2. is just geometry and math. Assuming that your http requests
results in some kml that includes a polyline then personally I would
build an array containing each line and then just work out the closest
distance to each one from my current location every x seconds or y
If you are further than a certain distance (which you have to decide)
from ALL of the lines then you know that the user has taken a detour
and you should simply resubmit a new routing request starting at your
current location and ending at the original location.
unless your kml has hundreds of polylines I'm not sure I'd even bother
optimize the algorithm - just brute force it.
I would be a little careful of what your app does though: you might
want to read the Maps TOS license restrictions carefully to make sure
you stay within them.
On Nov 29, 9:49 pm, James Black <planiturth...@gmail.com> wrote:
> I am working on a navigation program and I have two things that could
> make my program better.
> 1. How can I find alternate routes.
> I use this url currently:http://maps.google.com/maps?f=d&hl=en&saddr=xxx,zzz&daddr=yyy,www&ie=...
> 2. How can I tell when the user takes a detour from the path on the
> MathOverlay, so I can get a new route for them?
> Thank you.
> "I know that you believe you understand what you think I said, but I'm not
> sure you realize that what you heard is not what I meant."
> - Robert McCloske
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to email@example.com
To unsubscribe from this group, send email to
For more options, visit this group at