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HI all,

Been tearing my hair out with this one and I've run out of things to try. I'm hoping it's just a silly bug, but it may be some feature of the hardware I don't understand?!?

I have a sprite that is scaled to 50% H&V (SCB2=0x077f). That bit works fine. The Y location is 0x1F0 (top of visible area) and size (sprite window size) is set to 14 in SCB3. That equates to 14*16=224 pixels.

However, the sprite doesn't look like it should; the latter half (approximately) is a repeat of the bottom line of tile index #15 as per the wiki docs (and on this matter I don't understand as there are 32 tiles in a sprite).

This isn't supposed to happen unless the shrunken size is smaller than the sprite window. In my case, shrunken size (50% of 512) is 256, whereas the window is 224 pixels. I should see 28 of my tiles.

If I try shrinking the window to 8, it works fine; the sprite is 8*16=128 pixels high and the tiles look good. Of course that equates to 16 tiles visible in the sprite. Setting size to 9 or higher gives the right window height, but nothing past the 16th tile...

I should add, if I set my height to 33 instead if 14, I can see 28 tiles properly, but that's not how I need it to work. It's like the latter 16 tiles can only be used if height == 33???

Can anyone shed any light on this please?

TIA,
Mark

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Check out page 5 of the Hypernoid thread. NeoHomeBrew has some great info regarding shrinking among other things. Its a great read!

topics/171575-hypernoid-for-neo-geo-mvs-work-in-progress/5

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Mega Shocked (./2) :
Check out page 5 of the Hypernoid thread. NeoHomeBrew has some great info regarding shrinking among other things. Its a great read!

Thanks for this! Exactly what I am experiencing and this answers my question! The solution proposed is what I was considering as well.

It's annoying as it means the 2nd 16 tiles of each sprite are useless if you're shrinking sprites unless you use the special 'wrapping' width of 33. Can't imagine why there would be this limitation in the hardware except it is an oversight (bug). Oh well, nothing can be done about it.