Discussion A Bug free game seems impossible and it annoys me

I have this ability in my game (its a shield that blocks the first incoming damage)
95% of time the shield works as planned and negates the first damage taken.
but like 5% of time the shield does not pop
Its like so hard to debug when the bug itsself doesnt happen often.
how to go about this problem?

I was thinking of maby removing the shield ability completly or should i just be happy it works 95% of time?

 

How are you doing the shield? Is the shield called when pressing a button and does it have a duration? (or is the duration while button pressed?).

If you share that portion of the code, maybe some advice can be offered.

When something is acting flaky, my go to solution is an IEnumerator for the function

 

Yup, post the code. Maybe the issue is obvious.

 

Code (CSharp):

1. public class Shield : Ability, IAbility
2. {
3.     public override void AbilityEffect(Unit unit)
4.     {
5.        
6.         if(unit.bulletsToCalculate.Count > 0) //if has been hit by any bullets
7.         {
8.             Bullet hitBullet = unit.bulletsToCalculate[0];
9.             unit.bulletsToCalculate.Remove(hitBullet);
10.             Destroy(hitBullet.gameObject);  
11.             unit.abilities.Remove(this); //remove ability from unit
12.             Destroy(this.gameObject);
13.         }
14.     }
15. }

Thats the code for the shield. Should basically remove the first bullet hit. And the destroy itsself.

This function gets called every frame in update to cicle through all the abiities the unit has in the Unit class:

Code (CSharp):

1. private void UpdateAbilities()
2.     {
3.         abilities.OrderBy(x => x.priority).ToList();
4.         foreach(Ability ability in abilities.ToList())
5.         {
6.             ability.AbilityEffect(this);
7.         }
8.     }

 

Have tested it now for like 20 times + and the bug has not occured sofar anymore


Edit: the small chance bug that a bullet is not removed has occured again.

Code (CSharp):

1. public class Shield : Ability, IAbility
2. {
3.     public override void AbilityEffect(Unit unit)
4.     {
5.        
6.         if(unit.bulletsToCalculate.Count > 0) //if has been hit by any bullets
7.         {
8.             Debug.Log("Removing bullet");
9.             Bullet hitBullet = unit.bulletsToCalculate[0];
10.             unit.bulletsToCalculate.Remove(hitBullet);
11.             Destroy(hitBullet.gameObject);  
12.             unit.abilities.Remove(this); //remove ability from unit
13.             Destroy(this.gameObject);
14.         }
15.     }
16. }

note: the debug log ("Removing bullet") is not being shown in the case that the bullet does not destroy the shield -> meaning the bulletsToCalculate list is empty and the bullet did not get added to it

 

Remember that Destroy() does not happen until end of frame.

 

Going on what Kurt mentioned (destroy doesn't happen until the end of the frame, regardless of order), why don't you try hitBullet = null when you want it disabled, then destroy it at the end.

I suggest this, because there was a transform I needed to destory in a function (a ground detection transform), but because it wasn't being destroyed until the end of the frame, it was causing some funky reactions (during a "death" sequence). So = null on it when I needed it technically disabled, then destroyed it.

 

EDIT: Just noticed that you're not assigning the OrderBy result to a new variable

Code (CSharp):

1. // This line just wastes CPU and RAM for nothing
2. // OrderBy returns a new collection, it does not change the original collection
3. // Do not confuse .Sort() (which is a List method) with .OrderBy() (which is a LINQ extension)
4. one.abilities.OrderBy(x => x.priority).ToList();
5.  
6. // The correct way to do it:
7. var sortedAbilities = abilities.OrderBy(x => x.priority);
8.  
9. foreach (var ability in sortedAbilities)
10. {
11.     ability.AbilityEffect(this);
12. }

Also this looks super unoptimized, especially if it's running each frame... A solution is that you should only order the abilities once when they're added/removed, which would happen a lot less often than each update. Or you could just use a SortedList, which will take care of sorting for you. Also in the foreach loop you don't need to create another copy of the list (.ToList()) if you're only using the IEnumerable result from OrderBy only once. (which is the case here)

 

yep ur right, i already changed the ability ordering stuff when the unit is instatiated to only run once
but in the end i gave up on the shield ability and removed it completly

 

Are you sure that aren't two bullets with the exact same position and velocity? In that case it would just look like one bullet. Only one of the two bullets would be deleted and the other would still hit, making it look like the shield did nothing.