title: Continuos update of sprites in andEngine
body: <p>How can a sprite(say track) be continuosly looking/pointing at another sprite(say boxy) ... the thing i have tried is here(in onPopulate Scene) but it doesnt work :( . </p>
  
  <h2>Track(currently/Default pointing up)</h2>
  
  <p><img src="https://i.stack.imgur.com/BA6xg.png" alt="Tracky"></p>
  
  <pre><code>track.registerUpdateHandler(new IUpdateHandler() {
  
          @Override
          public void reset() {
  
          }
  
          @Override
          public void onUpdate(float pSecondsElapsed) {
  
                  float centre_tracky_width = track.getWidth() / 2;
                  float centre_tracky_height = track.getHeight() / 2;
                  float centre_boxy_width = boxy.getWidth() / 2;
                  float centre_boxy_height = boxy.getHeight() / 2;
                  float x_d = (centre_tracky_width - centre_boxy_width);
                  float y_d = (centre_tracky_height - centre_boxy_height);
                  float dtoboxy = (float) Math.pow(
                          (float) (Math.pow(y_d, 2) + Math.pow(x_d, 2)), 0.5);
                  track.setRotation((float) Math.toDegrees((float) Math
                          .acos(y_d / dtoboxy)));
  
  
          }
      });
  </code></pre>