Function index

docs/app/js/sanddance-app.js:130574–130576

(point)

        }
    }
    function index(point) {
        return point[0] * 2 + point[1] * (dx + 1) * 4;
    }
    function smoothLinear(ring, values, value) {
        ring.forEach((point)=>{
            var x = point[0], y = point[1], xt = x | 0, yt = y | 0, v0, v1 = values[yt * dx + xt];