Vertical shrinking & garbage

[tatsunootoshigo]

Vertical shrinking & garbage

[city41]

This thread might help

When the window height is taller than your tiles, the garbage is coming from the next tiles in the sprite's tile map.

So let's say you specify 4 tiles for a sprite, give it a height of 4, and then shrink it in half. The four tiles you defined will take up 32px of the window, and the next 32px will be determined by tiles 5, 6, 7 and 8. Those tiles will just be whatever happens to be in VRAM. A lot of the times, leftover VRAM is 0xff, as it seems the Neo initializes VRAM to that. But it can be anything just depends on what has happened to VRAM in your game.

Things get much weirder when you start working with sprites taller than 16. That neo-geo thread goes into that a bit.

[city41]

This is from that neo-geo thread. Here I wrote 0 to all VRAM memory addresses before starting the test, and I defined the first tile in my C ROM to be that square pattern. So in my case the garbage tiles became that square pattern due to VRAM having 0 for those tiles.

[tatsunootoshigo]

Thats exactly my issue!
My garbage pattern comes from CROM tile #0.
Thanks a lot for pointing it out!
Cheers

Oh and I will be interested to see the results of your ala AOF scaling 👍

[tatsunootoshigo]

Thats awesome you are making a game!
Cant wait to see that :)

[dciabrin]

Obviously I'm late at that, but I'm glad y'all sorted out!

Thanks for the links, this is very informative and hopefully it will be useful in the future.

[city41]

Awesome! Glad that fixed it.

I gave up on my scaling idea. My game no longer zooms in/out unfortunately. The problem is the Neo can only scale in 16 increments, and so no matter what my scaling was super janky. I think if you want to do zoom in/out like SNK fighters did, you are mostly limited to a 32 tile tall level that has one major axis, basically fighting game stages. Unless there is a really awesome trick I don't know about. Ah well, it's an old system :)

[tatsunootoshigo]

Its all good no worries. Thank you for your work!