[OSM-dev] Call to mobile developers: OSM binary file format

Chris Browet cbro at semperpax.com
Thu Aug 7 10:50:45 BST 2008


2008/8/7 Shaun McDonald <shaun at shaunmcdonald.me.uk>

> Chris Browet wrote:
>
>>
>>
>>    Do you think about floating-point or fixed-point
>>    coordinates?
>>
>>
>> This is one of the things to discuss. For mobile applications, fixed-point
>> is the most efficient but we have to balance this with the loss of
>> precision.
>>
> Actually the OSM db stores the node's lat and lon as integers. There is a
> scaling factor of 10000000 done on the fly when you read and write notes.
>
> http://trac.openstreetmap.org/browser/sites/rails_port/lib/geo_record.rb#L22
>

Ok, so I guess this is one decision taken!

- Chris -
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/dev/attachments/20080807/26d03a5f/attachment.html>


More information about the dev mailing list