更改 BufferedImage 的内容，然后更新 JFrame 以反映它
Change contents of BufferedImage, then update JFrame to reflect it
我正在尝试制作带有 GUI 的 Mandelbrot Set 渲染器，您可以在其中单击并拖动以放大特定区域。当 运行 时，它会进行初始计算和渲染，但当您尝试单击并拖动以放大时，控制台说它正在进行计算，但 JFrame 的内容没有更新。
但是，我什至不确定它是否正在重新计算，因为初始计算大约需要 8 秒，但是当您 click/drag 缩放时大约需要 6 毫秒。
我已经在下面发布了我的代码。
复数Class
public class Complex {
private double real, imag;
// Constructors
public Complex(){
real=0.0;
imag=0.0;
}
public Complex(double real, double imag) {
this.real=real;
this.imag=imag;
}
// add given complex number to this one, returning the Complex result
public Complex add(Complex other) {
return new Complex(this.real+other.real, this.imag+other.imag);
}
// multiply given complex number by this one, returning the Complex result
public Complex multiply(Complex other) {
return new Complex((this.real*other.real)-(this.imag*other.imag), (this.imag*other.real)+(this.real*other.imag));
}
// get the magnitude of this complex number
public double getMagnitude() {
return Math.sqrt((real*real)+(imag*imag));
}
}
可运行的 MandelbrotTask Class
public class MandelbrotTask implements Runnable {
private double x1, y1, x2, y2;
private int startCol, endCol, startRow, endRow, maxIters;
private int[][] iterCounts;
public MandelbrotTask(int maxIters, double x1, double y1, double x2, double y2, int startCol, int endCol, int startRow, int endRow, int[][] iterCounts) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
this.startCol = startCol;
this.endCol = endCol;
this.startRow = startRow;
this.endRow = endRow;
this.iterCounts = iterCounts;
this.maxIters=maxIters;
}
@Override
public void run() {
for (int i = startRow; i < endRow; i++) {
for (int j = startCol; j < endCol; j++) {
Complex c = getComplex(i, j);
int iterCount = countIters(c);
iterCounts[i][j] = iterCount;
}
}
}
public Complex getComplex(int i, int j){
//output image is 600 X 600 pixels
double incrementX;
double incrementY;
if(x2!=x1){
incrementX=(Math.abs(x2-x1)/600);
}
else{
throw new ArithmeticException("Error: area=0");
}
if(y2!=y1){
incrementY=(Math.abs(y2-y1)/600);
}
else{
throw new ArithmeticException("Error: area=0");
}
return new Complex(x1+((double)i*incrementX), y1+((double)j*incrementY));
}
public int countIters(Complex c){
Complex z=new Complex(0, 0);
int iters=0;
while(z.getMagnitude()<2 && iters<=maxIters){
z=z.multiply(z).add(c);
iters++;
}
return iters;
}
}
主要曼德尔布罗Class
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Scanner;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class Mandelbrot {
private static final int HEIGHT = 600;
private static final int WIDTH = 600;
private static final int maxIters=50000;
private static Rectangle zoomBox;
private static Point initialClick;
private static JLabel content; //bufferedImage will be put into this JLabel
private static int[][] iterCounts;
private static BufferedImage bufferedImage; //rendering will be written to this bufferedImage
private static JFrame frame;
public static void main(String[] args) throws IOException {
zoomBox=null;
Scanner keyboard = new Scanner(System.in);
double x1 = -2;
double y1 = -2;
double x2 = 2;
double y2 = 2;
/*System.out.print("Max iterations (16,581,375 supported): ");
int maxIters=50000;
if(maxIters>16581375){
throw new UnsupportedOperationException("Error: Max Iterations: Overflow.");
}
System.out.print("Output filename: ");
String fileName = keyboard.next();
if(!fileName.endsWith(".png") && !fileName.endsWith(".PNG")){
fileName=fileName + ".png";
}*/
// TODO: create the rendering, save it to a file
iterCounts=new int[WIDTH][HEIGHT];
recalculate(x1, y1, x2, y2, iterCounts);
bufferedImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
MouseAdapter listener = new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
handleMousePressed(e);
}
@Override
public void mouseDragged(MouseEvent e) {
handleMouseDragged(e);
}
@Override
public void mouseReleased(MouseEvent e) {
handleMouseReleased(e);
}
};
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, true)));
content.addMouseListener(listener);
content.addMouseMotionListener(listener);
/*OutputStream os = new BufferedOutputStream(new FileOutputStream(fileName));
try {
ImageIO.write(bufferedImage, "PNG", os);
} finally {
os.close();
}*/
frame = new JFrame("Mandelbrot Viewer");
frame.getContentPane().add(content);
frame.pack();
frame.setSize(new Dimension(WIDTH, HEIGHT));
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static BufferedImage render(int[][] iterCounts, BufferedImage bufferedImage, Rectangle zoomBox, boolean updated){
bufferedImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
Graphics g = bufferedImage.getGraphics();
Graphics2D g2=(Graphics2D) g;
if(updated){
for(int i=0; i<WIDTH; i++){
for(int j=0; j<HEIGHT; j++){
if(iterCounts[i][j]<maxIters){
String hexCode= String.format("#%06x", (0xFFFFFF & (32*iterCounts[i][j])));
g.setColor(Color.decode(hexCode));
}
else{
g.setColor(Color.CYAN);
}
g.drawLine(i, j, i, j);
}
}
}
else{
if(zoomBox!=null){
g2.setStroke(new BasicStroke(7));
g2.draw(zoomBox);
}
}
return bufferedImage;
}
public static int[][] recalculate(double x1, double y1, double x2, double y2, int[][] iterCounts){
MandelbrotTask[] tasks=new MandelbrotTask[4];
tasks[0]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 0, HEIGHT/4, iterCounts);
tasks[1]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, HEIGHT/4, 2*(HEIGHT/4), iterCounts);
tasks[2]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 2*(HEIGHT/4), 3*(HEIGHT/4), iterCounts);
tasks[3]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 3*(HEIGHT/4), 4*(HEIGHT/4), iterCounts);
//parallelize computation
Thread[] threads=new Thread[4];
for(int i=0; i<4; i++){
threads[i]=new Thread(tasks[i]);
}
System.out.println("Working...");
//start timer, start computation
long start=System.currentTimeMillis();
for(int i=0; i<4; i++){
threads[i].start();
}
for(int i=0; i<4; i++){
try {
threads[i].join();
} catch (InterruptedException e) {
System.err.println("A thread was interrupted.");
}
}
//end timer
long end=System.currentTimeMillis();
long elapsed=end-start;
System.out.println("Done.");
System.out.println("Took " + elapsed + " ms.");
return iterCounts;
}
protected static void handleMousePressed(MouseEvent e) {
initialClick=e.getPoint();
}
protected static void handleMouseDragged(MouseEvent e) {
if(e.getX()>e.getY()){
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getX()), (int)(e.getY()-initialClick.getX()));
}
else if(e.getY()>e.getX()){
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getY()), (int)(e.getY()-initialClick.getY()));
}
else{
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getX()), (int)(e.getY()-initialClick.getY()));
}
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false)));
content.repaint();
}
protected static void handleMouseReleased(MouseEvent e) {
recalculate(initialClick.getX(), initialClick.getY(), e.getX(), e.getY(), iterCounts);
SwingUtilities.invokeLater(new Runnable(){
@Override
public void run() {
zoomBox=null;
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false)));
content.repaint();
}
});
}
}
首先，您在每次重新迭代时都创建了一个新的 JLabel，而这个 JLabel 没有被添加。
而是使用相同的 JLabel，而是创建一个新的 ImageIcon 并设置查看的 JLabel 的图标。
ImageIcon icon = new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false));
content.setIcon(icon);
您似乎也没有对重新计算返回的 int 数组做任何事情。
你的 handleMouseReleased 方法不应该有：
iterCounts = recalculate(initialClick.getX(), initialClick.getY(),
e.getX(), e.getY(), iterCounts);
此外，您的线程处理仍然很糟糕——您正在从 Swing 事件线程内对您的线程调用 join，这几乎肯定会冻结您的 GUI。使用 SwingWorker，然后在完成时收到工作人员的通知后，使用其数据。此外，您在 GUI 中严重过度使用静态变量。使您的 GUI 组件成为实例字段，而不是静态字段。
恐怕还有更多的逻辑错误我还没有发现...
程序的第二次迭代——使用 Mandelbrot 计算：
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.concurrent.ExecutionException;
import javax.swing.*;
@SuppressWarnings("serial")
public class Mandel2 extends JPanel {
private static final int GUI_HEIGHT = 600;
private static final int GUI_WIDTH = 600;
private static final int MAX_ITERS = 50000;
private BufferedImage image = new BufferedImage(GUI_WIDTH, GUI_HEIGHT,
BufferedImage.TYPE_INT_ARGB);
private Rectangle zoomRect;
private double myX0 = -2.5;
private double myY0 = -2.0;
private double myX1 = 1.5;
private double myY1 = 2.0;
private JDialog waitDialog;
public Mandel2() {
final MyMouse myMouse = new MyMouse();
int delayStartingCalc = 2 * 1000; // 2 second delay
Timer timer = new Timer(delayStartingCalc, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
addMouseListener(myMouse);
addMouseMotionListener(myMouse);
Rectangle myRect = new Rectangle(0, 0, GUI_WIDTH, GUI_HEIGHT);
createMandel(myRect);
}
});
timer.setRepeats(false);
timer.start();
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(GUI_WIDTH, GUI_HEIGHT);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null) {
g.drawImage(image, 0, 0, this);
}
Graphics2D g2 = (Graphics2D) g;
if (zoomRect == null) {
return;
}
g2.setXORMode(Color.gray);
g2.draw(zoomRect);
}
private double screenToLogicalX(double screenX) {
return myX0 + (screenX * (myX1 - myX0)) / GUI_WIDTH;
}
private double screenToLogicalY(double screenY) {
return myY0 + ((GUI_HEIGHT - screenY) * (myY1 - myY0)) / GUI_HEIGHT;
}
private void createMandel(Rectangle myRect) {
double x0 = screenToLogicalX(myRect.x);
double y0 = screenToLogicalY(myRect.y + myRect.height);
double x1 = screenToLogicalX(myRect.x + myRect.width);
double y1 = screenToLogicalY(myRect.y);
myX0 = x0;
myY0 = y0;
myX1 = x1;
myY1 = y1;
MandelWorker mandelWorker = new MandelWorker(MAX_ITERS, x0, y0, x1, y1);
mandelWorker.addPropertyChangeListener(new MandelWorkerListener());
mandelWorker.execute();
if (waitDialog == null) {
Window win = SwingUtilities.getWindowAncestor(Mandel2.this);
JProgressBar jProgressBar = new JProgressBar();
jProgressBar.setIndeterminate(true);
waitDialog = new JDialog(win, "Please Wait", ModalityType.APPLICATION_MODAL);
waitDialog.add(jProgressBar);
waitDialog.pack();
waitDialog.setLocationRelativeTo(win);
}
waitDialog.setVisible(true);
}
private class MyMouse extends MouseAdapter {
private Point p;
@Override
public void mousePressed(MouseEvent e) {
p = e.getPoint();
}
public void mouseDragged(MouseEvent e) {
zoomRect = createRect(e);
repaint();
};
@Override
public void mouseReleased(MouseEvent e) {
zoomRect = createRect(e);
repaint();
createMandel(zoomRect);
}
private Rectangle createRect(MouseEvent e) {
int x = Math.min(p.x, e.getX());
int y = Math.min(p.y, e.getY());
int width = Math.abs(p.x - e.getX());
int height = Math.abs(p.y - e.getY());
return new Rectangle(x, y, width, height);
}
}
private class MandelWorkerListener implements PropertyChangeListener {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getNewValue() == SwingWorker.StateValue.DONE) {
waitDialog.setVisible(false);
waitDialog.dispose();
MandelWorker worker = (MandelWorker) evt.getSource();
try {
image = worker.get();
zoomRect = null;
repaint();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
}
}
private class MandelWorker extends SwingWorker<BufferedImage, Void> {
private int maxIters;
private double x1;
private double y1;
private double x2;
private double y2;
public MandelWorker(int maxIters, double x1, double y1, double x2, double y2) {
this.maxIters = maxIters;
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
}
@Override
protected BufferedImage doInBackground() throws Exception {
int[][] iterGrid = new int[GUI_HEIGHT][GUI_WIDTH];
for (int i = 0; i < GUI_HEIGHT; i++) {
double y = y1 + i * (y2 - y1) / GUI_HEIGHT;
for (int j = 0; j < GUI_WIDTH; j++) {
double x = x1 + j * (x2 - x1) / GUI_WIDTH;
int iIndex = GUI_HEIGHT - i - 1;
iterGrid[iIndex][j] = calcMandel(x, y);
}
}
return render(iterGrid);
}
private BufferedImage render(int[][] iterGrid) {
int w = GUI_WIDTH;
int h = GUI_HEIGHT;
BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
for (int i = 0; i < w; i++) {
for (int j = 0; j < h; j++) {
if (iterGrid[i][j] < maxIters) {
String hexCode = String.format("#%06x", (0xFFFFFF & (32 * iterGrid[i][j])));
g2.setColor(Color.decode(hexCode));
} else {
g2.setColor(Color.CYAN);
}
g2.drawLine(j, i, j, i);
}
}
g2.dispose();
return img;
}
private int calcMandel(double x, double y) {
Complex c = new Complex(x, y);
Complex z = new Complex();
int iters = 0;
while (z.getMagnitude() < 2 && iters <= maxIters) {
z = z.multiply(z).add(c);
iters++;
}
return iters;
}
}
private class Complex {
private double real, imag;
// Constructors
public Complex() {
real = 0.0;
imag = 0.0;
}
public Complex(double real, double imag) {
this.real = real;
this.imag = imag;
}
// add given complex number to this one, returning the Complex result
public Complex add(Complex other) {
return new Complex(this.real + other.real, this.imag + other.imag);
}
// multiply given complex number by this one, returning the Complex
// result
public Complex multiply(Complex other) {
return new Complex((this.real * other.real) - (this.imag * other.imag),
(this.imag * other.real) + (this.real * other.imag));
}
// get the magnitude of this complex number
public double getMagnitude() {
return Math.sqrt((real * real) + (imag * imag));
}
}
private static void createAndShowGui() {
Mandel2 mainPanel = new Mandel2();
JFrame frame = new JFrame("Mandel2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.setResizable(false);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
第二次迭代 -- 它进行计算，但效率不高。
我正在尝试制作带有 GUI 的 Mandelbrot Set 渲染器，您可以在其中单击并拖动以放大特定区域。当 运行 时，它会进行初始计算和渲染，但当您尝试单击并拖动以放大时，控制台说它正在进行计算，但 JFrame 的内容没有更新。
但是，我什至不确定它是否正在重新计算，因为初始计算大约需要 8 秒，但是当您 click/drag 缩放时大约需要 6 毫秒。
我已经在下面发布了我的代码。
复数Class
public class Complex {
private double real, imag;
// Constructors
public Complex(){
real=0.0;
imag=0.0;
}
public Complex(double real, double imag) {
this.real=real;
this.imag=imag;
}
// add given complex number to this one, returning the Complex result
public Complex add(Complex other) {
return new Complex(this.real+other.real, this.imag+other.imag);
}
// multiply given complex number by this one, returning the Complex result
public Complex multiply(Complex other) {
return new Complex((this.real*other.real)-(this.imag*other.imag), (this.imag*other.real)+(this.real*other.imag));
}
// get the magnitude of this complex number
public double getMagnitude() {
return Math.sqrt((real*real)+(imag*imag));
}
}
可运行的 MandelbrotTask Class
public class MandelbrotTask implements Runnable {
private double x1, y1, x2, y2;
private int startCol, endCol, startRow, endRow, maxIters;
private int[][] iterCounts;
public MandelbrotTask(int maxIters, double x1, double y1, double x2, double y2, int startCol, int endCol, int startRow, int endRow, int[][] iterCounts) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
this.startCol = startCol;
this.endCol = endCol;
this.startRow = startRow;
this.endRow = endRow;
this.iterCounts = iterCounts;
this.maxIters=maxIters;
}
@Override
public void run() {
for (int i = startRow; i < endRow; i++) {
for (int j = startCol; j < endCol; j++) {
Complex c = getComplex(i, j);
int iterCount = countIters(c);
iterCounts[i][j] = iterCount;
}
}
}
public Complex getComplex(int i, int j){
//output image is 600 X 600 pixels
double incrementX;
double incrementY;
if(x2!=x1){
incrementX=(Math.abs(x2-x1)/600);
}
else{
throw new ArithmeticException("Error: area=0");
}
if(y2!=y1){
incrementY=(Math.abs(y2-y1)/600);
}
else{
throw new ArithmeticException("Error: area=0");
}
return new Complex(x1+((double)i*incrementX), y1+((double)j*incrementY));
}
public int countIters(Complex c){
Complex z=new Complex(0, 0);
int iters=0;
while(z.getMagnitude()<2 && iters<=maxIters){
z=z.multiply(z).add(c);
iters++;
}
return iters;
}
}
主要曼德尔布罗Class
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Scanner;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class Mandelbrot {
private static final int HEIGHT = 600;
private static final int WIDTH = 600;
private static final int maxIters=50000;
private static Rectangle zoomBox;
private static Point initialClick;
private static JLabel content; //bufferedImage will be put into this JLabel
private static int[][] iterCounts;
private static BufferedImage bufferedImage; //rendering will be written to this bufferedImage
private static JFrame frame;
public static void main(String[] args) throws IOException {
zoomBox=null;
Scanner keyboard = new Scanner(System.in);
double x1 = -2;
double y1 = -2;
double x2 = 2;
double y2 = 2;
/*System.out.print("Max iterations (16,581,375 supported): ");
int maxIters=50000;
if(maxIters>16581375){
throw new UnsupportedOperationException("Error: Max Iterations: Overflow.");
}
System.out.print("Output filename: ");
String fileName = keyboard.next();
if(!fileName.endsWith(".png") && !fileName.endsWith(".PNG")){
fileName=fileName + ".png";
}*/
// TODO: create the rendering, save it to a file
iterCounts=new int[WIDTH][HEIGHT];
recalculate(x1, y1, x2, y2, iterCounts);
bufferedImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
MouseAdapter listener = new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
handleMousePressed(e);
}
@Override
public void mouseDragged(MouseEvent e) {
handleMouseDragged(e);
}
@Override
public void mouseReleased(MouseEvent e) {
handleMouseReleased(e);
}
};
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, true)));
content.addMouseListener(listener);
content.addMouseMotionListener(listener);
/*OutputStream os = new BufferedOutputStream(new FileOutputStream(fileName));
try {
ImageIO.write(bufferedImage, "PNG", os);
} finally {
os.close();
}*/
frame = new JFrame("Mandelbrot Viewer");
frame.getContentPane().add(content);
frame.pack();
frame.setSize(new Dimension(WIDTH, HEIGHT));
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static BufferedImage render(int[][] iterCounts, BufferedImage bufferedImage, Rectangle zoomBox, boolean updated){
bufferedImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
Graphics g = bufferedImage.getGraphics();
Graphics2D g2=(Graphics2D) g;
if(updated){
for(int i=0; i<WIDTH; i++){
for(int j=0; j<HEIGHT; j++){
if(iterCounts[i][j]<maxIters){
String hexCode= String.format("#%06x", (0xFFFFFF & (32*iterCounts[i][j])));
g.setColor(Color.decode(hexCode));
}
else{
g.setColor(Color.CYAN);
}
g.drawLine(i, j, i, j);
}
}
}
else{
if(zoomBox!=null){
g2.setStroke(new BasicStroke(7));
g2.draw(zoomBox);
}
}
return bufferedImage;
}
public static int[][] recalculate(double x1, double y1, double x2, double y2, int[][] iterCounts){
MandelbrotTask[] tasks=new MandelbrotTask[4];
tasks[0]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 0, HEIGHT/4, iterCounts);
tasks[1]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, HEIGHT/4, 2*(HEIGHT/4), iterCounts);
tasks[2]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 2*(HEIGHT/4), 3*(HEIGHT/4), iterCounts);
tasks[3]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 3*(HEIGHT/4), 4*(HEIGHT/4), iterCounts);
//parallelize computation
Thread[] threads=new Thread[4];
for(int i=0; i<4; i++){
threads[i]=new Thread(tasks[i]);
}
System.out.println("Working...");
//start timer, start computation
long start=System.currentTimeMillis();
for(int i=0; i<4; i++){
threads[i].start();
}
for(int i=0; i<4; i++){
try {
threads[i].join();
} catch (InterruptedException e) {
System.err.println("A thread was interrupted.");
}
}
//end timer
long end=System.currentTimeMillis();
long elapsed=end-start;
System.out.println("Done.");
System.out.println("Took " + elapsed + " ms.");
return iterCounts;
}
protected static void handleMousePressed(MouseEvent e) {
initialClick=e.getPoint();
}
protected static void handleMouseDragged(MouseEvent e) {
if(e.getX()>e.getY()){
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getX()), (int)(e.getY()-initialClick.getX()));
}
else if(e.getY()>e.getX()){
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getY()), (int)(e.getY()-initialClick.getY()));
}
else{
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getX()), (int)(e.getY()-initialClick.getY()));
}
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false)));
content.repaint();
}
protected static void handleMouseReleased(MouseEvent e) {
recalculate(initialClick.getX(), initialClick.getY(), e.getX(), e.getY(), iterCounts);
SwingUtilities.invokeLater(new Runnable(){
@Override
public void run() {
zoomBox=null;
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false)));
content.repaint();
}
});
}
}
首先，您在每次重新迭代时都创建了一个新的 JLabel，而这个 JLabel 没有被添加。
而是使用相同的 JLabel，而是创建一个新的 ImageIcon 并设置查看的 JLabel 的图标。
ImageIcon icon = new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false));
content.setIcon(icon);
您似乎也没有对重新计算返回的 int 数组做任何事情。
你的 handleMouseReleased 方法不应该有：
iterCounts = recalculate(initialClick.getX(), initialClick.getY(),
e.getX(), e.getY(), iterCounts);
此外，您的线程处理仍然很糟糕——您正在从 Swing 事件线程内对您的线程调用 join，这几乎肯定会冻结您的 GUI。使用 SwingWorker，然后在完成时收到工作人员的通知后，使用其数据。此外，您在 GUI 中严重过度使用静态变量。使您的 GUI 组件成为实例字段，而不是静态字段。
恐怕还有更多的逻辑错误我还没有发现...
程序的第二次迭代——使用 Mandelbrot 计算：
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.concurrent.ExecutionException;
import javax.swing.*;
@SuppressWarnings("serial")
public class Mandel2 extends JPanel {
private static final int GUI_HEIGHT = 600;
private static final int GUI_WIDTH = 600;
private static final int MAX_ITERS = 50000;
private BufferedImage image = new BufferedImage(GUI_WIDTH, GUI_HEIGHT,
BufferedImage.TYPE_INT_ARGB);
private Rectangle zoomRect;
private double myX0 = -2.5;
private double myY0 = -2.0;
private double myX1 = 1.5;
private double myY1 = 2.0;
private JDialog waitDialog;
public Mandel2() {
final MyMouse myMouse = new MyMouse();
int delayStartingCalc = 2 * 1000; // 2 second delay
Timer timer = new Timer(delayStartingCalc, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
addMouseListener(myMouse);
addMouseMotionListener(myMouse);
Rectangle myRect = new Rectangle(0, 0, GUI_WIDTH, GUI_HEIGHT);
createMandel(myRect);
}
});
timer.setRepeats(false);
timer.start();
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(GUI_WIDTH, GUI_HEIGHT);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null) {
g.drawImage(image, 0, 0, this);
}
Graphics2D g2 = (Graphics2D) g;
if (zoomRect == null) {
return;
}
g2.setXORMode(Color.gray);
g2.draw(zoomRect);
}
private double screenToLogicalX(double screenX) {
return myX0 + (screenX * (myX1 - myX0)) / GUI_WIDTH;
}
private double screenToLogicalY(double screenY) {
return myY0 + ((GUI_HEIGHT - screenY) * (myY1 - myY0)) / GUI_HEIGHT;
}
private void createMandel(Rectangle myRect) {
double x0 = screenToLogicalX(myRect.x);
double y0 = screenToLogicalY(myRect.y + myRect.height);
double x1 = screenToLogicalX(myRect.x + myRect.width);
double y1 = screenToLogicalY(myRect.y);
myX0 = x0;
myY0 = y0;
myX1 = x1;
myY1 = y1;
MandelWorker mandelWorker = new MandelWorker(MAX_ITERS, x0, y0, x1, y1);
mandelWorker.addPropertyChangeListener(new MandelWorkerListener());
mandelWorker.execute();
if (waitDialog == null) {
Window win = SwingUtilities.getWindowAncestor(Mandel2.this);
JProgressBar jProgressBar = new JProgressBar();
jProgressBar.setIndeterminate(true);
waitDialog = new JDialog(win, "Please Wait", ModalityType.APPLICATION_MODAL);
waitDialog.add(jProgressBar);
waitDialog.pack();
waitDialog.setLocationRelativeTo(win);
}
waitDialog.setVisible(true);
}
private class MyMouse extends MouseAdapter {
private Point p;
@Override
public void mousePressed(MouseEvent e) {
p = e.getPoint();
}
public void mouseDragged(MouseEvent e) {
zoomRect = createRect(e);
repaint();
};
@Override
public void mouseReleased(MouseEvent e) {
zoomRect = createRect(e);
repaint();
createMandel(zoomRect);
}
private Rectangle createRect(MouseEvent e) {
int x = Math.min(p.x, e.getX());
int y = Math.min(p.y, e.getY());
int width = Math.abs(p.x - e.getX());
int height = Math.abs(p.y - e.getY());
return new Rectangle(x, y, width, height);
}
}
private class MandelWorkerListener implements PropertyChangeListener {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getNewValue() == SwingWorker.StateValue.DONE) {
waitDialog.setVisible(false);
waitDialog.dispose();
MandelWorker worker = (MandelWorker) evt.getSource();
try {
image = worker.get();
zoomRect = null;
repaint();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
}
}
private class MandelWorker extends SwingWorker<BufferedImage, Void> {
private int maxIters;
private double x1;
private double y1;
private double x2;
private double y2;
public MandelWorker(int maxIters, double x1, double y1, double x2, double y2) {
this.maxIters = maxIters;
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
}
@Override
protected BufferedImage doInBackground() throws Exception {
int[][] iterGrid = new int[GUI_HEIGHT][GUI_WIDTH];
for (int i = 0; i < GUI_HEIGHT; i++) {
double y = y1 + i * (y2 - y1) / GUI_HEIGHT;
for (int j = 0; j < GUI_WIDTH; j++) {
double x = x1 + j * (x2 - x1) / GUI_WIDTH;
int iIndex = GUI_HEIGHT - i - 1;
iterGrid[iIndex][j] = calcMandel(x, y);
}
}
return render(iterGrid);
}
private BufferedImage render(int[][] iterGrid) {
int w = GUI_WIDTH;
int h = GUI_HEIGHT;
BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
for (int i = 0; i < w; i++) {
for (int j = 0; j < h; j++) {
if (iterGrid[i][j] < maxIters) {
String hexCode = String.format("#%06x", (0xFFFFFF & (32 * iterGrid[i][j])));
g2.setColor(Color.decode(hexCode));
} else {
g2.setColor(Color.CYAN);
}
g2.drawLine(j, i, j, i);
}
}
g2.dispose();
return img;
}
private int calcMandel(double x, double y) {
Complex c = new Complex(x, y);
Complex z = new Complex();
int iters = 0;
while (z.getMagnitude() < 2 && iters <= maxIters) {
z = z.multiply(z).add(c);
iters++;
}
return iters;
}
}
private class Complex {
private double real, imag;
// Constructors
public Complex() {
real = 0.0;
imag = 0.0;
}
public Complex(double real, double imag) {
this.real = real;
this.imag = imag;
}
// add given complex number to this one, returning the Complex result
public Complex add(Complex other) {
return new Complex(this.real + other.real, this.imag + other.imag);
}
// multiply given complex number by this one, returning the Complex
// result
public Complex multiply(Complex other) {
return new Complex((this.real * other.real) - (this.imag * other.imag),
(this.imag * other.real) + (this.real * other.imag));
}
// get the magnitude of this complex number
public double getMagnitude() {
return Math.sqrt((real * real) + (imag * imag));
}
}
private static void createAndShowGui() {
Mandel2 mainPanel = new Mandel2();
JFrame frame = new JFrame("Mandel2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.setResizable(false);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
第二次迭代 -- 它进行计算，但效率不高。