仅在圆形边界内移动项目的逻辑

Question

我是游戏编程的新手。我正在尝试开发一个简单的射击游戏。我正在尝试的游戏场地是圆形的。游戏有 1 名射手和 5 名机器人。射手和机器人只能在圆形区域内移动。以下是我尝试过的代码片段。

我尝试使用状态设计模式来实现游戏。 在不允许射击者跨越圆形边界的逻辑中获得结构。 请帮助完成具有更改射手逻辑的StateImpl类 位置。

public class Board extends JPanel implements ActionListener {
        private static final long serialVersionUID = -397810249729996307L;
        private final Timer timer;
        private final Shooter shooter;

    public Board(Point boardDimensions) {
        addKeyListener(new TAdapter());
        setFocusable(true);
        setBackground(Color.WHITE);
        setDoubleBuffered(true);
        setSize(boardDimensions.x, boardDimensions.y);
        shooter = new Shooter(new Point(200, 225), boardDimensions);
        timer = new Timer(5, this);
        timer.start();
    }

    @Override
    public void paint(Graphics g) {
        super.paint(g);
        Graphics2D g2d = (Graphics2D) g;
        // g2d.draw(new Ellipse2D.Double(20, 10,350,350));
        Ellipse2D.Double circle1 = new Ellipse2D.Double(20, 10, 350, 350);
        g2d.draw(circle1);
        g2d.drawImage(shooter.getImage(), shooter.getShooterPosition().x,
                shooter.getShooterPosition().y, this);

        g2d.setColor(Color.BLUE);

        Toolkit.getDefaultToolkit().sync();
        g.dispose();
    }

    /**
     * Called by the AWT just after the user informs the listened-to component
     * that an action should occur.
     */
    public void actionPerformed(ActionEvent e) {
        repaint();
    }

    private class TAdapter extends KeyAdapter {

        @Override
        public void keyPressed(KeyEvent e) {

            // Method to enable use of keys for control of the craft;
            int key = e.getKeyCode();

            if (key == KeyEvent.VK_LEFT) {
                shooter.moveLeft();
            }
            if (key == KeyEvent.VK_UP) {
                shooter.moveForward();
            }
            if (key == KeyEvent.VK_RIGHT) {
                shooter.moveRight();
            }
            if (key == KeyEvent.VK_DOWN) {
                shooter.moveBackward();
            }
        }
    }

    public void twait() {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            System.out.println("main thread interrupted");
        }
    }
}


public class Shooter {

    private Point shooterPosition;

    private final State state;

    protected Image image;

    public Shooter(Point shooterPosition, Point boardSize) {
        super();
        this.shooterPosition = shooterPosition;
        this.state = new StateImpl(this);
        ImageIcon ii = new ImageIcon(this.getClass().getResource("bld2.png"));
        image = ii.getImage();
    }

    public Point getShooterPosition() {
        return shooterPosition;
    }

    public void setShooterPosition(Point shooterPosition) {
        this.shooterPosition = shooterPosition;
    }

    public void moveLeft() {
        this.shooterPosition = state.moveLeft();
    }

    public void moveRight() {
        this.shooterPosition = state.moveright();
    }

    public void moveForward() {
        this.shooterPosition = state.moveForward();
    }

    public void moveBackward() {
        this.shooterPosition = state.moveBackward();
    }

    public Image getImage() {
        return image;
    }

    public void setImage(Image image) {
        this.image = image;
    }

    @Override
    public String toString() {
        return "Shooter [shooterPosition=" + shooterPosition + ", state="
                + state + ", image=" + image + "]";
    }

}


public interface State {

    public Point moveForward();

    public Point moveBackward();

    public Point moveLeft();

    public Point moveright();

    public void shoot();

}

public class StateImpl implements State {

    private final Shooter shooter;
    private final int boardSize = 200;

    public StateImpl(Shooter shooter) {
        this.shooter = shooter;
    }

    public Point moveForward() {
        Point currentShooterPosition = this.shooter.getShooterPosition();
        int newY = (currentShooterPosition.y + 1) > boardSize ? boardSize
                : currentShooterPosition.y + 1;
        return new Point(currentShooterPosition.x, newY);
    }

    public Point moveBackward() {
        Point currentShooterPosition = this.shooter.getShooterPosition();
        return new Point(currentShooterPosition.x, currentShooterPosition.y - 1);
    }

    public Point moveLeft() {
        Point currentShooterPosition = this.shooter.getShooterPosition();
        return new Point(currentShooterPosition.x - 1, currentShooterPosition.y);
    }

    public Point moveright() {

        Point currentShooterPosition = this.shooter.getShooterPosition();
        int newX = (currentShooterPosition.x + 1) > boardSize ? boardSize
                : currentShooterPosition.x + 1;
        return new Point(newX, currentShooterPosition.y);
    }

    public void shoot() {

    }
}

Answer 1

不要在 Paint() 方法中初始化圆，而是将其（更重要的是其中心）保留在类变量中。然后，每当射手移动时，测量圆心与射手新位置之间的距离。如果该距离大于圆的半径，则阻止射击者的移动。