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Miscellaneous Forums => Scripting and Reverse Engineering => Topic started by: Micky on 2010-06-01 07:27:31

Title: Blending on PSX
Post by: Micky on 2010-06-01 07:27:31

I already have Halkun's PSX doc and did some Google search, but there are two bits still unclear:
- There is a special case for colour 0x0000. If it is marked as transparent, does it take part as "black" in the blend operation, or is it like an alpha-kill that doesn't write the pixel into the frame buffer at all?
- What are the rules for untextured polys? Do they just get blended as a whole if alpha blend is enabled?

Title: Re: Blending on PSX
Post by: Gemini on 2010-06-01 10:03:57

1) Pure black is always invisible, no matter the attributes of a primitive.
2) Simple polygons follow exactly the same rules as other draw primitives with tpage flags indicating transparency is enabled.

Title: Re: Blending on PSX
Post by: Micky on 2010-06-01 20:42:42

Thank you, that's a massive improvement. I wasn't totally sure about the 0x0000 thing, but it makes a significant difference.