Function zero

docs/app/js/sanddance-app.js:70038–70042

(out)

    return Math.acos(Math.min(Math.max(cosine, -1), 1));
}
function zero(out) {
    out[0] = 0.0;
    out[1] = 0.0;
    return out;
}
function str(a) {
    return "vec2(" + a[0] + ", " + a[1] + ")";
}