Unity C# - Radar works but performance is horrible (Update & LateUpdate)

Question

Hello I need help to optimize this code. I have a radar and it gets the enemies from a list and adds an image to their location to track them. I use Update to remove the images and LateUpdate to add the images. Is there any way I can do this without costing performance. I have a list of all the Enemies. I have a pool of over 40 images to use as tracking for the radar. Enemy is always moving. Any ideas?

private void Update()
{
    if (statsView_Panel.activeInHierarchy)
    {
        if (showIndicators_Enemies)
        {
            if (!enemyListHolder.activeInHierarchy)
            {
                enemyListHolder.SetActive(true);
            }

            Remove_PositionIndicatorOnEnemies();
        }
    }
}

private void LateUpdate()
{
    if (showIndicators_Enemies)
    {
        if (!enemyListHolder.activeInHierarchy)
        {
            enemyListHolder.SetActive(true);
        }

        Add_PositionIndicatorOnEnemies();
    }
}

private void Add_PositionIndicatorOnEnemies()
{
    //  Do if ListHolder is Active
    if (enemyListHolder.activeInHierarchy)
    {
        //  Run if 1 or more Enemies
        if (EnemiesManager.Count > 0)
        {
            //  Check All Enemies
            for (int i = 0; i < EnemiesManager.Count; i++)
            {
                //  Check All Indicators
                for (int s = 0; s < enemyIndicList.Count; s++)
                {
                    //  Choose Indicator that is not active *****BUG: Will Add All Deactivated Indicators to Active Enemies*****
                    if (enemyIndicList[s].gameObject.activeInHierarchy == false)
                    {
                        //  Activate Indicator and Reposition
                        enemyIndicList[s].gameObject.SetActive(true);
                        Vector3 aLocatorPos;
                        aLocatorPos = theCam.WorldToScreenPoint(satManager.GetByIndex(i).transform.position);
                        aLocatorPos.z = 0;
                        enemyIndicList[s].transform.position = aLocatorPos;

                        //  Break from Loop
                        break;
                    }
                }
            }
        }
    }
}

private void Remove_PositionIndicatorOnEnemies()
{
    //  Do if ListHolder is Active
    if (enemyListHolder.activeInHierarchy)
    {
        //  Run if 1 or more Enemies
        if (EnemiesManager.Count > 0)
        {
            //  Check All Indicators
            for (int s = 0; s < enemyIndicList.Count; s++)
            {
                //  Choose Indicator that is active
                if (enemyIndicList[s].gameObject.activeInHierarchy == true)
                {
                    //  Deactivate Indicator
                    enemyIndicList[s].gameObject.SetActive(false);
                }
            }
        }
    }
}

Answer 1

Let's review the code from bottom to top.

Remove_PositionIndicatorOnEnemies

• Having an underscore in a method name doesn't fit with the .NET naming guidelines.
• By reverting the first if condition you can return early if enemyListHolder.activeInHierarchy is false which saves you one level of indentation.
• The next if condition can be omitted because that check is done inside the loop condition.
• Instead of using a for loop I would prefer a foreach loop and would restrict the items to only them where activeInHierarchy is true by a Where() clause.

Implementing the mentioned changes will lead to

private void RemovePositionIndicatorOnEnemies()
{
    if (!enemyListHolder.activeInHierarchy) { return; }

    foreach (var enemy in enemyIndicList.Where(e=> e.gameObject.activeInHierarchy))
    {
        enemy.gameObject.SetActive(false);
    }
}  

Add_PositionIndicatorOnEnemies

Here, the first three points from above apply as well.

• The inner for loop can be replaced by FirstOrFDefault() which is more readable.

Implementing the mentioned changes will lead to

private void Add_PositionIndicatorOnEnemies()
{
    if (!enemyListHolder.activeInHierarchy) {return; }

    for (int i = 0; i < EnemiesManager.Count; i++)
    {
        var enemy = enemyIndicList.FirstOrDefault(e=> !e.gameObject.activeInHierarchy);
        if (enemy != null)
        {
            enemy.gameObject.SetActive(true);
            Vector3 aLocatorPos = theCam.WorldToScreenPoint(satManager.GetByIndex(i).transform.position);
            aLocatorPos.z = 0;
            enemy.transform.position = aLocatorPos;
        }
    }
}  

LateUpdate

• Again returning early will save one level of indentation.

Implementing the mentioned changes will lead to

private void LateUpdate()
{
    if (!showIndicators_Enemies) { return; }

    if (!enemyListHolder.activeInHierarchy)
    {
        enemyListHolder.SetActive(true);
    }

    Add_PositionIndicatorOnEnemies();
}  

Update

• Here we can save two levels of indentation by reverting and combining the first two if conditions.

Implementing the mentioned changes will lead to

private void Update()
{
    if (!statsView_Panel.activeInHierarchy || !showIndicators_Enemies) { return; }

    if (!enemyListHolder.activeInHierarchy)
    {
        enemyListHolder.SetActive(true);
    }

    Remove_PositionIndicatorOnEnemies();
}