[Gdal-dev] OGR Questions
hacker at tc.fluke.com
Fri Dec 12 18:01:45 EST 2003
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
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
"Lotto: A tax on people who are bad at math!"
"Windows: Microsoft's tax on computer illiterates!" -- WE7U
"The world DOES revolve around me: I picked the coordinate system!"
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