How am I causing a StackOverflow

Questions & Answers
1

When I change the direction of the laser it causes a StackOverflow. It only does it in certain directions as well, I know stack overflows are caused when code is being called to many times but can’t see the reason why it does it in my code and in certain directions.

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

public class LaserBeam
{
	Vector3 pos, dir;
	public GameObject laserObj;
	LineRenderer laser;
	List<Vector3> laserIndices = new List<Vector3>();

	public LaserBeam ( Vector3 pos , Vector3 dir , Material material )
	{
		this.laser = new LineRenderer();
		this.laserObj = new GameObject();
		this.laserObj.name = "Laser Beam";
		this.pos = pos;
		this.dir = dir;
		this.laser = this.laserObj.AddComponent(typeof(LineRenderer)) as LineRenderer;
		this.laser.startWidth = 0.1f;
		this.laser.endWidth = 0.1f;
		this.laser.material = material;
		this.laser.startColor = Color.green;
		this.laser.endColor = Color.green;
		CastRay(pos, dir, laser);
	}

	void CastRay ( Vector3 pos , Vector3 dir , LineRenderer laserbeam )
	{
		laserIndices.Add(pos);
		//UpdateLaser();
		Ray ray = new Ray(pos, dir);
		RaycastHit hit;
		if(Physics.Raycast( ray, out hit, 30))
		{
			CheckHit(hit,dir,laser);
		}
		else
		{
			laserIndices.Add(ray.GetPoint(30));
			UpdateLaser();
		}
	}

	void UpdateLaser ()
	{
		int count = 0;
		laser.positionCount = laserIndices.Count;
		foreach( Vector3 idx in laserIndices )
		{
			//Debug.Log("1");
			laser.SetPosition(count, idx);
			count++;
		}
	}

	void CheckHit ( RaycastHit hitInfo , Vector3 direction , LineRenderer line )
	{
		if (hitInfo.collider.gameObject.tag == "Mirror")
		{
			Vector3 pos = hitInfo.point;
			Vector3 dir = hitInfo.transform.forward;
			CastRay(pos, dir, line);
		}
		else if (hitInfo.collider.gameObject.tag == "Endpos")
		{
			Debug.Log("You win");
			laserIndices.Add(hitInfo.point);
			UpdateLaser();
		}
		else if (hitInfo.collider.gameObject == laser)
		{
			laserIndices.Add(hitInfo.point);
			UpdateLaser();
		}
		/*else
		{
			laserIndices.Add(hitInfo.point);
			//UpdateLaser();
		}*/
	}
}
2

LineRenderer is not causing a StackOverflow but your code does, mate. When you see a stack overflow next time think “infinite loop in my code”, because that is exactly what is causing it.

  1. LaserBeam’s constructor calls CastRay

  2. CastRay calls CheckHit when ray hit something

  3. CheckHit calls CastRay back when hitInfo.collider.gameObject.tag == "Mirror"

  4. You hit a loop without a break at this point already

    CastRay() → CheckHit() → CastRay() → CheckHit() → … (loop)

Every single call increments the cpu stack index and when it hits it’s limit - an exception is thrown, it’s that simple.

To fix this rewrite your code to make sure there is 0% chance of this happening ever again. How? Start with merging those methods into a single one. I know a lot of internet programing gurus say that every tiny piece of code should be it’s own method (file even!) but that is just crazy bs and here is a prime example of that.