利用Java绘制由圆组成的分形图案

Question

我上星期一直在做这个项目，想不出该怎么解决它。我觉得自己离我很近，却无法发现自己的错误！我的作业要求我使用Java图形类沿着一条假想的线画圆。在中心画一个半径为n的圆。然后画出两个endpoint与圆的左右弧相交的半径为n/2的圆。

我已经能够在第一个圆圈的左右画出两个圆圈的第二步了。然而，我的程序应该然后递归地画出四个相同大小的圆。一个圆圈位于左圆圈的左右两侧，一个圆圈位于右圆圈的左右两侧。我的代码有可疑之处。

如有任何帮助，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...画出圆圈，然后通过再次调用相同的函数来画出它的2个子圈。

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);
}