D16448: [libkwineffects] Port AnimationEffect to TimeLine

zzag added inline comments.

INLINE COMMENTS

> davidedmundson wrote in kwinanimationeffect.cpp:308
> This is different.  Though IMHO arguably more correct - please can you check.
> 
> Lets say I'm animating opacity 0 to 1 for 10 seconds.
> 
> After 5 seconds through I decide I want to make it 15 seconds, so I call retarget(id, 1, 10)
> 
> With the old code I'm 1/3 of the way through a 15s animation that goes from 0.5 -> 1   which means my current value is 0.666
> 
> With the new code I'm at the start of a 10s animation from 0.5 to 1. Which means my current value is 0.5

That's why I posted video of the Morphing Popups. :-)

IMHO, the behavior of the old code is incorrect. If I retarget animation from the current position to a new position, then there should not be any jumps. Animation should go from the current position to the new target position.

> With the new code I'm at the start of a 10s animation from 0.5 to 1. Which means my current value is 0.5

This is the correct behavior, imho. The opacity should go from 0.5 to 1.0, otherwise animation won't be smooth.

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D16448

To: zzag, #kwin
Cc: davidedmundson, abetts, kwin, mkulinski, ragreen, jackyalcine, Pitel, iodelay, bwowk, ZrenBot, lesliezhai, ali-mohamed, hardening, jensreuterberg, sebas, apol, mart