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Re: timing functions in reversed animations

From: Garrett Smith <dhtmlkitchen@gmail.com>
Date: Fri, 15 Mar 2013 10:15:46 -0700
Message-ID: <CABZUbM3kHXBrt93oonwMwZnbVjec9jo3tt=C9m0TY4Z8M2a+xg@mail.gmail.com>
To: Brian Birtles <bbirtles@mozilla.com>
Cc: www-style@w3.org
On 2/20/13, Brian Birtles <bbirtles@mozilla.com> wrote:
> (2013/02/21 3:09), Dean Jackson wrote:
>> This was discussed at the call today:
>> http://lists.w3.org/Archives/Public/www-style/2011Mar/0744.html
>>
>> What was intended in the original spec proposal, and what WebKit
>> implements is actually pretty simple.
>>
>> For any animation/transition, you calculate a "progress" based on
>> (currentTime - startTime) / duration,
>> where startTime is the time the current iteration began, producing a value
>> between 0 and 1. You use this
>> value directly when animating forwards. When you are in the reverse cycle,
>> you use (1 - progress). This
>> value is then input into the style calculation.
>>
>> Effectively this means a reverse phase is a mirror image of the forwards
>> phase, as Simon said.
>
> That sounds like what we've specified for Web Animations as per this
> diagram:
>
>
> https://dvcs.w3.org/hg/FXTF/raw-file/default/web-anim/img/time-calculations.svg

That diagram needs a key!

What's "inherited timeline"?
 "Active time" -- is that Elapsed Time?
 "Scaled Active Time"?
 "Iteration time"
 "Directed time"

My problem solution has timeLimit for the animation's running time and
a rationalValue of how far along the timeline. How do you apply such
concepts?
-- 
Garrett
Twitter: @xkit
personx.tumblr.com
Received on Friday, 15 March 2013 17:16:14 GMT

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