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https://issues.apache.org/jira/browse/SIS-368?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Martin Desruisseaux closed SIS-368.
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> When a coordinate operation change the longitude axis range from [-180 …
> +180]° to [0 … 360]°, the Envelopes.transform(…) result should be normalized
> accordingly
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: SIS-368
> URL: https://issues.apache.org/jira/browse/SIS-368
> Project: Spatial Information Systems
> Issue Type: Improvement
> Components: Referencing
> Affects Versions: 0.5, 0.6, 0.7
> Reporter: Martin Desruisseaux
> Assignee: Martin Desruisseaux
> Priority: Major
> Fix For: 0.8
>
>
> There is at least two conventions regarding the range of longitude values:
> -180° to 180° or 0° to 360°. The range is specified with
> {{CoordinateSystemAxis}} minimum and maximum attributes. Most of the times,
> we use the -180° to +180° convention. However when an envelope is transformed
> with {{Envelopes.transform(CoordinateOperation, Envelope)}} method, if the
> longitude range declared in the coordinate system changes, we expect the
> envelope longitude values to be updated accordingly.
> We could invoke {{GeneralEnvelope.normalize()}} after envelope
> transformation, but we don't want to invoke it systematically. If the
> {{CoordinateOperation}} does not change the longitude range, then it is safer
> to let the longitude values as we found them, even if they are slightly
> outside the expected range. Example:
> * If source CRS uses longitudes in the \[-180 … +180\]° range and target CRS
> uses longitudes are in the \[-180 … +180\]° range, then do nothing. Even if
> the transformation result is an envelope spanning 175° to 185° of longitude,
> leave it as-is because the original envelope was probably already crossing
> the anti-meridian (not necessarily using longitudes; we can cross the
> anti-meridian with the Mercator projection too).
> * If source CRS uses longitudes in the \[0 … 360\]° range and target CRS uses
> longitudes are in the \[0 … 360\]° range, do nothing for the same reason than
> above.
> * If source CRS uses longitudes in the \[-180 … +180\]° range and target CRS
> uses longitudes are in the \[0 … 360\]° range, then if the envelope result is
> outside the \[0 … 360\]° range, brings it back to the \[0 … 360\]° range as
> described in {{GeneralEnvelope.normalize()}}.
> * If source CRS uses longitudes in the \[0 … 360\]° range and target CRS uses
> longitudes are in the \[-180 … +180\]° range, then if the envelope result is
> outside the \[-180 … +180\]° range, brings it back to the \[-180 … +180\]°
> range.
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