[mapserver-dev] PROJ4 and EPSG database

[Daniel Morissette]

As we all know, PROJ4's processing of init files (the infamous epsg 
file) is quite slow and a few options have been discussed on this list 
to solve this, going from optimizations directly in PROJ to caching in 
MapServer or even having MapServer use its own optimized database.

While working on WMS 1.3.0 we have come accross another need that 
PROJ4's current init file setup doesn't address: the ability to lookup 
extra information about a given SRS such as the axis order.

That gives one more argument for leaving the current PROJ4 init stuff 
behind and developing an optimized (but simple) SRS database system.

I'd hate to do something specific to MapServer, so perhaps we could 
develop a simple API that sits well on top of PROJ4 and that could be 
used by all PROJ4-based applications to provide a shared projection 
database format and API. We could even look at the database format used 
by other systems such as GeoTools or GeoServer (I have no clue what they 
use, just thinking out loud) so that we try sharing as much as possible 
with them. I'd like to discuss that approach at the Toronto code sprint.

This is turning into a question for the MetaCRS project, but I wanted to 
  run the idea by the MapServer group first since we are the ones with 
the most pressing need for this.

Daniel
-- 
Daniel Morissette
http://www.mapgears.com/