Routing, polylines in iPhone Google Maps

In our iPhone app we need to draw a route on Google Maps (GMaps is the only option, we can't consider other maps).

We draw the route while the user walks around - GPS tracking basically. Then we display all saved routes on the map. The problem is that Google Maps is almost unusable. It is impossible to scroll the map, zoom it (everything is extremely slow).

Now we draw the route on a transparent layer [UIColor clearColor] in the method - (void)drawRect:(CGRect)rect which is called using [ setNeedsDisplay] through UIGraphicsGetCurrentContext. Our task is to draw a route 开发者_StackOverflow社区(almost like in native iPhone GMaps app) so that the map will be scrollable and easy to zoom and the route won't be glitchy.

As an example of what we need to do I can point to this app http://itunes.apple.com/us/app/endomondo-tracker/id333210180?mt=8 Maybe you can point me to any of the libraries that do this? Thank you for your help.

You might want to have a look at http://github.com/mobilemelting/nvpolyline This solution is especially targeted at iPhone OS versions prior to v.4.0

Although it can also be used in v.4.0 Hope this helps.