and I bet you can optimize your code ^^

oh yes !! I have a lot of thing who need to be optimised

well...
in screenshot, there is about 15 wall and remove wall always increase speed ; but if we remove this wall, we going to have a transparancy problem, because for remove the transparancy, I need to display each wall 

don't think so because the engine don't care if wall are perpendicular or diagonnal... 

wow, that's then a pretty cool engine

thank.
(but I think he can be improve a lot)

Great news! I must say it already looked awesome and pretty fast. But this is even better!

what is more fast : an ion assembly prog or a noshell assembly prog ?

They are the same, just a different header I think. Both is z80 asm, but Ion gives compatibility to other shells.

Glad to see you managed to get better speed. As for diagonal walls I was refering to how in your screenshots, your maps did not seem tilemapped. In Gemini, every wall are at 90° angles because the map data is like a matrix, where if a square is detected as solid, it displays a cubic wall block there. The fact your engine supports walls at different angles than 90°, 180°, 270° and 360° makes it even more amazing.

once again sorry for the time. 10% speed +

I will  realase soon an axe librairy with the functions I use for my 3d.

to do :
water,
floor,
more speed (if I can),
maybe light.

And when it's done I finish my demo.