public class GLRenderer implements GLEventListener
{
    public void init(GLAutoDrawable drawable)
    {
        GL gl = drawable.getGL();
        gl.glClearColor(0f,0f,1f,1f);
    }
    public void display(GLAutoDrawable drawable)
    {
        GL gl = drawable.getGL();
        gl.glClear(GL.GL_COLOR_BUFFER_BIT);
        gl.glColor3f(1f, 0f, 0f);
        gl.glRectf(-25f,25f,25f,-25f);
        gl.glFlush();
    }
    public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height)
    {
        GL gl = drawable.getGL();
        float aspectRatio;
        if(height == 0)
            height = 1;
        gl.glViewport(0,0,width,height);
        gl.glMatrixMode(GL.GL_PROJECTION);
        gl.glLoadIdentity();
        aspectRatio=(float) width/ (float) height;
        if(width<height)
            gl.glOrtho(-100,100,-100/aspectRatio,100/aspectRatio,1,-1);
        else
            gl.glOrtho(-100*aspectRatio,100*aspectRatio,-100,100,1,-1);
        gl.glMatrixMode(GL.GL_MODELVIEW);
        gl.glLoadIdentity();
    }
    public void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged)
    {
    }
}