Unity start game when touch screen

Question

I made a mobile 2D game in which you need to tap the screen to start moving the ball but something went wrong. This is my code:

void Start () 
{   
    if (Input.touchCount >=1)
    {
        GetComponent<Rigidbody2D> ().AddForce (new Vector2 (1f, 0.5f) * force);
    }

When I tap the screen, the ball is still fixed.

read this: http://stackoverflow.com/questions/22459112/in-unity3d-click-touch — ivan, Dec 23 '15 at 18:09
This is for click mode. I need for one tap mobile device screen. Why my code doesn't work? — mavericks, Dec 23 '15 at 18:46

Cenkisabi · Answer 1 · 2022-04-14T10:17:15.823

1

Your code doesn't work because you are checking input count in Start method. Start method is called when Scene is created. After that it will not check your if statement. Write it into Update method like this.

bool started = false;
void Update() 
{   
    if (Input.touchCount >=1 && !started)
    {
        GetComponent<Rigidbody2D> ().AddForce (new Vector2 (1f, 0.5f) * force);
        started=true;
    }
}

edited Apr 14 '22 at 10:17

answered Dec 23 '15 at 18:56

Cenkisabi

1,066
8
25

Thanks, it works. But my problem now is that every time I touch my screen is AddForce to my ball. So that is the reason why I put code to Start function. What do you think how can I solve this? I have a ball in which I need just one tap to start game and start ball. That's it :) – mavericks Dec 23 '15 at 19:06

ゴスエンヘンリ · Accepted Answer · 2015-12-23T19:43:51.053

1

As mentioned you used the code on Start method. If you want to use the touch to move the ball only one time, use a bool perhaps. Declare this:

    public class movingBall : MonoBehaviour {
        bool gameStart;

    void Start(){
        gameStart=false;
    }

    void Update() 
    {   
        if (Input.touchCount >=1)
        {
           if (gameStart){
               //game already started, do stuff with touch action in game
           }else{
              //game not started yet, move the ball once
              gameStart=true;
              GetComponent<Rigidbody2D> ().AddForce (new Vector2 (1f, 0.5f) * force);
           }

       }
    }
}

For a game over, just remember to set it false again.

If you gonna use the touch input ONLY for start you can do like:

public class movingBall : MonoBehaviour {
      bool gameStart;

    void Start(){
            gameStart=false;
        }

    void Update() 
    {   

           if (!gameStart){
               if (Input.touchCount >=1) {
             gameStart=true;
             GetComponent<Rigidbody2D> ().AddForce (new Vector2 (1f, 0.5f) * force);
              }
           }
    }
}

edited Dec 23 '15 at 19:43

answered Dec 23 '15 at 19:20

ゴスエンヘンリ

843
13
26

Yes, I need touch input ONLY once for start. I put your code. This is my console message: The private field `movingBall.gameStart' is assigned but its value is never used – mavericks Dec 23 '15 at 19:28
all code inside same script? I mean, you declared the bool AND inserted the code in the Update method? – ゴスエンヘンリ Dec 23 '15 at 19:30
Yes. Or its need to be separate? if yes, how? :) – mavericks Dec 23 '15 at 19:32
mmm, weird. where do you add the 'bool gameStart=false;' ? I've updated the code, please check if the bool is outside any methods! – ゴスエンヘンリ Dec 23 '15 at 19:33
I added into public class... Before all functions. This is ok? – mavericks Dec 23 '15 at 19:35
It works now. Thank you so much. You helped me several times today. Thank you thousand times :) – mavericks Dec 23 '15 at 19:54

score 0 · Answer 3 · answered Dec 23 '15 at 19:37

Modifying ゴスエンヘンリ's answer.

public class movingBall : MonoBehaviour {
    bool _gameStarted = false; // In the class but outside any function

    void Update()
    {
        if (!_gameStarted ){
            if (Input.GetMouseButtonDown(0)){ // It will work on mobile too.
                _gameStarted = true;
                GetComponent<Rigidbody2D> ().AddForce (new Vector2 (1f, 0.5f) * force);
            }
        }
    }
}

Unity start game when touch screen

3 Answers3