Edits to 4.4.1 The unaccumulated animation value of a path animation effect

--HG--
extra : rebase_source : a5cf8bcc55cfbc2d7124b0d11a7a3b7d3fed7fd4

Author: birtles

index.html

@@ -3753,44 +3753,48 @@ <h3>The unaccumulated animation value of a path animation effect</h3>
           value</a> is given by the following process:
           <ol>
             <li>
-              The <a>current element</a> and <a>element fraction</a>
-              are calculated by applying the process defined in 
-              <a href='#calculating-the-current-element-and-element-fraction' class='sectionRef'>
+              Determine the <a>current path element</a> and
+              <a>element fraction</a> for the given <a>time fraction</a> using
+              the procedure defined in 
+              <a href='#determining-the-current-element-and-element-fraction' class='sectionRef'>
               </a>.
-            </li>
             <li>
-              The <a>rotation value</a> is calculated by applying
-              the process defined in 
-              <a href='#calculating-the-rotation-value-of-the-current-element' class='sectionRef'></a>.
-            </li>
+              Calculate the <a>rotation value</a> using the process defined in 
+              <a href='#calculating-the-rotation-value-of-the-current-path-element' class='sectionRef'></a>.
             <li>
-              Let <a>translation value</a> is calculated by 
-              applying the process defined in
-              <a href='#calculating-the-translation-value-of-the-current-element' class='sectionRef'></a>.
-            </li>
+              Calculate the <a>translation value</a> using the process defined
+              in
+              <a href='#calculating-the-translation-value-of-the-current-path-element' class='sectionRef'></a>.
             <li>
               Let the <var>transform value</var> be the result of combining
               the <a>rotation value</a> and <a> translation value</a>
               by constructing a transform list consisting of the
               translation value followed by the rotation value.
-            </li>
             <li>
-              If the <a title='operation'>composition operation</a> is 
-              <a title='composition operation replace'>replace</a>, then the
-              <a>unaccumulated animation value</a> of the effect is the
-              <var>transform value</var>.
-            </li>
-            <li>
-              Otherwise, the <a>unaccumulated animation value</a> of the 
-              effect is the <a>underlying value</a> accumulated with the
-              <var>transform value</var> according to the process defined in
-              <a href='#the--transform-function--type' class='sectionRef'></a>.
-            </li>
+              The <a>unaccumulated animation value</a> of the <a>path animation
+              effect</a> depends on the value of its <a>composition
+              operation</a> as follows,
+              <dl class="switch">
+                <dt>If the <a>composition operation</a> of this <a>path
+                    animation effect</a> is <a title='composition operation
+                    replace'>replace</a>,</dt>
+                <dd>
+                  the <a>unaccumulated animation value</a> of the effect is
+                  <var>transform value</var>.
+                </dd>
+                <dt>Otherwise,</dt>
+                <dd>
+                  the <a>unaccumulated animation value</a> of the effect is the
+                  result of adding <var>transform value</var> to the
+                  <a>underlying value</a> according to the process defined in <a
+                  href='#the--transform-function--type' class='sectionRef'></a>.
+                </dd>
+              </dl>
           </ol>
         </p>
       </section>
       <section>
-        <h3>Calculating the current element and element fraction</h3>
+        <h3>Determining the current element and element fraction</h3>
         <div class='informative'>
           <p>
             Each element in the path (excluding moveto elements) is allocated
@@ -3805,54 +3809,58 @@ <h3>Calculating the current element and element fraction</h3>
           </p>
         </div>
         <p>
-          The <dfn>current element</dfn> and <dfn>element fraction</dfn> are
-          determined using the following procedure:
+          The <dfn>current path element</dfn> and <dfn>element fraction</dfn>
+          for a given <a>time fraction</a>, <var>progress</var>, are
+          determined by following the steps corresponding to the first matching
+          condition from below:
         </p>
         <dl class='switch'>
           <dt>
-            If the <a>current time fraction</a> is greater than or equal to 1
+            If <var>progress</var> is greater than or equal to 1,
           </dt>
           <dd>
-            the <var>current element</var> is the last element in the path,
+            the <var>current path element</var> is the last element in the
+            <a>path</a>,
             and the <var>element fraction</var> is 1.
           </dd>
           <dt>
-            If the <a>current time fraction</a> is less than 0
+            If <var>progress</var> is less than 0,
           </dt>
           <dd>
-            the <var>current element</var> is the first element in the path,
+            the <var>current path element</var> is the first element in the
+            path,
             and the <var>element fraction</var> is 0.
           </dd>
           <dt>
-            Otherwise
+            Otherwise,
           </dt>
           <dd>
             <ol>
               <li>
                 Let <var>effective element list</var> be a clone of the
-                <a>element list</a> with all moveto elements removed.
+                list of <a>path elements</a> with all moveto elements removed.
               </li>
               <li>
-                Let <var>time index</var> be the <a>current time fraction</a>
-                multiplied by the number of elements in the <var>effective
+                Let <var>time index</var> be <var>progress</var>
+                multiplied by the number of elements in <var>effective
                 element list</var>.
               </li>
               <li>
                 Let <var>current element</var> be the element in the
-                <a>effective element list</a> at the index given by
-                <code>floor(<var>time index</var>)</code>.
+                <var>effective element list</var> at the index given by
+                <code>floor(<var>progress</var>)</code>.
               </li>
               <li>
                 Let <var>element fraction</var> be the value given by
-                <code><var>time index</var> - floor(<var>time index</var>)
+                <code><var>progress</var> - floor(<var>progress</var>)
                 </code>.
               </li>
             </ol>
           </dd>
         </dl>
       </section>
       <section>
-        <h3>Calculating the rotation value of the current element</h3>
+        <h3>Calculating the rotation value of the current path element</h3>
         <p>
           The <dfn>rotation value</dfn> of the <a>current element</a> is the
           rotation produced by that element at the <a>element fraction</a>.
@@ -3925,9 +3933,9 @@ <h3>Calculating the rotation value of the current element</h3>
         </p>
       </section>
       <section>
-        <h3>Calculating the translation value of the current element</h3>
+        <h3>Calculating the translation value of the current path element</h3>
         <p>
-          The <dfn>translation value</dfn> of the <a>current element</a> is
+          The <dfn>translation value</dfn> of the <a>current path element</a> is
           determined using the following process:
         </p>
         <ol>