0
\$\begingroup\$

My collision detection in libgdx is somehow buggy. player.png is 20*80px and ball.png 25*25px.

Code:

@Override
public void create() {      
    // ...
    batch = new SpriteBatch();
    playerTex = new Texture(Gdx.files.internal("data/player.png"));
    ballTex = new Texture(Gdx.files.internal("data/ball.png"));

    player = new Rectangle();
    player.width = 20;
    player.height = 80;
    player.x =  Gdx.graphics.getWidth() - player.width - 10;
    player.y = 300;


    ball = new Circle();
    ball.x = Gdx.graphics.getWidth() / 2;
    ball.y = Gdx.graphics.getHeight() / 2;
    ball.radius = ballTex.getWidth() / 2;
}

@Override
public void render() {      
    Gdx.gl.glClearColor(1, 1, 1, 1);
    Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);

    camera.update();

    // draw player, ball
    batch.setProjectionMatrix(camera.combined);
    batch.begin();
    batch.draw(ballTex, ball.x, ball.y);
    batch.draw(playerTex, player.x, player.y);

    batch.end();

    // update player position
    if(Gdx.input.isKeyPressed(Keys.DOWN)) player.y -= 250 * Gdx.graphics.getDeltaTime();
    if(Gdx.input.isKeyPressed(Keys.UP)) player.y += 250 * Gdx.graphics.getDeltaTime();
    if(Gdx.input.isKeyPressed(Keys.LEFT)) player.x -= 250 * Gdx.graphics.getDeltaTime();
    if(Gdx.input.isKeyPressed(Keys.RIGHT)) player.x += 250 * Gdx.graphics.getDeltaTime();

     // don't let the player leave the field
     if(player.y < 0) player.y = 0;
     if(player.y > 600 - 80) player.y = 600 - 80;

     // check collision
     if (Intersector.overlaps(ball, player))
         Gdx.app.log("overlaps", "yes");
}

enter image description here

\$\endgroup\$
  • \$\begingroup\$ Questions that are essentially "debug my code for me" are not a good fit for this site. Since they typically only benefit the original poster. Glad you found your problem. \$\endgroup\$ – MichaelHouse Oct 19 '13 at 14:58
2
\$\begingroup\$

Found the problem:

Replace

batch.draw(ballTex, ball.x, ball.y);

with

batch.draw(ballTex, ball.x-ball.radius, ball.y-ball.radius);

That's because batch.draw draws with the lower left corner at x/y.

\$\endgroup\$
  • \$\begingroup\$ Please mark this as an answer. \$\endgroup\$ – sinistersnare Oct 20 '13 at 2:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.