向量負(fù)責(zé)用于計(jì)算力，繪圖庫(kù)負(fù)責(zé)把向量表示出來
下面是勻速圓周運(yùn)動(dòng)的例子
圖片如下：


code
import Vector;
import fbook.graphics.pen.*;
import fbook.graphics.draw2d.*;
import fbook.graphics.draw2d.arrow.*;
import fbook.graphics.GDI;
var cur_mc = this;
//給球的即時(shí)速度，看受力圖時(shí)可加大速度
var vel = new Vector(200, 500);
//速度向量的長(zhǎng)度
var l=vel.getLength()
//位置向量
var pos = new Vector(move_mc._x, move_mc._y);
/***繪圖****/
var _p1:IPen = new SolidPen(1, 0x000000, 100);
var _g:GDI = GDI.getInstance();
setInterval(this, "move", 30);
function move() {
??//繩子拉力
??var _lal = new Vector(move_mc._x-top_mc._x, move_mc._y-top_mc._y);
??//向量相加
??var f2 = vel.plusNew(_lal);
??_g.line(_p1, new SolidLineArrow(true, move_mc._x, move_mc._y, vel.x+move_mc._x, vel.y+move_mc._y));
??//半徑
??var r = _lal.getLength();
??//相加后的長(zhǎng)度
??var len = f2.getLength();
??//單位化
??f2.normal();
??//重新設(shè)置長(zhǎng)度
??f2.scale(len-r);
??//改變方向后的速度
??vel.minus(f2);
??var len = vel.getLength();
??_g.target = this.createEmptyMovieClip("mc", 1);
??_g.line(_p1, new SolidLineArrow(true, top_mc._x, top_mc._y, _lal.x+top_mc._x, _lal.y+top_mc._y));
??_g.line(_p1, new SolidLineArrow(true, move_mc._x, move_mc._y, vel.x+move_mc._x, vel.y+move_mc._y));
??//_g.line(_p1, new SolidLineArrow(true, move_mc._x, move_mc._y, f3.x+move_mc._x, f3.y+move_mc._y));
??//_g.line(_p1, new SolidLineArrow(true, top_mc._x, top_mc._y, f.x+top_mc._x, f.y+top_mc._y));
??pos.plus(vel);
??
??move_mc._x = pos.x;
??move_mc._y = pos.y;
??//設(shè)置成原來的速度
??vel.normal()
??vel.setLength(l)
??
}
本文轉(zhuǎn)自：http://www.5uflash.com/flashjiaocheng/Flashyingyongkaifa/883.html

在flash里用向量來制作運(yùn)動(dòng)模擬