GMap.NET prefetch cache database thinning

Dec 19, 2009 at 6:20 AM


First, thank you very much for making this fantastic software.  I am very new to mapping and this tool has made my project so much easier.

I have prefetched the tiles for the entire state of Georgia from OpenStreetMaps, by selecting a square around it ( an option to select an irregular shape would be nice ).  Now, I would like to reduce the size of the .gmdb cache file by removing the bordering states and ocean tiles.

Looking at the tables in the cached database file, I couldn't find anything that allowed me to associate a tile record with a Lat and Lon position, or which state it was part of. How can Gmap.NET continue to find street names and addresses perfectly using this cached file when the required data doesn't appear to be in it?

Am I looking in the wrong place?  Is the data embedded in the PNG blob field?  How can I selectively remove un-needed tiles?

Thanks in advance.

Dec 19, 2009 at 3:14 PM

only if can dump google geochache names dadabase ;} ..and you can remove un-needed tiles by deleting them ;} but there is no built-in function for that, maybe i'll create more functional coaching tool some day

Dec 19, 2009 at 5:21 PM

How does GMap.NET still find streets and addresses on a "Cache-Only" OpenStreetMaps map when I'm disconnected from the network? Is the Google geochache names database embedded somewhere?

Please don't get me wrong, I'm very impressed, but I'd just like to know how it works and where the data is coming from. I thought the data would have to be in the "data.gmdb" file, but I didn't see anything.

Thanks again for this great tool.


Dec 19, 2009 at 6:13 PM

there is local cache for geocoding, look at C:\Users\xxxxxx\AppData\Roaming\GMap.NET

Dec 20, 2009 at 1:06 AM

O.k., I see what's happening now. 

I thought the "CacheOnly" mode meant "no network needed at all".  But in reality, the demo still connects to Google's Geocoding database when doing new searches using the "goto" text box.





Dec 20, 2009 at 1:32 AM

yes, mode is just for tiles

Feb 3, 2010 at 12:24 AM

Is there any way to cache everything needed so the entire map can be rendered completely offline? I will need to use the program in an area not connected to the internet.

Feb 3, 2010 at 5:37 AM

define 'everything needed' ?

Feb 3, 2010 at 5:56 AM

donnell said: I thought the "CacheOnly" mode meant "no network needed at all".  But in reality, the demo still connects to Google's Geocoding database when doing new searches using the "goto" text box.

everything needed = cached tiles + geocoding database + ...?

Is there already a way to use GMap completely unplugged from the internet? Also how do I get to the Instance property?


Feb 3, 2010 at 5:59 AM

offline geocoding database, that a big base ;} where do you suppose you get it? All you can do is just prefetch wanted area in wanted zoom levels

Feb 3, 2010 at 6:03 AM

I noticed the demo does not zoom out all of the way. I want to prefetch the earth's surface.


Feb 3, 2010 at 6:07 AM

..but demos are just demos, they are created just for functionality show, you can easily create your custom tool for exactly what you need

Feb 3, 2010 at 6:12 AM

:(  I'm only a beginning programmer. It's tough for me.


Feb 3, 2010 at 6:15 AM

..but i have some plans for 'CacheMaker', for now you can use prefetcher in demos

Feb 3, 2010 at 6:21 AM

Thanks. I'm looking forward to your CacheMaker. :)  By the way, what do you think about opening up the Documentation area as a Wiki? All of the users could post documentation as they figure out how to do certain things. This would save you the time of having to do it yourself. Also, can we donate money to the project if we cannot contribute in other ways?


Feb 3, 2010 at 9:30 AM

..maybe but there are not so much what to document, donation is ok but not required, anyway it's free project ;}