[gdal-dev] Layer operations, a proposal

[Ari Jolma]

On 04/18/2012 02:32 AM, Frank Warmerdam wrote:
> Ari,
>
> I think this would be an interesting addition.   Would you be willing
> to write up an RFC?

http://trac.osgeo.org/gdal/wiki/rfc39_ogr_layer_algebra

In there I call for discussion on the method names. They are now:

Intersection, Union, Identity, Update, Clip, Erase

all require three layers (self (or A), B and C). A is the "input layer", 
B is the "method layer" and C is the result layer. C should be empty 
from features and have no fields in input. I think A and B should not 
have conflicting field names but that is not crucial.

The names are from 
http://courses.washington.edu/gis250/lessons/Model_Builder/ (thus the 
names ArcInfo uses), except Intersect, which is Intersection in my 
patch. There are also illustrations how the methods should work on the page.

In addition Append (not spatial, just add all features from B according 
to current filters) and Buffer (buffer all geometries) could be included 
(not in the patch).

I have not checked the patch for memory leaks. I have tested the patch 
with Perl bindings in a graphical environment but not extensively.

Best regards,

Ari