火拼《俄罗斯方块》解析

一.简介

俄罗斯方块（Tetris, 俄文：Тетрис）是一款风靡全球的电视游戏机和掌上游戏机游戏，它由俄罗斯人阿列克谢·帕基特诺夫发明，故得此名。俄罗斯方块的基本规则是移动、旋转和摆放游戏自动输出的各种方块，使之排列成完整的一行或多行并且消除得分。由于上手简单、老少皆宜，从而家喻户晓，风靡世界。

二.需求分析

(完全按照QQ游戏的制作，如下图：)

三.技术分析与实现

1.方块位置定位

解决方案：建立盒子模型

由于长条的存在，所以建立一个4*4的盒子模型，任何一个方块都会存在该盒子当中，方块的定位就===盒子的定位。

2.颜色状态的生成与保存

随机生成颜色：

 function randomColor() {
        //16进制方式表示颜色0-F
        var arrHex = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"];
        var strHex = "#";
        var index;
        for (var i = 0; i < 6; i++) {
            //取得0-15之间的随机整数
            index = Math.round(Math.random() * 15);
            strHex += arrHex[index];
        }
        return strHex;

 } 

    

颜色保存：（那一个方块的一种状态做示例）

   var diamonds = new Array();
    diamonds[0] = { x: appearPosition.position.x + 1, y: appearPosition.position.y, diamondColor: color };
    diamonds[1] = { x: appearPosition.position.x + 0, y: appearPosition.position.y + 1, diamondColor: color };
    diamonds[2] = { x: appearPosition.position.x + 1, y: appearPosition.position.y + 1, diamondColor: color };
    diamonds[3] = { x: appearPosition.position.x + 2, y: appearPosition.position.y + 1, diamondColor: color };

所有生成的方块有个diamondColor属性，用于存颜色。appearPosition.position是盒子模型的位置。

3.碰撞检测

碰撞分两种，一种是元素与左右墙壁和底部的碰撞，另外一种是方块与底部方块的接触碰撞

a.元素与左右墙壁和底部的碰撞

    a.1元素与底部的碰撞检测

  if (diamonds[i].y * height + height >= canvasHeight) {
        appearPosition.position.x = Math.round(appearPosition.position.x);
        appearPosition.position.y = Math.round(appearPosition.position.y);
        createElement();
        breakTag = 1;

   }  

a.2元素与左右墙壁的碰撞检测

   function returnRightOrLeft() {
        var max_X = 11;
        for (i = 0; i < diamonds.length; i++) {
            if (diamonds[i].x > max_X) {
                max_X = diamonds[i].x;
            }
        }
        if (max_X != 11) appearPosition.position.x = appearPosition.position.x - (max_X - 11);
        var min_X = 0;
        for (i = 0; i < diamonds.length; i++) {
            if (diamonds[i].x < min_X) {
                min_X = diamonds[i].x;
            }
        }
        if (min_X != 0) appearPosition.position.x = appearPosition.position.x - min_X;
    }

b.元素与元素碰撞检测

    //判断下面是否有元素
    for (j = 0; j < bottomElement.length; j++) {
        if (bottomElement[j].x == diamonds[i].x) {
            if (Math.round(bottomElement[j].y) == Math.round(diamonds[i].y + 1)) {
                appearPosition.position.x = Math.round(appearPosition.position.x);
                appearPosition.position.y = Math.round(appearPosition.position.y);
                createElement();
                breakTag = 1;
            }
        }
    }
    //判断arrayOne是否在arrayTwo的右边
    function IsAtRight(arrayOne, arrayTwo) {
        for (i = 0; i < arrayOne.length; i++) {
            for (j = 0; j < arrayTwo.length; j++) {
                if (Math.round(arrayOne[i].y) == Math.round(arrayTwo[j].y)) {
                    if (arrayTwo[j].x == arrayOne[i].x + 1) return true;
                }
            }
        }
        return false;
    }
    //判D断arrayOne是否在arrayTwo的左边
    function IsAtLeft(arrayOne, arrayTwo) {
        for (i = 0; i < arrayOne.length; i++) {
            for (j = 0; j < arrayTwo.length; j++) {
                if (Math.round(arrayOne[i].y) == Math.round(arrayTwo[j].y)) {
                    if (arrayTwo[j].x == arrayOne[i].x - 1) return true;
                }
            }
        }
        return false;
    }

4.方块变形

    var direction = 0;
    if (e.keyCode == 87) {
        direction++;
        direction %= 4;
    }

W键是变形，0123分别代表四种。

如果是长条或者只有两种状态的直接  if (direction % 2 == 0) {}，如果是正方块直接忽略direction，因为它就一种形状。

5.键盘捕获（目前WSAD+空格，W是变形，S和空格都是加速，IE9和FF异常，建议在谷歌浏览器下运行）

    document.onkeydown = function (e) {
        if (e.keyCode == 65) {
            for (i = 0; i < diamonds.length; i++) {
                if (diamonds[i].x == 0) {
                    return;
                }
            }
            if (IsAtLeft(diamonds, bottomElement)) {
                return;
            }
            appearPosition.position.x -= 1;
        }
        if (e.keyCode == 87) {
            direction++;
            direction %= 4;
        }
        if (e.keyCode == 68) {
            for (i = 0; i < diamonds.length; i++) {
                if (diamonds[i].x == 11) {
                    return;
                }
            }
            if (IsAtRight(diamonds, bottomElement)) {
                return;
            }
            appearPosition.position.x += 1;
        }
        if (e.keyCode == 32) {
            delay = 1;
        }
        if (e.keyCode == 83) {
            delay = 1;
        }
    }
    document.onkeyup = function (e) {
        if (e.keyCode == 32) {
            delay = 20;
        }
        if (e.keyCode == 83) {
            delay = 20;
        }
    }
  

6.消除加分

    //一行满了的话，消除并加分
    function clearUp() {
        for (var line = 0; line < 21; line++) {
            var count = 0;
            for (var i = 0; i < bottomElement.length; i++) {
                if (bottomElement[i].y == line) {
                    count++;
                }
            }
            if (count == 12) clearByLineNum(line);
        }
        // if(count==12)
    }
    function clearByLineNum(num) {
        //以上的元素下降一行
        score++;
        var count = 0;
        for (i = 0; i < bottomElement.length; i++) {
            if (bottomElement[i].y == num) {
                count++;
            }
        }
        for (var j = 0; j < count; j++) {
            for (var i = 0; i < bottomElement.length; i++) {
                if (bottomElement[i].y == num) {
                    bottomElement.splice(i, 1);
                    break;
                }
            }
        }
        for (i = 0; i < bottomElement.length; i++) {
            if (bottomElement[i].y < num) {
                bottomElement[i].y += 1;
            }
        }
    }

消除加分有一个潜在的逻辑就是，在该行以上的元素的位置下降一个格子。

7.控制核心Jscex  Show Time

    var JropAsync = eval(Jscex.compile("async", function () {
        var breakTag = 0;
        while (true) {
            color = randomColor();
            rectBlockIndex = MR() * 7 | 0;
            direction = MR() * 3 | 0;
            $await(Jscex.Async.sleep(1));
            while (true) {
                for (i = 0; i < diamonds.length; i++) {
                    if (diamonds[i].y * height + height >= 525) {
                        appearPosition.position.x = Math.round(appearPosition.position.x);
                        appearPosition.position.y = Math.round(appearPosition.position.y);
                        createElement();
                        breakTag = 1;
                    }
                    //判D断?下?面?是?否?有D元a素?
                    for (j = 0; j < bottomElement.length; j++) {
                        if (bottomElement[j].x == diamonds[i].x) {
                            if (Math.round(bottomElement[j].y) == Math.round(diamonds[i].y + 1)) {
                                appearPosition.position.x = Math.round(appearPosition.position.x);
                                appearPosition.position.y = Math.round(appearPosition.position.y);
                                createElement();
                                breakTag = 1;
                            }
                        }
                    }
                }
                if (breakTag == 1) {
                    for (i = 0; i < diamonds.length; i++) {
                        //alert(diamonds[i].x + "____" + diamonds[i].y)
                        bottomElement.push(diamonds[i]);
                    }
                    clearUp();
                    //清?空?下?降μ的?元a素?
                    diamonds.splice(0, diamonds.length);
                    appearPosition = { position: { x: 4, y: -2 }, direction: 0 };
                    breakTag = 0;
                    break;
                }
                appearPosition.position.y += step;
                draw();
                $await(Jscex.Async.sleep(delay));
            }
        }
    }));

这是也整个俄罗斯方块的控制核心,由两个while循环构成，简单大方。