java - Swing 动画

Question

我有一个动画，希望当它到达显示区域的左侧时逐渐消失。

AffineTransform at = new AffineTransform();
at.scale(-1, 1);
at.translate((-clip.x + (clip.x - xPositionToPixel(imgX))), clip.y - 1);
if ((clip.x - clip.width) < (at.getTranslateX() - bufImg.getWidth())) {
  g2d.drawImage(bufImg, at, null);
} else {
at = new AffineTransform();
                    at.scale(-1, 1);
                    at.translate((-clip.x + (clip.x - xPositionToPixel(imgX))), clip.y - 1);
                    g2d.drawImage(bufImg, (int)at.getTranslateX(), clip.y - 1, (int)(bufImg.getWidth() - (xPositionToPixel(imgX) + bufImg.getWidth())), clip.height, null);
}

我从右向左绘制动画，这就是我缩放和平移每个坐标的原因。 Clip.x 是显示区域的起点，imgX 是新的 x 坐标。

感谢您的帮助。

我尝试了几种方法来实现我想要的，最接近的是:

AffineTransform at = new AffineTransform();
at.scale(-1, 1);
at.translate((-clip.x + (clip.x - xPositionToPixel(imgX))), clip.y - 1);

if ((clip.x - clip.width) < (at.getTranslateX() - bufImg.getWidth())) {
  g2d.drawImage(bufImg, at, null);
} else { 
at = new AffineTransform();
                    at.scale(-1, 1);
                    at.translate((-clip.x + (clip.x - xPositionToPixel(imgX))), clip.y - 1);
                    g2d.drawImage(bufImg, (int)at.getTranslateX(), clip.y - 1, (int)(bufImg.getWidth() - (xPositionToPixel(imgX) + bufImg.getWidth())), clip.height, null);
}

但仍然不是一个好的解决方案，我只是缩小图像的宽度，但仍然完全绘制它。

Answer 1

仍然不知道问题到底是什么(动画还是变换？)，这里有一个简单的代码片段:

    final JButton button = new JButton("Swinging!");
    button.setSize(button.getPreferredSize());
    button.doLayout();
    final BufferedImage image = new BufferedImage(
            button.getWidth(), button.getHeight(), BufferedImage.TYPE_INT_RGB);
    Graphics2D g = image.createGraphics();
    button.paint(g);
    g.dispose();
    final Point location = new Point(500, 100);
    final JPanel panel = new JPanel() {
        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D gd = (Graphics2D) g.create();
            gd.translate(location.x, location.y);
            gd.scale(-1, 1);
            gd.drawImage(image, 0, 0, this);
            gd.dispose();
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(button.getWidth()* 10, button.getHeight() * 20);
        }


    };
    ActionListener l = new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            location.x -= 5;
            panel.repaint();
            if (location.x < - button.getWidth()) {
                ((Timer) e.getSource()).stop();
            }
        }
    };
    new Timer(100, l).start();