JOGL creating window using NEWT - examples?

Question

I have been looking at using JOGL to create some things and have been looking through what documentation I can find.

Brief tutorials they all mention how using the JOGL version of canvas can have performance issues and instead you should use NEWT. However each and every tutorial / FAQ then goes on to use the canvas! Or simply specify a few tiny snippets of methods to create a window using NEWT but which (on my machine at least) I cannot get to correctly run.

Does anyone have a good source of examples of how to correctly implement creating and rendering to a window in JOGL using the NEWT method? I'm not even sure how it functions compared to the Canvas so an explanation of the differences between the two and a typical layout of methods to create / manage / render to a window would be ideal.

Just a little lost and cannot find anything useful. Hope someone's come across something before!

Answer 1

This tutorial helped me a lot, see chapter 3.9 - Yet Another Tutorial on JOGL. Also documentation is useful. Take a look at the attached example, please.

JOGL2NewtDemo.java

import javax.media.opengl.GLCapabilities;
import javax.media.opengl.GLProfile;
import com.jogamp.newt.event.WindowAdapter;
import com.jogamp.newt.event.WindowEvent;
import com.jogamp.newt.opengl.GLWindow;
import com.jogamp.opengl.util.FPSAnimator;

/**
 * A program that draws with JOGL in a NEWT GLWindow.
 *
 */
public class JOGL2NewtDemo {
    private static String TITLE = "JOGL 2 with NEWT";  // window's title
    private static final int WINDOW_WIDTH = 640;  // width of the drawable
    private static final int WINDOW_HEIGHT = 480; // height of the drawable
    private static final int FPS = 60; // animator's target frames per second

    static {
        GLProfile.initSingleton();  // The method allows JOGL to prepare some Linux-specific locking optimizations
    }

    /**
     * The entry main() method.
     */
    public static void main(String[] args) {
        // Get the default OpenGL profile, reflecting the best for your running platform
        GLProfile glp = GLProfile.getDefault();
        // Specifies a set of OpenGL capabilities, based on your profile.
        GLCapabilities caps = new GLCapabilities(glp);
        // Create the OpenGL rendering canvas
        GLWindow window = GLWindow.create(caps);

        // Create a animator that drives canvas' display() at the specified FPS.
        final FPSAnimator animator = new FPSAnimator(window, FPS, true);

        window.addWindowListener(new WindowAdapter() {
            @Override
            public void windowDestroyNotify(WindowEvent arg0) {
                // Use a dedicate thread to run the stop() to ensure that the
                // animator stops before program exits.
                new Thread() {
                    @Override
                    public void run() {
                        if (animator.isStarted())
                            animator.stop();    // stop the animator loop
                        System.exit(0);
                    }
                }.start();
            }
        });

        window.addGLEventListener(new JOGL2Renderer());
        window.setSize(WINDOW_WIDTH, WINDOW_HEIGHT);
        window.setTitle(TITLE);
        window.setVisible(true);
        animator.start();  // start the animator loop
    }
}

JOGL2Renderer.java

import javax.media.opengl.GL;
import javax.media.opengl.GL2;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLEventListener;

/**
 * Class handles the OpenGL events to render graphics.
 *
 */
public class JOGL2Renderer implements GLEventListener {
    private double theta = 0.0f;  // rotational angle

    /** 
     * Called back by the drawable to render OpenGL graphics 
     */
    @Override
    public void display(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();   // get the OpenGL graphics context

        gl.glClear(GL.GL_COLOR_BUFFER_BIT);    // clear background
        gl.glLoadIdentity();                   // reset the model-view matrix    

          // Rendering code - draw a triangle
        float sine = (float)Math.sin(theta);
        float cosine = (float)Math.cos(theta);
        gl.glBegin(GL.GL_TRIANGLES);
        gl.glColor3f(1, 0, 0);
        gl.glVertex2d(-cosine, -cosine);
        gl.glColor3f(0, 1, 0);
        gl.glVertex2d(0, cosine);
        gl.glColor3f(0, 0, 1);
        gl.glVertex2d(sine, -sine);
        gl.glEnd();

        update();
    }
    
    /** 
     * Update the rotation angle after each frame refresh 
     */
    private void update() {
        theta += 0.01;
    }

    /*... Other methods leave blank ...*/
}

Answer 2

take a look at JOGL's junit tests, they cover large parts of the NEWT API.