glcanvas.setCurrent();
GLProfile glprofile = GLProfile.getDefault();
final GLContext glcontext = GLDrawableFactory.getFactory( glprofile ).createExternalGLContext();
// fix the viewport when the user resizes the window
glcanvas.addListener( SWT.Resize, new Listener() {
public void handleEvent(Event event) {
Rectangle rectangle = glcanvas.getClientArea();
glcanvas.setCurrent();
glcontext.makeCurrent();
OneTriangle.setup( glcontext.getGL().getGL2(), rectangle.width, rectangle.height );