使用在 JavaScript 中实现康威的生命游戏

Question

我在用 JavaScript 实现 Conway 的生命游戏时遇到了一些问题。在德语维基百科中，它说这种模式在这里：

54代后将创建一个空世界，演变如下：

也就是说，第二代看起来像这样：

但是当使用我的代码时，第二代看起来像这样，世界也没有变空：

所以我的代码显然是错误的，但我没有看到我的错误：

var cellSize = 5,   // In px
    fieldSize = 70, // In cells
    canvas = document.getElementById("canvas"),
    ctx = canvas.getContext("2d"),
    thisGeneration = [],
    nextGeneration = [];

// Set canvas size
canvas.width = canvas.height = cellSize * fieldSize;


// Fill the generation array
for (var i = 0; i < fieldSize; i++){

    thisGeneration.push([]);

    for (var x = 0; x < fieldSize; x++){

        // thisGeneration[thisGeneration.length-1].push( (Math.random() >  0.08)? 0 : 1);

        thisGeneration[thisGeneration.length-1].push(0);

    }

}

// Draw pattern:

thisGeneration[35][35]      =   thisGeneration[35][36]  = thisGeneration[35][37] =

thisGeneration[36][35]                                  = thisGeneration[36][37] =
thisGeneration[37][35]                                  = thisGeneration[37][37] =


thisGeneration[39][35]                                  = thisGeneration[39][37] =
thisGeneration[40][35]                                  = thisGeneration[40][37] =
thisGeneration[41][35]      =   thisGeneration[41][36]  = thisGeneration[41][37] =
1;

// "slice" causes "nextGeneration" to be a copy, not a reference
nextGeneration = thisGeneration.slice(0);

setInterval(function(){

    for (var y = 0, l = thisGeneration.length, x, l2, n; y < l; y++){

        for (x = 0, l2 = thisGeneration[y].length;  x < l2; x++){

            ctx.fillStyle = thisGeneration[y][x]? "black" : "white";
            ctx.fillRect(x*cellSize, y*cellSize, cellSize, cellSize);

            // n := Number of neighbors of the cell
            n = 0;

            if (typeof (thisGeneration[y-1]) != "undefined"){

                n += (

                    (thisGeneration     [y-1]   [x-1]   ||0)+
                    (thisGeneration     [y-1]   [ x ]   ||0)+
                    (thisGeneration     [y-1]   [x+1]   ||0)

                );

            }

            n += (

                (thisGeneration     [ y ]   [x-1]   ||0)+
                (thisGeneration     [ y ]   [x+1]   ||0)

            );

            if (typeof (thisGeneration[y+1]) != "undefined"){

                n += (

                    (thisGeneration     [y+1]   [x-1]   ||0)+
                    (thisGeneration     [y+1]   [ x ]   ||0)+
                    (thisGeneration     [y+1]   [x+1]   ||0)

                );

            }

            if (n === 3 && !thisGeneration[y][x]){
            // Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.

                nextGeneration[y][x] = 1;

            }

            if (n < 2 && thisGeneration[y][x]){
            // Any live cell with fewer than two live neighbours dies, as if caused by under-population.

                nextGeneration[y][x] = 0;

            }

            if ((n === 2 || n === 3) && thisGeneration[y][x]){
            // Any live cell with two or three live neighbours lives on to the next generation.

                nextGeneration[y][x] = 1;

            }

            if (n > 3 && thisGeneration[y][x]){
            // Any live cell with more than three live neighbours dies, as if by overcrowding.

                nextGeneration[y][x] = 0;

            }

        }

    }

    thisGeneration = nextGeneration.slice(0); // "slice" causes "thisGeneration" to be a copy, not a reference

}, 1000);

我还想知道是否可以提高脚本的性能，因为你可以看到我使用二维数组保存单元格状态。

Answer 1

我不认为这一代和下一代像你想象的那样独立。我建议您用逐个单元复制替换切片操作，看看是否可以解决问题。