does disabled code affect performance

Question

if you have some portions of code disabled say like you have a game with mobile platform controls, as well as computer controls. then when you play it on the computer, do the disabled mobile controls portion have any negative effects besides making the game use more total memory?

do people usually make different versions of games for each platform, or just one dynamic game that picks the correct sections of code to run based on whats its being played on?

Answer 1

Best Answer

Answer by Bunny83 · Nov 25, 2013 at 02:29 AM

No, if you have code that you don't use (i.e. you don't execute it) it has no impact on the performance. Like you said it might result in a slightly larger memory footprint, but code is usually one of the smallest things in your application.

However you can even exclude certain code fragments from being compiled into the final app by using pre-processor tags. If you do so, keep in mind that code in an UNITY_IPHONE seciont literally doesn't exist when building for any other platform (PC, Android, ...). So make sure you don't build too tight dependencies between classes / methods. One way is in addition to the preprocessor directives to use the strategy pattern like iwaldrop showed you.

That way you can exclude things ment for other platforms but you don't rely on a certain class.

Add comment · Share

Answer 2

Answer by TunerSymphon · Nov 25, 2013 at 04:55 AM

As I understand, it won't affect performance, as it won't be actively using those sections of script, but it will affect load time, albeit only by a small amount. Short answer, no, I don't believe so.

Add comment · Share

Answer 3

Answer by iwaldrop · Nov 25, 2013 at 02:04 AM

It depends on your implementation. You could actually spawn an instance of the appropriate class depending on the control method you're using and never have the memory footprint required to have instances of control methods that aren't used on the target platform. Take this example:

 using UnityEngine;
 
 public interface IControl
 {
     void DetectInput();
 }
 
 public class JoystickControl : IControl
 {
     public void DetectInput()
     {
         // detect and do stuff with player input from a joystick
         Debug.Log("detecting input from joystick");
     }
 }
 
 public class KeyboardAndMouseControl : IControl
 {
     public void DetectInput()
     {
         // detect and do stuff with player input from the keyboard and mouse
         Debug.Log("detecting input from keyboard and mouse");
     }
 }
 
 
 public class InputController : MonoBehaviour
 {
     public bool useJoystick;  // for demonstrational purposes, replace with target platform sensing logic
     private IControl playerControlMethod;
 
     void Awake()
     {
         if (useJoystick)
             playerControlMethod = new JoystickControl();
         else
             playerControlMethod = new KeyboardAndMouseControl();
     }
 
     void Update()
     {
         playerControlMethod.DetectInput();
     }
 }

Add comment · Show 4 · Share

Bunny83 · Nov 25, 2013 at 02:19 AM 0

Share

That wouldn't make any difference. The "code" is still there. code also needs memory, even when not used, however it's usually just a few $$anonymous$$B depending on how much code ;)

iwaldrop · Nov 25, 2013 at 02:21 AM 0

Share

Right, but the instances wouldn't be allocated on the heap. The OP asked about disabled code, so I offered a method of instantiating only the objects that would be required.

Of course other methods include preprocessor directives, but now I'm just preaching to the choir. :)

Bunny83 · Nov 25, 2013 at 02:34 AM 0

Share

:) But in your case you have no data at all in your concrete instances. The instances you create just adds overhead in your case. So at the end your implementation needs more memory than having all in one class and just ignore one part.

Also code is never instantiate. Code is always static. The only thing you can have are virtual overrides, but they are just references to static methods. $$anonymous$$ethods belong to the class, not to an instance. They are not part of the "data".

iwaldrop · Nov 25, 2013 at 02:41 AM 0

Share

True. I didn't mean to lead anyone astray with my quick and dirty example of an alternative which didn't include member variables.

Thanks for covering my tracks. :)

does disabled code affect performance

3 Replies

Your answer

Welcome to Unity Answers

Follow this Question

Related Questions