You could set up a "track" as a grid. Each tile on the grid could be track or non-track. Check on what type of tile the car is on. If it is on a non-track grid, then reposition it so it gets pushed back. However, that is not a very good method at all. Sliding collision would be much much better. You could create fence objects and position them on the track. Just give them collision boxes, and give the car a collision box. Dark Basic can handle sliding collision quite quickly, and it will make the physics look pretty good. There are sliding collision tutorials and examples available. A sliding collision example comes with Dark Basic.
Xander Moser of Bolt Software
Firewall: Your Computer's First Defense - Real Time Strategy game
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