diff --git a/game.js b/game.js
index 65a5387..fe19933 100644
--- a/game.js
+++ b/game.js
@@ -5,7 +5,7 @@
 
 // requestAnimationFrame polyfill
 if (!Date.now)
-    Date.now = function() { return new Date().getTime(); };
+Date.now = function() { return new Date().getTime(); };
 (function() {
     'use strict';
     var vendors = ['webkit', 'moz'];
@@ -15,414 +15,414 @@ if (!Date.now)
         window.cancelAnimationFrame = (window[vp+'CancelAnimationFrame'] || window[vp+'CancelRequestAnimationFrame']);
     }
     if (/iP(ad|hone|od).*OS 6/.test(window.navigator.userAgent) // iOS6 is buggy
-        || !window.requestAnimationFrame || !window.cancelAnimationFrame) {
+    || !window.requestAnimationFrame || !window.cancelAnimationFrame) {
         var lastTime = 0;
         window.requestAnimationFrame = function(callback) {
             var now = Date.now();
             var nextTime = Math.max(lastTime + 16, now);
             return setTimeout(function() { callback(lastTime = nextTime); },
-                              nextTime - now);
+            nextTime - now);
         };
         window.cancelAnimationFrame = clearTimeout;
     }
 }());
 
 function Game(id,params){
-	var _ = this;
-	params = params||{};
-	var settings = {
-		width:960,						//画布宽度
-		height:640						//画布高度
-	};
-	var _extend = function(target,settings,params){
-		for(var i in settings){
-			target[i] = params[i]||settings[i];
-		}
-		return target;
-	};
-	_extend(this,settings,params);
-	var $canvas = document.getElementById(id);
-	$canvas.width = _.width;
-	$canvas.height = _.height;
-	var _context = $canvas.getContext('2d');	//画布上下文环境
-	var _stages = [];							//布景对象队列
-	var _events = {};							//事件集合
-	var _index=0,								//当前布景索引
-		_hander;  								//帧动画控制
-	//活动对象构造
-	var Item = function(params){
-		this._params = params||{};
-		this._settings = {
-			x:0,					//位置坐标:横坐标
-			y:0,					//位置坐标:纵坐标
-			width:20,				//宽
-			height:20,				//高
-			type:0,					//对象类型,0表示普通对象(不与地图绑定),1表示玩家控制对象,2表示程序控制对象
-			color:'#F00',			//标识颜色
-			status:1,				//对象状态,0表示未激活/结束,1表示正常,2表示暂停,3表示临时,4表示异常
-			orientation:0,			//当前定位方向,0表示右,1表示下,2表示左,3表示上
-			speed:0,				//移动速度
-			//地图相关
-			location:null,			//定位地图,Map对象
-			coord:null,				//如果对象与地图绑定,需设置地图坐标;若不绑定,则设置位置坐标
-			path:[],				//NPC自动行走的路径
-			vector:null,			//目标坐标
-			//布局相关
-			stage:null,				//绑定对象与所属布景绑定
-			index:0,				//对象索引
-			frames:1,				//速度等级,内部计算器times多少帧变化一次
-			times:0,				//刷新画布计数(用于循环动画状态判断)
-			timeout:0,				//倒计时(用于过程动画状态判断)
-			control:{},				//控制缓存,到达定位点时处理
-			update:function(){}, 	//更新参数信息
-			draw:function(){}		//绘制
-		};
-		_extend(this,this._settings,this._params);
-	};
-	Item.prototype.bind = function(eventType,callback){
-		if(!_events[eventType]){
-			_events[eventType] = {};
-			$canvas.addEventListener(eventType,function(e){
-				var position = _.getPosition(e);
-				_stages[_index].items.forEach(function(item){
-					if(Math.abs(position.x-item.x)<item.width/2&&Math.abs(position.y-item.y)<item.height/2){
-						var key = 's'+_index+'i'+item.index;
-						if(_events[eventType][key]){
-							_events[eventType][key](e);
-						}
-					}
-				});
-				e.preventDefault();
-			});
-		}
-		_events[eventType]['s'+this.stage.index+'i'+this.index] = callback.bind(this);  //绑定作用域
-	};
-	//地图对象构造器
-	var Map = function(params){
-		this._params = params||{};
-		this._settings = {
-			x:0,						//地图起点坐标
-			y:0,
-			size:20,					//地图单元的宽度
-			data:[],					//地图数据
-			stage:null,					//布景
-			x_length:0,					//二维数组x轴长度
-			y_length:0,					//二维数组y轴长度
-      frames:1,				//速度等级,内部计算器times多少帧变化一次
-			times:0,				//刷新画布计数(用于循环动画状态判断)
-      cache:false,    //是否静态（如静态则设置缓存）
-			update:function(){},		//更新地图数据
-			draw:function(){},			//绘制地图
-		};
-		_extend(this,this._settings,this._params);
-	};
-	//获取地图上某点的值
-	Map.prototype.get = function(x,y){
-		if(this.data[y]&&typeof this.data[y][x]!='undefined'){
-			return this.data[y][x];
-		}
-		return -1;
-	};
-	//设置地图上某点的值
-	Map.prototype.set = function(x,y,value){
-		if(this.data[y]){
-			this.data[y][x] = value;
-		}
-	};
-	//地图坐标转画布坐标
-	Map.prototype.coord2position = function(cx,cy){
-		return {
-			x:this.x+cx*this.size+this.size/2,
-			y:this.y+cy*this.size+this.size/2
-		};
-	};
-	//画布坐标转地图坐标
-	Map.prototype.position2coord = function(x,y){
-		var fx = Math.abs(x-this.x)%this.size-this.size/2;
-		var fy = Math.abs(y-this.y)%this.size-this.size/2;
-		return {
-			x:Math.floor((x-this.x)/this.size),
-			y:Math.floor((y-this.y)/this.size),
-			offset:Math.sqrt(fx*fx+fy*fy)
-		};
-	};
-	//寻址算法
-	Map.prototype.finder = function(params){
-		var defaults = {
-			map:null,
-			start:{},
-			end:{},
-      type:'path'
-		};
-		var options = _extend({},defaults,params);
-		var result = [];
-		if(options.map[options.start.y][options.start.x]||options.map[options.end.y][options.end.x]){ //当起点或终点设置在墙上
-			return [];
-		}
-		var finded = false;
-		var y_length  = options.map.length;
-		var x_length = options.map[0].length;
-		var steps = []; 	//步骤的映射
-    var steps_length = 0;
-		for(var y=y_length;y--;){
-			steps[y] = [];
-			for(var x=x_length;x--;){
-				steps[y][x] = 0;
-			}
-		}
-    var _getValue = function(x,y){  //获取地图上的值
-      if(options.map[y]&&typeof options.map[y][x]!='undefined'){
-        return options.map[y][x];
-      }
-      return -1;
+    var _ = this;
+    params = params||{};
+    var settings = {
+        width:960,						//画布宽度
+        height:640						//画布高度
     };
-    var _next = function(to){ //判定是非可走,可走放入列表
-      var value = _getValue(to.x,to.y);
-      if(value<1){
-        if(value==-1){
-          to.x = (to.x+x_length)%x_length;
-          to.y = (to.y+y_length)%y_length;
-          to.change = 1;
+    var _extend = function(target,settings,params){
+        for(var i in settings){
+            target[i] = params[i]||settings[i];
         }
-        if(!steps[to.y][to.x]){
-          result.push(to);
-        }
-      }
+        return target;
     };
-		var _render = function(list){//找线路
-			var new_list = [];
-			var next = function(from,to){
-				var value = _getValue(to.x,to.y);
-				if(value<1){	//当前点是否可以走
-					if(value==-1){
-						to.x = (to.x+x_length)%x_length;
-						to.y = (to.y+y_length)%y_length;
-						to.change = 1;
-					}
-					if(to.x==options.end.x&&to.y==options.end.y){
-						steps[to.y][to.x] = from;
-						finded = true;
-					}else if(!steps[to.y][to.x]){
-						steps[to.y][to.x] = from;
-						new_list.push(to);
-					}
-				}
-			};
-			for(var i=0,len=list.length;i<len;i++){
-				var current = list[i];
-				next(current,{y:current.y+1,x:current.x});
-				next(current,{y:current.y,x:current.x+1});
-				next(current,{y:current.y-1,x:current.x});
-				next(current,{y:current.y,x:current.x-1});
-			}
-			if(!finded&&new_list.length){
-				_render(new_list);
-			}
-		};
-		_render([options.start]);
-		if(finded){
-      var current=options.end;
-      if(options.type=='path'){
-  			while(current.x!=options.start.x||current.y!=options.start.y){
-  				result.unshift(current);
-  				current=steps[current.y][current.x];
-  			}
-      }else if(options.type=='next'){
-        _next({x:current.x+1,y:current.y});
-        _next({x:current.x,y:current.y+1});
-        _next({x:current.x-1,y:current.y});
-        _next({x:current.x,y:current.y-1});
-      }
-		}
-		return result;
-	};
-	//布景对象构造器
-	var Stage = function(params){
-		this._params = params||{};
-		this._settings = {
-			status:0,						//布景状态,0表示未激活/结束,1表示正常,2表示暂停,3表示临时,4表示异常
-			maps:[],						//地图队列
-			audio:[],						//音频资源
-			images:[],						//图片资源
-			items:[],						//对象队列
-			timeout:0,						//倒计时(用于过程动画状态判断)
-			update:function(){}				//嗅探,处理布局下不同对象的相对关系
-		};
-		_extend(this,this._settings,this._params);
-	};
-	//重置物体位置
-	Stage.prototype.resetItems = function(){
-		this.status = 1;
-		this.items.forEach(function(item,index){
-			_extend(item,item._settings,item._params);
-			item.index = index;
-			item.stage = this;
-			if(item.location){
-				var position = item.location.coord2position(item.coord.x,item.coord.y);
-				item.x = position.x;
-				item.y = position.y;
-			}
-		}.bind(this));
-	};
-	//重置地图
-	Stage.prototype.resetMaps = function(){
-		this.status = 1;
-		this.maps.forEach(function(map){
-			_extend(map,map._settings,map._params);
-			map.data = JSON.parse(JSON.stringify(map._params.data));
-			map.stage = this;
-			map.y_length = map.data.length;
-			map.x_length = map.data[0].length;
-		}.bind(this));
-	};
-	//重置
-	Stage.prototype.reset = function(){
-		_extend(this,this._settings,this._params);
-		this.resetItems();
-		this.resetMaps();
-	};
-	//添加对象
-	Stage.prototype.createItem = function(options){
-		var item = new Item(options);
-		//动态属性
-		item.stage = this;
-		item.index = this.items.length;
-		if(item.location){
-			var position = item.location.coord2position(item.coord.x,item.coord.y);
-			item.x = position.x;
-			item.y = position.y;
-		}
-		this.items.push(item);
-		return item;
-	};
-	//获取对象列表
-	Stage.prototype.getItemsByType = function(type){
-		var items = this.items.filter(function(item){
-			if(item.type==type){
-				return item;
-			}
-		});
-		return items;
-	};
-	//添加地图
-	Stage.prototype.createMap = function(options){
-		var map = new Map(options);
-		//动态属性
-		map.data = JSON.parse(JSON.stringify(map._params.data));
-		map.stage = this;
-		map.y_length = map.data.length;
-		map.x_length = map.data[0].length;
-    map.imageData = null;
-		this.maps.push(map);
-		return map;
-	};
-	//绑定事件
-	Stage.prototype.bind = function(eventType,callback){
-		if(!_events[eventType]){
-			_events[eventType] = {};
-			window.addEventListener(eventType,function(e){
-				var key = 's' + _index;
-				if(_events[eventType][key]){
-					_events[eventType][key](e);
-				}
-				e.preventDefault();
-			});
-		}
-		_events[eventType]['s'+this.index] = callback.bind(this);	//绑定事件作用域
-	};
-	//动画开始
-	this.start = function() {
-		var f = 0;		//帧数计算
-		var fn = function(){
-			var stage = _stages[_index];
-			_context.clearRect(0,0,_.width,_.height);		//清除画布
-			f++;
-			if(stage.timeout){
-				stage.timeout--;
-			}
-			if(stage.update()!=false){		//update返回false,则不绘制
-				if(stage.maps.length){
-					stage.maps.forEach(function(map){
-            if(!(f%map.frames)){
-							map.times = f/map.frames;		//计数器
-						}
-						map.update();
-            if(map.cache){
-              if(!map.imageData){
-                _context.save();
-                map.draw(_context);
-                map.imageData = _context.getImageData(0,0,_.width,_.height);
-                _context.restore();
-              }else{
-                _context.putImageData(map.imageData,0,0);
-              }
-            }else{
-              map.draw(_context);
+    _extend(this,settings,params);
+    var $canvas = document.getElementById(id);
+    $canvas.width = _.width;
+    $canvas.height = _.height;
+    var _context = $canvas.getContext('2d');	//画布上下文环境
+    var _stages = [];							//布景对象队列
+    var _events = {};							//事件集合
+    var _index=0,								//当前布景索引
+    _hander;  								//帧动画控制
+    //活动对象构造
+    var Item = function(params){
+        this._params = params||{};
+        this._settings = {
+            x:0,					//位置坐标:横坐标
+            y:0,					//位置坐标:纵坐标
+            width:20,				//宽
+            height:20,				//高
+            type:0,					//对象类型,0表示普通对象(不与地图绑定),1表示玩家控制对象,2表示程序控制对象
+            color:'#F00',			//标识颜色
+            status:1,				//对象状态,0表示未激活/结束,1表示正常,2表示暂停,3表示临时,4表示异常
+            orientation:0,			//当前定位方向,0表示右,1表示下,2表示左,3表示上
+            speed:0,				//移动速度
+            //地图相关
+            location:null,			//定位地图,Map对象
+            coord:null,				//如果对象与地图绑定,需设置地图坐标;若不绑定,则设置位置坐标
+            path:[],				//NPC自动行走的路径
+            vector:null,			//目标坐标
+            //布局相关
+            stage:null,				//绑定对象与所属布景绑定
+            index:0,				//对象索引
+            frames:1,				//速度等级,内部计算器times多少帧变化一次
+            times:0,				//刷新画布计数(用于循环动画状态判断)
+            timeout:0,				//倒计时(用于过程动画状态判断)
+            control:{},				//控制缓存,到达定位点时处理
+            update:function(){}, 	//更新参数信息
+            draw:function(){}		//绘制
+        };
+        _extend(this,this._settings,this._params);
+    };
+    Item.prototype.bind = function(eventType,callback){
+        if(!_events[eventType]){
+            _events[eventType] = {};
+            $canvas.addEventListener(eventType,function(e){
+                var position = _.getPosition(e);
+                _stages[_index].items.forEach(function(item){
+                    if(Math.abs(position.x-item.x)<item.width/2&&Math.abs(position.y-item.y)<item.height/2){
+                        var key = 's'+_index+'i'+item.index;
+                        if(_events[eventType][key]){
+                            _events[eventType][key](e);
+                        }
+                    }
+                });
+                e.preventDefault();
+            });
+        }
+        _events[eventType]['s'+this.stage.index+'i'+this.index] = callback.bind(this);  //绑定作用域
+    };
+    //地图对象构造器
+    var Map = function(params){
+        this._params = params||{};
+        this._settings = {
+            x:0,						//地图起点坐标
+            y:0,
+            size:20,					//地图单元的宽度
+            data:[],					//地图数据
+            stage:null,					//布景
+            x_length:0,					//二维数组x轴长度
+            y_length:0,					//二维数组y轴长度
+            frames:1,				//速度等级,内部计算器times多少帧变化一次
+            times:0,				//刷新画布计数(用于循环动画状态判断)
+            cache:false,    //是否静态（如静态则设置缓存）
+            update:function(){},		//更新地图数据
+            draw:function(){},			//绘制地图
+        };
+        _extend(this,this._settings,this._params);
+    };
+    //获取地图上某点的值
+    Map.prototype.get = function(x,y){
+        if(this.data[y]&&typeof this.data[y][x]!='undefined'){
+            return this.data[y][x];
+        }
+        return -1;
+    };
+    //设置地图上某点的值
+    Map.prototype.set = function(x,y,value){
+        if(this.data[y]){
+            this.data[y][x] = value;
+        }
+    };
+    //地图坐标转画布坐标
+    Map.prototype.coord2position = function(cx,cy){
+        return {
+            x:this.x+cx*this.size+this.size/2,
+            y:this.y+cy*this.size+this.size/2
+        };
+    };
+    //画布坐标转地图坐标
+    Map.prototype.position2coord = function(x,y){
+        var fx = Math.abs(x-this.x)%this.size-this.size/2;
+        var fy = Math.abs(y-this.y)%this.size-this.size/2;
+        return {
+            x:Math.floor((x-this.x)/this.size),
+            y:Math.floor((y-this.y)/this.size),
+            offset:Math.sqrt(fx*fx+fy*fy)
+        };
+    };
+    //寻址算法
+    Map.prototype.finder = function(params){
+        var defaults = {
+            map:null,
+            start:{},
+            end:{},
+            type:'path'
+        };
+        var options = _extend({},defaults,params);
+        var result = [];
+        if(options.map[options.start.y][options.start.x]||options.map[options.end.y][options.end.x]){ //当起点或终点设置在墙上
+            return [];
+        }
+        var finded = false;
+        var y_length  = options.map.length;
+        var x_length = options.map[0].length;
+        var steps = []; 	//步骤的映射
+        var steps_length = 0;
+        for(var y=y_length;y--;){
+            steps[y] = [];
+            for(var x=x_length;x--;){
+                steps[y][x] = 0;
             }
-					});
-				}
-				if(stage.items.length){
-					stage.items.forEach(function(item){
-						if(!(f%item.frames)){
-							item.times = f/item.frames;		//计数器
-						}
-						if(stage.status==1&&item.status!=2){  	//对象及布景状态都处于正常状态下
-							if(item.location){
-								item.coord = item.location.position2coord(item.x,item.y);
-							}
-							if(item.timeout){
-								item.timeout--;
-							}
-							item.update();
-						}
-						item.draw(_context);
-					});
-				}
-			}
-			_hander = requestAnimationFrame(fn);
-		};
-		_hander = requestAnimationFrame(fn);
-	};
-	//动画结束
-	this.stop = function(){
-		_hander&&cancelAnimationFrame(_hander);
-	};
-	//事件坐标
-	this.getPosition = function(e){
-		var box = $canvas.getBoundingClientRect();
-		return {
-			x:e.clientX-box.left*(_.width/box.width),
-			y:e.clientY-box.top*(_.height/box.height)
-		};
-	}
-	//创建布景
-	this.createStage = function(options){
-		var stage = new Stage(options);
-		stage.index = _stages.length;
-		_stages.push(stage);
-		return stage;
-	};
-	//指定布景
-	this.setStage = function(index){
-		_stages[_index].status = 0;
-		_index = index;
-		_stages[_index].status = 1;
-		return _stages[_index];
-	};
-	//下个布景
-	this.nextStage = function(){
-		if(_index<_stages.length-1){
-			_stages[_index].status = 0;
-			_index++;
-			_stages[_index].status = 1;
-			return _stages[_index];
-		}else{
-			throw new Error('unfound new stage.');
-		}
-	};
-	//初始化游戏引擎
-	this.init = function(){
-		_index = 0;
-		this.start();
-	};
+        }
+        var _getValue = function(x,y){  //获取地图上的值
+            if(options.map[y]&&typeof options.map[y][x]!='undefined'){
+                return options.map[y][x];
+            }
+            return -1;
+        };
+        var _next = function(to){ //判定是非可走,可走放入列表
+            var value = _getValue(to.x,to.y);
+            if(value<1){
+                if(value==-1){
+                    to.x = (to.x+x_length)%x_length;
+                    to.y = (to.y+y_length)%y_length;
+                    to.change = 1;
+                }
+                if(!steps[to.y][to.x]){
+                    result.push(to);
+                }
+            }
+        };
+        var _render = function(list){//找线路
+            var new_list = [];
+            var next = function(from,to){
+                var value = _getValue(to.x,to.y);
+                if(value<1){	//当前点是否可以走
+                    if(value==-1){
+                        to.x = (to.x+x_length)%x_length;
+                        to.y = (to.y+y_length)%y_length;
+                        to.change = 1;
+                    }
+                    if(to.x==options.end.x&&to.y==options.end.y){
+                        steps[to.y][to.x] = from;
+                        finded = true;
+                    }else if(!steps[to.y][to.x]){
+                        steps[to.y][to.x] = from;
+                        new_list.push(to);
+                    }
+                }
+            };
+            for(var i=0,len=list.length;i<len;i++){
+                var current = list[i];
+                next(current,{y:current.y+1,x:current.x});
+                next(current,{y:current.y,x:current.x+1});
+                next(current,{y:current.y-1,x:current.x});
+                next(current,{y:current.y,x:current.x-1});
+            }
+            if(!finded&&new_list.length){
+                _render(new_list);
+            }
+        };
+        _render([options.start]);
+        if(finded){
+            var current=options.end;
+            if(options.type=='path'){
+                while(current.x!=options.start.x||current.y!=options.start.y){
+                    result.unshift(current);
+                    current=steps[current.y][current.x];
+                }
+            }else if(options.type=='next'){
+                _next({x:current.x+1,y:current.y});
+                _next({x:current.x,y:current.y+1});
+                _next({x:current.x-1,y:current.y});
+                _next({x:current.x,y:current.y-1});
+            }
+        }
+        return result;
+    };
+    //布景对象构造器
+    var Stage = function(params){
+        this._params = params||{};
+        this._settings = {
+            status:0,						//布景状态,0表示未激活/结束,1表示正常,2表示暂停,3表示临时,4表示异常
+            maps:[],						//地图队列
+            audio:[],						//音频资源
+            images:[],						//图片资源
+            items:[],						//对象队列
+            timeout:0,						//倒计时(用于过程动画状态判断)
+            update:function(){}				//嗅探,处理布局下不同对象的相对关系
+        };
+        _extend(this,this._settings,this._params);
+    };
+    //重置物体位置
+    Stage.prototype.resetItems = function(){
+        this.status = 1;
+        this.items.forEach(function(item,index){
+            _extend(item,item._settings,item._params);
+            item.index = index;
+            item.stage = this;
+            if(item.location){
+                var position = item.location.coord2position(item.coord.x,item.coord.y);
+                item.x = position.x;
+                item.y = position.y;
+            }
+        }.bind(this));
+    };
+    //重置地图
+    Stage.prototype.resetMaps = function(){
+        this.status = 1;
+        this.maps.forEach(function(map){
+            _extend(map,map._settings,map._params);
+            map.data = JSON.parse(JSON.stringify(map._params.data));
+            map.stage = this;
+            map.y_length = map.data.length;
+            map.x_length = map.data[0].length;
+        }.bind(this));
+    };
+    //重置
+    Stage.prototype.reset = function(){
+        _extend(this,this._settings,this._params);
+        this.resetItems();
+        this.resetMaps();
+    };
+    //添加对象
+    Stage.prototype.createItem = function(options){
+        var item = new Item(options);
+        //动态属性
+        item.stage = this;
+        item.index = this.items.length;
+        if(item.location){
+            var position = item.location.coord2position(item.coord.x,item.coord.y);
+            item.x = position.x;
+            item.y = position.y;
+        }
+        this.items.push(item);
+        return item;
+    };
+    //获取对象列表
+    Stage.prototype.getItemsByType = function(type){
+        var items = this.items.filter(function(item){
+            if(item.type==type){
+                return item;
+            }
+        });
+        return items;
+    };
+    //添加地图
+    Stage.prototype.createMap = function(options){
+        var map = new Map(options);
+        //动态属性
+        map.data = JSON.parse(JSON.stringify(map._params.data));
+        map.stage = this;
+        map.y_length = map.data.length;
+        map.x_length = map.data[0].length;
+        map.imageData = null;
+        this.maps.push(map);
+        return map;
+    };
+    //绑定事件
+    Stage.prototype.bind = function(eventType,callback){
+        if(!_events[eventType]){
+            _events[eventType] = {};
+            window.addEventListener(eventType,function(e){
+                var key = 's' + _index;
+                if(_events[eventType][key]){
+                    _events[eventType][key](e);
+                }
+                e.preventDefault();
+            });
+        }
+        _events[eventType]['s'+this.index] = callback.bind(this);	//绑定事件作用域
+    };
+    //动画开始
+    this.start = function() {
+        var f = 0;		//帧数计算
+        var fn = function(){
+            var stage = _stages[_index];
+            _context.clearRect(0,0,_.width,_.height);		//清除画布
+            f++;
+            if(stage.timeout){
+                stage.timeout--;
+            }
+            if(stage.update()!=false){		//update返回false,则不绘制
+                if(stage.maps.length){
+                    stage.maps.forEach(function(map){
+                        if(!(f%map.frames)){
+                            map.times = f/map.frames;		//计数器
+                        }
+                        map.update();
+                        if(map.cache){
+                            if(!map.imageData){
+                                _context.save();
+                                map.draw(_context);
+                                map.imageData = _context.getImageData(0,0,_.width,_.height);
+                                _context.restore();
+                            }else{
+                                _context.putImageData(map.imageData,0,0);
+                            }
+                        }else{
+                            map.draw(_context);
+                        }
+                    });
+                }
+                if(stage.items.length){
+                    stage.items.forEach(function(item){
+                        if(!(f%item.frames)){
+                            item.times = f/item.frames;		//计数器
+                        }
+                        if(stage.status==1&&item.status!=2){  	//对象及布景状态都处于正常状态下
+                            if(item.location){
+                                item.coord = item.location.position2coord(item.x,item.y);
+                            }
+                            if(item.timeout){
+                                item.timeout--;
+                            }
+                            item.update();
+                        }
+                        item.draw(_context);
+                    });
+                }
+            }
+            _hander = requestAnimationFrame(fn);
+        };
+        _hander = requestAnimationFrame(fn);
+    };
+    //动画结束
+    this.stop = function(){
+        _hander&&cancelAnimationFrame(_hander);
+    };
+    //事件坐标
+    this.getPosition = function(e){
+        var box = $canvas.getBoundingClientRect();
+        return {
+            x:e.clientX-box.left*(_.width/box.width),
+            y:e.clientY-box.top*(_.height/box.height)
+        };
+    }
+    //创建布景
+    this.createStage = function(options){
+        var stage = new Stage(options);
+        stage.index = _stages.length;
+        _stages.push(stage);
+        return stage;
+    };
+    //指定布景
+    this.setStage = function(index){
+        _stages[_index].status = 0;
+        _index = index;
+        _stages[_index].status = 1;
+        return _stages[_index];
+    };
+    //下个布景
+    this.nextStage = function(){
+        if(_index<_stages.length-1){
+            _stages[_index].status = 0;
+            _index++;
+            _stages[_index].status = 1;
+            return _stages[_index];
+        }else{
+            throw new Error('unfound new stage.');
+        }
+    };
+    //初始化游戏引擎
+    this.init = function(){
+        _index = 0;
+        this.start();
+    };
 }
diff --git a/index.js b/index.js
index 206f90c..905c3b3 100644
--- a/index.js
+++ b/index.js
@@ -97,7 +97,7 @@
 			switch(e.keyCode){
 				case 13:
 				case 32:
-					game.nextStage();
+				game.nextStage();
 				break;
 			}
 		});
@@ -176,59 +176,59 @@
 								var pos = this.coord2position(i,j);
 								switch(code){
 									case 1100:
-										context.beginPath();
-										context.arc(pos.x+this.size/2,pos.y-this.size/2,this.size/2,.5*Math.PI,1*Math.PI,false);
-										context.stroke();
-										context.closePath();
-										break;
+									context.beginPath();
+									context.arc(pos.x+this.size/2,pos.y-this.size/2,this.size/2,.5*Math.PI,1*Math.PI,false);
+									context.stroke();
+									context.closePath();
+									break;
 									case 110:
-										context.beginPath();
-										context.arc(pos.x+this.size/2,pos.y+this.size/2,this.size/2,Math.PI,1.5*Math.PI,false);
-										context.stroke();
-										context.closePath();
-										break;
+									context.beginPath();
+									context.arc(pos.x+this.size/2,pos.y+this.size/2,this.size/2,Math.PI,1.5*Math.PI,false);
+									context.stroke();
+									context.closePath();
+									break;
 									case 11:
-										context.beginPath();
-										context.arc(pos.x-this.size/2,pos.y+this.size/2,this.size/2,1.5*Math.PI,2*Math.PI,false);
-										context.stroke();
-										context.closePath();
-										break;
+									context.beginPath();
+									context.arc(pos.x-this.size/2,pos.y+this.size/2,this.size/2,1.5*Math.PI,2*Math.PI,false);
+									context.stroke();
+									context.closePath();
+									break;
 									case 1001:
+									context.beginPath();
+									context.arc(pos.x-this.size/2,pos.y-this.size/2,this.size/2,0,.5*Math.PI,false);
+									context.stroke();
+									context.closePath();
+									break;
+									default:
+									var arr = String.prototype.split.call(code,'');
+									if(+arr.pop()){
 										context.beginPath();
-										context.arc(pos.x-this.size/2,pos.y-this.size/2,this.size/2,0,.5*Math.PI,false);
+										context.moveTo(pos.x,pos.y);
+										context.lineTo(pos.x-this.size/2,pos.y);
 										context.stroke();
 										context.closePath();
-										break;
-									default:
-										var arr = String.prototype.split.call(code,'');
-										if(+arr.pop()){
-											context.beginPath();
-											context.moveTo(pos.x,pos.y);
-											context.lineTo(pos.x-this.size/2,pos.y);
-											context.stroke();
-											context.closePath();
-										}
-										if(+arr.pop()){
-											context.beginPath();
-											context.moveTo(pos.x,pos.y);
-											context.lineTo(pos.x,pos.y+this.size/2);
-											context.stroke();
-											context.closePath();
-										}
-										if(+arr.pop()){
-											context.beginPath();
-											context.moveTo(pos.x,pos.y);
-											context.lineTo(pos.x+this.size/2,pos.y);
-											context.stroke();
-											context.closePath();
-										}
-										if(+arr.pop()){
-											context.beginPath();
-											context.moveTo(pos.x,pos.y);
-											context.lineTo(pos.x,pos.y-this.size/2);
-											context.stroke();
-											context.closePath();
-										}
+									}
+									if(+arr.pop()){
+										context.beginPath();
+										context.moveTo(pos.x,pos.y);
+										context.lineTo(pos.x,pos.y+this.size/2);
+										context.stroke();
+										context.closePath();
+									}
+									if(+arr.pop()){
+										context.beginPath();
+										context.moveTo(pos.x,pos.y);
+										context.lineTo(pos.x+this.size/2,pos.y);
+										context.stroke();
+										context.closePath();
+									}
+									if(+arr.pop()){
+										context.beginPath();
+										context.moveTo(pos.x,pos.y);
+										context.lineTo(pos.x,pos.y-this.size/2);
+										context.stroke();
+										context.closePath();
+									}
 								}
 							}
 						}
@@ -415,42 +415,42 @@
 					if(this.status!=4){
 						context.fillStyle = isSick?'#BABABA':this.color;
 						context.beginPath();
-	        	context.arc(this.x,this.y,this.width*.5,0,Math.PI,true);
-	        	switch(this.times%2){
-	        		case 0:
-	        			context.lineTo(this.x-this.width*.5,this.y+this.height*.4);
-	        			context.quadraticCurveTo(this.x-this.width*.4,this.y+this.height*.5,this.x-this.width*.2,this.y+this.height*.3);
-	            	context.quadraticCurveTo(this.x,this.y+this.height*.5,this.x+this.width*.2,this.y+this.height*.3);
-	            	context.quadraticCurveTo(this.x+this.width*.4,this.y+this.height*.5,this.x+this.width*.5,this.y+this.height*.4);
-	            	break;
-	            case 1:
-	            	context.lineTo(this.x-this.width*.5,this.y+this.height*.3);
-	            	context.quadraticCurveTo(this.x-this.width*.25,this.y+this.height*.5,this.x,this.y+this.height*.3);
-	            	context.quadraticCurveTo(this.x+this.width*.25,this.y+this.height*.5,this.x+this.width*.5,this.y+this.height*.3);
-	            	break;
-	        	}
-	        	context.fill();
-	        	context.closePath();
+						context.arc(this.x,this.y,this.width*.5,0,Math.PI,true);
+						switch(this.times%2){
+							case 0:
+							context.lineTo(this.x-this.width*.5,this.y+this.height*.4);
+							context.quadraticCurveTo(this.x-this.width*.4,this.y+this.height*.5,this.x-this.width*.2,this.y+this.height*.3);
+							context.quadraticCurveTo(this.x,this.y+this.height*.5,this.x+this.width*.2,this.y+this.height*.3);
+							context.quadraticCurveTo(this.x+this.width*.4,this.y+this.height*.5,this.x+this.width*.5,this.y+this.height*.4);
+							break;
+							case 1:
+							context.lineTo(this.x-this.width*.5,this.y+this.height*.3);
+							context.quadraticCurveTo(this.x-this.width*.25,this.y+this.height*.5,this.x,this.y+this.height*.3);
+							context.quadraticCurveTo(this.x+this.width*.25,this.y+this.height*.5,this.x+this.width*.5,this.y+this.height*.3);
+							break;
+						}
+						context.fill();
+						context.closePath();
 					}
-        	context.fillStyle = '#FFF';
+					context.fillStyle = '#FFF';
 					if(isSick){
 						context.beginPath();
-          	context.arc(this.x-this.width*.15,this.y-this.height*.21,this.width*.08,0,2*Math.PI,false);
-          	context.arc(this.x+this.width*.15,this.y-this.height*.21,this.width*.08,0,2*Math.PI,false);
-          	context.fill();
-          	context.closePath();
+						context.arc(this.x-this.width*.15,this.y-this.height*.21,this.width*.08,0,2*Math.PI,false);
+						context.arc(this.x+this.width*.15,this.y-this.height*.21,this.width*.08,0,2*Math.PI,false);
+						context.fill();
+						context.closePath();
 					}else{
 						context.beginPath();
-          	context.arc(this.x-this.width*.15,this.y-this.height*.21,this.width*.12,0,2*Math.PI,false);
-          	context.arc(this.x+this.width*.15,this.y-this.height*.21,this.width*.12,0,2*Math.PI,false);
-          	context.fill();
-          	context.closePath();
+						context.arc(this.x-this.width*.15,this.y-this.height*.21,this.width*.12,0,2*Math.PI,false);
+						context.arc(this.x+this.width*.15,this.y-this.height*.21,this.width*.12,0,2*Math.PI,false);
+						context.fill();
+						context.closePath();
 						context.fillStyle = '#000';
-          	context.beginPath();
-          	context.arc(this.x-this.width*(.15-.04*_COS[this.orientation]),this.y-this.height*(.21-.04*_SIN[this.orientation]),this.width*.07,0,2*Math.PI,false);
-          	context.arc(this.x+this.width*(.15+.04*_COS[this.orientation]),this.y-this.height*(.21-.04*_SIN[this.orientation]),this.width*.07,0,2*Math.PI,false);
-          	context.fill();
-          	context.closePath();
+						context.beginPath();
+						context.arc(this.x-this.width*(.15-.04*_COS[this.orientation]),this.y-this.height*(.21-.04*_SIN[this.orientation]),this.width*.07,0,2*Math.PI,false);
+						context.arc(this.x+this.width*(.15+.04*_COS[this.orientation]),this.y-this.height*(.21-.04*_SIN[this.orientation]),this.width*.07,0,2*Math.PI,false);
+						context.fill();
+						context.closePath();
 					}
 				}
 			});
@@ -524,20 +524,20 @@
 			switch(e.keyCode){
 				case 13: //回车
 				case 32: //空格
-					this.status = this.status==2?1:2;
-					break;
+				this.status = this.status==2?1:2;
+				break;
 				case 39: //右
-					player.control = {orientation:0};
-					break;
+				player.control = {orientation:0};
+				break;
 				case 40: //下
-					player.control = {orientation:1};
-					break;
+				player.control = {orientation:1};
+				break;
 				case 37: //左
-					player.control = {orientation:2};
-					break;
+				player.control = {orientation:2};
+				break;
 				case 38: //上
-					player.control = {orientation:3};
-					break;
+				player.control = {orientation:3};
+				break;
 			}
 		});
 	})();
@@ -573,11 +573,11 @@
 			switch(e.keyCode){
 				case 13: //回车
 				case 32: //空格
-					_SCORE = 0;
-					_LIFE = 3;
-					var st = game.setStage(1);
-					st.reset();
-					break;
+				_SCORE = 0;
+				_LIFE = 3;
+				var st = game.setStage(1);
+				st.reset();
+				break;
 			}
 		});
 	})();