Koch科赫曲线的实现

代码如下，加入了拉杆控制递推，每次拉杆控制参数变化都会刷新画布

package 科赫曲线;

import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.nio.channels.Pipe;

import javax.swing.JFrame;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

/*
 * 科赫曲线的实现 
 * @author LiuYuliang
 */
public class kehe extends JFrame {
	
	final static JSlider js = new JSlider(1,15,10);
	private  int count;
	private Graphics g;
	private double x1,y1,x2,y2;
	private int width=1000,height=500;
	double PI=Math.PI;
	
	public void showUI(int count){
		
		this.setSize(new Dimension(width,height));
		this.setTitle("科赫曲线");
		this.setVisible(true);
		this.setDefaultCloseOperation(3);
		this.setResizable(false);
		g=this.getGraphics();
		
		FlowLayout fl = new FlowLayout();//定义布局
		this.setLayout(fl);
		
		count=js.getValue();
		this.add(js);
		js.addChangeListener(new ChangeListener() {
			
			@Override
			public void stateChanged(ChangeEvent b) {
				update();//拉杆后刷新画布
			}
		});
		
		
		
		
		this.addMouseListener(new MouseAdapter() {
			//只需要重写需要的方法即可，因为父类不是接口：
			//鼠标按下时的点的坐标
			public void mouseReleased(MouseEvent e) {
				draw(e);
			}
		});
			
	}
	
	//定义刷新方法
	public void update(){
	    repaint();
	}
	
	//转换坐标系为左下角 为原点
	public void draw(MouseEvent e){
		x1=width/4;
		y1=height/4;
		x2=width*3/4;
		y2=height/4;
		draw_digui(g,x1,y1,x2,y2,js.getValue());

	}
	//递归函数
	public void draw_digui(Graphics g,double x1,double y1,double x2,double y2,int count){
		
		double x3,y3,//第一个三等分点
				x5,y5,//第二个三等分点
				x4,y4,//顶点
				l,theta;//正三角形底边长和角度
		
		if(count<=1){
			g.drawLine((int)x1,height-(int)y1,(int)x2,height-(int)y2);//由于转换了坐标系，所以相应的要转换会原来以右上角为坐标原点的坐标系，只需要变化Y的值即可
			
		}else{
				//第一个三等分点
				x3 = x1+(x2-x1)/3;
				y3 = y1+(y2-y1)/3;
				
				//第二个三等分点
				x5= x2-(x2-x1)/3;
				y5= y2-(y2-y1)/3;
				
				//求三角形边长和三角形底边的倾斜角
				l=Math.sqrt((y5-y3)*(y5-y3)+(x5-x3)*(x5-x3));
				theta=Math.atan((y5-y3)/(x5-x3));
				
				//对角的条件的限制
				if((theta>=0) && ((x5-x3)<0)||(theta<=0)&&((x5-x3)<0)){
					theta=theta+PI;
				}
				
				//顶点
				x4=x3+Math.cos(theta+PI/3)*l;
				y4=y3+Math.sin(theta+PI/3)*l;
				
				
				
				count--;
				draw_digui(g,x1,y1,x3,y3,count);
				draw_digui(g,x3,y3,x4,y4,count);
				draw_digui(g,x4,y4,x5,y5,count);
				draw_digui(g,x5,y5,x2,y2,count);

		
		}
		
	
	}
	
	//主入口
	public static void main(String []args){
		kehe kh= new kehe();
		kh.showUI(js.getValue());
	}
}