add weights and cost to enemy spawner

levels/enemy_entry.gd

@@ -0,0 +1,5 @@
+class_name EnemyEntry
+extends Resource
+
+@export var scene: PackedScene
+@export var cost: float

levels/enemy_entry.gd.uid

@@ -0,0 +1 @@
+uid://cx7xhojlh0s0f

levels/enemy_spawner.gd

@@ -6,7 +6,12 @@ var points: Array[Vector3]
 const MAX_CACHED_POINTS := 100
 var doomed_point_idx := 0
 
-@export var enemy_scenes: Array[PackedScene]
+@export var enemy_scenes: Array[EnemyEntry]
+var weights: Array[float]
+var total_cost := 0.
+var money := 5.
+
+var rng := RandomNumberGenerator.new()
 
 func _get_point() -> Vector3:
 	assert(not boxes.is_empty())
@@ -26,6 +31,11 @@ func _ready() -> void:
 		if child is CSGBox3D:
 			boxes.push_back(child)
 	
+	for entry in enemy_scenes:
+		total_cost += entry.cost
+	
+	for entry in enemy_scenes:
+		weights.push_back(total_cost - entry.cost + 1.)
 func _process(_delta: float) -> void:
 	var v := _get_point()
 	v.y = 50.
@@ -49,15 +59,26 @@ func _process(_delta: float) -> void:
 
 func _on_timer_timeout() -> void:
 	if not Level.is_active(): return
+
+	money += 2.
+	if randf() > .1: return
+
 	if points.is_empty(): 
 		push_warning("tried to spawn enemy, but can't find a point!")
 		return
 
+	while money > 3.:
+		var entry: EnemyEntry = enemy_scenes.pick_random()
+		if entry.cost > money:
+			return
+		var scene := entry.scene
+
 		var pos: Vector3 = points.pick_random()
 		pos += Vector3.UP * 0.02
-	var scene: PackedScene = enemy_scenes.pick_random()
 		var car: Node3D = scene.instantiate()
 		car.position = pos
 		get_tree().current_scene.add_child(car)
 
+		money -= entry.cost
+