It’s that easy to reference a component from another object!? I have indeed discovered the fire, thank you!
And yeah, here’s my code presently. I set “starShip.enabled = true;” in the StartGame method, but that gives me the largest NullReferenceException I’ve ever seen:
GameManagerScript:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;
using UnityEngine.SceneManagement;
using UnityEngine.UI;
public class GameManagerScript : MonoBehaviour
{
public GameObject titleScreen;
public bool isGameActive;
public GameObject gameOverScreen;
public GameObject[] asteroidPrefab;
public GameObject powerupPrefab;
private float spawnRangeX = 24;
private float spawnPosY = 0;
private float spawnPosZ = 20;
private float startDelay = 2;
private float asteroidSpawnInterval = 1.5f;
private float powerupSpawnInterval = 15.0f;
private StarshipScript starShip;
// Start is called before the first frame update
void Start()
{
isGameActive = false;
starShip = GetComponent<StarshipScript>();
}
// Starts the game with difficulty from DifficultyButtonScript.cs, sets game to active, starts spawning objects, deactivates Title Screen objects
public void StartGame(int difficulty)
{
asteroidSpawnInterval = asteroidSpawnInterval / difficulty;
isGameActive = true;
StartCoroutine(SpawnAsteroid());
StartCoroutine(SpawnPowerup());
titleScreen.SetActive(false);
starShip.enabled = true;
}
// Sets game to inactive and activates game over screen
public void GameOver()
{
isGameActive = false;
gameOverScreen.gameObject.SetActive(true);
}
// Restart game by reloading the scene
public void RestartGame()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().name);
}
// Spawns asteroid prefabs
IEnumerator SpawnAsteroid()
{
while(isGameActive)
{
yield return new WaitForSeconds(asteroidSpawnInterval); // Waits seconds in between spawns
int asteroidIndex = Random.Range(0, asteroidPrefab.Length); // Randomly spawns a type of asteroid
Vector3 asteroidSpawnPos = new Vector3(Random.Range(-spawnRangeX, spawnRangeX), spawnPosY, spawnPosZ); // Random location for spawn
InvokeRepeating("SpawnAsteroid", startDelay, asteroidSpawnInterval); // Repeats spawn with delay
if(isGameActive) // <--Might be able to remove this and add the instantiate to the while-loop
{
Instantiate(asteroidPrefab[asteroidIndex], asteroidSpawnPos, asteroidPrefab[asteroidIndex].transform.rotation); // Spawns
}
}
}
// Spawns powerup prefab
IEnumerator SpawnPowerup()
{
while(isGameActive)
{
yield return new WaitForSeconds(powerupSpawnInterval); // Waits seconds in between spawns
Vector3 powerupSpawnPos = new Vector3(Random.Range(-spawnRangeX, spawnRangeX), spawnPosY, spawnPosZ); // Randomly spawns a type of asteroid
InvokeRepeating("SpawnPowerup", startDelay, powerupSpawnInterval); // Repeats spawn with delay
if(isGameActive) // <--Might be able to remove this and add the instantiate to the while-loop
{
Instantiate(powerupPrefab, powerupSpawnPos, powerupPrefab.gameObject.transform.rotation); // Spawns
}
}
}
}
StarshipScript:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class StarshipScript : MonoBehaviour
{
public float speed;
private float southBound = -900.0f;
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
// Moves the background via translate * time * speed variable
transform.Translate(Vector3.forward * Time.deltaTime * speed, Space.World);
// Destroys the background if it moves too far south
if (transform.position.z < southBound)
{
Destroy(gameObject);
}
}
}
DifficultyButtonScript:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class DifficultyButtonScript : MonoBehaviour
{
private Button button;
private GameManagerScript gameManagerScript;
public int difficulty;
// Start is called before the first frame update
void Start()
{
gameManagerScript = GameObject.Find("Game Manager").GetComponent<GameManagerScript>(); // Sets reference to GameManagerScript.cs
button = GetComponent<Button>(); // Sets reference to the button component
button.onClick.AddListener(SetDifficulty); // Listens for a click and then runs SetDifficulty method
}
// When a button is clicked, call the StartGame() method and pass it the difficulty value (1, 2, 3) from the button
public void SetDifficulty()
{
gameManagerScript.StartGame(difficulty); // Passes in difficulty variable from GameManager.cs when a button is pressed
}
}
NullReferenceException Error:
NullReferenceException: Object reference not set to an instance of an object
GameManagerScript.StartGame (System.Int32 difficulty) (at Assets/Scripts/GameManagerScript.cs:38)
DifficultyButtonScript.SetDifficulty () (at Assets/Scripts/DifficultyButtonScript.cs:23)
UnityEngine.Events.InvokableCall.Invoke () (at <40205bb2cb25478a9cb0f5e54cf11441>:0)
UnityEngine.Events.UnityEvent.Invoke () (at <40205bb2cb25478a9cb0f5e54cf11441>:0)
UnityEngine.UI.Button.Press () (at Library/PackageCache/com.unity.ugui@1.0.0/Runtime/UI/Core/Button.cs:70)
UnityEngine.UI.Button.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) (at Library/PackageCache/com.unity.ugui@1.0.0/Runtime/UI/Core/Button.cs:114)
UnityEngine.EventSystems.ExecuteEvents.Execute (UnityEngine.EventSystems.IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at Library/PackageCache/com.unity.ugui@1.0.0/Runtime/EventSystem/ExecuteEvents.cs:57)
UnityEngine.EventSystems.ExecuteEvents.Execute[T] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.ExecuteEvents+EventFunction`1[T1] functor) (at Library/PackageCache/com.unity.ugui@1.0.0/Runtime/EventSystem/ExecuteEvents.cs:272)
UnityEngine.EventSystems.EventSystem:Update() (at Library/PackageCache/com.unity.ugui@1.0.0/Runtime/EventSystem/EventSystem.cs:501)
in this case you get the all