- From: Zack Weinberg <zackw@panix.com>
- Date: Sun, 8 Mar 2015 14:06:26 -0400
- To: www-style list <www-style@w3.org>
The current level of css-compositing specifies four blend modes that replace one or two of the hue, saturation, and luminosity components of the bottom color with those from the top color, but there are six possible such modes; two are missing. Mode Hue Saturation Luminosity ---------- ------ ---------- ---------- hue top bottom bottom saturation bottom top bottom luminosity bottom bottom top color top top bottom ??? top bottom top ??? bottom top top I don't have a use case for replacing hue and luminosity, but I do for saturation and luminosity: suppose you want to define a background pattern which consists of variations on one hue, and reuse the same pattern in more than one place with different base hues. Not all such variations can be achieved by varying only saturation or luminosity. In particular, making a light color _appear_ darker often requires both reducing its luminosity and _increasing_ its saturation. I'd suggest 'shade' for the name of the mode that replaces saturation and luminosity. I don't have a name for the other one but I think it should exist for completeness. zw
Received on Sunday, 8 March 2015 18:06:49 UTC