hi, as I see it, there are two ways of doing this, one simple and crude, one complex and elegant.
simlpe methond:
If you map is flat, you can convert the screen coordinate to a map coordinate.
This will give you the map-pixel. Now you divide by the size of each tile, and you’ve got the tile under the mouse.
This only works if you map is flat (or else you would need a rather more complex convertion algorythm).
The complex method:
Have each tile stored as a sprite in a huge array containing all the sprites that are drawn into your isometric world.
Sort the array isometrically and make an exception so that tiles are allways beneth other sprites.
Now you must rig your sprites to store where they were drawn to each time their drawn.
When you want to know which tile the cursor is over, you need to do som Z-order stuff. like this:
Reverse through the sprite list (start at the end). This way you check the object drawn the last (ei is closest to the camera) first.
for each object in the sprite list check if the mouse is within it’s clipping box.
If the mouse is within the spritebox, you need to check if the mouse is over a oppaque part of the sprite.
If it is, this is your sprite/tile!
If it is not, reverse further down the list.
This method can be a pain to write. But once it’s completed it works like a charm!
Any Questions? =)
