public IEnumerable <GeoIndex> Enumerate(GeoPoint point, Distance distance)
{
if (distance < Distance.FromMetres(0))
{
return(Enumerable.Empty <GeoIndex>());
}
var center = indexes.GetIndex(point);
if (!indexes.IsIndexValid(center))
{
throw new ArgumentOutOfRangeException(nameof(point), $"Geo map data does not cover location {point}");
}
var length = Math.Max((int)Math.Floor(distance / resolution) - 1, 0);
var right = center.X + length;
while (indexes.GetGeoPoint(new GeoIndex(right + 1, center.Y)).GetDistance(point) <= distance)
{
right++;
}
var left = center.X - length;
while (indexes.GetGeoPoint(new GeoIndex(left - 1, center.Y)).GetDistance(point) <= distance)
{
left--;
}
left = indexes.ClampX(left);
right = indexes.ClampX(right);
return(Enumerate(Enumerable.Range(center.X, right - center.X + 1).Reverse(), center.Y, point, distance)
.Concat(Enumerate(Enumerable.Range(left, center.X - left), center.Y, point, distance)));
}
private IEnumerable <GeoIndex> NaiveNearestIndexes(GeoPoint point, Distance distance)
{
var center = indexes.GetIndex(point);
var length = (int)Math.Ceiling(distance / resolution) * 2;
if (length == 0)
{
var index = new GeoIndex(center.X, center.Y);
if (indexes.IsIndexValid(index))
{
yield return(index);
}
yield break;
}
for (var x = center.X - length; x <= center.X + length; x++)
{
for (var y = center.Y - length; y <= center.Y + length; y++)
{
var index = new GeoIndex(x, y);
if (indexes.IsIndexValid(index) && indexes.GetGeoPoint(index).GetDistance(point) <= distance)
{
yield return(index);
}
}
}
}
public List <Suburb> this[GeoPoint point]
{
get
{
var index = indexes.GetIndex(point);
if (!indexes.IsIndexValid(index))
{
throw new IndexOutOfRangeException(point.ToString());
}
return(suburbs[index.X][index.Y]);
}
set
{
var index = indexes.GetIndex(point);
if (!indexes.IsIndexValid(index))
{
throw new IndexOutOfRangeException(point.ToString());
}
suburbs[index.X][index.Y] = value?.ToList();
}
}