[css-ruby] Check in some commented-out notes on bidi reordering, to review and write up properly later.

Author: fantasai

css-ruby/Overview.src.html

@@ -642,13 +642,15 @@ <h3 id="ruby-bidi">
 	<p class="issue">The easiest thing would be to treat each <i>ruby base</i> as an embedding of its 'direction'.
 	But this means that implicit bidi reordering is scoped to within a single base.
 
+<!--
+
 	<p>The Unicode bidirectional algorithm orders logically-stored text for visual presentation
 	when characters from scripts of opposing directionalities are mixed
 	within a single paragraph.
 	(See [[CSS3-WRITING-MODES]] for a more in-depth discussion of bidirectional text in CSS.)
 	Bidi reordering of ruby-annotation pairs is controlled by the ordering of the base text, as follows:
 
-<h4 id="bidi-B">Proposal B</h4>
+<h4 id="bidi-B">Proposal A</h4>
 
 	<p class="note">This proposal is simpler, but will require more frequent tagging of mixed-directionality content.
 
@@ -659,14 +661,17 @@ <h4 id="bidi-B">Proposal B</h4>
 	to their respective <i>ruby bases</i>,
 	a few restrictions are imposed:
 	<ul>
-		<li>The contents of a <i>ruby base</i> must remain contiguous.
-			To this end, the contents of 
+		<li>The contents of a <i>ruby base</i> or <i>ruby annotation</i> must remain contiguous.
+			To this end, the contents of each <i>ruby base</i> and <i>ruby annotation</i> are treated as if within a <i>bidi isolation</i>.
+		<li>For the purpose of ordering <i>ruby bases</i> within a <i>ruby container</i>,
+			each <i>ruby base</i> is treated as a strong character of its specified 'direction'.
+			(<i>Ruby annotations</i> are positioned with respect to their <i>bases</i>,
+			so are affected by reordering, but do not themselves participate in reordering.)
 		<li>All <i>bases</i> spanned by a single <i>annotation</i> must remain contiguous.
+			To this end, the embedding level of all bases spanned by a spanning <i>annotation</i>
+			is increased by two prior to reordering.
 	</ul>
 
-		<li>When a <i>ruby base</i> is moved due to bidi reordering,
-			all of its corresponding <i>ruby annotations</i> must follow.
-
 <h4 id="bidi-B">Proposal B</h4>
 
 	<p class="note">This preserves some aspects of implicit bidi.
@@ -681,7 +686,6 @@ <h4 id="bidi-B">Proposal B</h4>
 	to their respective <i>ruby bases</i>,
 	a few restrictions are imposed:
 	<ul>
-		<li>
 		<li>The contents of a <i>ruby base</i> must remain contiguous.
 		<li>All <i>bases</i> spanned by a single <i>annotation</i> must remain contiguous.
 	</ul>
@@ -692,13 +696,6 @@ <h4 id="bidi-B">Proposal B</h4>
 	(or the embedding level assigned to the isolation, if the <i>ruby base</i> is <i>bidi-isolated</i>)
 	is further increased by two.
 
-	<p>
-
-<!--
-	<p>
-	Each <i>ruby base</i> within a <i>ruby container</i> is treated
-	as a strong character with the directionality of its 'direction' property.
-	When resolving the embedding levels of 
 -->
 
 <h3 id="line-height">
@@ -1407,7 +1404,8 @@ <h3 id="default-ua-ruby" class="no-num">
 <!--	-->rb   { display: ruby-base; white-space: nowrap; }
 <!--	-->rt   { display: ruby-text; white-space: nowrap; font-size: 50%; }
 <!--	-->rbc  { display: ruby-base-container; }
-<!--	-->rtc  { display: ruby-text-container; }</pre>
+<!--	-->rtc  { display: ruby-text-container; }
+<!--	-->ruby, rb, rt, rbc, rtc { unicode-bidi: isolate; }</pre>
 
 	<p>Additional rules for UAs supporting the relevant features of [[CSS3-TEXT-DECOR]] and [[CSS3-FONTS]]:
 	<pre>rt { font-variant-east-asian: ruby; text-emphasis: none; }</pre>