javascript - 使用分隔符将二维数组分成多个数组

Question

我已将 JavaScript spritesheet 转换为 2D 整数数组，现在我尝试将 2D 整数数组拆分为多个 2D 数组，使用 1 作为“分隔符”数字。

有没有办法使用分隔符数字将如下所示的 2D JavaScript 数组分隔成多个数组，如下所示？

function separate2DArray(arrToSeparate, separator){
    //separate the 2D array into multiple 2D arrays, using a
    //specific number as the separator
}

//array to separate:
[
[5, 5, 5, 1, 5, 4, 5],
[5, 5, 4, 1, 4, 3, 4],
[1, 1, 1, 1, 1, 1, 1], //1 is the "separator number", which splits the array
[9, 2, 1, 4, 2, 4, 5],       //horizontally and vertically
]
//The array above would produce the following 2D arrays:

5 5 5
5 5 4

5 4 5
4 3 4

9 2

4 2 4 5

我想到的这个算法的主要应用是 Sprite 表图像分离。

Answer 1

鉴于分隔区域是矩形，这将起作用:

function separate2DArray(array, sep){
    //separate the 2D array into multiple 2D arrays, using a
    //specific number as the separator
    var result = [],
        currentSubs = {}; // using x coordinate as key

    for (var y=0; y<array.length; y++) {
        var line = array[y],
            subBegin = 0;
        for (var x=0; x<=line.length; x++) {
            if (x == line.length || line[x] == sep) {
                if (subBegin < x) {
                    var sub = line.slice(subBegin, x);
                    if (subBegin in currentSubs)
                        currentSubs[subBegin].push(sub);
                    else
                        currentSubs[subBegin] = [sub];
                } else { // a line of separators, subBegin == x
                    if (subBegin in currentSubs) {
                        result.push(currentSubs[subBegin]);
                        delete currentSubs[subBegin];
                    }
                }
                subBegin = x+1;
            }
        }
    }
    for (var begin in currentSubs)
        result.push(currentSubs[begin]);
    return result;
}

这里的结果只是一个非常简单的子区域数组，没有任何关于它们在原始区域中的位置的信息。改进版本:

function separate2DArray(array, sep){
    var result = [],
        currentSubs = {};
    for (var y=0; y<array.length; y++) {
        var line = array[y],
            subBegin = 0;
        for (var x=0; x<=line.length; x++) {
            if (x == line.length || line[x] == sep) {
                if (subBegin < x) {
                    var subline = line.slice(subBegin, x);
                    if (! (subBegin in currentSubs)) {
                        var subarea = [];
                        result.push({x:x, y:y, area:subarea});
                        currentSubs[subBegin] = subarea;
                    }
                    currentSubs[subBegin].push(subline);
                } else {
                    if (subBegin in currentSubs)
                        delete currentSubs[subBegin];
                }
                subBegin = x+1;
            }
        }
    }
    return result;
}