今天來寫k階科赫雪花的遞歸實現，(k值需要你手動輸入)至于科赫雪花是什么請大家自行百度。
首先來思考這個程序怎么寫，當 count = 0 時就應該是一個三角形，這三個點是你一開始就確定的，以后的改變都依據這三個點發展的。當不是0的時候就需要計算相對于這個三角形的9個點，分別是每條邊上的兩個點，和它對應的三角形第三個頂點。
首先在jframe中添加一個panel，我們需要在這個panel上畫圖。
大家再來看這個圖片，這張圖介紹了通過兩個點來計算其他三個點的過程。
現在開始在panel中畫圖：
java" id="highlighter_252477">
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
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);//畫一個簡單的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); } |
現在開始寫遞歸函數。
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
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個jtextfield jta 它輸入的數據要傳入到number中。所以為其添加一個監聽器。 已有數據輸入就調用其中的setnumber()函數設置number變量。
|
1
2
3
4
5
6
|
jta.addactionlistener(new actionlistener() { public void actionperformed(actionevent arg0) { spl.setnumber(integer.parseint(jta.gettext())); } }); |
所以總體已經完成了，剩下的就是簡答的窗體設置。
下面貼一個完整的java代碼：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
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);//畫一個簡單的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); } } |
效果圖：
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
原文鏈接：https://blog.csdn.net/A948433271/article/details/49560071
