How to make an Actor follow my finger

Question

I'm back with another question that may be really simple.

I've a texture drawn on my spritebatch and I'm making it move up or down (y-axis only) with Libgdx's Input Handler: touchDown and touchUp.

@Override
public boolean touchDown(int screenX, int screenY, int pointer, int button) {
    myWhale.touchDownY = screenY;
    myWhale.isTouched = true;
    return true;
}

@Override
public boolean touchUp(int screenX, int screenY, int pointer, int button) {
    myWhale.isTouched = false;
    return false;
}

myWhale is an object from Whale Class where I move my texture position:

public void update(float delta) {
    this.delta = delta;
    if(isTouched){
        dragWhale();
    }
}

public void dragWhale() {
    if(Gdx.input.getY(0) - touchDownY < 0){
        if(Gdx.input.getY(0)<position.y+height/2){
            position.y = position.y - velocidad*delta;
        }
    }
    else{
        if(Gdx.input.getY(0)>position.y+height/2){
            position.y = position.y + velocidad*delta;
        }
    }
}

So the object moves to the center of the position where the person is pressing his/her finger and most of the time it works fine but the object seems to take about half a second to move up or down and sometimes when I press my finger it wont move.

Maybe there's another simplier way to do this. I'd highly appreciate if someone points me on the right direction.

Answer 1

Try to extend the whale as an Actor and add an ActorGestureListener to it. Use the pan function to drag the whale. It will be something like this:

void pan(event, x, y, deltaX, deltaY){
    myWhale.position.add(deltaX, deltaY);
}

And I think you'll have to use Stage for that, but I'm not sure.

Answer 2

No need to take an extra class for Input just write the following code in render method :-

if (Gdx.input.isTouched())
 {                
    Rectangle   touchRectangle = new Rectangle(Gdx.input.getX( ),
                        Gdx.graphics.getHeight() - Gdx.input.getY( ), 10,
                        10);

//just check if your finger overlaps on your character then move according to it
                if (touchRectangle 
                        .overlaps(whaleRectangle)) {
                      whaleRectangle.x=Gdx.input.getX();
                      whaleRectangle.y=Gdx.input.getY();

   }
   }

Answer 3

If your class implements InputProcessor:

  @Override
  public boolean touchDown(int screenX, int screenY, int pointer, int button) {

    MoveToAction mta = new MoveToAction();
    mta.setPosition(screenX, Math.abs(stage.getHeight()-screenY));
    mta.setDuration(5f);  //moves to new location by this time interval
    stage.addAction(mta);
    return false;
  }