Function encloseBasis2

docs/app/js/sanddance-app.js:138031–138038

(a, b)

    };
}
function encloseBasis2(a, b) {
    var x1 = a.x, y1 = a.y, r1 = a.r, x2 = b.x, y2 = b.y, r2 = b.r, x21 = x2 - x1, y21 = y2 - y1, r21 = r2 - r1, l = Math.sqrt(x21 * x21 + y21 * y21);
    return {
        x: (x1 + x2 + x21 / l * r21) / 2,
        y: (y1 + y2 + y21 / l * r21) / 2,
        r: (l + r1 + r2) / 2
    };
}
function encloseBasis3(a, b, c) {
    var x1 = a.x, y1 = a.y, r1 = a.r, x2 = b.x, y2 = b.y, r2 = b.r, x3 = c.x, y3 = c.y, r3 = c.r, a2 = x1 - x2, a3 = x1 - x3, b2 = y1 - y2, b3 = y1 - y3, c2 = r2 - r1, c3 = r3 - r1, d1 = x1 * x1 + y1 * y1 - r1 * r1, d2 = d1 - x2 * x2 - y2 * y2 + r2 * r2, d3 = d1 - x3 * x3 - y3 * y3 + r3 * r3, ab = a3 * b2 - a2 * b3, xa = (b2 * d3 - b3 * d2) / (ab * 2) - x1, xb = (b3 * c2 - b2 * c3) / ab, ya = (a3 * d2 - a2 * d3) / (ab * 2) - y1, yb = (a2 * c3 - a3 * c2) / ab, A = xb * xb + yb * yb - 1, B = 2 * (r1 + xa * xb + ya * yb), C = xa * xa + ya * ya - r1 * r1, r = -(A ? (B + Math.sqrt(B * B - 4 * A * C)) / (2 * A) : C / B);
    return {