我开始制作一个 mandelbrot 集分形查看器。在放大分形时,我遇到了很多问题。如果您尝试缩放,查看器只会靠近中心。我已尽我所能来理解这种困境。我如何才能以这样一种方式放大我的分形,即当我放大时,它会放大到屏幕的中心,而不是分形的中心?
import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import java.awt.event.*;
public class Mandelbrot extends JFrame implements ActionListener {
private JPanel ctrlPanel;
private JPanel btnPanel;
private int numIter = 50;
private double zoom = 130;
private double zoomIncrease = 100;
private int colorIter = 20;
private BufferedImage I;
private double zx, zy, cx, cy, temp;
private int xMove, yMove = 0;
private JButton[] ctrlBtns = new JButton[9];
private Color themeColor = new Color(150,180,200);
public Mandelbrot() {
super("Mandelbrot Set");
setBounds(100, 100, 800, 600);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
plotPoints();
Container contentPane = getContentPane();
contentPane.setLayout(null);
ctrlPanel = new JPanel();
ctrlPanel.setBounds(600,0,200,600);
ctrlPanel.setBackground(themeColor);
ctrlPanel.setLayout(null);
btnPanel = new JPanel();
btnPanel.setBounds(0,200,200,200);
btnPanel.setLayout(new GridLayout(3,3));
btnPanel.setBackground(themeColor);
ctrlBtns[1] = new JButton("up");
ctrlBtns[7] = new JButton("down");
ctrlBtns[3] = new JButton ("left");
ctrlBtns[5] = new JButton("right");
ctrlBtns[2] = new JButton("+");
ctrlBtns[0] = new JButton("-");
ctrlBtns[8] = new JButton(">");
ctrlBtns[6] = new JButton("<");
ctrlBtns[4] = new JButton();
contentPane.add(ctrlPanel);
contentPane.add(new imgPanel());
ctrlPanel.add(btnPanel);
for (int x = 0; x<ctrlBtns.length;x++){
btnPanel.add(ctrlBtns[x]);
ctrlBtns[x].addActionListener(this);
}
validate();
}
public class imgPanel extends JPanel{
public imgPanel(){
setBounds(0,0,600,600);
}
@Override
public void paint (Graphics g){
super.paint(g);
g.drawImage(I, 0, 0, this);
}
}
public void plotPoints(){
I = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
for (int y = 0; y < getHeight(); y++) {
for (int x = 0; x < getWidth(); x++) {
zx = zy = 0;
cx = (x - 320+xMove) / zoom;
cy = (y - 290+yMove) / zoom;
int iter = numIter;
while (zx * zx + zy * zy < 4 && iter > 0) {
temp = zx * zx - zy * zy + cx;
zy = 2 * zx * zy + cy;
zx = temp;
iter--;
}
I.setRGB(x, y, iter | (iter << colorIter));
}
}
}
public void actionPerformed(ActionEvent ae){
String event = ae.getActionCommand();
switch (event){
case "up":
yMove-=100;
break;
case "down":
yMove+=100;
break;
case "left":
xMove-=100;
break;
case "right":
xMove+=100;
break;
case "+":
zoom+=zoomIncrease;
zoomIncrease+=100;
break;
case "-":
zoom-=zoomIncrease;
zoomIncrease-=100;
break;
case ">":
colorIter++;
break;
case "<":
colorIter--;
break;
}
plotPoints();
validate();
repaint();
}
public static void main(String[] args) {
new Mandelbrot().setVisible(true);
}
}
最佳答案
Mandelbrot 集存在于具有自然坐标的数学平面中。您使用“视口(viewport)”坐标用 BufferedImage 来“查看”它。这一切都在这些之间的映射中。您已将视口(viewport)坐标标记为 x 和 y,并将进入 Mandelbrot 空间的“真实”坐标标记为 cx 和 cy。这些是公式:
cx = (x - 320+xMove) / zoom;
cy = (y - 290+yMove) / zoom;
为了放大和缩小特定的“真实”点,您希望位移量在缩放时保持不变。问题是位移量按缩放量缩放。请记住 cx 和 cy 是 Mandelbrot 平面中的实际坐标,x 和 y 是视口(viewport)坐标。因此,当您查看视口(viewport)的中间时,随着您更改缩放比例,您希望 cx 和 cy 保持不变。
我猜你想要这样的东西:
cx = ((x - 320) / zoom) + xMove;
cy = ((y - 290) / zoom) + yMove;
这将使 Mandelbrot 平面中的“移动”与缩放量无关。我假设 320 和 290 与视口(viewport)大小有关,并在视口(viewport)中间给你一个零。
您希望 xMove 和 yMove 在击键时更改的量不是固定量 (100),而是取决于缩放级别的量。当您放大很多时,您希望每次击键时真实 Mandelbrot 平面中的移动量更小。
关于java - 放大 Java 中的 Mandelbrot 集分形,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14097559/