Re: [csswg-drafts] [compositing-1][compositing-2]I am looking for a concrete example of the application of the simple alpha blending formula (#8211)

I suspect that the color spaces used for composition and blending has something to do with this. 

I did a quick test to check which color space is used for blending, by setting alpha to 1: 
https://codepen.io/johannesodland/pen/rNKbENO

It seems like both Safari and Chrome (with experimental web features flag turned on) on my mac does blending in a color space that yields similar results as if blending was done in `display-p3`. Adding a filter property like `filter: contrast(100%)` seems to force the blending to happen in srgb. 

It seems like the color space used for blending varies both depending on the UA, the output device and on properties like `filter`, yielding very different results. 

It would be helpful if the spec stated which color space blending and composition should be done in, or explicitly stated that it's undefined behaviour. Maybe authors could explicitly set which color space blending and composition should be done in through a property.


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Received on Monday, 12 December 2022 07:05:17 UTC