title: openGL ES 2.0. image fit screen in landscape and portrait orientation Android
body: <p>I start learning openGL ES 2.0. Now i can add texture to objects and create elementary figures(sphere, triangle, cube etc).
  But now I have some problem. I have rectangle with texture. It is my target image. And now I want make this image fitted the drawing region in landscape and portrait orientation. Basically images are landscape oriented.
  For exaple:
  <img src="https://i.stack.imgur.com/rBrpN.jpg" alt="for portarait orientation">
  <img src="https://i.stack.imgur.com/b5Mtm.jpg" alt="for landscape orientation"></p>
  
  <p>Screen must be without black lines near the borders of screen. When screen change they orientation - image must change size and fit screeen again.
  I don't know how implement it on OpenGl on Android. what should I change? parameters of viewport or other parameters? and how i do this? </p>