java Swing 图片缓冲机制-白红宇

java Swing 图片缓冲机制

阅读量：7053 次

发布时间：2019-06-28

本文共 11345 字，大约阅读时间需要 37 分钟。

java Swing 图片缓冲机制：

参考：http://jorneyr.iteye.com/blog/868858#comments

package util;import java.awt.geom.Point2D;public class GeometryUtil {    // 两点之间的距离    public static double distanceOfPoints(Point2D p1, Point2D p2) {        double disX = p2.getX() - p1.getX();        double disY = p2.getY() - p1.getY();        double dis = Math.sqrt(disX * disX + disY * disY);        return dis;    }    // 两点的中点    public static Point2D middlePoint(Point2D p1, Point2D p2) {        double x = (p1.getX() + p2.getX()) / 2;        double y = (p1.getY() + p2.getY()) / 2;        return new Point2D.Double(x, y);    }    // 在两点所在直线上，以从startPoint到endPoint为方向，离startPoint的距离disToStartPoint的点    public static Point2D extentPoint(Point2D startPoint, Point2D endPoint, double disToStartPoint) {        double disX = endPoint.getX() - startPoint.getX();        double disY = endPoint.getY() - startPoint.getY();        double dis = Math.sqrt(disX * disX + disY * disY);        double sin = (endPoint.getY() - startPoint.getY()) / dis;        double cos = (endPoint.getX() - startPoint.getX()) / dis;        double deltaX = disToStartPoint * cos;        double deltaY = disToStartPoint * sin;        return new Point2D.Double(startPoint.getX() + deltaX, startPoint.getY() + deltaY);    }    // 绕原点的旋转矩阵，绕任意点旋转，可以先移动到原点，旋转，然后再移回去    // cosθ -sinθ 0    // sinθ +conθ 0    // 0000 +0000 1    // x = r*cosα, y = r*sinα    // x' = r*cos(α+θ) = r*cosα*cosθ - r*sinα*sinθ = x*cosθ - y*sinθ    // y' = r*sin(α+θ) = r*sinα*cosθ + r*cosα*sinθ = x*sinθ + y*cosθ    // (x, y)绕圆心旋转degree度    public static Point2D rotate(double x, double y, double degree) {        return rotate(x, y, 0, 0, degree);    }    // (x, y)绕(ox, oy)旋转degree度    public static Point2D rotate(double x, double y, double ox, double oy, double degree) {        x -= ox;        y -= oy;        double cos = Math.cos(Math.toRadians(degree));        double sin = Math.sin(Math.toRadians(degree));        double temp = x * cos - y * sin;        y = x * sin + y * cos;        x = temp;        return new Point2D.Double(x + ox, y + oy);    }    public static void main(String[] args) {        Point2D p = rotate(50, 10, 10);        System.out.println(p);        p = rotate(100, 60, 50, 50, 10);        System.out.println(p);    }}

import java.awt.Color;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.GraphicsConfiguration;import java.awt.GraphicsDevice;import java.awt.GraphicsEnvironment;import java.awt.RenderingHints;import java.awt.Transparency;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.geom.Point2D;import java.awt.image.BufferedImage;import java.util.ArrayList;import java.util.List;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.SwingUtilities;import javax.swing.Timer;import util.GeometryUtil;@SuppressWarnings("serial")public class Growing extends JPanel {    private List
     
       ps = new ArrayList
      
       ();    private Timer timer;    private boolean stopped = false;    public Growing() {        ps.add(new Point2D.Double(0, 0));        ps.add(new Point2D.Double(800, 0));        timer = new Timer(500, new ActionListener() {            @Override            public void actionPerformed(ActionEvent e) {                grow();                repaint();            }        });        timer.start();    }    public void grow() {        if (stopped) {            return;        }        List
       
         temp = new ArrayList
        
         ();        temp.add(ps.get(0));        for (int i = 0; i < ps.size() - 1; ++i) {            Point2D p0 = ps.get(i);            Point2D p4 = ps.get(i + 1);            double len = GeometryUtil.distanceOfPoints(p0, p4);            if (len < 0.02) {                // 当线条长度小于1时，就停止再增长                System.out.println(ps.size());                timer.stop();                return;            }            Point2D p1 = GeometryUtil.extentPoint(p0, p4, len / 3);            Point2D p3 = GeometryUtil.extentPoint(p0, p4, len * 2 / 3);            Point2D p2 = GeometryUtil.rotate(p3.getX(), p3.getY(), p1.getX(), p1.getY(), 60);            temp.add(p1);            temp.add(p2);            temp.add(p3);            temp.add(p4);        }        // 将增长的计算结果赋予ps变量；        ps = null;        ps = temp;        temp = null;    }    int i = 0; // 记录绘制了几次；    @Override    protected void paintComponent(Graphics g) {        super.paintComponent(g);        Graphics2D g2d = (Graphics2D) g;        // 修改type的值使用不同的绘制方式，1为compatible image, 2为swing的back-buffer        int type = 2;        // 改变窗口的大小，可以看到直接对intermediate image操作比直接对swing back-buffer操作快很多.        // 所以有很多绘制操作时，使用triple buffer是很有必要的(因为Swing已经默认使用了双缓冲).        if (type == 1) {            // [[[1]]]: 操作 compatible image 速度非常快            renderWithBuf(g2d, getWidth(), getHeight());        } else {            // [[[2]]]: 操作Swing的 back-buffer 速度非常慢            render(g2d, getWidth(), getHeight());        }        System.out.println("Growing.paintComponent(Graphics):" + i++);    }    private BufferedImage bufImg;    protected void renderWithBuf(Graphics2D g2d, int w, int h) {        if (bufImg == null || bufImg.getWidth() != w || bufImg.getHeight() != h) {            bufImg = createCompatibleImage(w, h, Transparency.OPAQUE);            // bufImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);        }        Graphics2D gg = bufImg.createGraphics();        render(gg, w, h);        gg.dispose();        g2d.drawImage(bufImg, 0, 0, null);    }    protected void render(Graphics2D g2d, int w, int h) {        g2d.setBackground(Color.BLACK);        g2d.clearRect(0, 0, w, h);        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);        g2d.translate(0, h - 20);        g2d.setColor(Color.WHITE);        for (int i = 0; i < ps.size() - 1; ++i) {            Point2D sp = ps.get(i);            Point2D ep = ps.get(i + 1);            g2d.drawLine((int) sp.getX(), -(int) sp.getY(), (int) ep.getX(), -(int) ep.getY());        }    }    // 创建硬件适配的缓冲图像，为了能显示得更快速    public static BufferedImage createCompatibleImage(int w, int h, int type) {        GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();        GraphicsDevice device = env.getDefaultScreenDevice();        GraphicsConfiguration gc = device.getDefaultConfiguration();        return gc.createCompatibleImage(w, h, type);    }    private static void createGuiAndShow() {        JFrame frame = new JFrame("Growing");        frame.getContentPane().add(new Growing());        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        frame.setSize(800, 400);        frame.setAlwaysOnTop(true);        frame.setLocationRelativeTo(null);        frame.setVisible(true);    }    public static void main(String[] args) {        SwingUtilities.invokeLater(new Runnable() {            @Override            public void run() {                createGuiAndShow();            }        });    }}

import java.awt.geom.Point2D;import java.util.ArrayList;import java.util.List;import org.eclipse.swt.SWT;import org.eclipse.swt.events.PaintEvent;import org.eclipse.swt.events.PaintListener;import org.eclipse.swt.graphics.GC;import org.eclipse.swt.graphics.Image;import org.eclipse.swt.graphics.Rectangle;import org.eclipse.swt.graphics.Transform;import org.eclipse.swt.layout.FillLayout;import org.eclipse.swt.widgets.Canvas;import org.eclipse.swt.widgets.Display;import org.eclipse.swt.widgets.Shell;import util.GeometryUtil;public class GrowingSWT{    private final Shell shell;    private final Canvas canvas;    private List
     
       ps = new ArrayList
      
       ();    private boolean stopped = false;    Image image = null;    int type = 1;    private final Runnable timer = new Runnable() {        public void run()        {            shell.getDisplay().timerExec(500, timer);            grow();            canvas.redraw();        }    };    GrowingSWT(final Display display)    {        shell = new Shell(display, SWT.DOUBLE_BUFFERED | SWT.SHELL_TRIM);        shell.setLayout(new FillLayout());        canvas = new Canvas(shell, SWT.NULL);        canvas.addPaintListener(new PaintListener() {            public void paintControl(PaintEvent e)            {                long time = System.currentTimeMillis();                if (type == 1) {                    e.gc.drawImage(getBuffer(false), 0, 0);                } else {                    render(e.gc);                }                time = System.currentTimeMillis() - time;                if (time > 10) {                    System.out.println(time);                }            }        });        ps.add(new Point2D.Double(0, 0));        ps.add(new Point2D.Double(800, 0));        display.timerExec(500, timer);    }    Image getBuffer( boolean withRefresh)    {        Rectangle bounds = canvas.getBounds();        if (image == null || !image.getBounds().equals(bounds)) {            image = new Image(shell.getDisplay(), bounds);            renderWithBuffer(image);        } else if (withRefresh) {            renderWithBuffer(image);        }        return image;    }    public void grow()    {        if (stopped) {            return;        }        List
       
         temp = new ArrayList
        
         ();        temp.add(ps.get(0));        for (int i = 0; i < ps.size() - 1; ++i) {            Point2D p0 = ps.get(i);            Point2D p4 = ps.get(i + 1);            double len = GeometryUtil.distanceOfPoints(p0, p4);            if (len < 0.1) {                // 当线条长度小于1时，就停止再增长                System.out.println(ps.size());                shell.getDisplay().timerExec(-1, timer);                return;            }            Point2D p1 = GeometryUtil.extentPoint(p0, p4, len / 3);            Point2D p3 = GeometryUtil.extentPoint(p0, p4, len * 2 / 3);            Point2D p2 = GeometryUtil.rotate(p3.getX(), p3.getY(), p1.getX(), p1.getY(), 60);            temp.add(p1);            temp.add(p2);            temp.add(p3);            temp.add(p4);        }        ps = null;        ps = temp;        temp = null;        if (type == 1) {            getBuffer(true);        }    }    private void renderWithBuffer(Image image)    {        GC _gc = new GC(image);        render(_gc);        _gc.dispose();    }    private void render(GC gc)    {        Display display = shell.getDisplay();        gc.setBackground(display.getSystemColor(SWT.COLOR_BLACK));        Rectangle bounds = canvas.getBounds();        gc.fillRectangle(bounds);        gc.setAdvanced(true);        gc.setAntialias(SWT.ON);        Transform transform = new Transform(display);        transform.translate(0, bounds.height - 20);        gc.setTransform(transform);        gc.setForeground(display.getSystemColor(SWT.COLOR_WHITE));        for (int i = 0; i < ps.size() - 1; ++i) {            Point2D sp = ps.get(i);            Point2D ep = ps.get(i + 1);            gc.drawLine((int) sp.getX(), -(int) sp.getY(), (int) ep.getX(), -(int) ep.getY());        }    }    public static void main(String[] args)    {        Display display = Display.getDefault();        Shell shell = new GrowingSWT(display).shell;        shell.setSize(800, 400);        shell.open();        while (!shell.isDisposed()) {            if (!display.readAndDispatch()) {                display.sleep();            }        }    }}