Sprite Priority Overlay Bug

• Example

SP4CEBAR 2024-07-08 11:00

This scene has the following elements:

1. The horizontal lines are characters with priority
2. The vertical lines are a sprite with priority that draws on top of the horizontal lines
3. The blocks are a sprite without priority but with a lower sprite number than the sprite that has priority

When all three overlap, the background cells with priority will draw on top of everything

NX's graphics overlaying system likely only considers the sprite with the lowest sprite number, which would result in this bug.

Timo 2024-07-08 11:21

It's not a bug, it's a feature! :)
Yes, actually LowRes NX simulates the behavior of the Mega Drive. It doesn't seem to make a lot of sense, it was just how the video chips worked. And it was used for masking effects in some games! You can cut out parts of sprites using this "bug".

I think this program shows the same effect:

Prios.nx | Open in app

2024-07-08 11:21

SP4CEBAR 2024-07-08 11:25

Interesting!