[postgis-devel] [PostGIS] #1058: [raster] Two-raster spatial operations framework proposal

[PostGIS]

#1058: [raster] Two-raster spatial operations framework proposal
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 Reporter:  bnordgren       |       Owner:  pracine      
     Type:  enhancement     |      Status:  new          
 Priority:  medium          |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  1.5.X        
 Keywords:                  |  
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Comment(by mcayland):

 :)  Well let me clarify how I would see things working.

 Firstly: liblwgeom is intended to be standalone in that it should be
 possible to make use of it without PostgreSQL present at all. So the
 current route of trying to link against postgis.so is incorrect so please
 don't spend any more time on it.

 I'd envisage something along the following lines:

 1) Create a new file liblwgeom/lwgeom_proj.c

 2) Add some basic APIs which take a proj4text and return a projPJ handle

 3) Move the main reprojection function from postgis/lwgeom_transform.c
 into liblwgeom/lwgeom_proj.c taking a projPJ handle as a primary parameter

 4) Rework postgis/lwgeom_transform.c so it calls the underlying liblwgeom
 routines instead

 5) Rework postgis/lwgeom_transform.c cache code so it uses the underlying
 liblwgeom routines... and while you're there, also refactor it into a
 simple API so that adding caching to any other functions within PostGIS
 (as in linked with PostgreSQL) becomes much easier (and indeed, I believe
 you can test this by making the prepared geometry cache use your new code
 too).


 Does that make more sense now?

 Mark.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/1058#comment:7>
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