[mapserver-dev] PROJ4 and EPSG database

[Frank Warmerdam]

Yewondwossen Assefa wrote:
> Frank Warmerdam wrote:
>>
>> Folks,
>>
>> I would point out that MapServer already has a concept of axis ordering
>> implemented for WCS.  Of note are the msAxisNormalizePoints() and
>> msAxisDenormalizePoints() functions in mapproject.c.  These are tied to
>> epsgaxis= settings which can be "en" for easting,northing or "ne" for
>> northing,easting.
>>
>> Currently mapfile.c's proj init function has a special case to set this
>> parameter for EPSG urn's in a particular range.  In the short term I
>> think this is the logical mechanism to extend when working on WMS 1.3.0.
>>
> 
> Frank,
> 
> This is exactly how I am implementing the proj support for wms1.3.0: 
> extend the functions to support more CRS codes and the AUTO2.  The only 
> difference that I saw from WCS1.1 would be to allow all EPSG projection 
> strings (given as Urns or just ESPG:XXXX) to pass though the functions 
> to set the axes order for those particular ESPG ranges.

Assefa,

I do not think we can have EPSG:4326 be assumed to be lat/long for all
services, so some mechanism will need to be put in place to alter the
behavior in WMS 1.3 mode.  Possibly you could alter EPSG: to EPSGA: in
the WMS 1.3 handler code and we could look for that.   Or even replace
the EPSG: with the corresponding URN before calling the
msLoadProjectionString() function.  What I don't want is for the axis
stuff to be altered when folks have EPSG: metadata set or with WMS 1.1.

Best regards,

-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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