[Gdal-dev] OGR Questions

[Curt Mills]

1) Can the coordinate system change per layer in a vector file?  If
not, shouldn't the call to get the spatial reference be based on the
datasource instead of the layer?

2) Shapefile "hole" polygons:  Are there other OGR formats that do
something similar?  Should I check whether the datasource is a
shapefile and implement "hole" polygons only for them?

3) Is there a standard anywhere for how to specify drawing
preferences across GIS systems?  I'm talking about things like
enabling/disabling layers, deciding which field is the label for the
object, colors, layer stackup, line widths, polygon fill or outline,
etc.  The sorts of things that might be written to a file that
accompanies a dataset, or perhaps covers a directory heirarchy of
GIS files.

4) Getting the number of points in a feature:  Is that always an
"inexpensive" operation?  If it can be "expensive", is there a way
to gain the entire set of vectors instead that would be faster?  I
saw nothing in ogr_api.h about it.

Again, I'm using the C API to OGR.

-- 
Curt Mills, WE7U                    hacker_NO_SPAM_ at tc.fluke.com
Senior Methods Engineer/SysAdmin
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