根據Math.cos和Math.sin來實現不同的方位判斷，想著藉助該Demo可以做成時鐘計時的小事例、類似於彈彈堂中的調整炮彈發射方向的小Demo。主要根據下面函式來計算：

var angleRadians:Number = angle * Math.PI / 180; //換算成弧度

var p:Point = new Point(Math.cos(angleRadians) * RADIUS, Math.sin(angleRadians) * RADIUS); //計算偏移量

AS3中的示例程式碼：

package mytest

{

    import flash.display.Sprite;

    import flash.geom.Point;

    public class MyTest  extends Sprite

    {

       private const CENTRE:Point = new Point(100, 150); //圓心

       private const RADIUS:Number = 100; //半徑

       private const START_ANGLE:Number = 15; //起初角度

       private const Tile_TOTAL:Number = 9; //元件個數

       private const

       public function MyTest()

       {

           for(var i:uint=0; i<Tile_TOTAL; i++){

              var pb:Tile = new Tile(); //新建元件

              var angle:uint = i * SINGLE_ANGLE + START_ANGLE; //角度

              var p:Point = getPoint(angle);

              pb.x = p.x; pb.y = p.y; //移動元件

              pb.rotation = angle - 90; //旋轉元件

              this.addChild(pb);//加到舞臺

           }

       }

       private function getPoint(angle:uint):Point{

           var angleRadians:Number = angle * Math.PI / 180; //換算成弧度

           var p:Point = new Point(Math.cos(angleRadians) * RADIUS, Math.sin(angleRadians) * RADIUS); //計算偏移量

           p.x += CENTRE.x; //跟據圓心對偏移量進行修正

           p.y += CENTRE.y; //跟據圓心對偏移量進行修正

           return p;

       }

    }

}

package mytest

{

    import flash.display.Sprite;

    public class Tile extends Sprite

    {

       public function Tile()

       {

           super();

           graphics.lineStyle(1, 0x0000ff);

           graphics.beginFill(0xcccccc,0.5);

           graphics.endFill();

           graphics.drawRect(0, 0, 50, 20);

       }

    }

}

AS3效果圖：

JAVA中的示例程式碼：

/**一個時鐘Demo的雛形*/

package mychTest;

import java.applet.Applet;

import java.awt.Color;

import java.awt.Graphics;

import java.awt.Image;

public class EclipsePaint extends Applet{

    private Graphics drawOffScreen;

    private Image offScreen;

    private int appWidth, appHeight;

    private Clock clock;     //鐘錶實體類

    public void init(){

       appWidth = getSize().width;

       appHeight = getSize().height;

       offScreen = createImage(appWidth, appHeight);

       drawOffScreen = offScreen.getGraphics();

       clock = new Clock(appWidth, appHeight);

       new Thread(new PaintThread()).start();

    }

    public void paint(Graphics g){

       clock.draw(drawOffScreen);

       g.drawImage(offScreen, 0, 0, this);

    }

    public void update(Graphics g){

       paint(g);

    }

    class PaintThread implements Runnable{

       @Override

       public void run() {

           while(true){

              try {

                  Thread.sleep(41);

              } catch (InterruptedException e) {

                  e.printStackTrace();

              }

              repaint();

           }

       }

    }

}

class Clock{

    private int x, y, width, height, appWidth, appHeight;          //外圓框的基本資訊

    private int heartX, heartY, heartWidth, heartHeight;        //圓心座標和寬度、高度

    private int minuteAimX, minuteAimY;                            //秒針的X,Y座標

    private double minuteAngle;                                 //秒針的當前角度

    public Clock(int appWidth, int appHeight){

       this.appWidth = appWidth;

       this.appHeight = appHeight;

       width = 80;                                   //外圓直徑，記住是直徑

       height = 80;

       x = appWidth / 2 - width / 2;                 //繪製外圓的X座標

       y = appHeight / 2 - height / 2;               //繪製外圓的Y座標

       heartWidth = 5;                               //圓心直徑

       heartHeight = 5;

       heartX = x + width / 2 - heartWidth/2;        //繪製圓心的X座標

       heartY = y + height / 2 - heartHeight/2;      //繪製圓心的Y座標

       minuteAngle = 60;                         //當前角度

    }

    public void draw(Graphics g){

       //繪製外圓框

       g.setColor(Color.RED);

       g.drawOval(x, y, width, height);

       //繪製中心點

       g.setColor(Color.BLACK);

       g.fillOval(heartX, heartY, heartWidth, heartHeight);

       //繪製秒線

       g.setColor(Color.BLUE);

       minuteAimX = (int)(Math.cos(minuteAngle * Math.PI / 180) * width/2) + (x + width / 2);           

       minuteAimY = (int)(Math.sin(minuteAngle * Math.PI / 180) * height/2) + (y + height / 2);

       g.drawLine((x + width / 2), (y + height / 2), minuteAimX, minuteAimY);

       //這裡的(x + width / 2)， (y + height / 2)相當於圓心的X座標，Y座標； 因為heartX， heartY減去了圓心的半徑，所以只是適用於繪製的時候

    }

}

JAVA效果圖：