title: Blank screen when using gluOrtho2D
body: <p>First, sorry if my English is bad :(</p>
  
  <p>I'm currently trying to make game in Android, and using <a href="http://obviam.net/index.php/texture-mapping-opengl-android-displaying-images-using-opengl-and-squares/" rel="nofollow">this link</a> to start with.
  When I learned that we can use gluOrtho2D to draw parallel 2D (the tutorial using perspective), I switch my code. But it display nothing but blank screen.</p>
  
  <p>This is my code:</p>
  
  <pre><code>public class GLRenderer implements Renderer{
  
  private Triangle triangle;
  private Square square;
  private Context context;
  
  /** Constructor for GL
   * @return */
  public GLRenderer(Context context) {
      this.context = context;
  
      this.triangle = new Triangle();
      this.square = new Square();
  }
  
  @Override
  public void onDrawFrame(GL10 gl) {
      // TODO Auto-generated method stub
      // clear Screen and Depth Buffer
      gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
  
      // Reset the Modelview Matrix
      gl.glLoadIdentity();
  
      // Drawing
      //gl.glTranslatef(0.0f, 0.0f, -5.0f);     // move 5 units INTO the screen
                                             // is the same as moving the camera 5 units away
      square.Draw(gl);                      // Draw the triangle
  
  }
  
  @Override
  public void onSurfaceChanged(GL10 gl, int width, int height) {
      // TODO Auto-generated method stub
      if(height == 0) {                       //Prevent A Divide By Zero By
           height = 1;                         //Making Height Equal One
      }
  
  
  
      gl.glViewport(0, 0, width, height);     //Reset The Current Viewport
      gl.glMatrixMode(GL10.GL_PROJECTION);    //Select The Projection Matrix
      gl.glLoadIdentity();                    //Reset The Projection Matrix
  
      //Calculate The Aspect Ratio Of The Window
      //GLU.gluPerspective(gl, 1.0f, (float)width / (float)height, -1.0f, 100.0f);
      GLU.gluOrtho2D(gl, 0.0f, (float)width, 0.0f, (float)height);
  
      gl.glMatrixMode(GL10.GL_MODELVIEW);     //Select The Modelview Matrix
      gl.glLoadIdentity();         
  }
  
  @Override
  public void onSurfaceCreated(GL10 gl, EGLConfig config) {
      // TODO Auto-generated method stub
      // Load the texture for the square
      square.LoadGLTexture(gl, this.context, R.drawable.menu_main);
  
      gl.glEnable(GL10.GL_TEXTURE_2D);            //Enable Texture Mapping ( NEW )
      gl.glShadeModel(GL10.GL_SMOOTH);            //Enable Smooth Shading
      gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f);    //Black Background
      gl.glClearDepthf(1.0f);                     //Depth Buffer Setup
      gl.glEnable(GL10.GL_DEPTH_TEST);            //Enables Depth Testing
      gl.glDepthFunc(GL10.GL_LEQUAL);             //The Type Of Depth Testing To Do
  
      gl.glEnable(GL10.GL_BLEND);
      gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
  
      //Really Nice Perspective Calculations
      //gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
  }
  </code></pre>
  
  <p>}</p>
  
  <p>Any help?</p>