int
Point::nearest_point_index(PointPtrs &points) const
{
int idx = -1;
double distance = -1; // double because long is limited to 2147483647 on some platforms and it's not enough
for (PointPtrs::const_iterator it = points.begin(); it != points.end(); ++it) {
/* If the X distance of the candidate is > than the total distance of the
best previous candidate, we know we don't want it */
double d = pow(this->x - (*it)->x, 2);
if (distance != -1 && d > distance) continue;
/* If the Y distance of the candidate is > than the total distance of the
best previous candidate, we know we don't want it */
d += pow(this->y - (*it)->y, 2);
if (distance != -1 && d > distance) continue;
idx = it - points.begin();
distance = d;
if (distance < EPSILON) break;
}
return idx;
}
int
Point::nearest_point_index(const PointPtrs &points) const
{
PointConstPtrs p;
p.reserve(points.size());
for (PointPtrs::const_iterator it = points.begin(); it != points.end(); ++it)
p.push_back(*it);
return this->nearest_point_index(p);
}