AS3 draw sector function画扇形函数

code_intro

1. 下面示例中的
2. DrawSector(moviec,200,200,100,S_angle,270,0xffcc00);
3. 函数就是画扇形的函数，
4. moviec是扇形所在影片剪辑的名字
5. 第2，3个参数是扇形原点的横纵坐标
6. 第4个参数是扇形的半径
7. 第5个参数S_angle是扇形的角度
8. 第6个参数是扇形的起始角度
9. 第7个参数0xffcc00是扇形的颜色
11. /*
12. *Create by Geordi 14th Feb 2008
13. *function DrawSector is drawing a sector in the flash by
14. actionscript 3
15. */
16. import flash.display.MovieClip;
17. import flash.display.Sprite;
18. var stag:Sprite=new Sprite();
19. addChild(stag);
20. var moviec:MovieClip=new MovieClip;
21. stag.addChild(moviec);
22. var S_angle:int=60;
23. /* S_angle is expressed as a number between 0 and 360 degrees. it
24. will draw a 60
25. * degree sector in this example, but you could change it to what
26. ever you want
27. */
28. DrawSector(moviec,200,200,100,S_angle,270,0xffcc00);
29. /*
30. * mc the movieclip: the container of the sector.
31. * x,y the center position of the sector
32. * r the radius of the sector
33. * angle the angle of the sector
34. * startFrom the start degree counting point : 270 top, 180 left, 0
35. right, 90 bottom ,
36. * it is counting from top in this example.
37. * color the fil lin color of the sector
38. */
39. function
40. DrawSector(mc:MovieClip,x:Number=200,y:Number=200,r:Number=100,angle
41. :Number=27,startFrom:Number=270,color:Number=0xff0000):void {
42.   mc.graphics.beginFill(color,50);
43.  //remove this line to unfill the sector
44.  /* the border of the secetor with color 0xff0000 (red) , you
45. could replace it with any color
46.   * you want like 0x00ff00(green) or 0x0000ff (blue).
47.  */
48.   mc.graphics.lineStyle(0,0xff0000);
49.   mc.graphics.moveTo(x,y);
50.   angle=(Math.abs(angle)>360)?360:angle;
51.  var n:Number=Math.ceil(Math.abs(angle)/45);
52.  var angleA:Number=angle/n;
53.   angleA=angleA*Math.PI/180;
54.   startFrom=startFrom*Math.PI/180;
56. mc.graphics.lineTo(x+r*Math.cos(startFrom),y+r*Math.sin(startFrom));
57.  for (var i=1; i<=n; i++) {
58.    startFrom+=angleA;
59.   var angleMid=startFrom-angleA/2;
60.   var bx=x+r/Math.cos(angleA/2)*Math.cos(angleMid);
61.   var by=y+r/Math.cos(angleA/2)*Math.sin(angleMid);
62.   var cx=x+r*Math.cos(startFrom);
63.   var cy=y+r*Math.sin(startFrom);
64.    mc.graphics.curveTo(bx,by,cx,cy);
65.   }
66.  if (angle!=360) {
67.    mc.graphics.lineTo(x,y);
68.   }
69.   mc.graphics.endFill();// if you want a sector without filling
70. color , please remove this line.
71. }