JavaScriptは、テトリスのミニゲームを実現します.


<!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>     </title>
<style type="text/css">
	body{ width:530px; background:#F7F7F7; margin:20px auto}
	table#gameBoard{ border:1px solid black; border-collapse: collapse; float:left;}
	table#gameBoard td{ width:30px; height:30px; border: 1px dotted #0cc;}
	div#gameControl{ widows:160; float:right; height: 200px;; line-height: 200px;}
	.font{ font-family:'    '; font-size:18px; text-align:center;}
	div input { width: 60px; height:25px; }

</style>
<script type="text/javascript">
	

	var T = TETRIS = {
		aBoardGrids : [],
		aShapes: [
			[0xCC00], 
			[0x8888, 0xF00], 
			[0x8C40, 0x6C00], 
			[0x4C80, 0xC600], 
			[0x44C0, 0x8E00, 0xC880, 0xE200], 
			[0x88C0, 0xE800, 0xC440, 0x2E00], 
			[0x4E00, 0x8C80, 0xE400, 0x4C40]
		],																		//          
		init : function(){
			this.oDomBoard = document.getElementById("gameBoard");
			this.oDomScore = document.getElementById("score");
			this.aBoardGrids = new Array(18);
			for (var rows = 0 ; rows < 18 ; rows++){
				this.aBoardGrids[rows] = new Array(10);
				var oDomTr = this.oDomBoard.insertRow(-1);
				for	(var cols = 0 ; cols < 10 ; cols++){
					this.aBoardGrids[rows][cols] = 0;
					oDomTr.insertCell(cols);
				}
			}

			document.onkeydown = function(keyEvent){
				keyEvent = keyEvent || window.event;
				var ikeyNum = keyEvent.which || keyEvent.keyCode;
				switch(ikeyNum){
					case 37://←
						T.oBlock.move("left");
						break;
					case 38://↑	
						T.oBlock.rotate((function (){
							var vShape 		= T.aShapes[T.iShapeIdx][ (++T.index)%T.aShapes[T.iShapeIdx].length];
							var sShape 		= vShape.toString(2);								
							sShape 			= new Array(17 - sShape.length).join(0) + sShape;	
							T.matrix		= sShape.match(/\d{4}/g);	
							return T.matrix;
						})());	//  
						break;
					case 39://→
						T.oBlock.move("right");
						break;
					case 40://↓
						T.oBlock.move("down");
						break;
				}
			}
		},
		next : function (){
			
			this.iShapeIdx 	= parseInt(Math.random() * this.aShapes.length);
			this.index 		= 0;
			var vShape 		= this.aShapes[this.iShapeIdx][this.index];
			var sShape 		= vShape.toString(2);								// 16        
			sShape 			= new Array(17 - sShape.length).join(0) + sShape;	//  16 ,    0   
			this.matrix		= sShape.match(/\d{4}/g);							//         

			this.oBlock = new TETRIS.Block(this.matrix);
					
			clearInterval(T.timer);
			//     
			T.timer = setInterval(function (){
				T.oBlock.move("down");
			}, 1000);
			
			
			if( !T.oBlock.checkBlock() ){
				alert("Game Over~");
				clearInterval(T.timer);
			
			}
			
		},
		updateBoard : function (){		//    
			for(var i = 0 ; i < 4 ; i++){
				this.aBoardGrids[T.oBlock.shape[i].y][T.oBlock.shape[i].x] = 1;
			}
		},
		eraseLines : function (){
			var iLines = 0;
			for(var j = 17 ; j >= 0 ; j--){
				var num = 0;
				for(var i = 0 ; i< 10 ; i++){
					if(this.aBoardGrids[j][i] == 1)
						num ++;
				}
				if(num == 10){
					iLines ++;
					for(var m = 0 ; m < i ; m++){
						for(var n = j ; n > 0 ; n--){
							this.aBoardGrids[n][m] = this.aBoardGrids[n-1][m];
							T.oDomBoard.rows[n].cells[m].style.background = T.oDomBoard.rows[n-1].cells[m].style.background;
						}
						this.aBoardGrids[0][m] = 0;
					}
					j++;
				}
			}
			return iLines;
		},
		setScore : function (iLines){
			var iScore = parseInt(this.oDomScore.innerHTML);
			if(iLines == 1){
				iScore += 100;
			} else if(iLines == 2){
				iScore += 300;
			} else if(iLines == 3){
				iScore += 500;
			} else if(iLines == 4){
				iScore += 1000;
			}
			this.oDomScore.innerHTML = iScore;
		}
	}
	
	TETRIS.Block = function (matrix){

		this.shape = (function(){
			
			var aShape = [];
			for(var i = 0 ; i < matrix.length ; i++){
				var sValue = matrix[i];
				for(var j = 0 ; j < sValue.length ; j++){
					if(sValue.charAt(j) == "1"){
						aShape.push({ x : j+3 , y : i });
					}  
				}
			}
			
			return aShape;
			
		})();
		this.draw();
	}
	
	TETRIS.Block.prototype.move = function (direction){//  
		if(this.checkBlock(this.shape,direction)){
			this.draw("clear");
			for(var i = 0 ; i < 4 ; i++){
				switch(direction){
					case "left"://←	
						this.shape[i].x--;
						break;
					case "right":
						this.shape[i].x++;
						break;
					case "down":
						this.shape[i].y++;
						break;
				}
			}
			this.draw();
		} else {
			if(direction == "down"){
				this.draw();
				T.updateBoard();	//    
				var iLines = T.eraseLines();
				
				if(iLines > 0){
				
					T.setScore(iLines);
					
				}
				
				T.next();			//         
			}
		}
		
	}
	TETRIS.Block.prototype.rotate = function (matrix){//  
		
		this.shape = (function(oBlock){
			
			var aX = [];
			var aY = [];

			for(var i = 0 ; i < 4 ; i++){
				aX.push(oBlock.shape[i].x);
				aY.push(oBlock.shape[i].y);
			}
			var iMinX = aX.getMin();
			var iMinY = aY.getMin();
			
			
			var aShape = [];
			for(var i = 0 ; i < matrix.length ; i++){
				var sValue = matrix[i];
				for(var j = 0 ; j < sValue.length ; j++){
					if(sValue.charAt(j) == "1"){
						aShape.push({ x : j+iMinX , y : i+iMinY });
					}  
				}
			}
			if( !( oBlock.checkBlock(aShape)) )
				return oBlock.shape;
			oBlock.draw("clear");
			return aShape;
			
		})(this);

		this.draw();
	}

	TETRIS.Block.prototype.draw = function (opt){//  
		for(var i = 0 ; i < this.shape.length ; i++){
			var oShape = this.shape[i];
			T.oDomBoard.rows[oShape.y].cells[oShape.x].style.background = (opt==undefined?"#09F":"");
		}
	}
	TETRIS.Block.prototype.checkBlock = function (shape, direction){
		shape = shape || this.shape;
		for(var i = 0 ; i < 4 ; i++){
			if(direction == "left"){
					if(shape[i].x == 0 || T.aBoardGrids[shape[i].y][shape[i].x - 1] == 1){
						return false;
					}
			} else if(direction == "right"){
					if(shape[i].x == 9 || T.aBoardGrids[shape[i].y][shape[i].x + 1] == 1){
						return false;
					}
			} else if(direction == "down"){
					if(shape[i].y == 17 || T.aBoardGrids[shape[i].y + 1][shape[i].x] ==1){
						return false;
					}
			}
			if(shape[i].x < 0 || shape[i].x > 9 || shape[i].y < 0 || shape[i].y > 17)
				return false;
			if(T.aBoardGrids[shape[i].y][shape[i].x] == 1){
				return false;
			}
		}
		return true;
		
	}
	Array.prototype.getMin = function (){
		var iMin = this[0];
		for(var i = 0 ; i < this.length ; i++){
			if(this[i] < iMin)
				iMin = this[i];
		}
		return iMin;
	}
	window.onload = function(){
	
		T.init();
		
		var oBtnPlay = document.getElementById("btnPlay");
		oBtnPlay.onclick = function(){
			if(this.value == "begin"){
				T.next();
				this.value = "over";
			} else {
				this.value = "begin";
				alert("Game Over~");
				clearInterval(T.timer);
			} 
		
		}	
		var oBtnPause = document.getElementById("btnPause");
		oBtnPause.onclick = function (){
			if(this.value == "pause"){
				clearInterval(T.timer);
				this.value = "resume";
			} else {
				T.timer = setInterval(function (){
					T.oBlock.move("down");
				}, 1000);
				this.value = "pause";
			}
		}

	}

</script>
</head>

<body>
    <table id="gameBoard"></table>
    <div id="gameControl">
        Score : <span id="score">0</span><br />
      <input type="button" id="btnPlay" value="begin" />
      <input type="button" id="btnPause" value="pause" /><br/>
        <span>     </span>
    </div>
</body>
</html>
プログラムは最適化された改善が必要です.ご指摘ください.