main.java

可以用Bresenham算法实现最常规的画圆方法

/*
 * Main.java
 *
 * Created on 2007年10月14日, 下午8:40
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package huayuan;
import javax.swing.*;
import java.awt.*;
import java.io.*; 
/**
 *
 * @author hzj
 */
class SetPixel extends JPanel
{
    Color color;
    int radius;
    
    public SetPixel(int x1)
    {  
        color =Color.red;
        radius=x1;
    }

    public  void paintComponent(Graphics g)
    {
      g.setColor(color);
      drawLine(g,radius);
    }
    void drawLine(Graphics g,int rad)
    {
      
       // Bresenham算法 
     int x,y,d;
     x=0;y=rad;d=3-2*rad;
     while(x<y)
     {
         g.drawLine(x,y,x,y);
         if(d<0)d=d+4*x+6;
         else
         {
             d=d+4*(x-y)+10;
             y--;
         }
         x++;
     }
      if(x==y)
         g.drawLine(x,y,x,y);
    }
}
public class Main extends JFrame
{
    public Main()
    { 
        super("PixelColor");
        int a=0;
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); 
        try 
        {
             a=Integer.parseInt(br.readLine());
            
        }
        catch(Exception e) {}
       
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(new Rectangle(100,100,300,300));
        SetPixel set=new SetPixel(a);
        add(set);
    }
        public static void main(String[] args) {
        // TODO code application logic here
            Main setPixel=new Main();
            setPixel.show();
    }
}
//public class Main {
//    
//    /** Creates a new instance of Main */
//    public Main() {
//    }
//    
//    /**
//     * @param args the command line arguments
//     */
//    public static void main(String[] args) {
//        // TODO code application logic here
//    }
//    
//}