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This article is not entirely accurate. VDP1 is perfectly capable of rendering half-transparent sprites on top of each other. It was somewhat problematic for 3D games as the drawing algorithm resulted in some overdraw depending on how the quad was warped and there was a pretty big performance penalty, but for 2D games neither seems like an issue. The problem is when you want to use VDP2 for more than just displaying the frame buffer that VDP1 writes to. VDP1 only supports half-transparent mode when drawing in 15-bit color, but VDP2 only supports per-pixel translucency in indexed mode. So you can either have sprites be translucent with respect to each other or translucent with respect to VDP2 background layers, but not both.

The best workaround is to just use VDP1 for everything. I'm not sure why you wouldn't in a cross-platform 2D game given that it would be most analogous to what you needed to do on the Playstation. It didn't have any dedicated hardware for backgrounds so you needed to use textured triangles for everything.



Sounds like you worked on the Saturn back in the day? I'm just a fan of the console. I believe what you are referring to is addressed in Low Score Boy's video where he shows transparency between sprites but not VDP2 layers [1].

[1] https://www.youtube.com/watch?v=f_OchOV_WDg&t=6m52s


> Sounds like you worked on the Saturn back in the day?

Heh, I was only 11 when the Saturn came out. I've been involved in the Sega homebrew/emulation community for a long time though. Mostly focused on the 16-bit stuff, but I've toyed with the idea of working with the Saturn and read some documentation.




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