How to "Initialize" Input System?

Unity Engine
,
1

From the title, it may look like I’m a newbie to the new InputSystem but actually I’m quite experienced with it. I have been using a relatively complex ActionMap system in my standalone (Windows) based game for a long time.

Recently, I started to use the input system on iOS for the first time and I couldn’t find a solution to the problem I’m experiencing.

For the iOS project, I don’t have any action maps setup yet. I have to use Touch system directly, like this:

    void Start()
    {
        EnhancedTouchSupport.Enable();
    }

    void Update()
    {
        print(Touch.activeTouches.Count);
    }

But this code just prints 0 (zero) to the console on iOS device even if I touch the screen with my fingers.

Later, I noticed that activeTouches.Count starts working fine in a very interesting way.

To be able to debug the state of my test app, I implemented an old GUI system. As soon as I call some old UI methods, activeTouches.Count starts working.

It’s like old UI system somehow “initializes” the new input system so activeTouches.Count starts working.

            GUILayout.BeginHorizontal();
            {
                EnvironmentIndex = GUILayout.Toolbar(EnvironmentIndex, Environments, GUILayout.Width(200), GUILayout.Height(25));
            }
            GUILayout.EndHorizontal();

Can anyone from Unity InputSystem team tell me what special operation the old UI system doing to initialize the new UI system please?

2

From what I have check, to test in Game view, open the Input Debugger from Window > Analysis > Input Debugger.
Then enable this:
9299936--1302839--upload_2023-9-13_15-51-3.png

Alternative way, if you don’t want to use Input Debugger, you can use Simulator.
9299936--1302845--upload_2023-9-13_15-51-37.png

3

Thank you but the problem I described happens in the app build on the iOS device; not specific to Unity Editor.

4

That’s weird as there should not be any extra implementation needed for mobile device. On my side I don’t need to use the GUILayout. Does it work fine in the Editor without the GUILayout?

5

I tried but couldn’t test it in the editor. With the touch simulation enabled, Touch count is always zero in editor play mode, with or without my GUILayout hack. Weird.

6

Maybe it’s a bug. Try to redo it in a new project, or using another version of Unity or Input System.

7

Thank you for trying to help. I may have go deeper investigation if I have some free time but for now I’ll live with this quick hack I implemented.

using UnityEngine;

// This class is a hack.
// Normally we don't need to initialize InputSystem. We just need to enable an ActionMap in the InputSystem and it starts working as expected.
// But on iOS, for some reason, we can't get the correct behaviour from Touch.activeTouches.Count which is required for TouchConsolePro.
// It reports 0 (zero) even when we touch the screen as if the input system was not initialized.
// Interestingly, drawing a UI object using Unity's old UI system automatically initializes the input system and Touch.activeTouches starts working fine.
// With the script below, we are forcing the input system to be initialized on iOS.
// The problem was discussed here: https://discussions.unity.com/t/928611
// If we find a proper way to initialize the input system on iOS, we can get rid of this hack.
public class InputSystemInitializer : MonoBehaviour
{
    void OnGUI()
    {
        GUILayout.Label(".");
        Destroy(this);
    }
}
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