Posted by Martin on Oct 05, 2021; 11:16am
URL: https://forum.jogamp.org/Selecting-the-highest-possible-GL-profile-at-runtime-tp4041302p4041351.html

Hi Julien,

When

GL gl = drawable.getContext().getGL();
gl.getGL4bc().glClear(0);

Then I got

com.jogamp.opengl.GLException: Not a GL4bc implementation
        at jogamp.opengl.gl4.GL4bcImpl.getGL4bc(GL4bcImpl.java:40456)
        at org.jzy3d.demos.debugGL.GetOpenGLVersion_JOGL.main(GetOpenGLVersion_JOGL.java:65)


Despite the following output (see below the complete source code allowing to reproduce the issue)

GL INSTANCE : jogamp.opengl.gl4.GL4bcImpl

GL2    : true
GL2GL3 : true
GL3    : true
GL3bc  : false
GL4    : true
GL4ES3 : true
GL4bc  : false


Additionnaly,  when I explicitely ask for GLProfile.get(GLProfile.GL4bc), I got

Exception in thread "main" com.jogamp.opengl.GLException: Profile GL4bc is not available on null, but: [GLProfile[GL2ES1/GL2.hw], GLProfile[GL4ES3/GL4.hw], GLProfile[GL2ES2/GL4.hw], GLProfile[GL2/GL2.hw], GLProfile[GL2/GL2.hw], GLProfile[GL4/GL4.hw], GLProfile[GL3/GL4.hw], GLProfile[GL2GL3/GL4.hw]]
        at com.jogamp.opengl.GLProfile.get(GLProfile.java:991)
        at com.jogamp.opengl.GLProfile.get(GLProfile.java:1004)
        at org.jzy3d.demos.debugGL.GetOpenGLVersion_JOGL.main(GetOpenGLVersion_JOGL.java:24)

Whereas when I ask for GLProfile glp = GLProfile.getMaximum(true); - like in the example, I got a jogamp.opengl.gl4.GL4bcImpl


---------------------------------------

import com.jogamp.opengl.GL;
import com.jogamp.opengl.GLAutoDrawable;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.GLDrawableFactory;
import com.jogamp.opengl.GLProfile;

/**
 * This shows how to switch OpenGL version with JOGL.
 *
 * It requires to invoke the JVM with -Djogl.disable.openglcore=true to work.
 *
 * @see https://forum.jogamp.org/Selecting-the-highest-possible-GL-profile-at-runtime-td4041302.html
 */
public class GetOpenGLVersion_JOGL {

  public static void main(String[] args) throws Exception {
   
    // ------------------------------------------------------
    // Profile & capabilities
   
    //GLProfile glp = GLProfile.getDefault();
    //GLProfile glp = GLProfile.get(GLProfile.GL4bc);
    GLProfile glp = GLProfile.getMaximum(true);

    GLCapabilities caps = new GLCapabilities(glp);
    caps.setOnscreen(false);

    // ------------------------------------------------------
    // Drawable to get a GL context

    GLDrawableFactory factory = GLDrawableFactory.getFactory(glp);
    GLAutoDrawable drawable =
        factory.createOffscreenAutoDrawable(factory.getDefaultDevice(), caps, null, 100, 100);
    drawable.display();
    drawable.getContext().makeCurrent();

    GL gl = drawable.getContext().getGL();


    // ------------------------------------------------------
    // Report
   
    System.out.println("PROFILE       : " + glp);
    System.out.println("CAPS (query)  : " + caps);
    System.out.println("CAPS (found)  : " + drawable.getChosenGLCapabilities());
   
    System.out.println(getDebugInfo(gl));
   
    System.out.println("GL2    : " + GLProfile.isAvailable(GLProfile.GL2));
    System.out.println("GL2GL3 : " + GLProfile.isAvailable(GLProfile.GL2GL3));
    System.out.println("GL3    : " + GLProfile.isAvailable(GLProfile.GL3));
    System.out.println("GL3bc  : " + GLProfile.isAvailable(GLProfile.GL3bc));
    System.out.println("GL4    : " + GLProfile.isAvailable(GLProfile.GL4));
    System.out.println("GL4ES3 : " + GLProfile.isAvailable(GLProfile.GL4ES3));
    System.out.println("GL4bc  : " + GLProfile.isAvailable(GLProfile.GL4bc));

    // ------------------------------------------------------
    // Try invoking something

   
    //gl.getGL2().glClear(0);
   
    gl.getGL4bc().glClear(0);
   

    // ------------------------------------------------------
    // We are done, release context for further work
   
    drawable.getContext().release();
  }

  public static String getDebugInfo(GL gl) {
    StringBuffer sb = new StringBuffer();
    sb.append("GL_VENDOR     : " + gl.glGetString(GL.GL_VENDOR) + "\n");
    sb.append("GL_RENDERER   : " + gl.glGetString(GL.GL_RENDERER) + "\n");
    sb.append("GL_VERSION    : " + gl.glGetString(GL.GL_VERSION) + "\n");
   
    String ext = gl.glGetString(GL.GL_EXTENSIONS);

    if(ext!=null) {
      sb.append("GL_EXTENSIONS : " + "\n");
      for(String e: ext.split(" ")) {
        sb.append("\t" + e + "\n");
      }
    }
    else {
      sb.append("GL_EXTENSIONS : null\n");      
    }
   
    sb.append("GL INSTANCE : " + gl.getClass().getName() + "\n");
   
    return sb.toString();
  }
 
}