title: libGDX Pixmap and Texture performance
body: <p>I have a huge amount of 2d images in my game, with multiple layers. I use <code>spritebatch()</code> and <code>orthographicCamera()</code>. I have some basic questions about performances :</p>
  
  <ol>
  <li>Does using Atlas is the faster way to load images ?</li>
  <li>What is faster to work with, Pixmap (and convert to texture before draw) or Textures?</li>
  <li>When i make a multiple layer image, should I use <code>Texture.draw</code> (or <code>Pixmap.draw</code> for Pixmap), make a final image and then render it ? Or should i render everything in the <code>spritebatch.begin()</code> and <code>spritebatch.end()</code>?</li>
  <li>Is there a way to track "dirty sprites" (the part of the screen that changed between two frames) and render only this region to increase performance?</li>
  <li>Also, how can I see the memory amount taken by the program resources, and how should I manage it? (maybe this question is a little more difficult)</li>
  </ol>
  
  <p>Thank you for your help (any other general advice is welcome)</p>