Java,如何绘制不断变化的图形

以下是我的主要重写,其中有以下值得注意的变化:

• 我已经换了robot.getPixelColor(…)带robot.createScreenscapture创建(…)一次获取所有64个像素,而不是一次获取一个像素
• 我已经修复了线程,所以模型和视图的所有更新都发生在事件调度线程上

自动售票机不停地运行。当它检测到像素颜色的变化(由于鼠标移动到不同的区域或鼠标下的像素发生变化)时,它准确地检测到发生了什么变化,更新模型,然后请求视图重新绘制。这种方法会立即更新到人眼。289次屏幕更新累计耗时1秒。

对于一个安静的周六晚上来说,这是一个令人愉快的挑战。

import javax.swing.*;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;

public class ZoomPanel extends JPanel {

    private static final int STEP = 40;
    private int iter = 0;
    private long cumulativeTimeTaken = 0;


    public static void main(String[] args) {
        final JFrame frame = new JFrame("Image zoom");

        final ZoomPanel zoomPanel = new ZoomPanel();
        frame.getContentPane().add(zoomPanel);
        final Ticker t = new Ticker(zoomPanel);

        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent we) {
                t.done();
                frame.dispose();
            }
        });
        t.start();

        frame.setLocation(new Point(640, 0));
        frame.pack();
        frame.setVisible(true);
    }

    private final Color[][] model = new Color[8][8];

    public ZoomPanel() {
        setSize(new Dimension(400, 400));
        setMinimumSize(new Dimension(400, 400));
        setPreferredSize(new Dimension(400, 400));
        setOpaque(true);
    }

    private void setColorAt(int x, int y, Color pixelColor) {
        model[x][y] = pixelColor;
        repaint(40 + x * STEP, 45 + y * STEP, 40 + (x * STEP) - 3, 45 + (y * STEP) - 3);
    }

    private Color getColorAt(int x, int y) {
        return model[x][y];
    }

    public void paintComponent(Graphics g) {
        long start = System.currentTimeMillis();
        if (!SwingUtilities.isEventDispatchThread()) {
            throw new RuntimeException("Repaint attempt is not on event dispatch thread");
        }
        final Graphics2D g2 = (Graphics2D) g;
        g2.setColor(getBackground());
        try {

            for (int x = 0; x < 8; x++) {
                for (int y = 0; y < 8; y++) {
                    g2.setColor(model[x][y]);
                    Ellipse2D e = new Ellipse2D.Double(40 + x * STEP, 45 + y * STEP, STEP - 3, STEP - 3);
                    g2.fill(e);
                    g2.setColor(Color.GRAY);
                    g2.draw(e);
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        iter++;
        g2.setColor(Color.black);
        long stop = System.currentTimeMillis();
        cumulativeTimeTaken += stop - start;
        StringBuilder sb = new StringBuilder();
        sb.append(iter)
                .append(" frames in ")
                .append((double) (cumulativeTimeTaken) / 1000)
                .append("s.");

        System.out.println(sb);
    }

    private static class Ticker extends Thread {

        private final Robot robot;

        public boolean update = true;
        private final ZoomPanel view;

        public Ticker(ZoomPanel zoomPanel) {
            view = zoomPanel;
            try {
                robot = new Robot();
            } catch (AWTException e) {
                throw new RuntimeException(e);
            }
        }

        public void done() {
            update = false;
        }

        public void run() {
            int runCount = 0;
            while (update) {
                runCount++;
                if (runCount % 100 == 0) {
                    System.out.println("Ran ticker " + runCount + " times");
                }
                final Point p = MouseInfo.getPointerInfo().getLocation();

                Rectangle rect = new Rectangle(p.x - 4, p.y - 4, 8, 8);
                final BufferedImage capture = robot.createScreenCapture(rect);

                for (int x = 0; x < 8; x++) {
                    for (int y = 0; y < 8; y++) {
                        final Color pixelColor = new Color(capture.getRGB(x, y));

                        if (!pixelColor.equals(view.getColorAt(x, y))) {
                            final int finalX = x;
                            final int finalY = y;
                            SwingUtilities.invokeLater(new Runnable() {
                                public void run() {
                                    view.setColorAt(finalX, finalY, pixelColor);
                                }
                            });
                        }
                    }
                }

            }
        }

    }

}

如果你不介意用Swing,这个 example BufferedImage Icon . 在您的情况下,您需要8x8 缓冲图像 被填满了 mouseMoved() 用机器人看到的像素。

附录:这是你例子左上角的快照。

缩放本身并不重要。。。

example .

createScreenCapture() 史蒂夫·麦克劳德建议的方法很快,这是我的想法。您可以看到它的更新也更加顺利。请注意,松开鼠标按钮可以看到捕获的颜色。

import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;

/** @see https://stackoverflow.com/questions/3742731 */
public class Zoom extends JPanel implements MouseMotionListener {

    private static final int SIZE = 16;
    private static final int S2 = SIZE / 2;
    private static final int SCALE = 48;
    private BufferedImage img;
    private Robot robot;

    public Zoom() {
        super(true);
        this.setPreferredSize(new Dimension(SIZE * SCALE, SIZE * SCALE));
        img = new BufferedImage(SIZE, SIZE, BufferedImage.TYPE_INT_RGB);
        try {
            robot = new Robot();
        } catch (AWTException e) {
            e.printStackTrace(System.err);
        }
    }

    @Override
    protected void paintComponent(Graphics g) {
        g.drawImage(img, 0, 0, getWidth(), getHeight(), null);
    }

    @Override
    public void mouseMoved(MouseEvent e) {
        Point p = e.getPoint();
        int x = p.x * SIZE / getWidth();
        int y = p.y * SIZE / getHeight();
        int c = img.getRGB(x, y);
        this.setToolTipText(x + "," + y + ": "
            + String.format("%08X", c));
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        int x = e.getXOnScreen();
        int y = e.getYOnScreen();
        Rectangle rect = new Rectangle(x - S2, y - S2, SIZE, SIZE);
        img = robot.createScreenCapture(rect);
        repaint();
    }

    private static void create() {
        JFrame f = new JFrame("Click & drag to zoom.");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Zoom zoom = new Zoom();
        f.add(zoom);
        f.pack();
        f.setVisible(true);
        zoom.addMouseMotionListener(zoom);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                create();
            }
        });
    }
}

public void clear(Graphics g, Color currentColor) {
    g.setColor(backgroundColor);
    g.fillRect(0, 0, width, height);
    g.setColor(currentColor);
    int delay = 5; //milliseconds

    ActionListener taskPerformer = new ActionListener() {
    public void actionPerformed(ActionEvent evt) { } };

    new Timer(delay, taskPerformer).start();
} //run this right before you draw something

只需使用时间延迟循环。你呢然后可以通过调整i的限制来微调延迟。它还可以通过一些点击和试验来控制调整过渡速度。

对于(长i=0;i<=10000000000;i++);

画布.重绘();