[Gdal-dev] Re: how to extract data from OGR

[Frank Warmerdam]

Jacob Bensabat wrote:
> Hi
> I have now a conceptual question. I went over the file you have posted 
> and what I see is that you have defined other containers for
> processing the data stored in the OGR layers.  What is the rationale for 
> that ?
> Would it be justified to use directly OGR ? If not what is the reason ?
> thanks

Jacob,

I assume you are referring to the mapogr.cpp code?  MapServer had it's own
internal feature format before OGR support was introduced, so the reader
converts to it's internal format.  I am not sure whether OGRFeature's would
have been an appropriate internal format for MapServer or not.

There are applications that use the OGRFeature as the internal format, but it
more common to have some other application specific internal format and convert
to that during an import phase.

I would add that even when different internal representations are used, it is
convenient if applications can use a similar "simple features" geometry model
unless there is a specific reason to do something different like CAD packages
requiring 3D solids and curves, or a topological GIS.

Best regards,

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