startPadAngle and endPadAngle about d3-shape HOT 4 OPEN

 // Apply padding? Note that since r1 ≥ r0, da1 ≥ da0.
      if (rp > epsilon) {
        var p0s = asin(rp / r0 * sin(aps)),
            p0e = asin(rp / r0 * sin(ape)),
            p1s = asin(rp / r1 * sin(aps)),
            p1e = asin(rp / r1 * sin(ape));
        if ((da0 -= p0s+p0e) > epsilon) p0s *= (cw ? 1 : -1), a00 += p0s, a10 -= p0e;
        else da0 = 0, a00 = a10 = (a0 + a1) / 2;
        if ((da1 -= p1s+p1e) > epsilon) p1s *= (cw ? 1 : -1), a01 += p1s, a11 -= p1e;
        else da1 = 0, a01 = a11 = (a0 + a1) / 2;
      }