Offline Mapping API

Are there any services available that allow me to manipulate maps in an offline setting? I am working on a project that requires me to take a map and based on features on the map, generate a game world. I have looked at a few of the API's for different providers: Google, ms, etc. The API's I looked seem to be strictly showing a user a map. I am looking for something that allows me to create a derivative of a map (the Gameworld), that will never be seen by the public, and is only used by the game engine. However one caveat is that I would like to be able to link the derivative created for use by the game engine, with something I can show the user.

As an example. Think of a cross country racing sim. Users cannot control the vehicles directly in this game, they can only control the cars setup, driver, etc. I create a gameworld from a map. The gameworld data (driver position, etc) is overlayed onto a real map. A race might last several days. The only interaction users have with the real map is viewing their position on the map, and where they are in relation to the others.

I don't want to violate the terms of the API here. I read Googles API TOS, and it seems to me that creating the gameworld would violdate their TOS.

The features I really need are the following

• The ability to locate a specific place on the map by lat/long
• The ability/rights to grab those maps and save them as an image file temporarily for processing
• The ability/rights to store a gameworld that is based on the real map
• The ability to show a user a map with an overlay (this is optional. I can use googles API, or any other one that supports lat/long.)

Edit: The gameworld creation will only happen once intially, and partial updates may occur very infreque开发者_如何学JAVAntly. I will only need to generate the world in the beginning. This is also for a free game, so I am looking for something opensource

Edit: I only need maps of the US. I need maps that contain rivers and lakes.

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I found what I was looking for, actually I found something that should work. ITs GMap.net a program written in C#. The offline stuff it does is perfect, and it even allows you to connect to map servers other than google.

http://greatmaps.codeplex.com/releases/view/20235

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Why not try out openmaps http://openmaps.eu/ You should be able to download their maps locally which means total offline use.

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http://www.openstreetmap.org/ ?

(Also, if you have specific requirements, eg. for maps of certain places, or for certain types of data such as altitude or whatever, it might be an idea to edit your original question.)