java递归实现科赫雪花

今天来写k阶科赫雪花的递归实现，(k值需要你手动输入)至于科赫雪花是什么请大家自行百度。

首先来思考这个程序怎么写，当 count = 0 时就应该是一个三角形，这三个点是你一开始就确定的，以后的改变都依据这三个点发展的。当不是0的时候就需要计算相对于这个三角形的9个点，分别是每条边上的两个点，和它对应的三角形第三个顶点。

首先在jframe中添加一个panel，我们需要在这个panel上画图。

大家再来看这个图片，这张图介绍了通过两个点来计算其他三个点的过程。

现在开始在panel中画图：

static class showpanel extends jpanel{ 
    int number = 0; 
    public void setnumber(int number) { 
      this.number = number; 
      repaint(); 
    } 
    public void paintcomponent(graphics g) { 
      super.paintcomponent(g);//画一个简单的panel 
       
      int side =(int)(math.min((int)getwidth(),(int)getheight())*0.8); 
      int high =(int)(side*math.cos(math.toradians(30))); 
       
       point p1 = new point(getwidth() / 2, 10); 
       point p2 = new point(getwidth() / 2 - side / 2, 10 + high); 
       point p3 = new point(getwidth() / 2 + side / 2, 10 + high); 
        
       playkochsnowflake(g, number, p1, p2); 
       playkochsnowflake(g, number, p2, p3); 
       playkochsnowflake(g, number, p3, p1); 
       
    } 

现在开始写递归函数。

public static void playkochsnowflake(graphics g,int number,point p1,point p2) { 
      if(number == 0){ 
        g.drawline(p1.x, p1.y,p2.x, p2.y); 
      } 
      else{ 
         int deltax = p2.x - p1.x; 
          int deltay = p2.y - p1.y; 
 
          point x = new point(p1.x + deltax / 3, p1.y + deltay / 3); 
          point y = new point(p1.x + deltax * 2 / 3, p1.y + deltay * 2 / 3); 
          point z = new point( 
           (int)((p1.x + p2.x) / 2 + math.sin(math.toradians(60)) * (p1.y - p2.y) / 3), 
           (int)((p1.y + p2.y) / 2 + math.sin(math.toradians(60)) * (p2.x - p1.x) / 3)); 
          playkochsnowflake(g, number - 1, p1, x); 
          playkochsnowflake(g, number - 1, x, z); 
          playkochsnowflake(g, number - 1, z, y); 
          playkochsnowflake(g, number - 1, y, p2); 
      } 
    } 

然后在主面板中加入一个jtextfield   jta 它输入的数据要传入到number中。所以为其添加一个监听器。 已有数据输入就调用其中的setnumber()函数设置number变量。 

jta.addactionlistener(new actionlistener() { 
       
      public void actionperformed(actionevent arg0) { 
        spl.setnumber(integer.parseint(jta.gettext()));        
      } 
    }); 

 所以总体已经完成了，剩下的就是简答的窗体设置。

下面贴一个完整的java代码：

import java.awt.borderlayout; 
import java.awt.flowlayout; 
import java.awt.graphics; 
import java.awt.point; 
import java.awt.event.actionevent; 
import java.awt.event.actionlistener; 
import javax.swing.jframe; 
import javax.swing.jlabel; 
import javax.swing.jpanel; 
import javax.swing.jtextfield; 
 
public class snowflake extends jframe { 
   
  private jtextfield jta = new jtextfield(5); 
  private showpanel spl = new showpanel(); 
   
  static class showpanel extends jpanel{ 
    int number = 0; 
    public void setnumber(int number) { 
      this.number = number; 
      repaint(); 
    } 
    public void paintcomponent(graphics g) { 
      super.paintcomponent(g);//画一个简单的panel 
       
      int side =(int)(math.min((int)getwidth(),(int)getheight())*0.8); 
      int high =(int)(side*math.cos(math.toradians(30))); 
       
       point p1 = new point(getwidth() / 2, 10); 
       point p2 = new point(getwidth() / 2 - side / 2, 10 + high); 
       point p3 = new point(getwidth() / 2 + side / 2, 10 + high); 
        
       playkochsnowflake(g, number, p1, p2); 
       playkochsnowflake(g, number, p2, p3); 
       playkochsnowflake(g, number, p3, p1); 
       
    } 
    public static void playkochsnowflake(graphics g,int number,point p1,point p2) { 
      if(number == 0){ 
        g.drawline(p1.x, p1.y,p2.x, p2.y); 
      } 
      else{ 
         int deltax = p2.x - p1.x; 
          int deltay = p2.y - p1.y; 
 
          point x = new point(p1.x + deltax / 3, p1.y + deltay / 3); 
          point y = new point(p1.x + deltax * 2 / 3, p1.y + deltay * 2 / 3); 
          point z = new point( 
           (int)((p1.x + p2.x) / 2 + math.sin(math.toradians(60)) * (p1.y - p2.y) / 3), 
           (int)((p1.y + p2.y) / 2 + math.sin(math.toradians(60)) * (p2.x - p1.x) / 3)); 
          playkochsnowflake(g, number - 1, p1, x); 
          playkochsnowflake(g, number - 1, x, z); 
          playkochsnowflake(g, number - 1, z, y); 
          playkochsnowflake(g, number - 1, y, p2); 
      } 
    } 
  } 
   
  public snowflake() { 
    jpanel panel = new jpanel(); 
    panel.setlayout(new flowlayout()); 
    panel.add(new jlabel("please input the number")); 
    panel.add(jta); 
    add(spl,borderlayout.center); 
    add(panel,borderlayout.south); 
    jta.addactionlistener(new actionlistener() { 
       
      public void actionperformed(actionevent arg0) { 
        spl.setnumber(integer.parseint(jta.gettext()));        
      } 
    }); 
  } 
  public static void main(string args[]) { 
    snowflake snowflake = new snowflake(); 
    snowflake.setsize(300, 300); 
    snowflake.settitle("snowflake"); 
    snowflake.setlocationrelativeto(null); 
    snowflake.setvisible(true); 
  } 
} 

效果图：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。