Weather Routing

[seandepagnier]

Initial release of the weather routing plugin:

https://github.com/seandepagnier/weather_routing_pi

For this to work at all, you must be using the latest version of my enhanced grib plugin:

https://github.com/seandepagnier/OpenCPN
branch grib_enhancements

Also, if you post a pre-built binary, do not distribute only the plugin, the main executable must also be distributed (because I changed the core in a minor case included in grib_enhancements branch)

Do some testing! There are probably bugs.

To start out, open grib first and make sure you can see wind arrows where you want to do some routing. Next open the weather routing plugin dialog (a better icon for this is much desired) Open boat, and either load a polar file (qtvlm csv supported) or compute one. Then in settings make sure to have enough degree steps (enter 10 and generate should work) Then click reset if needed to sync the time to the current grib time. Right click on the map to set the start and end locations, click start.. and hopefully it does something good.

Basically a few things I know are not complete or fully functional:
boat polar calculation.. not even close to done.
relinquishing computation thread to make opencpn more responsive
integration with other weather sources besides grib
inverted regions still have some issues
currents are implemented but untested
optimization (could run many times faster)
substeps
destination report
graphs of sailing parameters over the course of a voyage
etc...