title: opengl - how to keep updating a scene forever
body: <p>For every incoming tweet, I was asked to put a point (corresponding to tweet location) on world map (opengl scene). Some thing like <a href="http://tweetping.net/" rel="nofollow noreferrer">this</a>. I tried to learn OpenGL. I cried. With time, OpenGL started feeling like my friend. He was on the way to become my best friend. Now, I used <code>GLSurfaceView</code> on Android and assumed like I can simply draw points one by one, one after another with out ever calling <code>glCear()</code>. This way I only have to keep current tweet coordinate in memory. Told to myself, you are a genius. I suffered like others, whose have explained there pains <a href="https://stackoverflow.com/q/14581938/1180117">here</a>, <a href="https://stackoverflow.com/q/17187032/1180117">here</a> and <a href="https://stackoverflow.com/q/17229066/1180117">here</a>. Now comes a master, who <a href="https://stackoverflow.com/a/17237835/1180117">taught</a> me the basics and told me, kiddo, you have to call <code>glClear</code> no matter what.</p>
  <p>I cannot keep adding/storing coordinates of all points in memory and call <code>glDrawArrarys</code> since this has to keep running for ever on mobile device. So the choices now are</p>
  <ol>
  <li>Draw <code>n</code> points. After that, try some thing like 'render to texture' and use that texture as background for the next drawing next <code>n</code> points.</li>
  <li>Use <code>EGL_BUFFER_PRESERVED</code> as in EGL Preserve sample at Mali <a href="http://malideveloper.arm.com/develop-for-mali/sdks/mali-opengl-es-sdk-for-android/" rel="nofollow noreferrer">sdk</a> . Needs NDK as Android <code>EGL14</code> cannot be used before Android API 17. Khronos EGL11 is not yet implemented in Android. People closest to my new friend tells, he doesn't like this at all.</li>
  </ol>
  <p>Do I have any other choices or am I solving the wrong problem ? I would like to know what is OpenGL's approach to updating a scene for ever.</p>