Dunno if it's a bug but i wanna ask @dink:
About Popeye driver....
On the real Popeye hardware, sprite colour 0 is not transparent with respect to overlapping sprites. It's only transparent with respect to the
background graphics. When two sprites overlap in Popeye, the sprite with the highest priority completely overdraws the sprite underlying it, including
the transparent area (pixel with colour value 0). The result is that instead of proper sprite prioritzing, overlapping sprites are overdrawn like chunky blocks.
In FBNeo the overlap of the sprites has transparent background, in mame not. And it seems the correct visualization is in mame.
FBNeo:
Mame:
Surely FBNeo visualization is surely much better but not pcb-accurate... or not?
In this real hardware video you can see behavior at minute 1:43
https://youtu.be/ZT6d8nca3MI