[OSM-dev] Final kinks in osmosis planet dumping

Brett Henderson brett at bretth.com
Mon Sep 10 11:32:23 BST 2007

Frederik Ramm wrote:
> So difficult to add a fixed "header" on output? I certainly can live
> without <bound>; it is used for JOSM etc. to show the downloaded area
> (which is *not* identical to the min and max lat/lon in the file!) but
> nobody will ever load the planet in JOSM...
It's easy to add a fixed header but the problem is that the task that 
writes the xml file is the generic --write-xml task.  It is not limited 
to planet generation and used any time you need to write data to an xml 
destination.  It's not impossible to resolve but would require an 
additional "bound" data type being supported by the pipeline which would 
be modified by each task in the pipeline as required (eg. a bounding box 
task would resize the bound box, a polygon may have to modify the box to 
surround the extremities of the polygon) but it's not a 5 minute task.

A simpler somewhat hacky solution might be to add an optional argument 
to the --write-xml task to allow the user to specify what is written ...
> I don't see a reason why we should not upgrade dev to 1.6; then again
> the casual user would surely be happy to have a 1.5 compatible
> version without the polygon task. I guess there's no magic way to
> simply disable the polygon stuff when the user running osmosis has
> only 1.5?
Not that I can think of.  I can always maintain a separate 1.5 
compatible branch without polygon support if there's enough demand for 
it but was hoping to avoid that.

Alternatively I can modify the polygon task to use the jdk 1.5 
GeneralPath class which I think uses float data types instead of the 
Path2D.Double class which unsurprisingly uses double data types.  
Perhaps this is a better solution.  Again, I was just hoping to avoid 
the hassle and possible data accuracy issues.  In a year's time when we 
have free java/IcedTea implementations this should be much easier :-)

Is float accuracy sufficient for a polygon extraction task?


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