添加背景图片时Java游戏速度变慢

Question

I am having this problem whenever I load a background image no matter how small the size of the image. I am adding an image of 1010x600 png picture with a size of 3.81kb. I am using timer from swing in order to repaint this. The game just slows down whenever I add and paint the bg.paintIcon method.

public void paintComponent(Graphics g){
    super.paintComponent(g);
    bg.paintIcon(null, g, 0, 0);
    p.img.paintIcon(null, g, p.x, p.y);
    g2p = (Graphics2D)g;
    g2p.setColor(Color.green);
    g2p.fillRect(20, 10, (int)Math.ceil((p.health/1000.0)*960), 20);
    life.paintIcon(null, g, 0, 8);

    g2p.setColor(Color.black);
    g2p.drawRect(19, 34, 960+1, 20+1);
    g2p.setColor(Color.blue);
    g2p.fillRect(20, 35, (int)Math.ceil((p.mana/500.0)*960), 20);

    //System.out.println(df.format(p.health/1000.0));
    jl.setLocation(p.x, p.y);
    //jl.setText("Current Health: "+p.health);
    for (int i = 0 ; i < 20 ; i++){//IMPORTANT
        g2[i] = (Graphics2D) g;
        e[i].img.paintIcon(null, g, e[i].getx(), e[i].gety());
        if (e[i].dead){
            gen[i] = new Thread(new Generation(i));
            if (letalive){
                letalive = false;
                gen[i].start();
            }
        }
    }
}

Answer 1

Your paintComponent code should paint. Period. Nothing else.

Here's how your paintComponent method should look.

public void paintComponent(Graphics g){
    super.paintComponent(g);
    bg.paintIcon(null, g, 0, 0);
    p.img.paintIcon(null, g, p.x, p.y);
    g2p = (Graphics2D)g;
    g2p.setColor(Color.green);
    g2p.fillRect(20, 10, (int)Math.ceil((p.health/1000.0)*960), 20);
    life.paintIcon(null, g, 0, 8);

    g2p.setColor(Color.black);
    g2p.drawRect(19, 34, 960+1, 20+1);
    g2p.setColor(Color.blue);
    g2p.fillRect(20, 35, (int)Math.ceil((p.mana/500.0)*960), 20);

    //System.out.println(df.format(p.health/1000.0));
    jl.setLocation(p.x, p.y);
    //jl.setText("Current Health: "+p.health);
    for (int i = 0 ; i < 20 ; i++){//IMPORTANT
        e[i].img.paintIcon(null, g, e[i].getx(), e[i].gety());
    }
}

This code belongs in your controller.

   for (int i = 0 ; i < 20 ; i++) {
       if (e[i].dead){
            gen[i] = new Thread(new Generation(i));
            if (letalive){
                letalive = false;
                gen[i].start();
            }
        }
    }