http://www.gamedev.net/reference/programming/isotile/article747.asp

http://www.gamedev.net/reference/programming/isotile/article748.asp

hopefully, these two articles will help.

Hey there, I''m developing an isometric game and I''ve worked out many ways of doing it, but the best way seems to be to treat each tile as a polygon and check if a point is within the polygon. This not only allows you to check for mouse pointers but for collision detection against ridges and special tiles. Take a look at: http://www.gamasutra.com/features/20000210/lander_pfv.htm

It has some good stuff and some simple source listings for C

Good Luck!
- Ben

P.S. This method of using 2D polygons can work wonders in a 2D game!

Oops I forgot, I don''t actually treat all the tiles as polygons. First I do a simple rectangular check, to see if it''s even close to inside the tile, then is it''s within the rectangle I''ll inspect further.

Ah, you''ll figure out a smarter way! I don''t need to exsplain, just take a look at that article!
See ya,
Ben

P.S. You can e-mail me at cyberbenNOSPAM@home.com
Just remove the NOSPAM. Thanks!