bool SSurface::IsCylinder(Vector *axis, Vector *center, double *r,
Vector *start, Vector *finish)
{
SBezier sb;
if(!IsExtrusion(&sb, axis)) return false;
if(!sb.IsCircle(*axis, center, r)) return false;
*start = sb.ctrl[0];
*finish = sb.ctrl[2];
return true;
}
