Function rgba

docs/app/js/sanddance-app.js:2398–2401

(r, g, b, a)

    return new Rgb(n >> 16 & 0xff, n >> 8 & 0xff, n & 0xff, 1);
}
function rgba(r, g, b, a) {
    if (a <= 0) r = g = b = NaN;
    return new Rgb(r, g, b, a);
}
function rgbConvert(o) {
    if (!(o instanceof Color)) o = color(o);
    if (!o) return new Rgb;