注：顶点坐标可以点击
1 package
2 {
3 import flash.display.Shape;
4 import flash.display.Sprite;
5 import flash.events.MouseEvent;
6 import flash.geom.Point;
7 import flash.text.TextField;
8
9 /**
10 * @author Frost.Yen
11 * @E-mail [email protected]
12 * @create 2015-8-18 下午3:16:57
13 *
14 */
15 [SWF(width="1024",height="768")]
16 public class DrawTriangle extends Sprite
17 {
18 private var _pointArr:Array = [new Point(200,150),new Point(500,300),new Point(150,400)];
19 private var _btn:TextField;
20 private var _container:Sprite;
21 private var _heightShape:Shape;
22 private var _pointA:TextField;
23 private var _pointB:TextField;
24 private var _pointC:TextField;
25 private var _pointD:TextField;
26
27 public function DrawTriangle()
28 {
29 initViews();
30 initEventListeners();
31 }
32 private function initViews():void
33 {
34 _container = new Sprite();
35 _btn = new TextField();
36 _heightShape = new Shape();
37 _btn.selectable = false;
38 _btn.border = true;
39 _btn.htmlText = "点击随机生成";
40 _btn.autoSize = "left";
41 _btn.background = true;
42 _btn.backgroundColor = 0xdddddd;
43 _btn.x = 100;
44 _btn.y = 100;
45 _pointA = getText(_container);
46 _pointB = getText(_container);
47 _pointC = getText(_container);
48 _pointD = getText(_container);
49 this.addChild(_btn);
50 this.addChild(_container);
51 this.addChild(_heightShape);
52 }
53 private function initEventListeners():void
54 {
55 _btn.addEventListener(MouseEvent.CLICK,onCreatClick);
56 _pointA.addEventListener(MouseEvent.CLICK,onGetHeight);
57 _pointB.addEventListener(MouseEvent.CLICK,onGetHeight);
58 _pointC.addEventListener(MouseEvent.CLICK,onGetHeight);
59 }
60 private function onCreatClick(e:MouseEvent):void
61 {
62 creatTriangle();
63 }
64
65 private function creatTriangle():void
66 {
67 _pointArr = [];
68 for(var i:int = 0;i<3;i++){
69 var point:Point = new Point(Math.floor(Math.random()*400)+150,Math.floor(Math.random()*400+150));
70 _pointArr.push(point);
71 }
72 _pointArr.sortOn("y");
73 _heightShape.graphics.clear();
74 _container.graphics.clear();
75 _container.graphics.lineStyle(2,0xff0000);
76 _container.graphics.moveTo(_pointArr[0].x,_pointArr[0].y);
77 _container.graphics.lineTo(_pointArr[1].x,_pointArr[1].y);
78 _container.graphics.moveTo(_pointArr[1].x,_pointArr[1].y);
79 _container.graphics.lineTo(_pointArr[2].x,_pointArr[2].y);
80 _container.graphics.moveTo(_pointArr[2].x,_pointArr[2].y);
81 _container.graphics.lineTo(_pointArr[0].x,_pointArr[0].y);
82 setText(_pointD,"");
83 setText(_pointA,"A("+_pointArr[0].x+","+_pointArr[0].y+")",_pointArr[0].x,_pointArr[0].y);
84 setText(_pointB,"B("+_pointArr[1].x+","+_pointArr[1].y+")",_pointArr[1].x,_pointArr[1].y);
85 setText(_pointC,"C("+_pointArr[2].x+","+_pointArr[2].y+")",_pointArr[2].x,_pointArr[2].y);
86 }
87 private function onGetHeight(e:MouseEvent):void
88 {
89 var point:Point;
90 var start:Point;
91 switch(e.currentTarget){
92 case _pointA:
93 point = getCrossoverByVertex(_pointArr[0],_pointArr[1],_pointArr[2]);
94 break;
95 case _pointB:
96 point = getCrossoverByVertex(_pointArr[1],_pointArr[0],_pointArr[2]);
97 break;
98 case _pointC:
99 point = getCrossoverByVertex(_pointArr[2],_pointArr[0],_pointArr[1]);
100 break;
101 }
102 setText(_pointD,"C("+point.x+","+point.y+")",point.x,point.y);
103
104 }
105 /**
106 * 获取顶点的高线与对边的交点
107 * @param vertex 顶点
108 * @param point1 三角形另外两点之一
109 * @param point2 三角形另外两点之一
110 * @return
111 */
112 private function getCrossoverByVertex(vertex:Point,point1:Point,point2:Point):Point
113 {
114 var k1:Number;//顶点对角线的斜率（即A点对角线为BC）
115 var b1:Number;//顶点对角线的直线方程的常数
116 var k2:Number;//高所在直线的斜率
117 var b2:Number;//高所在直线方程的常数
118 var crossPoint:Point = new Point();//高线和顶点对角线的交点
119 k1 = (point2.y - point1.y)/(point2.x - point1.x);
120 b1 = point1.y - k1 * point1.x;
121 k2 = -1 / k1 ;
122 b2 = vertex.y-k2*vertex.x;
123 crossPoint.x = (b1 - b2)/(k2 - k1);
124 crossPoint.y = k1 * ((b1 - b2)/(k2 - k1)) + b1;
125 drawHeight(vertex,crossPoint);
126 return crossPoint;
127 }
128 private function drawHeight(start:Point,end:Point):void
129 {
130 _heightShape.graphics.clear();
131 _heightShape.graphics.lineStyle(2,0xff00ff);
132 _heightShape.graphics.moveTo(start.x,start.y);
133 _heightShape.graphics.lineTo(end.x,end.y);
134 _heightShape.graphics.endFill();
135 }
136 private function getText(parent:Sprite):TextField
137 {
138 var t:TextField = new TextField;
139 t.autoSize = "left";
140 t.selectable = false;
141 parent.addChild(t);
142 return t;
143 }
144 private function setText(t:TextField,text:String,x:Number=0,y:Number=0):void
145 {
146 t.text = text;
147 t.x = x;
148 t.y = y;
149 }
150 }
151 }
时间： 2024-10-06 00:31:01