bool geohashBoundingBox(double latitude, double longitude, double radius_meters,
double *bounds) {
if (!bounds)
return false;
double latr, lonr;
latr = deg_rad(latitude);
lonr = deg_rad(longitude);
double distance = radius_meters / EARTH_RADIUS_IN_METERS;
double min_latitude = latr - distance;
double max_latitude = latr + distance;
/* Note: we're being lazy and not accounting for coordinates near poles */
double min_longitude, max_longitude;
double difference_longitude = asin(sin(distance) / cos(latr));
min_longitude = lonr - difference_longitude;
max_longitude = lonr + difference_longitude;
bounds[0] = rad_deg(min_latitude);
bounds[1] = rad_deg(min_longitude);
bounds[2] = rad_deg(max_latitude);
bounds[3] = rad_deg(max_longitude);
return true;
}
QPointF EmptyMapAdapter::displayToCoordinate(const QPoint& point) const
{
qreal longitude = (point.x()*(360/(numberOfTiles*mytilesize)))-180;
qreal latitude = rad_deg(atan(sinh((1-point.y()*(2/(numberOfTiles*mytilesize)))*PI)));
return QPointF(longitude, latitude);
}
double merc_lat (double y) {
double ts = exp ( -y / R_MAJOR);
double phi = M_PI_2 - 2 * atan(ts);
double dphi = 1.0;
int i;
for (i = 0; fabs(dphi) > 0.000000001 && i < 15; i++) {
double con = ECCENT * sin (phi);
dphi = M_PI_2 - 2 * atan (ts * pow((1.0 - con) / (1.0 + con), COM)) - phi;
phi += dphi;
}
return rad_deg (phi);
}
double merc_lon(double x) { return rad_deg(x) / R_MAJOR; }
