VRCycling/Assets/Scripts/TrafficSimulation/CarPool.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace TrafficSimulation{
    public class CarPool : MonoBehaviour
    {
        public TrafficSystem trafficSystem;
        public static CarPool SharedInstance;
        public List<GameObject> carModels;
        public List<GameObject> pooledCars;
        public int poolSize;

        void Awake() {
            SharedInstance = this;    
            pooledCars = new List<GameObject>();
            GameObject tmpInstance;
            for(int i = 0; i < poolSize; i++){
                tmpInstance = Instantiate(carModels[Random.Range (0, carModels.Count)]);
                VehicleAI vAI = tmpInstance.GetComponent<VehicleAI>();
                if(vAI == null){
                    Debug.Log("Carmodel has no AI. Destorying Instance!");
                    Destroy(tmpInstance);
                    continue;
                }
                vAI.trafficSystem = this.trafficSystem;

                CarSitter carSitter = tmpInstance.GetComponent<CarSitter>();
                if(carSitter != null){
                    carSitter.carPool = this;
                }
                tmpInstance.SetActive(false);
                pooledCars.Add(tmpInstance);
            }
        }

        public GameObject getCar(){
            foreach(GameObject car in pooledCars){
                if(!car.activeInHierarchy){
                    return car;
                }
            }
            Debug.Log("no car free to use. returning null!");
            return null;
        }
        public GameObject SpawnCar(Transform spawnTranform){
            return SpawnCar(spawnTranform.position, spawnTranform.rotation, null);
        }
        public GameObject SpawnCar(Vector3 spawnPos, Quaternion spawnRot, Transform lookAt)
        {
            GameObject car = this.getCar();
            if (car == null)
            {
                Debug.Log("No car was available. Spawn aborted");
                return null;
            }
            car.transform.position = spawnPos;
            car.transform.rotation = spawnRot;
            if(lookAt != null)
            {
                car.transform.LookAt(lookAt);
            }
            car.SetActive(true);
            return car;
        }
        public void despawnCar(GameObject car){
            car.SetActive(false);
        }
    }
}