title: Using unProject correctly in Java Libgdx
body: <p>I want to make a button clickable, but it isn't working - it seems like I need to use <code>unproject()</code> but I can't figure out how. The code in question is:</p>
  
  <pre><code>Texture playButtonImage;
  SpriteBatch batch;
  ClickListener clickListener;
  Rectangle playButtonRectangle;
  Vector2 touchPos;
  OrthographicCamera camera;
  
  @Override
  public void show() {
      playButtonImage = new Texture(Gdx.files.internal("PlayButton.png"));
  
      camera = new OrthographicCamera();
      camera.setToOrtho(false, 800, 480);
      batch = new SpriteBatch();
  
      playButtonRectangle = new Rectangle();
      playButtonRectangle.x = 400;
      playButtonRectangle.y = 250;
      playButtonRectangle.width = 128;
      playButtonRectangle.height = 64;
  }
  
  @Override
  public void render(float delta) {
      Gdx.gl.glClearColor(0, 0, 0.2f, 1);
      Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
  
      camera.update();
      batch.setProjectionMatrix(camera.combined);
  
      batch.begin();
      batch.draw(playButtonImage, playButtonRectangle.x, playButtonRectangle.y);
      batch.end();
  
      if (Gdx.input.isTouched()) {
          Vector2 touchPos = new Vector2();
          touchPos.set(Gdx.input.getX(), Gdx.input.getY());
  
  
          if (playButtonRectangle.contains(touchPos)) {
              batch.begin();
              batch.draw(playButtonImage, 1, 1);
              batch.end();
          }
      }
  }
  </code></pre>