Lookup timezone for GPX coordinates

[blackenstock]

the shown time on the movie can be looked up using an api/library.

there is a list of solutions:
https://stackoverflow.com/questions/16086962/how-to-get-a-time-zone-from-a-location-using-latitude-and-longitude-coordinates

due to the fact a gpx file has lots of entries take care of take advantage of a library which is offline. it has to be checked if the timezone information is correctly taken. --> china has only one time zone which covers 5 time zones. so if at the same longitude more up north the solution has to lookup different time zone information.

[n76]

The TimeShape java library linked to from the above stackoverflow sounds interesting. Apparently it would add about 1 second to the start up time of gpx-animator but since it runs off line it should be fast to run for individual lookups.

This might give the ability to look up the timezone for each point in the GPX file while rendering. That would mean that a track that crosses a timezone boundary will work pretty well, the displayed time properly showing the shift.

This might not be an issue for many/most as timezones are pretty big. But I can see a use for that near where I live.

[McPringle]

The initialization of the TimeShape library can be done before rendering. That will not affect the startup time and we'll able to initialize it with the bounding box of the loaded GPX file to reduce memory footprint. This initialization can be done asynchronously while GPX Animator is reading the map tiles. That would not affect the speed at all. At least not recognizable.

That library sounds very interesting. I like that idea, we should do that! :-)

[McPringle]

I'll target it for the 2.0 release. If you (or someone else) starts working on it, please create a branch. And comment here, so others know, that someone is working on it.