I was wondering how to do Bitmasks with Blt(). I''m needing them for my isoengine. Thanks.

DON''T USE BITBLT AND MASKS FOR AN ISO ENGINE!!
It''s already quite slow for a square tiled engine.. I''ve made about 4 different iso engines, the first being in VB w/ BitBlt, bad move! But I learned a bit, I''d suggest learning DirectX, even VB w/ DirectX is a good start point but iso engines always take twice the speed in tile painting so you''ll want to move to C or C++ or Asm eventually. Also with DiretX you can use Transparent colours, so it simplifies it a bit.

If you still would really like to use BitBlt e-mail me and I''ll send you some code... What language are you using? With C++ you could have DD initialised and drawing one tile within a couple days, same with vb. Asm is a little harder but not really that hard, just no suggested for begginers.
See ya,
Ben

I''m using DDraw, and it''s Blt() function.
I tried to draw transparent tiles, but tiles which are
higher leave the top of them selves at the edge of the map.
I''m using a diagonal diamond shaped map, like a chessboard.

What I am gathering from your post, is that ''Artifacts'' of the tops of tiles are being left at the edges of the map. You can fix this by clearing the screen between updates. Any part of a surface that you dont draw to retains the pixel information that was there previously. So when you get to the edge of your map, part of the screen is not being update, so old pixels are being drawn.

I am not too clear on your problem, so my answer may be totally off.

A better way to fix it is to not let the player/user see past the edge of the map. This keeps you from having to clear the surface every frame. If you want a black area try using black tiles to surround the map...


Hope something here helps.

-Will