Address feedback

Author: Kevin Ellis

web-animations-2/Overview.bs

@@ -153,39 +153,53 @@ Add:
 > used to calculate the [=intrinsic iteration duration=] for the target effect
 > of an animation that is associated with the timeline when the effect's
 > [=iteration duration=] is 'auto'. The value is computed such that the effect
-> fills the available time.  For a monotonic timeline, there is no upper bound
-> on current time, and [=timeline duration=] is unresolved. For a progress based
-> timeline, the [=timeline duration=] is 100%.
+> fills the available time. For a monotonic timeline, there is no upper bound
+> on current time, and [=timeline duration=] is unresolved. For a non-monotonic
+> (i.e. scroll) timeline, the duration has a fixed upper bound. In this
+> case, the timeline is a <dfn lt="progress-based timeline">progress-based
+> timeline</dfn>, and its [=timeline duration=] is 100%.
 
 <h3 id="animations">Animations</h3>
 
 Add:
 
-> Animation effects associated with a progress-based timeline require their
+> Animation effects associated with a [=progress-based timeline=] require their
 > timing properties to be converted to proportions. The procedure for converting
-> a <dfn lt="time-based animation to a proportional animation"></dnf> is as
+> a <dfn lt="time-based animation to a proportional animation"></dfn> is as
 > follows:
 >
 > 1.  If the [=iteration duration=] is auto, then perform the following steps.
+>         * Set [=start delay=] and [=end delay=] to 0, as it is not
+>           possible to mix time and proportions.
+>           <div class='note'>
+>           Future versions may allow these properties to be assigned
+>           percentages, at which point the delays are only to be ignored if
+>           their values are expressed as times and not as percentages.
+>           </div>
+>     Otherwise:
+>          1. Let <var>total time</var> be equal to |end time|
+>          1. Set [=start delay=] to be the result of evaluating
+>             <code>|specified start delay| / |total time| *
+>             |timeline duration|</code>.
+>          1. Set [=iteration duration=] to be the result of evaluating
+>             <code>|specified iteration duration| / |total time| *
+>             |timeline duration|</code>.
+>          1. Set [=end delay=] to be the result of evaluating
+>             <code>|specified end delay| / |total time| *
+>             |timeline duration|</code>.
 >
->     1.   Compute [=start delay=] and [=end delay=] to 0, as it is not possible
->          to mix time and proportions. Future versions may allow these properties
->          to be assigned percentages.
+> The procedure to <dfn>normalize specified timing</dfn> is as follows:
 >
-> 1.  Otherwise,
->
-> 1.  Let <var>total time</var> be equal to the result of evaluating
->     <code>|start delay| + |iteration count| * |iteration duration| +
->     |end delay|</code>.
->
-> 1.  Compute [=start delay=] to be the result of evaluating
->     <code>|start delay| / |total time| * |timeline duration|</code>.
->
-> 1.  Compute [=iteration duration=] to be the result of evaluating
->     <code>|iteration duration| / |total time| * |timeline duration|</code>.
->
-> 1.  Compute [=end delay=] to be the result of evaluating
->     <code>|end delay| / |total time| * |timeline duration|</code>.
+> If [=timeline duration=] is resolved:
+>     * Follow the procedure to convert a [=time-based animation to a
+>       proportional animation=]
+> Otherwise:
+>     1.   Set [=start delay=] = |specified start delay|
+>     1.   Set [=end delay=] = |specified end delay|
+>     1.   If |iteration duration| is auto:
+>              * Set [=iteration duration=] = |intrinsic iteration duration|
+>          Otherwise:
+>              * Set [=iteration duration=] = |specified iteration duration|
 
 <h4 id="setting-the-timeline">Setting the timeline of an animation</h4>
 
@@ -861,9 +875,6 @@ If the <a>inherited time</a> is <a>unresolved</a> then the local time
 is also <a>unresolved</a>.
 
 
-
-
-
 <h4 id="animation-effect-phases-and-states">Animation effect phases and
 states</h4>
 
@@ -1557,7 +1568,7 @@ number of <a>child effects</a> as follows.
         after calculating the <a>end time</a> of each <a>child
         effect</a> in the group. The <a>end time</a> may be
         expressed as a time or a percentage (in the case of a
-        progress based animation). In the event of mixed time and
+        [=progress-based animation=]). In the event of mixed time and
         percentage <a>end time</a>s, the largest time based value
         equates to 100% for the purpose of time scaling.
     2.  The <a>intrinsic iteration duration</a> is the result of
@@ -2113,40 +2124,34 @@ partial dictionary OptionalEffectTiming {
 :   <dfn>delay</dfn>
 ::  Update the description as:
 
-    > The <a>start delay</a> which represents the number of milliseconds from an
-    > <a>animation effect</a>'s <a lt="animation effect start time">start
-    > time</a> to the start of the <a>active interval</a>.
-    > If the <a lt="timeline duration">duration</dfn> of the Animation's
-    > <a>timeline</a> is a percentage, the start delay will be treated as the
-    > result of applying the procedure to convert a
-    > [=time-based animation to a proportional animation=].
+    > The <dfn>specified start delay</dfn> which represents the number of
+    > milliseconds from an <a>animation effect</a>'s
+    > <a lt="animation effect start time">start time</a> to the start of the
+    > <a>active interval</a>.
+    > The |specified start delay| is converted to a <a>start delay</a> following
+    > the [=normalize specified timing=] procedure.
 
 :   <dfn>endDelay</dfn>
 ::  Update the description as:
 
-    > The <a>end delay</a> which represents the number of milliseconds
+    > The <dfn>specified end delay</dfn> which represents the number of milliseconds
     > from the end of an <a>animation effect</a>'s <a>active interval</a>
     > until the <a lt='animation effect start time'>start time</a> of any
-    > <a>animation effect</a> that may
-    > follow, for example, in a <a>sequence effect</a>.
-    > If the <a lt="timeline duration">duration</dfn> of the Animation's
-    > <a>timeline</a> is a percentage, the end delay will be treated as the
-    > result of applying the procedure to convert a
-    > [=time-based animation to a proportional animation=].
-
-</div>
+    > <a>animation effect</a> that may follow, for example, in a <a>sequence
+    >  effect</a>. The |specified end delay| is converted to an <a>end delay</a>
+    > following the [=normalize specified timing=] procedure.
 
 :   <dfn>duration</dfn>
-::  Add:
-
-    > If the <a lt="timeline duration">duration</dfn> of the Animation's
-    > <a>timeline</a> is a percentage, a non <code>auto</code> duration will
-    > be treated as the result of applying the procedure to convert a
-    > [=time-based animation to a proportional animation=].
+::  Update the description as:
 
-    > The string value <code>auto</code> is used to indicate that the
+    > The <dfn>specified iteration duration</dfn> which is a real number greater
+    > than or equal to zero (including positive infinity) representing the
+    > time taken to complete a single iteration of the <a>animation
+    > effect</a>, or the string value <code>auto</code> to indicate that the
     > <a>iteration duration</a> reflects the animation effect's
-    > <a>intrinsic iteration duration</a>.
+    > <a>intrinsic iteration duration</a>.  The |specified iteration duration|
+    > is converted to an <a>iteration duration</a> following  the
+    > [=normalize specified timing=] procedure.
 
 :   <dfn dict-member for=EffectTiming>playbackRate</dfn>
 ::  The <a>animation effect</a>'s <a
@@ -2156,6 +2161,47 @@ partial dictionary OptionalEffectTiming {
 
 </div>
 
+<h3 id="updating-animationeffect-timing">Updating the timing of an
+AnimationEffect</h3>
+
+Replace:
+
+> Assign each member <a>present</a> in |input| to the corresponding timing
+>    property of |effect| as follows:
+>
+>    *   {{EffectTiming/delay}} &rarr; [=start delay=]
+>    *   {{EffectTiming/endDelay}} &rarr; [=end delay=]
+>    *   {{EffectTiming/fill}} &rarr; [=fill mode=]
+>    *   {{EffectTiming/iterationStart}} &rarr; [=iteration start=]
+>    *   {{EffectTiming/iterations}} &rarr; [=iteration count=]
+>    *   {{EffectTiming/duration}} &rarr; [=iteration duration=]
+>    *   {{EffectTiming/direction}} &rarr; [=playback direction=]
+>    *   {{EffectTiming/easing}} &rarr; [=timing function=]
+
+with:
+
+> Assign each member <a>present</a> in |input| to the corresponding timing
+>    property of |effect| as follows:
+>
+>    *   {{EffectTiming/delay}} &rarr; [=specified start delay=]
+>    *   {{EffectTiming/endDelay}} &rarr; [=specified end delay=]
+>    *   {{EffectTiming/fill}} &rarr; [=fill mode=]
+>    *   {{EffectTiming/iterationStart}} &rarr; [=iteration start=]
+>    *   {{EffectTiming/iterations}} &rarr; [=iteration count=]
+>    *   {{EffectTiming/duration}} &rarr; [=specified iteration duration=]
+>    *   {{EffectTiming/direction}} &rarr; [=playback direction=]
+>    *   {{EffectTiming/easing}} &rarr; [=timing function=]
+
+Add:
+
+>    Follow the procedure to [=normalize specified timing=].
+>
+>    <p class="note">
+>    Timing properties may also be updated due to a style change. Any change to
+>    a CSS animation property that affects timing requres rerunning the
+>    procedure to [=normalize specified timing=].
+>    </p>
+
 <h3 id="the-computedeffecttiming-dictionary">The
   <code>ComputedEffectTiming</code> dictionary</h3>