Processing division

division.js

(function () {
    var queue;
    queue = createQueue(0, 0, 100, 100, 25, function (xMin, yMin, xMax, yMax) {
        var x, y;
        for (x = xMin; x < xMax; x++) {
            for (y = yMin; y < yMax; y++) {
                // do someThing
            }
        }
    });

    // lazy output
    (function lazyLoop(i) {
        var task = queue[i++];
        task();
        if (i < queue.length) {
            setTimeout(function () {
                lazyLoop(i);
            }, 50);
        }
    }(0));

    function createQueue(startW, startH, endW, endH, delta, callback) {
        var queue = [], startX, startY, endX, endY, updateY;
        for (startY = startH, endY = endH; startY < endY; startY) {
            for (startX = startW, endX = endW; startX < endX; startX) {
                let x = startX,
                    y = startY,
                    xz = ((endW < startX + delta) ? endW : startX + delta),
                    yz = ((endH < startY + delta) ? endH : startY + delta);

                updateY = yz;
                queue.push(function () {
                    callback(x, y, xz, yz);
                });
                startX = xz;
            }
            startY = updateY;
        }

        return queue;

        /*
        return [
            function () {
                callback(0, 0, 25, 25);
            },
            function () {
                callback(25, 0, 50, 25);
            },
            function () {
                callback(50, 0, 75, 25);
            },
            function () {
                callback(75, 0, 100, 25);
            },
            function () {
                callback(0, 25, 25, 50);
            },
            function () {
                callback(25, 25, 50, 50);
            },
            function () {
                callback(50, 25, 75, 50);
            },
            function () {
                callback(75, 25, 100, 50);
            },
            function () {
                callback(0, 50, 25, 75);
            },
            function () {
                callback(25, 50, 50, 75);
            },
            function () {
                callback(50, 50, 75, 75);
            },
            function () {
                callback(75, 50, 100, 75);
            },
            function () {
                callback(0, 75, 25, 100);
            },
            function () {
                callback(25, 75, 50, 100);
            },
            function () {
                callback(50, 75, 75, 100);
            },
            function () {
                callback(75, 75, 100, 100);
            }
        ];
        */
    }
}());