Issue with Highway drive

[raphaelmor]

from @Erulezz

I am simulating an Highway drive with the Simulator and saving all the coordinates. What it normally >should do is follow the complete highway in the San Francisco Bay area, but i'm getting polylines >back like this:

{zbFtdzgVnCbsALfALfALfANhANhANfANfANhANhANdANfANhANfALbALfANhANfALhALfABjAFhABjA@jA?jACjAEjAIjAKjAMhAQhASfAWfAYfAYfAYfAYfAYfAWdAWfAYdAWfAUhAQhAOfAMhAKhAIjAEhACjAAjA@jABjADhAFjAHhAJhALhAJhALfALjALhALjALhAJhAJhAHdAFfABfA@dA?dACfAEfAGdAIdAMdAOdAQdAUdAWbAYbA[A]~@?@|@c@z@e@x@g@x@i@t@k@v@k@v@k@v@i@t@i@t@g@t@g@v@g@v@e@x@c@z@a@z@c@z@c@|@c@z@a@|@a@|@c@~@a@|@a@|@?@z@c@|@a@|@a@z@a@|@?@|@a@~@]z@]~@]~@?@A[~@]|@?@~@?@|@a@|@c@x@e@v@g@t@g@n@i@p@i@n@i@p@g@l@i@p@i@n@g@l@i@n@e@p@e@r@c@t@a@t@?@x@?@x@[|@[~@Y|@[A[A[bA[bA[bA]bA[A]bA[bA[dA[bA[A[A]A]|@?@|@c@z@e@x@g@v@i@r@m@p@o@n@m@j@q@h@q@f@q@d@q@d@s@d@q@f@s@f@s@f@q@f@o@h@o@l@m@l@k@p@i@p@g@t@c@r@a@v@c@x@?@z@]z@]|@[~@W~@UAUAQbASdAQbAObAQdAQdAQbAOdASdAUbAWAY~@]~@]|@?@|@?@z@a@|@g@x@g@t@g@t@i@r@k@r@k@n@o@l@q@h@q@h@s@d@u@b@y@b@w@b@w@@w@@y@^y@b@w@@y@@w@b@w@f@s@f@q@j@q@n@o@p@k@t@i@v@g@z@c@z@c@|@?@|@]~@YAWAUbASdAQfAMhAKhAIjAEjACjAAjA?jA?lA?hAAjAAjAAjAEhAIhAKhAOfAQfASdAUdAUfAUdAUdASfAUdASbASbASbAQbASbASbASbAUbAUbAUbAYbA[A]A?@~@a@~@e@~@e@z@g@x@i@v@k@t@k@p@m@p@o@n@q@n@o@j@o@l@q@l@q@j@o@l@o@j@q@j@q@j@o@j@q@j@o@j@o@l@m@j@o@h@q@h@q@l@o@j@o@l@o@l@o@p@o@l@m@n@m@r@m@p@k@r@m@r@m@r@m@r@m@r@m@r@m@r@m@p@m@n@m@p@o@n@q@j@s@h@q@d@u@d@u@@u@^w@\y@Z{@X{@T{@P_AN}@L}@L{@J_AJ}@J}@J{@J}@L{@L{@Pw@T{@R{@Pq@j@u@@q@b@o@l@m@j@i@n@k@n@g@r@c@t@a@v@?@z@]z@[~@W~@UASbAQbAKbAKfAIfAIfAKfAIhAIfAIfAIhAKfAKfAKfAMbASbAUbAUbA[A[A?@~@?@z@a@z@a@z@c@|@c@|@c@|@c@|@c@~@]AYbAYdAUdAQfAOfAKfAIfAGhAEfAChACfAEhACfAEjAGfAIdAKdAOfAQdASbAUAWbA[~@]|@?@x@c@z@c@x@e@t@g@t@i@r@k@n@m@l@m@l@o@n@o@l@m@l@o@j@o@n@o@l@o@l@o@l@q@n@o@n@o@p@o@p@q@p@q@p@q@n@q@n@q@p@q@p@q@p@q@n@o@p@q@p@q@n@q@p@o@p@q@n@o@p@o@n@o@p@o@n@o@n@o@n@o@n@o@n@o@n@o@l@o@n@o@p@o@n@o@n@o@l@m@n@m@n@m@l@m@n@m@n@m@n@i@p@i@r@g@t@e@t@c@x@c@|@a@z@?@|@[|@[AYAWbAUbAUdAUdAUbAUbAUfAUdAUdAUdAUdAWfAUdAUbAWfAUfAWfAUfAUfAUfAUfAWfAWhAUhAWfAWfAWfAWhAUhAWfAWhAWfAWfAUhAWfAUhAUfAUfAWfAWfAWfA[A]dA?@Aa@~@c@|@g@z@g@z@i@x@k@t@m@r@o@p@o@n@o@n@o@n@m@l@m@j@k@p@k@t@g@t@g@x@c@v@c@z@?@~@]~@[~@YbAWbAUbAQbAOdAMfAKdAIdAIfAKfAIhAIhAKjAKjAKhAKlAOjAMjAQjAUfAWhA[dA[dA]`Ac@bAe@~@e@z@g@x@g@z@g@x@g@x@g@v@g@x@g@x@g@x@g@x@i@z@i@x@g@x@g@x@i@z@i@z@g@z@g@x@i@z@i@z@i@z@i@z@k@z@m@x@m@x@

As you can see the line is getting off the highway. The first 2-3 km or so is correct. If i check the >coordinates saved in the array they are always on the highway, even the last coordinate in the array. >Strange thing is, it doesn't always happen. It is properly some value in the coordinate that is going >wrong or something.

[EricDRX]

I have taken some images with an example: This is the simulator:

This is the polyline:

Doing some more tests with also a City Run this afternoon :)

[raphaelmor]

I managed to reproduce the issue, and found a fix (https://github.com/raphaelmor/Polyline/pull/4). When two coordinates are separated by 0.00016, the encoder behaved badly. I also fixed some rounding, so now the results are identical to Google Map iOS SDK. (but not exactly to the online tool, see README for more details).

Please let me know if it fixes your issue.

[EricDRX]

Thanks for your explanation :) It is working perfect now:

Thanks a lot!

[raphaelmor]

No problem ! I'm happy you find it useful !