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：
java" id="highlighter_252477">
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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);
}
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现在开始写递归函数。
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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);
}
}
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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。
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jta.addactionlistener(new actionlistener() {
public void actionperformed(actionevent arg0) {
spl.setnumber(integer.parseint(jta.gettext()));
}
});
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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：
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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);
}
}
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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服务器之家。
原文链接：https://blog.csdn.net/A948433271/article/details/49560071