Implemented removal of cars if the node they're on gets removed

src/infrastructure_helpers.odin

@@ -76,6 +76,15 @@ delete_entity :: proc(self: ^Simulator, entity_index: u32, type: common.Entity)
 	
 	switch type {
 	case .Node:
+		// get cars that are on that node
+		
+		for i in 0..<len(self.cars) {
+			pos := self.cars[i].pos
+			if pos.type != .Node || pos.ref != entity_index do continue
+			
+			delete_entity(self, u32(i), .Car)
+		}
+		
 		unordered_remove(&self.nodes, entity_index)
 		if !swap_made do return {}, false
 		
@@ -103,15 +112,13 @@ get_free_node :: proc(self: ^Simulator) -> Maybe(u32) {
 	car_occupied_nodes: [dynamic]u32
 	
 	for car in self.cars {
-		node, ok := car.node_pos.?
-		if !ok do continue
+		if car.pos.type != .Node do continue
 		
-		if common.list_contains(car_occupied_nodes[:], node) do continue
-		append(&car_occupied_nodes, node)
+		if common.list_contains(car_occupied_nodes[:], car.pos.ref) do continue
+		append(&car_occupied_nodes, car.pos.ref)
 	}
 	
 	if len(car_occupied_nodes) == len(self.nodes) do return nil
-	
 	for {
 		node := rand.uint32_max(u32(len(self.nodes)))