// The native method for swapBuffers - onscreen only
@Override
void swapBuffers(Canvas3D cv, Context ctx, Drawable drawable) {
if (VERBOSE) System.err.println("JoglPipeline.swapBuffers()");
GLDrawable draw = drawable(drawable);
draw.swapBuffers();
}
// native method for setting Material when no material is present
@Override
void updateMaterialColor(Context ctx, float r, float g, float b, float a) {