Koch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() {@Overridepublic 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());}}?