Java 屏幕渲染

Question

我正在努力学习 Java 游戏开发，希望有一天能上大学。我目前正在学习教程并学习基础知识。但是，在遵循教程后，我的渲染并未完全渲染，它仅渲染了预期屏幕的一半。以下代码是我使用过的两个类。我是否搞砸了构造函数、缩放，this.height 是否不正确？我似乎无法弄清楚。

public class Game extends Canvas implements Runnable{

private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9;
public static int scale = 3;

private Thread thread;
private JFrame frame;
private boolean running = false;

private Screen screen;

private BufferedImage image = new BufferedImage(width, height, 
BufferedImage.TYPE_INT_RGB);
private int[] pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData();

public Game() {
    Dimension size = new Dimension(width * scale, height * scale);
    setPreferredSize(size);

    screen = new Screen(width, height);
    frame = new JFrame();

}

public synchronized void start() {
    running = true;
    thread = new Thread(this, "Display");
    thread.start();
}

public synchronized void stop() {
    running = false;
    try {
    thread.join();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

public void run() {         
    while (running) {
        update();
        render();
    }
}

public void update() {

}

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

    screen.render();        
    for (int i  = 0; i < pixels.length; i++) {
        pixels[i] = screen.pixels[i];
    }

    Graphics g = bs.getDrawGraphics();
    g.setColor(new Color(0,0,0));
    g.fillRect(0, 0, getWidth(), getHeight());
    g.drawImage(image, 0, 0, getWidth(), getHeight(), null);
    g.dispose();
    bs.show();
}


public static void main(String[] args) {
    Game game = new Game();
    game.frame.setResizable(false);
    game.frame.setTitle("My First Game");
    game.frame.add(game);
    game.frame.pack();
    game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    game.frame.setLocationRelativeTo(null);
    game.frame.setVisible(true);

    game.start();

    }
}


public class Screen {

private int width, height;
public int[] pixels;

public Screen(int width, int height) {
    this.width = width;
    this.height = height;
    pixels = new int[width * height];
}

public void render() {
    for (int y = 0; y < height; y++ ) {
        for (int x = 0; x < height; x++ ) {
            pixels[x + y * width] =(0xFF00FF);
            }
    }

}
}

Answer 1

为了使整个屏幕呈现粉红色，您需要进行 2 项调整:

1) 在第 5 行计算高度时更改操作数的顺序，以便先乘后除，如下所示:

public static int height = width * 9 / 16;

原因:表达式是从左到右计算的。由于所有运算符都是整数，因此每个子表达式的结果都会向下舍入。查看差异:

300 / 16 * 9 = 18 * 9 = 162

对比

300 * 9 / 16 = 2700 / 16 = 168

2) render 方法中有一个拼写错误，两次使用了 height 而不是 width。因此渲染出一个矩形。您需要将内部 for 循环中的 height 变量更改为 width。

public void render() {
    for (int y = 0; y < height; y++) {
        for (int x = 0; x < width; x++) { // use width here instead of height
            pixels[x + y * width] = (0xFF00FF);
        }
    }
}