https://drafts.fxtf.org/compositing/#porterduffcompositingoperators_plus_lighter
The difference between lighter and plus-lighter is that plus-lighter caps to 1. However, I can't find any cases where lighter allows values to go above 1. Here's a couple of canvases that I'd expect to be different if values were allowed to go above 1 https://static-misc-3.glitch.me/composite-test/cap.html - in this case both the red channel and alpha channel would go above 1.
plus-lighter and plus-darker were added when the compositing-2 doc was added 10f0d3d. I can't find any discussion of these, but I guess there must have been. @cabanier, @dbaron do either of you know the history here?
I wonder if it would make sense to specify that all blend and compositing modes are clamped to 0-1. Then, remove plus-lighter from the spec, and rename plus-darker to darker and remove the clamping (since it'd be covered by the overall clamping.
https://drafts.fxtf.org/compositing/#porterduffcompositingoperators_plus_lighter
The difference between
lighterandplus-lighteris thatplus-lightercaps to 1. However, I can't find any cases wherelighterallows values to go above 1. Here's a couple of canvases that I'd expect to be different if values were allowed to go above 1 https://static-misc-3.glitch.me/composite-test/cap.html - in this case both the red channel and alpha channel would go above 1.plus-lighterandplus-darkerwere added when the compositing-2 doc was added 10f0d3d. I can't find any discussion of these, but I guess there must have been. @cabanier, @dbaron do either of you know the history here?I wonder if it would make sense to specify that all blend and compositing modes are clamped to 0-1. Then, remove
plus-lighterfrom the spec, and renameplus-darkertodarkerand remove the clamping (since it'd be covered by the overall clamping.