I am doing a maprouting application. Several people have suggested me, that I do a datastructure where I split the map in a grid. In theory it sounds really good, but I am not to sure because of the bad performance I get when I implement it.
In the worst case you have to draw every road. If you divide the map in a grid, the sum of roads in all the cells in the grid, will be much larger than if you put all roads in a list.(each cell must have more roads than actually needed if a road goes through it).
If I have to zoom in I can see some smartness in using a grid, but if I keep it in a list I can just decrease the numbers of roads each time I zoom in. As it is now(by using the list) it is not really fast, so I am all for making it faster. But in practice dividing in a grid makes it slower for me.
Any suggestigion for what datastructure I should be using and/or what I might be doing wrong?
See this question for related information:
What algorithms compute directions from point A to point B on a map?
Somebody who writes this kind of software for a living has answered it.
Also for rendering see:
What is the best way to read, represent and render map data?
I’m not quite sure if you’re trying to do routing quick or rendering!