libgdx touchDown called just once

问题

I'm new to LibGdx, and have problem with input handling.

My player needs to shoot bullets whenever touch is down. But it seems that this method is called just once...

And then user have to click again to shoot another bullet.

I want always to shoot bullets while click is down...

Is there a way to handle this use case?

回答1:

Look into "polling" on the touch input, instead of getting Input events. So, in your render or update method, use something like this:

 boolean activeTouch = false;

 if (Gdx.input.isTouched(0)) {
    if (activeTouch) {
       // continuing a touch ...
    } else {
       // starting a new touch ..
       activeTouch = true;
    }     
 } else {
    activeTouch = false;
 }

回答2:

I've succeeded to work this out, without pooling concept.

I have custom InputProccesor, int I've used similar logic like P.T. mentioned. I touchDown I start thread that shoots bullets and do some calculation, because I access to some methods from Renderer class I've to use

   Gdx.app.postRunnable(new Runnable() {
        @Override
        public void run() {
        // process the result, e.g. add it to an Array<Result> field of the ApplicationListener.
        shootBullet(screenX, screenY);
        }
    });

To avoid OpenGL context exception.

In touchUp method I cancel shooting thread.

Tnx for idea!

回答3:

I have use Continuous Input handle

This is done by setting a flag to your actor eg:

public class Player{
  private boolean firing = false;
  private final Texture texture = new Texture(Gdx.files.internal("data/player.png"));

  public void updateFiring(){
    if (firing){
        // Firing code here
        Gdx.app.log(TAG, "Firing bullets");
    }
  }

  public void setFiring(boolean f){
    this.firing  = f;
  }

  Texture getTexture(){
    return this.texture;
  }

}

Now in my Application class implementing InputProcessor

@Override
public void create() {
    player= new Player();
    batch = new SpriteBatch();
    sprite = new Sprite(player.getTexture());
    Gdx.input.setInputProcessor(this);
}
@Override
public void render() {
    Gdx.gl.glClearColor(1, 1, 1, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    batch.begin();
    sprite.draw(batch);
    // Update the firing state of the player
    enemyJet.updateFiring();
    batch.end();
}

@Override
public boolean keyDown(int keycode) {
    switch (keycode){
        case Input.Keys.SPACE:
            Gdx.app.log(TAG, "Start firing");
            player.setFiring(true);

    }
    return true;
}

@Override
public boolean keyUp(int keycode) {
    switch (keycode){
        case Input.Keys.SPACE:
            Gdx.app.log(TAG, "Stop firing");
            player.setFiring(false);

    }
    return true;
}

Done

来源：https://stackoverflow.com/questions/15316146/libgdx-touchdown-called-just-once

标签

libgdx