text adventure js code

/* This function takes a list of DOM elements as well as a
 * localStorage key. It retrieves thee value N from localStorage and
 * hides all but the Nth element from the list of elements. This is
 * used to display different things based on game state.
 */

function createSwitch(elements, lskey) {
    if (elements.length < 2) return -1;
    var i, lsval = localStorage.getItem(lskey);

    // make sure true/false switches aren't bungled
    if (lsval === false) lsval = 0;
    if (lsval === true) lsval = 1;

    for (i = 0; i < elements.length; i++) {
        if ((lsval === null && i == 0) || lsval == i) {
            elements[i].style.display = "";
        } else {
            elements[i].style.display = "none";
        }
    }
}

var updateInterval = 5; // ms
function morphColor(c1, c2, time, updatefunc, finish) {
    if (time <= updateInterval) {
        updatefunc(c2);
        return -1;
    }

    var r = c1[0], g = c1[1], b = c1[2];
    var R = c2[0], G = c2[1], B = c2[2];

    var dr = R-r, dg = G-g, db = B-b;

    var steps = time / updateInterval;

    var rstep = dr / steps;
    var gstep = dg / steps;
    var bstep = db / steps;

    var i = 0;
    var inter = window.setInterval(function() {
        r += rstep;
        g += gstep;
        b += bstep;

        updatefunc([parseInt(r,10),parseInt(g,10),parseInt(b,10)]);

        if (++i >= steps) {
            clearInterval(inter);
            if (finish) finish();
        }

    }, updateInterval);

    return inter;
}

function setbg(el) {
    return function(c) {
        el.style.backgroundColor = "rgb("+c[0]+","+c[1]+","+c[2]+")";
    };
}