唔哇哈哈，拉霸机

 demo: www.jd85.net/labaji.html

最近做转职系统，需要一个抽奖拉霸机来随机获取职业相关的物品。这里是不是在快速运动中直接停下，而是在做减速运动。不过没有用到神马恶心的物理变加速运动公式，原理其实就两个容器来回切，然后逐帧减速最后停下。

主要靠状态来区分，状态，微妙的状态~~

package
{
    import flash.display.MovieClip;
    import flash.display.SimpleButton;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.MouseEvent;

    /**
     * 从当前格子走到目标格子的走法
     * 
     * 条件：
     *     1，确保从当前格子走到目标格子中间的格子数不得低于LOWEST_ITEM_COUNT，不能出现急撒车;
     *        2，确保在LOWEST_ITEM_COUNT这最后几个格子的运动过程中是在减速运动;
     *     3，确保停在目标格子时的速度不得低于LOWEST_SPEED
     * 
     * 收到目标格子的位置后就走到状态f
     * 
     *        
     *        状态
     *         a: idle
     *         b: running
     *         c：就在这一圈内判断当到达目标item时停下 ，判断剩下要走的距离低于LOWEST_ITEM_COUNT时这时开始减速
     *         d: 走完这一圈，然后切到c,判断剩下要走的距离低于LOWEST_ITEM_COUNT时这时开始减速
     *         e: 走完这一圈，然后切到d,判断剩下要走的距离低于LOWEST_ITEM_COUNT时这时开始减速
     *         f: 走完这一圈，然后切到e,判断剩下要走的距离低于LOWEST_ITEM_COUNT时这时开始减速
     * 
     * 
     * @author ding.jia
     * 
*/
public class RandomAwardMachine extends Sprite
{
    //--------------------------------------------------------------------------
    //        Constructor
    //--------------------------------------------------------------------------
    public function RandomAwardMachine()
    {
        init();
    }

    //--------------------------------------------------------------------------
    //        Variables
    //--------------------------------------------------------------------------
    
    //--------------------------------------------------------------------------
    //        Propertise
    //--------------------------------------------------------------------------    
    private const ICON_WIDTH:int = 120;
    private const ICON_HEIGHT:int = 113;
    private const VERTICAL_GAP:int = 5;
    
    private const STATUS_A:String = "a";
    private const STATUS_B:String = "b";
    private const STATUS_C:String = "c";
    private const STATUS_D:String = "d";
    private const STATUS_E:String = "e";
    private const STATUS_F:String = "f";
    
//    private const LOWEST_ITEM_COUNT:int = 28;
//    private const LOWEST_SPEED:Number = 2;
//    private const SPEED_subtract:Number = 1;
    
    private const LOWEST_ITEM_COUNT:int = 17;
    private const LOWEST_SPEED:Number = 2;
    private const SPEED_subtract:Number = 1;

    private var crtStatus:String; //当前机器运行状态
    private var speed:Number; 
    private var iconList:Array; //所有要显示出的icon列表
    private var iconListLength:int;
    private var bgAsset:AwardBg; 
    private var bg:MovieClip; //背景
    private var btn:SimpleButton;
    private var containerMask:Sprite; //两个icon容器所在容器的遮罩
    private var iconContainerA:Sprite; //第一张icon容器
    private var iconContainerB:Sprite; //第二张icon容器
    private var crtBottomIconContainer:Sprite; //当前处在下方的icon容器
    private var container:Sprite; //上下两个icon所在的容器
    private var crtLatestIconIndex:int; //当前最新的icon的数组索引值
    private var targetIconIndex:int;
    
    //--------------------------------------------------------------------------
    //        Methods
    //--------------------------------------------------------------------------
    public function receiveTargat(index:int):void
    {
        targetIconIndex = index;
//        crtStatus = STATUS_F;
        crtStatus = STATUS_E;
    }
    //--------------------------------------------------------------------------
    //        Event Handler
    //--------------------------------------------------------------------------
    protected function btnClickHandler(event:MouseEvent):void
    {
        readyRun();
    }
    
    protected function efHandler(event:Event):void
    {
        switch(crtStatus)
        {
            case STATUS_B:
                doStatusB();
                break;
            case STATUS_C:
                doStatusC();
                break;
            case STATUS_D:
                doStatusD();
                break;
            case STATUS_E:
                doStatusE();
                break;
//            case STATUS_F:
//                doStatusF();
                break;
            default:
                break;
        }
    }
    
    //--------------------------------------------------------------------------
    //        Private
    //--------------------------------------------------------------------------
    private function doStatusB():void
    {
        runUP();
    }
    
    //是否是走到了c段之后走到了目标,当由d切换到c时，可能正好就是在目标位置,但这时还未走到c段类
    private var specialC:int;
    private function doStatusC():void
    {
        //c段里目标点的距离
        var c:int = Math.abs(crtLatestIconIndex - targetIconIndex);
        if(c <= LOWEST_ITEM_COUNT)
        {
            slowDown();
        }
        
        if(crtLatestIconIndex != targetIconIndex)
        {
            specialC = 1;
        }
        
        //判断在这一圈内到达目标格子就停下
        if(crtLatestIconIndex == targetIconIndex)
        {
            if(specialC == 1)
            {
                if(crtBottomIconContainer.y <= 3)
                {
                    finished();            
                }
                else
                {
                    runUP();
                }
            }
            else
            {
                runUP();
            }
        }
        else
        {
            runUP();
        }
    }
    private var finishRoundD:Boolean;
    private function doStatusD():void
    {
        if(crtLatestIconIndex == iconListLength - 1)
        {
            if(finishRoundD)
            {
                finishRoundD = false;
                crtStatus = STATUS_C;
            }
            else
            {
                runUP();
            }
        }
        else
        {
            finishRoundD = true;
            runUP();
        }
        
        //c段走到目标点的距离
        var c:int = targetIconIndex;
        //d段开始降速时到d端最后一张还剩下的距离
        var dLong:int = LOWEST_ITEM_COUNT - c;
        //求出d段减速点的索引
        var dIndex:int = iconListLength - dLong;
        if(crtLatestIconIndex >= dIndex)
        {
            slowDown();
        }
    }
    
    //在状态e下是否走完了一整圈后才开始算到达最后一张
    private var finishRoundE:Boolean;
    private function doStatusE():void
    {
//        //先要知道减速点是否在e段
//        var d:int = iconListLength;
//        var c:int = targetIconIndex;
//
//
//        //判断是否到达了减速点 e(未必满) + d（满） + c(未必满)
//        var e:int = iconListLength - crtLatestIconIndex;
//        var tempNum:int = e + d + c;
//        if(tempNum <= LOWEST_ITEM_COUNT)
//        {
//            slowDown();
//        }
        
        if(crtLatestIconIndex == iconListLength - 1)
        {
            if(finishRoundE)
            {
                finishRoundE = false;
                crtStatus = STATUS_D;
            }
            else
            {
                runUP();
            }
        }
        else
        {
            finishRoundE = true;
            runUP();
        }
        
    }
    
//    private function doStatusF():void
//    {
//        //判断是否到达了减速点 e(满) + d(满) + c(未必满) + f(未必满)
//        var e:int = iconListLength; 
//        var d:int = iconListLength;
//        var c:int = iconListLength - targetIconIndex;
//        var f:int = iconListLength - crtLatestIconIndex;
//        var tempNum:int = e + d + c + f;
//        if(tempNum <= LOWEST_ITEM_COUNT)
//        {
//            slowDown();
//        }
//
//        if(crtLatestIconIndex == iconListLength - 1) //判断是否走完了一圈
//        {
//            crtStatus = STATUS_E;
//        }
//        else
//        {
//            runUP();
//        }
//    }
    
    private function slowDown():void
    {
        //第一次开始降速是的降速点索引,目标点索引，和当前状态
        trace("crtLatestIconIndex:",crtLatestIconIndex,"targetIconIndex:",targetIconIndex,"crtstatus:",crtStatus);
        
        speed -= SPEED_subtract;
        if(speed <= LOWEST_SPEED)
        {
            speed = LOWEST_SPEED;
        }
        trace("speed:",speed);
    }
    
    private function finished():void
    {
        crtBottomIconContainer.y = 0;
        removeEventListener(Event.ENTER_FRAME,efHandler);
        crtStatus = STATUS_A;
        specialC = 0;
        finishRoundD = false;
        finishRoundE = false;
        speed = 65;
    }
    
    private function runUP():void
    {
        if(iconContainerA.y < iconContainerB.y)
        {
            if(iconContainerB.y <= 0)
            {
                iconContainerA.y = iconContainerB.y + ICON_HEIGHT;
                crtBottomIconContainer = iconContainerA;
                addNextIcon();
            }
        }
        else if(iconContainerA.y > iconContainerB.y)
        {
            if(iconContainerA.y <= 0)
            {
                iconContainerB.y = iconContainerA.y + ICON_HEIGHT;
                crtBottomIconContainer = iconContainerB;
                addNextIcon();
            }
        }
        
        iconContainerA.y -= speed;
        iconContainerB.y -= speed;
    }
    
    private function addNextIcon():void
    {
        crtLatestIconIndex++;
        if(crtLatestIconIndex > iconListLength - 1)
        {
            crtLatestIconIndex = 0;
        }
        
        if(crtBottomIconContainer.numChildren > 0)
        {
            crtBottomIconContainer.removeChildAt(0);
        }
        crtBottomIconContainer.addChild(iconList[crtLatestIconIndex]);
    }
    
    private function init():void
    {
        crtStatus = STATUS_A;
        speed = 65;
        
        setIconsAsset();
        addBgAssst();
        addContainer();
        addContainerMask();
        addIconContainers();
        
        addChild(btn);
        
    }
    
    private function addContainer():void
    {
        container = new Sprite();
        container.graphics.beginFill(0xff0000,0);
        container.graphics.drawRect(0,0,bg.width,bg.height);
        addChild(container);
    }
    
    private function addContainerMask():void
    {
        containerMask = new Sprite();
        containerMask.graphics.beginFill(0x00ff33,0);
        containerMask.graphics.drawRect(0,0,bg.width,bg.height - 8);
        containerMask.y = 4;
        addChild(containerMask);
        
//        container.mask = containerMask;
    }
    
    /**
     * 刚最后一张显示时，把第一张icon移动最下面 
     * 
*/    
    private function resetIconsPos():void
    {
        
    }
    
    private function addIconContainers():void
    {
        iconContainerA = new Sprite();
        iconContainerB = new Sprite();
        
        iconContainerA.graphics.beginFill(0x000000,0);
        iconContainerA.graphics.drawRect(0,0,bg.width,bg.height);
        iconContainerA.x = 0;
        iconContainerA.y = ICON_HEIGHT;
        crtLatestIconIndex = 0;
        iconContainerA.addChild(iconList[crtLatestIconIndex]);
        container.addChild(iconContainerA);
    
        iconContainerB.graphics.beginFill(0xffff00,0);
        iconContainerB.graphics.drawRect(0,0,bg.width,bg.height);
        iconContainerB.x = 0;
        iconContainerB.y = ICON_HEIGHT * 2;
        crtLatestIconIndex = 1;
        iconContainerB.addChild(iconList[crtLatestIconIndex]);
        container.addChild(iconContainerB);
        
        crtBottomIconContainer = iconContainerB;
    }
    
    private function addBgAssst():void
    {
        bgAsset = new AwardBg();
        addChild(bgAsset);
        bg = bgAsset._bg;
        btn = bgAsset._btn;
        btn.addEventListener(MouseEvent.CLICK,btnClickHandler);
    }
    
    private function readyRun():void
    {
        if(crtStatus == STATUS_A)
        {
            crtStatus = STATUS_B;
            addEventListener(Event.ENTER_FRAME,efHandler);
        }
    }
    
    private function setIconsAsset():void
    {
        iconList = [];
        var icon1:AwardIcon = new AwardIcon(new ICON_1(),AwardIconIndex.ICON_1);
        var icon2:AwardIcon = new AwardIcon(new ICON_2(),AwardIconIndex.ICON_2);
        var icon3:AwardIcon = new AwardIcon(new ICON_3(),AwardIconIndex.ICON_3);
        var icon4:AwardIcon = new AwardIcon(new ICON_4(),AwardIconIndex.ICON_4);
        var icon5:AwardIcon = new AwardIcon(new ICON_5(),AwardIconIndex.ICON_5);
        var icon6:AwardIcon = new AwardIcon(new ICON_6(),AwardIconIndex.ICON_6);
        var icon7:AwardIcon = new AwardIcon(new ICON_7(),AwardIconIndex.ICON_7);
        var icon8:AwardIcon = new AwardIcon(new ICON_8(),AwardIconIndex.ICON_8);
        var icon9:AwardIcon = new AwardIcon(new ICON_9(),AwardIconIndex.ICON_9);
        var icon10:AwardIcon = new AwardIcon(new ICON_10(),AwardIconIndex.ICON_10);
        var icon11:AwardIcon = new AwardIcon(new ICON_11(),AwardIconIndex.ICON_11);
        var icon12:AwardIcon = new AwardIcon(new ICON_12(),AwardIconIndex.ICON_12);
        var icon13:AwardIcon = new AwardIcon(new ICON_13(),AwardIconIndex.ICON_13);
        var icon14:AwardIcon = new AwardIcon(new ICON_14(),AwardIconIndex.ICON_14);
        var icon15:AwardIcon = new AwardIcon(new ICON_15(),AwardIconIndex.ICON_15);
        var icon16:AwardIcon = new AwardIcon(new ICON_16(),AwardIconIndex.ICON_16);
        var icon17:AwardIcon = new AwardIcon(new ICON_17(),AwardIconIndex.ICON_17);
        var icon18:AwardIcon = new AwardIcon(new ICON_18(),AwardIconIndex.ICON_18);
        var icon19:AwardIcon = new AwardIcon(new ICON_19(),AwardIconIndex.ICON_19);
        var icon20:AwardIcon = new AwardIcon(new ICON_20(),AwardIconIndex.ICON_20);
        var icon21:AwardIcon = new AwardIcon(new ICON_21(),AwardIconIndex.ICON_21);
        
        iconList.push(icon1,icon2,icon3,
            icon4,
            icon5,
            icon6,icon7,
            icon8,icon9,
            icon10,icon11,icon12,icon13,icon14,icon15,icon16,icon17,icon18,icon19,icon20,icon21);
        
        iconListLength = iconList.length;
        
    }
    
    //--------------------------------------------------------------------------
    //        Dispose
    //--------------------------------------------------------------------------    
}
}

package
{
import flash.display.Sprite;
import flash.display.StageScaleMode;
import flash.events.MouseEvent;
import flash.events.TimerEvent;
import flash.text.TextField;
import flash.utils.Timer;

/**
 * 
 * @author ding.jia
 * 
 */
[SWF(width="1200",height="1000",frameRate="24")]
public class Main extends Sprite
{
    //--------------------------------------------------------------------------
    //        Constructor
    //--------------------------------------------------------------------------
    public function Main()
    {
        stage.scaleMode = StageScaleMode.NO_SCALE;
        
        machine = new RandomAwardMachine();
        
        machine.x = 200;
        machine.y = 200;
        addChild(machine);
        
        textField = new TextField();
        textField.x = 350;
        textField.y = 200;
        textField.text = "点击走到目标";
        addChild(textField);
        
        textField.addEventListener(MouseEvent.CLICK,tfClickHandler);
    }
    
    //--------------------------------------------------------------------------
    //        Variables
    //--------------------------------------------------------------------------
    private var machine:RandomAwardMachine;
    private var textField:TextField;
    //--------------------------------------------------------------------------
    //        Propertise
    //--------------------------------------------------------------------------    

    //--------------------------------------------------------------------------
    //        Methods
    //--------------------------------------------------------------------------

    //--------------------------------------------------------------------------
    //        Event Handler
    //--------------------------------------------------------------------------
    private function tfClickHandler(event:MouseEvent):void
    {
        machine.receiveTargat(AwardIconIndex.ICON_1);
        textField.text = "icon1";        
    }
    //--------------------------------------------------------------------------
    //        Private
    //--------------------------------------------------------------------------
    
    //--------------------------------------------------------------------------
    //        Dispose
    //--------------------------------------------------------------------------    
}
}