func makeGeoRect(lat, lon, radius float64) (rtreego.Rect, error) {
earth := float64(6371000)
dlat := (radius / (math.Pi * earth)) * 180.0
r := earth * math.Cos((math.Pi*lat)/180.0)
dlon := (radius / (math.Pi * r)) * 180.
lon -= dlon
lat -= dlat
return rtreego.NewRect(rtreego.Point{lon, lat}, [2]float64{2 * dlon, 2 * dlat})
}
func makeOfferLocation(id string, date time.Time, loc *Location) (
*OfferLoc, error) {
if loc == nil {
return nil, nil
}
lon := loc.Lon - locExtent[0]/2
lat := loc.Lat - locExtent[1]/2
rect, err := rtreego.NewRect(rtreego.Point{lon, lat}, locExtent)
if err != nil {
return nil, err
}
return &OfferLoc{
Id: id,
Date: date,
Loc: rect,
Point: Point{
Lon: loc.Lon,
Lat: loc.Lat,
},
}, nil
}