Making my first attempt at a 2D two-player game in Java, but without using any external libraries. The issue I am running into is I am trying to split the window in half so two people can play the game against each other. I have successfully been able to create a second window using GridLayout, but the second screen is all white. This seems like it could work, but it creates two windows when I would rather it be just one. Otherwise, the window displays fine and has all my GameObjects displayed when it is not split and I was able to implement a camera object to track player 1. I have provided both Game() and Window() for reference. I have also read about getSubimage, is that a better way to achieve my goal?

public void tick() {
        for (int i=0; i<handler.object.size(); i  ) {
            if (handler.object.get(i).getId() == ID.Player) {
                camera.tick(handler.object.get(i));
            }
        }
        handler.tick();
    }

    public void render() {
        BufferStrategy bs = this.getBufferStrategy();
        if (bs == null) {
            this.createBufferStrategy(3);
            return;
        }

        Graphics g = bs.getDrawGraphics();
        Graphics2D g2d = (Graphics2D) g;
        //////////////////////////////////////////////
        //// This is where graphics is displayed /////

        //g.setColor(Color.red);
        //g.fillRect(0,0, 1000, 563);

        g2d.translate(-camera.getX(), -camera.getY());

        for (int xx=0; xx<30*72; xx =32) {
            for (int yy=0; yy<30*72; yy =32) {
                g.drawImage(floor, xx, yy,null);
            }
        }

        handler.render(g);

        g2d.translate(camera.getX(), camera.getY());

        //hp Player 1 display
        g.setColor(Color.gray);
        g.fillRect(5,5,200,32);
        g.setColor(Color.green);
        g.fillRect(5,5,hpPlayer1*2,32);
        g.setColor(Color.black);
        g.drawRect(5,5,200,32);

        //ammo display player 1
        g.setColor(Color.white);
        g.drawString("Ammo: "   ammoPlayer1,10,50);

        //Player 1 total points
        g.setColor(Color.GREEN);
        g.drawString("Points: "   pointsPlayer1, 110, 50);

        //hp Player 2 display
        g.setColor(Color.gray);
        g.fillRect(780,5,200,32);
        g.setColor(Color.green);
        g.fillRect(780,5,hpPlayer2*2,32);
        g.setColor(Color.black);
        g.drawRect(780,5,200,32);

        //ammo display player 2
        g.setColor(Color.white);
        g.drawString("Ammo: "   ammoPlayer2,790,50);

        //Player 2 total points
        g.setColor(Color.GREEN);
        g.drawString("Points: "   pointsPlayer2, 890, 50);

        ///// End of Graphics Displayed /////
        /////////////////////////////////////
        g.dispose();
        bs.show();
    }
    //Loading level
    private void loadLevel(BufferedImage image) {
        int w = image.getWidth();
        int h = image.getHeight();

        for (int xx=0; xx<w; xx  ) {
            for (int yy=0; yy<h; yy  ) {
                int pixel = image.getRGB(xx, yy);
                int red = (pixel >> 16) & 0xff;
                int green = (pixel >> 8) & 0xff;
                int blue = (pixel) & 0xff;

                // wall
                if (red == 255 && green == 0 && blue == 0)
                    handler.addObject(new Block(xx*32,yy*32, ID.Block, ss));
                // Breakable Wall
                if (red == 255 && green == 128 && blue == 0)
                    handler.addObject(new BreakableBlock(xx*32,yy*32,ID.BreakableBlock,handler,ss));
                // player 1
                if (red == 0 && green == 0 && blue == 255)
                    handler.addObject(new Tank(xx*32,yy*32, ID.Player, handler,this, ss));
                // player 2
                if (red == 255 && green == 255 && blue == 0)
                    handler.addObject(new Tank(xx*32,yy*32, ID.Player2, handler,this, ss));
                // enemy
                if (red == 0 && green == 255 && blue == 0)
                    handler.addObject(new MovableEnemy(xx*32,yy*32, 
                                ID.MovableEnemy,handler,this,ss));
                //if (red == 125 && green == 125 && blue == 0)
                //handler.addObject(new FollowEnemy(xx*32,yy*32, ID.FollowEnemy, handler,this, ss));
                // crate
                if (red == 0 && green == 255 && blue == 255)
                    handler.addObject(new Crate(xx*32,yy*32, ID.Crate, ss));
                // overshield
                if (red == 200 && green == 0 && blue == 200)
                    handler.addObject(new Overshield(xx*32,yy*32, ID.Overshield, ss));
            }
        }

    }

public class Window {
    public Window(int width, int height, String title, Game game) {
        JFrame frame = new JFrame(title);

        // size of frame
        frame.setPreferredSize(new Dimension(width, height));
        frame.setMaximumSize(new Dimension(width, height));
        frame.setMinimumSize(new Dimension(width, height));

        /*frame.setSize(new Dimension(width, height));
        GridLayout layout = new GridLayout(2,1);
        frame.setLayout(layout);*/

        frame.add(game); //add in game class to frame
        //frame.add(game);
        frame.pack();

        frame.setResizable(false); //cannot resize window
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null); //when game started box will start center of window
        frame.setVisible(true); //lets us see window
    }
}