score = -1
@@ -618,7 +676,7 @@ func _add_compatible_biome(grid_pos: Vector2i) -> void:
 		for c in valid_candidates:
 			if c.score == max_score: best_candidate.append(c)
 				
-		var choise = best_candidate.pick_random()
+		var choise = _pick_weighted_candidate(best_candidate)
 		var new_chunk = choise.scene.instantiate()
 		new_chunk.position = Vector3(grid_pos.x * chunk_size, 0, grid_pos.y * chunk_size)
 		new_chunk.rotation.y = choise.rotation * (-PI / 2.0)
@@ -641,18 +699,21 @@ func _add_compatible_biome(grid_pos: Vector2i) -> void:
 			"heights": choise.data["heights"], 
 			"node": new_chunk, 
 			"info": info_new,
-			"have_lamppost": have_lamppost
+			"have_lamppost": have_lamppost,
+			"uniqueness": choise.uniqueness
 		}
 		
 		if have_lamppost:
 			_queue_lamppost_wire_connection(grid_pos)
 
 	else:	
-		var backup = zone_catalogue[0].instantiate()
+		var backup_scene = _pick_backup_scene(zone_catalogue, grid_pos)
+		var backup = backup_scene.instantiate()
 		backup.position = Vector3(grid_pos.x * chunk_size, 0, grid_pos.y * chunk_size)
 		add_child(backup)
 		
-		var info_backup = _get_cached_chunk_info(backup, zone_catalogue[0])
+		var info_backup = _get_cached_chunk_info(backup, backup_scene)
+		var backup_uniqueness = _get_chunk_uniqueness_from_info(info_backup)
 	
 		var safe_heights = {
 			"north": req_height_north if req_height_north != -1 else height_target,
@@ -668,7 +729,8 @@ func _add_compatible_biome(grid_pos: Vector2i) -> void:
 			"heights": safe_heights, 
 			"node": backup,
 			"info": info_backup,
-			"have_lamppost": false
+			"have_lamppost": false,
+			"uniqueness": backup_uniqueness
 		}
 
 func _calculate_river_flow_direction(grid_pos: Vector2i, river_connections: Dictionary) -> Vector2:

core/biome_generator/chunk_info.gd

@@ -5,6 +5,7 @@ class_name ChunkInfo
 
 @export_group("Set Piece Rules (Unique pieces)")
 @export var exclusive_biome: String = "" # Es: "Forest"
+@export_range(0, 5, 1) var uniqueness: int = 0 #0=common; 5=unique
 
 @export_group("Base exit")
 @export var north: bool = false