/// <summary>
/// Adjusts region coordinate prefixes to be aligned with precision<see cref="Region"/>/>
/// </summary>
/// <param name="region">Input <see cref="Region"/></param>
/// <returns><see cref="Region"/> - region with adjusted coordinate prefixes</returns>
public static Region AdjustToPrecision(Region region)
{
return(new Region(
PrecisionHelper.Round(region.LatitudePrefix, region.Precision),
PrecisionHelper.Round(region.LongitudePrefix, region.Precision),
region.Precision
));
}
/// <summary>
/// Enumerates all <see cref="Region"/>s of given precision covering given area/>
/// Current implementation only returns single region associated with area center.
/// Under assumption of radius of area to be significantly below precision resolution and usage of extension >= 1 in search,
/// that is enough
/// </summary>
/// <param name="area"><see cref="Area"/></param>
/// <param name="precision">Precision. Any integer number</param>
/// <returns>Collection of <see cref="Region"/>s</returns>
public static IEnumerable <Region> GetRegionsCoverage(Area area, int precision)
{
yield return(new Region
{
LatitudePrefix = PrecisionHelper.Round(area.Location.Latitude, precision),
LongitudePrefix = PrecisionHelper.Round(area.Location.Longitude, precision),
Precision = precision
});
}
/// <summary>
/// Adjusts region coordinate prefixes to be aligned with precision<see cref="Region"/>/>
/// </summary>
/// <param name="region">Input <see cref="Region"/></param>
/// <returns><see cref="Region"/> - region with adjusted coordinate prefixes</returns>
public static Region AdjustToPrecision(Region region)
{
return new Region
{
LatitudePrefix = PrecisionHelper.Round(region.LatitudePrefix, region.Precision),
LongitudePrefix = PrecisionHelper.Round(region.LongitudePrefix, region.Precision),
Precision = region.Precision
};
}
/// <summary>
/// Creates a new <see cref="Region"/>
/// </summary>
/// <param name="lat">Precise latitude</param>
/// <param name="lng">Precise longitude</param>
/// <param name="precision">Precision parameter</param>
/// <remarks>
/// This constructor allows backward-compatibility with previous
/// API versions which defined lat/lng as <see cref="double"/>.
/// </remarks>
public static Region CreateRegion(double lat, double lng, int precision = Region.MAX_PRECISION)
{
return(new Region
{
LatitudePrefix = PrecisionHelper.Round(lat, Region.MAX_PRECISION),
LongitudePrefix = PrecisionHelper.Round(lng, Region.MAX_PRECISION),
Precision = precision
});
}
private static IEnumerable <Region> GetRegionCoveragePositive(Coordinates location, float radiusMeters, int precision)
{
int latMax = (int)Coordinates.MAX_LATITUDE;
int lonMax = (int)Coordinates.MAX_LONGITUDE;
int step = PrecisionHelper.GetStep(precision);
int latCurrent = PrecisionHelper.Round(location.Latitude, precision);
int latNext = Math.Min(latCurrent + step, latMax);
int lonCurrent = PrecisionHelper.Round(location.Longitude, precision);
int lonNext = Math.Min(lonCurrent + step, lonMax);
//region itself
yield return(new Region(latCurrent, lonCurrent, precision));
if (precision > 0)
{
if (latCurrent > 0)
{
// South-West
if (lonCurrent > 0 && GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = (float)latCurrent, Longitude = (float)lonCurrent
}) < radiusMeters)
{
yield return(new Region(latCurrent - step, lonCurrent - step, precision));
}
// South
if (GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = (float)latCurrent, Longitude = location.Longitude
}) < radiusMeters)
{
yield return(new Region(latCurrent - step, lonCurrent, precision));
}
// South-East
if (GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = (float)latCurrent, Longitude = (float)lonNext
}) < radiusMeters)
{
yield return(new Region(latCurrent - step, lonNext == lonMax ? -lonCurrent : lonNext, precision));
}
}
if (lonCurrent > 0)
{
// West
if (GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = location.Latitude, Longitude = (float)lonCurrent
}) < radiusMeters)
{
yield return(new Region(latCurrent, lonCurrent - step, precision));
}
//North-West
if (latNext < latMax && GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = (float)latNext, Longitude = (float)lonCurrent
}) < radiusMeters)
{
yield return(new Region(latNext, lonCurrent - step, precision));
}
}
if (latNext < latMax)
{
//North
if (GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = (float)latNext, Longitude = location.Longitude
}) < radiusMeters)
{
yield return(new Region(latNext, lonCurrent, precision));
}
//North-East
if (GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = (float)latNext, Longitude = (float)lonNext
}) < radiusMeters)
{
yield return(new Region(latNext, lonNext == lonMax ? -lonCurrent : lonNext, precision));
}
}
//East
if (GeoHelper.DistanceMeters(location, new Coordinates {
Latitude = location.Latitude, Longitude = (float)lonNext
}) < radiusMeters)
{
if (lonNext < lonMax)
{
yield return(new Region(latCurrent, lonNext, precision));
}
else if (lonCurrent > 0)
{
yield return(new Region(latCurrent, -lonCurrent, precision));
}
}
}
}