for (StopList::const_iterator s = _stops.begin(); s != _stops.end(); ++s) {
double r, g, b, a;
color_to_rgba (s->second, r, g, b, a);
_gradient->add_color_stop_rgba (s->first, r, g, b, a);
}
for (StopList::const_iterator s = _stops.begin(); s != _stops.end(); ++s) {
double r, g, b, a;
color_to_rgba (s->second, r, g, b, a);
_gradient->add_color_stop_rgba (s->first, r, g, b, a);
}