Touching a 2d sprite?

Im trying to code a start button for a 2d game for android but I cannot figure it out. My code currently is:

if (Input.touchCount == 1)
{
Vector3 wp = Camera.main.ScreenToWorldPoint(Input.GetTouch(0).position);
Vector2 touchPos = new Vector2(wp.x, wp.y);

if (collider2D.OverlapPoint(touchPos))
{
//your code
//Application.LoadLevel("RunLevel");
msg = Physics2D.OverlapPoint(touchPos).gameObject.transform.tag;
}
}

This should be checking going to the next scene if i press the play button, but if i press anywhere on the screen its returning the collider its attached to.

 

I'd recommend using raycasts instead, and some better touch-handling, to prevent multitouches (taken from the Unity script reference).

Code for touches (cannot test it myself, though):

Code (csharp):

1.  
2.     for (var i = 0; i < Input.touchCount; ++i) {
3.         if (Input.GetTouch(i).phase == TouchPhase.Began) {
4.             RaycastHit2D hitInfo = Physics2D.Raycast(Camera.main.ScreenToWorldPoint(Input.GetTouch(i).position), Vector2.zero);
5.             // RaycastHit2D can be either true or null, but has an implicit conversion to bool, so we can use it like this
6.             if(hitInfo)
7.             {
8.                 Debug.Log( hitInfo.transform.gameObject.name );
9.                 // Here you can check hitInfo to see which collider has been hit, and act appropriately.
10.             }
11.         }
12.     }
13.  

...but I tested this for use with mouse-clicks, and it works perfectly.

Code (csharp):

1.  
2.     if (Input.GetMouseButtonDown (0)) {
3.         Debug.Log ("Clicked");
4.         Vector2 pos = new Vector2(Input.mousePosition.x, Input.mousePosition.y);
5.         RaycastHit2D hitInfo = Physics2D.Raycast(Camera.main.ScreenToWorldPoint(pos), Vector2.zero);
6.         // RaycastHit2D can be either true or null, but has an implicit conversion to bool, so we can use it like this
7.         if(hitInfo)
8.         {
9.             Debug.Log( hitInfo.transform.gameObject.name );
10.             // Here you can check hitInfo to see which collider has been hit, and act appropriately.
11.         }
12.     }
13.  

Just remember that your sprite must have some kind of 2D collider on it to be registered.

 

It's still not working, no matter where I touch on the screen it always returns with the play button? Its weird, the play button is the only box collider on the screen and if I click say the background it returns "playbutton" instead of null.... so weird! If the sprite box collider's size is less then 1 it will only return the backgrounds collider, if its over size of 1 and it only returns the box collider on the play button.

 

It's like the ray is off or something, if the boundary for the playbutton is over 1 then even if I click outside the collider it returns play button!? If my x scale on box collider is over 1.5, no matter where i press on the screen, it always returns the playbutton, and if I do under 1.3 it doesnt detect anything, even if im right ontop of it.

 

Yup, I'm officially dumb... haha. I forgot to turn my camera to orthographic for 2d games! DOH! Thanks a ton ultro the code works perfectly.

 

Heheh, happens to the best

And you're very welcome. It's a 3-minute mix-match of 2 different pages in the Unity Script Reference, so it darn well should work

Remember that local variables, like that Vector2 pos and the hitInfo, would probably be better off as a global temp-variable, if you're running this script in an Update() method. If the code is very situational, it should be fine the way it is.

 

do we write that function on update?

 

Thanks for the code works perfectly!