使用 Java 绘制由圆组成的分形图案

Question

我上周一直在做这个项目，但不知道如何解决它。我觉得我离得很近，但无法发现我的错误！我的作业要求我使用 Java Graphics 类沿着假想线绘制圆。在中心画一个半径为 n 的圆。然后绘制两个半径为 n/2 的圆，其端点与圆的左弧和右弧相交。

我已经能够在第一个圆的左右两侧绘制两个圆的第二步。但是，我的程序应该递归地绘制四个相同大小的圆圈。一个圆圈到左圆的左右两侧，一个圆圈到右圆圈的左右两侧。我的代码可疑。

任何帮助将不胜感激。

 package fractalcircles;
 import java.awt.*;
 import javax.swing.*;
 public class FractalCircles {
/**
 * @param args the command line arguments
 */
public static void main(String[] args) 
{   //create a MyCanvas object
    MyCanvas canvas1 = new MyCanvas();
    //set up a JFrame to hold the canvas
    JFrame frame = new JFrame();
    frame.setTitle("FractalCircles.java");
    frame.setSize(500,500);
    frame.setLocation(100,100);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    //add the canvas to the frame as a content panel
    frame.getContentPane().add(canvas1);
    frame.setVisible(true);
}//end main
 }//end class
 class MyCanvas extends Canvas
 {
public MyCanvas()
{} //end MyCanvas() constructor
//this method will draw the initial circle and invisible line
public void paint (Graphics graphics)
{
    int x1,x2,y1,y2; //future x and y coordinates
    int radius=125; //radius of first circle
    int xMid=250, yMid=250; //center point (x,y) of circle
    //draw invisible line
    graphics.drawLine(0,250,500,250);
    //draw first circle
    graphics.drawOval(xMid-radius,yMid-radius,radius*2,radius*2);

    //run fractal algorithm to draw 2 circles to the left and right
   drawCircles(graphics, xMid, yMid, radius);
}
void drawCircles (Graphics graphics, int xMid, int yMid, int radius)
{
    //used to position left and right circles
    int x1 = xMid-radius-(radius/2);
    int y1 = yMid-(radius/2);
    int x2 = xMid+radius-(radius/2);
    int y2= yMid-(radius/2);
    if (radius > 5)
    {
         //draw circle to the left
    graphics.drawOval(x1, y1, (radius/2)*2, (radius/2)*2);
    //draw circle to the right
    graphics.drawOval(x2, y2, (radius/2)*2, (radius/2)*2);
    }
    drawCircles (graphics, xMid, yMid, radius/2);  
}

Answer 1

一些使用递归的改编版本...绘制圆，然后通过再次调用相同的函数来绘制其 2 个子项。

void drawCircles(Graphics graphics, int xMid, int yMid, int radius) {
    // end recursion
    if(radius < 5)
        return;
    // Draw circle
    graphics.drawOval(xMid - radius, yMid - radius, radius * 2, radius * 2);
    // start recursion
    //left
    drawCircles(graphics, xMid-radius, yMid, radius / 2);
    //right
    drawCircles(graphics, xMid+radius, yMid, radius / 2);
}

Answer 2

看起来您的

drawCircles函数中只有一个drawCircles调用。这不可能是正确的，因为每次绘制圆圈时，都需要调用递归函数两次。我看到你在画两个圆，但这实际上是倒退的。

要使其正常工作，您需要绘制一个圆圈，并调用递归函数两次。

以下是您需要更改的内容：

• 使 drawCircle 绘制一个圆，以坐标为中心
• 在 drawCircle 中，调用 drawCircle 两次，一次用左圆坐标，一次用右圆坐标

这应该可以做到。

Answer 3

你只从大圆的每一边画 1 个圆。您需要更改代码。我只写了一个简短的修复程序，但没有测试。祝你好运

void drawCircles (Graphics graphics, int xMid, int yMid, int radius)
{
//used to position left and right circles
int x1 = xMid-radius-(radius/2);
int x2 = xMid+radius-(radius/2);
int x3 = xMid+radius+(radius/2);
int x4 = xMid-radius+(radius/2);
int y = yMid-(radius/2);

if (radius > 5)
{
     //draw 4 circles
   graphics.drawOval(x1, y, (radius/2)*2, (radius/2)*2);
   graphics.drawOval(x2, y, (radius/2)*2, (radius/2)*2);
   graphics.drawOval(x3, y, (radius/2)*2, (radius/2)*2);
   graphics.drawOval(x4, y, (radius/2)*2, (radius/2)*2);
}
//left
drawCircles(graphics, xMid-radius, yMid, radius / 2);
//right
drawCircles(graphics, xMid+radius, yMid, radius / 2);  
}