getRandomShapes.js

function getRandomShapes(width, height) {
    var shapeArray = new Array();

    for (var y = 0; y < height; y++) {
        for (var x = 0; x < width; x++) {

            var topTab = undefined;
            var rightTab = undefined;
            var bottomTab = undefined;
            var leftTab = undefined;

            if (y == 0)
                topTab = 0;

            if (y == height - 1)
                bottomTab = 0;

            if (x == 0)
                leftTab = 0;

            if (x == width - 1)
                rightTab = 0;

            shapeArray.push(
                ({
                    topTab: topTab,
                    rightTab: rightTab,
                    bottomTab: bottomTab,
                    leftTab: leftTab
                })
            );
        }
    }

    for (var y = 0; y < height; y++) {
        for (var x = 0; x < width; x++) {

            var shape = shapeArray[y * width + x];

            var shapeRight = (x < width - 1) ?
                shapeArray[y * width + (x + 1)] :
                undefined;

            var shapeBottom = (y < height - 1) ?
                shapeArray[(y + 1) * width + x] :
                undefined;

            shape.rightTab = (x < width - 1) ?
                getRandomTabValue() :
                shape.rightTab;

            if (shapeRight)
                shapeRight.leftTab = - shape.rightTab;

            shape.bottomTab = (y < height - 1) ?
                getRandomTabValue() :
                shape.bottomTab;

            if (shapeBottom)
                shapeBottom.topTab = - shape.bottomTab;
        }
    }
    return shapeArray;
}