Summary:
this patch refactories a momentum scroll animator logics.
1. animation duration
animating runs within a one second now.
and if it needs more time to animate, it decrease intepolation progress by dividing some value.
current logic makes sense however, it is not easy to read to know how it works.
this patch modify current logic to calculate distance to move, and time to animate.
2. distance to move
we can apply simple physics something like mass of pan and friction of scroller itself.
but this patch apply just geometric seqeunce to calculate distance to go.
it's more easy to customize behavior of scroller than current sine graph based one.
3. accelerate logic
scroller sets 'extra_time' to accelerate a scroller for now.
but this patch modify logic not to use it.
however it uses current momenutum velocity as a bais of next momentum animating.
@feature
Reviewers: zmike, #reviewers, Hermet
Reviewed By: #reviewers, Hermet
Subscribers: Hermet, cedric, zmike
Tags: #efl, #do_not_merge
Differential Revision: https://phab.enlightenment.org/D6643