package gl4bug;
import java.awt.*;
import java.awt.event.*;
import javax.media.opengl.*;      
import javax.media.opengl.awt.*;  

/**
 * Shows a bug (?) with the combination GLProfile.get(GLProfile.GL4) / GL4 gl = drawable.getGL().getGL4();
   In that case the stacktrace starts like:

     [java] Exception in thread "AWT-EventQueue-0" javax.media.opengl.GLException: Not a GL4 implementation
     [java] 	at jogamp.opengl.gl4.GL4bcImpl.getGL4(GL4bcImpl.java:32456)
     [java] 	at firstopengl.GL4Bug.init(GL4Bug.java:31)
     [java] 	at jogamp.opengl.GLDrawableHelper.init(GLDrawableHelper.java:132)
     
   In all other cases everything looks ok, and for instance GL4 gl = (GL4) drawable.getGL(); works, and 
   correctly reports an OpenGL version 4.1.0. 
   
   Similar code but with GLProfile.get(GLProfile.GL3) / GL3 gl = drawable.getGL().getGL3() shows version 3.3.0 and works ok.
   
   Tested with NVidia GTX 460 and GTX 560, driver version 275.33, on Windows 7 64-bit/32-bit Java 1.6.0_26
   Jogl versions: jogl-2.0-b23-20110303-windows-i586.7z and jogl-2.0-b417-20110802-windows-i586.7z

 */
public class GL4Bug implements GLEventListener  {

   public GL4Bug() {
      //GLProfile glp = GLProfile.getDefault();       // This works ok, and reports OGL version 4.1.0 later on
      //GLProfile glp = GLProfile.get(GLProfile.GL3); // This works ok, but will report OGL version 3.3.0 later on
      GLProfile glp = GLProfile.get(GLProfile.GL4);   // ===> This will fail later on, but ONLY with the getGL4() call, not with (GL4) drawable.getGL()
      GLCapabilities caps = new GLCapabilities(glp);
      GLCanvas canvas = new GLCanvas(caps);
      canvas.addGLEventListener(this);
      
      Frame frame = new Frame();
      frame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {  System.exit(0);  }
      });
      frame.setSize(256, 128);
      frame.setLocation(256, 256);
      frame.add(canvas);
      frame.setVisible(true); 
   }
 
   public void init(GLAutoDrawable drawable) {
      GL4 gl = drawable.getGL().getGL4();       // this fails for GLProfile.get(GLProfile.GL4), but works ok for GLProfile.getDefault()
      //GL4 gl = (GL4) drawable.getGL();   // This always works ok, next line will print correct version 4.1.0 (or 3.3.0 for GLProfile.GL3)
      System.out.println("GLVERSION: " + gl.glGetString(GL.GL_VERSION));

   }

   public void dispose(GLAutoDrawable drawable) { }
   public void reshape(GLAutoDrawable gl, int x, int y, int width, int height) { }
   public void display(GLAutoDrawable drawable) { }

   public static void main(String[] arg) {     
      GLProfile.initSingleton(false);	
      new GL4Bug();
   }
}