JavaScript簡單貪喫蛇,基本面向對象

作者:pcenshao
   轉載請註明來自:
     http://blog.csdn.net/pywepe  


     程序包括一個html文件:snake.html和一個js文件:snake.js

     snake.html:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>JavaScript簡單貪喫蛇</title>
<script type="text/javascript" src="snake.js"></script>
<script type="text/javascript" >
    $s(function(){
        $s.SnakeContext.init();        
    });
</script>
</head>
<body>    
<div id="headLocation"></div>
<div id="keyup"></div>
</body>
</html>

snake.js:

/*
 * JavaScript簡單貪喫蛇.基本面向對象.
 * 規則:
 *    1.沒有牆,左與右連接,上與下連接.
 *    2.當蛇頭碰撞到自身時死亡.
 * 兼容性:
 *    完全支持Firefox,Chrome
 *    基本支持IE(除了調試部分)
 *
 * 作者:pcenshao
 * 轉載請註明來自:
 *    http://blog.csdn.net/pywepe
 *    http://pcenshao.taobao.com
 */
(function(){
    
    $s = function(){
        if(arguments.length == 1){
            if(typeof arguments[0] == "string"){
                return document.getElementById(arguments[0]);    
            }else if(typeof arguments[0] == "function"){
                window.onload = arguments[0];
            }  
        }
    };    
    
    $s.UNIT_WIDTH = 10; // 單元的寬度
    $s.UNIT_HEIGHT = 10;
    $s.PANEL_WIDTH = 30; // 邏輯寬度    
    $s.PANEL_HEIGHT = 20; // 邏輯高度
    $s.STEP = 250 ;  // 每一步的時間
    $s.HEAD_COLOR = "red"; // 蛇頭顏色
    $s.BODY_COLOR = "black"; // 蛇體顏色
    /*
     * 食物的顏色
     */
    $s.COLORS = ["blue","green","#494e8f","#905d1d","#845538","#77ac98","#8552a1"];
    
    /*
     * 調試相關
     * $s.DEBUG 調試信息顯示開關
     * $s.KEY_UP_DIR_ID 監視方向鍵的結點id,若不存在,則不顯示
     * $s.HEAD_LOCATION_ID 監視蛇頭位置的結點id,若不存在,則不顯示
     */
    $s.DEBUG = false;
    $s.KEY_UP_DIR_ID = "keyup";
    $s.HEAD_LOCATION_ID = "headLocation";
    
    $s.Dir = {  // 代表方向,強制以$s.Dir.UP方法調用,避免參數錯誤
        UP : {},
        DOWN : {},
        LEFT : {},
        RIGHT : {},
        NONE : {}
    };
    
    $s.State = { // 代表狀態
        STOP : {},
        RUNNGIN : {},
        PAUSE : {}            
    };
    
    $s.Unit = function(){ // 一個單元格,用MVC的眼光看,Unit是模型,UnitView是視圖
        this.x = 0;
        this.y = 0;
        this.view = new $s.UnitView();
        this.view.unit = this;
        this.color = $s.BODY_COLOR;
    };
    $s.Unit.prototype.repaint = function(){
        if(this.view != null){
            this.view.repaint(); // 通知重繪    
        }    
    };            
    
    $s.Snake = function(){
        this.units = [];
    };    
    
    $s.Snake.prototype.init = function(dir,count){
        var x = 5;
        var y = 5;
        for(var i = 0 ; i < count ; i ++){
            var u = new $s.Unit();
            u.x = x ;
            u.y = y ++;
            this.units.push(u);
            if(i == (count - 1 )){
                u.color = $s.HEAD_COLOR;
            }
            u.repaint();
        }
    };
    
    $s.Snake.prototype.crash = function(x,y){ // 傳入頭部的位置,返回true表示碰撞自身
        for(var i = this.units.length - 2 ; i >= 0 ; i --){ // 不包括頭自身
            var u = this.units[i];
            if(u.x == x && u.y == y){
                return true;    
            }
        }
        return false;
    };
    
    $s.Snake.prototype.go = function(){
        // 判斷前方是否有食物
        // 是否撞牆
        var _x = 0 , _y = 0;
        var head = this.units[this.units.length - 1];
        _x = head.x;
        _y = head.y;
        var dir = $s.SnakeContext.dir;
        
        if(this.crash(_x,_y)){ // 判斷是否碰撞到自身
            $s.SnakeContext.stop();
            $s.SnakeContext.ondead(); // 觸發dead事件
            return;
        }
        
        if(dir == $s.Dir.LEFT){
            _x --;        
        }else if(dir == $s.Dir.RIGHT){
            _x ++;
        }else if(dir == $s.Dir.UP){
            _y --;
        }else if(dir == $s.Dir.DOWN){
            _y ++;
        }
        
        // 實現左右連接,上下連接
        if(_x >= $s.PANEL_WIDTH){
            _x = 0;
        }
        if(_x < 0){
            _x = $s.PANEL_WIDTH - 1;    
        }
        if(_y >= $s.PANEL_HEIGHT){
            _y = 0;
        }
        if(_y < 0){
            _y = $s.PANEL_HEIGHT - 1;    
        }
        
        var h = new $s.Unit(); // 新頭
        if($s.SnakeContext.hasFood(_x,_y)){ // 下一步碰到食物
            this.eat(_x,_y);
            head = this.units[this.units.length - 1]; // 因爲eat方法可以改變頭部,所以重新獲取
            _x = head.x;
            _y = head.y;
            
            if(dir == $s.Dir.LEFT){
                _x --;        
            }else if(dir == $s.Dir.RIGHT){
                _x ++;
            }else if(dir == $s.Dir.UP){
                _y --;
            }else if(dir == $s.Dir.DOWN){
                _y ++;
            }
            head.color = $s.HEAD_COLOR;
            head.repaint();
            var oldHead = this.units[this.units.length - 2];
            oldHead.color = $s.BODY_COLOR;
            oldHead.repaint();
            return;
        }
        
        var tail = this.units.shift();
        $s.NodePool.releaseNode(tail);        
        
        h.x = _x;
        h.y = _y;
        this.units.push(h);
        
        for(var i = this.units.length - 1; i >= 0; i --){
            var u = this.units[i];
            if(i == (this.units.length - 1)){ // 頭
                u.color = $s.HEAD_COLOR;
            }else{
                u.color = $s.BODY_COLOR;
            }
            u.repaint();
        }
        
    };
    
    $s.Snake.prototype.eat = function(x,y){
        var food = $s.SnakeContext.food;
        if(food != null){
            food.alive = false;
            this.units.push(food.unit);
            $s.SnakeContext.oneat();
        }else{
            alert("error:no food on (" + x + "," + y + ")");    
        }        
    }
    
    /*
     * 隨機數產生器,提供簡便的方法
     */
    $s.Random = {
        randomNumber : function(lower,upper){ // 返回區間[lower,upper]的整數
            var choices = upper - lower + 1;
            return Math.floor(Math.random() * choices + lower); // value = Math.floor(Math.random() * 可能值的個數 + 第一個可能的值)
        },
        randomLocation : function(maxX,maxY){
            var x = $s.Random.randomNumber(0,maxX);
            var y = $s.Random.randomNumber(0,maxY);
            return {x:x,y:y};
        }    
    };
    
    $s.Food = function(x,y){ // 代表食物,由一個Unit表示
        this.unit = new $s.Unit();
        this.unit.x = x;
        this.unit.y = y;
        var color = $s.COLORS[$s.Random.randomNumber(0,$s.COLORS.length - 1)];
        this.unit.color = color;
        this.alive = true;
        
        this.unit.repaint();
    };
    $s.Food.prototype.locateOn = function(x,y){
        return this.unit.x == x && this.unit.y == y;
    };
    
    /*
     * HTML結點池,主要目的是提高效率
     * 因爲snake的移動是通過刪除尾部結點並向頭部添加結點實現的,
     * 在這個過程中會有大量的結點創建操作,爲了操作效率,所以對結點進行池化管理.
     * 尾部的結點不刪除,而是隱藏,需要結點時可以重用之
     */    
    $s.NodePool = {
        nodes : []
    };
    $s.NodePool._findHideNode = function(){ // 查找隱藏的div結點        
        for(var i = 0 ; i < this.nodes.length ; i ++){
            var n = this.nodes[i];
            if(n.style.display == "none"){
                return n;    
            }    
        }
        return null;
    };
    $s.NodePool.createNode = function(){
        var pooledNode = this._findHideNode();
        if(pooledNode != null){
            return pooledNode;    
        }else{
            var newNode = document.createElement("div");
            this.nodes.push(newNode);
            return newNode;
        }
    };
    $s.NodePool.releaseNode = function(node){
        if(node != undefined && node != null){
            if(node instanceof $s.Unit){
                var view = node.view;
                if(view != null){
                    var div = view.node;
                    div.style.display = "none";
                }
            }            
        }    
    }
    
    $s.UnitView = function(){ // Unit的視圖
        this.unit = null;
        this.node = null;
    };
    $s.UnitView.prototype.repaint = function(){
        if(this.node == null){ // 初始化
            var tag = $s.NodePool.createNode();
            tag.style.width = $s.UNIT_WIDTH + "px";
            tag.style.height = $s.UNIT_HEIGHT + "px";
            tag.style.borderStyle = "dotted";
            tag.style.borderWidth = "1px";
            tag.style.borderColor = "white";        
            tag.style.margintLeft = "1px";
            tag.style.marginRight = "1px";
            tag.style.marginTop = "1px";
            tag.style.marginBottom = "1px";
            tag.style.backgroundColor =  this.unit.color; // 顏色由模型Unit指定
            tag.style.position = "absolute"; //容器的position指定爲relative,孩子的position指定爲absolute時,表示孩子相對容器絕對定位.
            
            tag.style.display = "block"; // 重要,因爲從NodePool取現的結點是隱藏狀態的
            
            var x = this.unit.x * $s.UNIT_WIDTH;
            var y = this.unit.y * $s.UNIT_HEIGHT;
            tag.style.top = y + "px";
            tag.style.left = x + "px";
            
            this.node = tag;
            $s.SnakeContext.panelView.append(this);
        }else{
            var tag = this.node;
            
            var x = this.unit.x * $s.UNIT_WIDTH;
            var y = this.unit.y * $s.UNIT_HEIGHT;
            tag.style.top = y + "px";
            tag.style.left = x + "px";
            tag.style.backgroundColor = this.unit.color;
        }
    };    
    
    $s.PanelView = function(){ // 整個遊戲區域,包括按鈕區
        var panel = document.createElement("div");
        panel.style.width = ($s.PANEL_WIDTH * $s.UNIT_WIDTH ) + "px";
        panel.style.height = ($s.PANEL_HEIGHT * $s.UNIT_HEIGHT ) + "px";
        panel.style.borderStyle = "dotted";
        panel.style.borderColor = "red";
        panel.style.borderWidth = "1px";
        panel.style.marginLeft = "auto";
        panel.style.marginRight = "auto";
        panel.style.marginTop = "50px";
        panel.style.position = "relative"; // 容器的position指定爲relative,孩子的position指定爲absolute時,表示孩子相對容器絕對定位.
        panel.style.marginBottom = "auto";
        this.node = panel;
        document.body.appendChild(panel);
        
        var len = document.createElement("div");
        len.style.marginLeft = "auto";
        len.style.marginRight = "auto";
        len.style.marginBottom = "20px";
        len.style.color = "gray";
        len.style.fontSize = "12px";
        len.innerHTML = "長度:";
        document.body.appendChild(len);
        $s.SnakeContext._len = len;
        
        var startBn = document.createElement("button");
        startBn.innerHTML = "開始";
        startBn.style.marginLeft = "10px";
        startBn.onclick = function(){
            $s.SnakeContext.run();
        };
        $s.SnakeContext._startBn = startBn;
        document.body.appendChild(startBn);
        
        var pauseBn = document.createElement("button");
        pauseBn.innerHTML = "暫停";
        pauseBn.style.marginLeft = "10px";
        pauseBn.onclick = function(){
            $s.SnakeContext.pause();    
        };
        $s.SnakeContext._pauseBn = pauseBn;
        document.body.appendChild(pauseBn);
        
        /*
        var stopBn = document.createElement("button");
        stopBn.innerHTML = "停止";
        stopBn.style.marginLeft = "10px";
        stopBn.onclick = function(){
            $s.SnakeContext.stop();    
        };
        $s.SnakeContext._stopBn = stopBn;
        document.body.appendChild(stopBn);
        */
        
        var restartBn = document.createElement("button");
        restartBn.innerHTML = "重新開始";
        restartBn.style.marginLeft = "10px";
        restartBn.onclick = function(){
            window.location.href = window.location.href;
        };
        $s.SnakeContext._restartBn = restartBn;
        document.body.appendChild(restartBn);
        
        var line = document.createElement("div");
        line.style.height = "10px";
        document.body.appendChild(line);
        
        var span = document.createElement("span");
        span.style.color = "gray";
        span.style.fontSize = "12px";
        span.innerHTML = "調試";
        document.body.appendChild(span);
        
        var debug = document.createElement("input");
        debug.type = "checkbox";        
        debug.checked = $s.DEBUG;
        debug.onchange = function(){
            $s.SnakeContext.setDebug(debug.checked);
        };        
        document.body.appendChild(debug);
        
    };
    $s.PanelView.prototype.append = function(unitView){
        try{
            this.node.appendChild(unitView.node);
        }catch(e){
            alert(e);    
        }        
    };
    
    /*
     * 全局環境類,代表應用        
     * 約定以_開頭的成員爲私有成員
     * 啓動程序的方法:
     * window.onload = function(){
     *     $s.SnakeContext.init();
     * }
     */
    $s.SnakeContext = {    
        dir : $s.Dir.NONE,
        state : $s.State.STOP,
        goTimer : null,        
        run : function(){            
            if(this.state != $s.State.RUNNGIN){
                this.state = $s.State.RUNNGIN;
                this.goTimer = window.setInterval(function(){
                                                    $s.SnakeContext.updateFood();
                                                    $s.SnakeContext.snake.go();        
                                                 },$s.STEP);
            }
            
        },
        stop : function(){
            this._setState($s.State.STOP);
        },
        pause : function(){
            this._setState($s.State.PAUSE);
        },
        _setState : function(s){
            if(this.state != s && this.goTimer != null){
                window.clearInterval(this.goTimer);
                this.goTimer = null;
                this.state = s;
            }    
        },
        getFood : function(x,y){
            for(var f in this.foods){
                if(f.x == x && f.y == y){
                    return f;    
                }    
            }    
            return null;
        },
        init : function(){    
            this.panelView = new $s.PanelView();
            this.snake = new $s.Snake();
            this.dir = $s.Dir.DOWN;
            this.snake.init($s.Dir.UP,3);
            this._len.innerHTML = "長度:" + 3;
            
            document.body.onkeyup = function(e){
                var code = null;
                if(window.event){ // fuck的IE
                    code =     window.event.keyCode;
                }else{
                    code =     e.keyCode;
                }
                var str = "";
                var oldDir = $s.SnakeContext.dir;
                switch(code){
                    case 37: // left
                        if($s.SnakeContext.dir != $s.Dir.RIGHT){
                            $s.SnakeContext.dir = $s.Dir.LEFT;    
                        }    
                        str = "left";
                        break;
                    case 38 : // up
                        if($s.SnakeContext.dir != $s.Dir.DOWN){
                            $s.SnakeContext.dir = $s.Dir.UP;    
                        }            
                        str = "up";
                        break;
                    case 39: // right
                        if($s.SnakeContext.dir != $s.Dir.LEFT){
                            $s.SnakeContext.dir = $s.Dir.RIGHT;    
                        }            
                        str = "right";
                        break;
                    case 40: // down
                        if($s.SnakeContext.dir != $s.Dir.UP){
                            $s.SnakeContext.dir = $s.Dir.DOWN;    
                        }                
                        str = "down";
                        break;
                }
                if($s.SnakeContext.dir != oldDir){
                    if($s.DEBUG){
                        var v = $s($s.KEY_UP_DIR_ID);
                        if(v){
                            v.innerHTML = "方向鍵:" + str;
                        }                        
                    }
                    
                    if($s.SnakeContext.goTimer != null){
                        window.clearInterval($s.SnakeContext.goTimer);
                        $s.SnakeContext.goTimer = null;            
                    }    
                    $s.SnakeContext.snake.go();
                    $s.SnakeContext.goTimer = window.setInterval(function(){
                                                            $s.SnakeContext.updateFood();
                                                            $s.SnakeContext.snake.go();        
                                                         },$s.STEP);
                }            
            };
            
            var loc = $s.Random.randomLocation($s.PANEL_WIDTH - 1, $s.PANEL_HEIGHT - 1);
            this.food = new $s.Food(loc.x,loc.y);
            
        },
        snake : null,
        foods : [],
        panelView : null,
        food : null,
        updateFood : function(){
            if(this.food.alive){ // 當前Food還存活
                return;    
            }
            var loc = null;
            do{


               // 隨機產生一個點,直到不Snake重疊   
                loc = $s.Random.randomLocation($s.PANEL_WIDTH - 1,$s.PANEL_HEIGHT - 1);
            }while(this.overlap(loc));    
            this.food = new $s.Food(loc.x,loc.y);
            
        },
        overlap : function(loc){ // 檢查是否與Snake重疊,當重疊時返回true
            var x = loc.x;
            var y = loc.y;
            for(var i = 0 ; i < this.snake.units.length ; i ++ ){
                var u = this.snake.units[i];
                if(u.x == x && u.y == y){
                    return true;    
                }
            }
            return false;
        },
        hasFood : function(x,y){
            if($s.DEBUG){
                var xt = $s($s.HEAD_LOCATION_ID);
                if(xt){
                    xt.innerHTML = "頭部位置:(" +  x + "," + y + ")";        
                }                
            }                
            return this.food.locateOn(x,y);
        },
        setDebug : function(enable){
            if(enable != $s.DEBUG){
                $s.DEBUG = enable;
                if($s.DEBUG){ // 顯示
                    var i = $s($s.KEY_UP_DIR_ID);
                    $s.SnakeContext._show(i);
                    i = $s($s.HEAD_LOCATION_ID);
                    $s.SnakeContext._show(i);
                }else{ // 隱藏
                    var i = $s($s.KEY_UP_DIR_ID);
                    $s.SnakeContext._hide(i);
                    i = $s($s.HEAD_LOCATION_ID);
                    $s.SnakeContext._hide(i);
                }
            }    
        },
        _show : function(tag){
            if(tag){
                tag.style.display = "block";    
            }    
        },
        _hide : function(tag){
            if(tag){
                tag.style.display = "none";    
            }    
        },
        ondead : function(){ // Snake死亡時回調
            if(this._startBn){
                this._startBn.disabled = true;
            }
            if(this._pauseBn){
                this._pauseBn.disabled = true;    
            }
            if(this._stopBn){
                this._stopBn.disabled = true;    
            }
            alert("掛了");    
        },
        oneat : function(){ // Snake長度增加時回調
            this._len.innerHTML = "長度:" + this.snake.units.length;    
        },
        _startBn : null,
        _pauseBn : null,
        _stopBn : null,
        _restartBn : null,
        _len : null
    };
    
})();




發表評論
所有評論
還沒有人評論,想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.
相關文章