public MRect?GetExtent()
{
if (_provider.GetExtent() == null)
{
return(null);
}
var extent = _provider.GetExtent() !;
if (!CrsHelper.IsProjectionNeeded(_provider.CRS, CRS))
{
return(extent);
}
if (!CrsHelper.IsCrsProvided(_provider.CRS, CRS))
{
throw new NotSupportedException($"CRS is not provided. From CRS: {_provider.CRS}. To CRS {CRS}");
}
// This projects the full extent of the source. Usually the full extent of the source does not change,
// so perhaps this should be calculated just once. Then again, there are probably situations where it does
// change so a way to refresh this should be possible.
var copiedExtent = new MRect(extent);
_projection.Project(_provider.CRS, CRS, copiedExtent);
return(copiedExtent);
}
public IEnumerable <IFeature> GetFeatures(FetchInfo fetchInfo)
{
// Note that the FetchInfo.CRS is ignored in this method. A better solution
// would be to use the fetchInfo.CRS everywhere, but that would only make
// sense if GetExtent would also get a CRS argument. Room for improvement.
if (fetchInfo.Extent == null)
{
return(new List <IFeature>());
}
var copiedExtent = new MRect(fetchInfo.Extent);
// throws exception when CRS or _provider.CRS is null (so I don't have to check it here)
_projection.Project(CRS !, _provider.CRS !, copiedExtent);
fetchInfo = new FetchInfo(copiedExtent, fetchInfo.Resolution, CRS, fetchInfo.ChangeType);
var features = _provider.GetFeatures(fetchInfo) ?? new List <IFeature>();
if (!CrsHelper.IsProjectionNeeded(_provider.CRS, CRS))
{
return(features);
}
if (!CrsHelper.IsCrsProvided(_provider.CRS, CRS))
{
throw new NotSupportedException($"CRS is not provided. From CRS: {_provider.CRS}. To CRS {CRS}");
}
var copiedFeatures = features.Copy().ToList();
_projection.Project(_provider.CRS, CRS, copiedFeatures);
return(copiedFeatures);
}
public static IEnumerable <IFeature> Project(this IEnumerable <IFeature> features, string?fromCRS,
string?toCRS, IProjection?projection = null)
{
if (!CrsHelper.IsProjectionNeeded(fromCRS, toCRS))
{
return(features);
}
if (!CrsHelper.IsCrsProvided(fromCRS, toCRS))
{
throw new NotSupportedException($"CRS is not provided. From CRS: {fromCRS}. To CRS {toCRS}");
}
var result = features.Copy().ToList();
(projection ?? ProjectionDefaults.Projection).Project(fromCRS, toCRS, result);
return(result);
}
