[css-fonts-4] Merge font-variant-east-asian from CSS Fonts 3 #1653

Author: svgeesus

css-fonts-4/Overview.bs

@@ -4582,6 +4582,112 @@ span.alt-U {
 <h3 id="font-variant-east-asian-prop">
 East Asian text rendering: the 'font-variant-east-asian' property</h3>
 
+
+<pre class="propdef">
+Name: font-variant-east-asian
+
+Value: 	normal | [ <<east-asian-variant-values>> || <<east-asian-width-values>> || ruby ]
+Initial: normal
+Applies to: all elements
+Inherited: yes
+Percentages: n/a
+Computed value: as specified
+Animation type: discrete
+</pre>
+
+
+<p>Allows control of glyph substitution and sizing in East Asian text.</p>
+
+<pre class="prod"><dfn id="east-asian-variant-values"><var>&lt;east-asian-variant-values&gt;</var></dfn> = [ <span>jis78</span> | <span>jis83</span> | <span>jis90</span> | <span>jis04</span> | <span>simplified</span> | <span>traditional</span> ]</pre>
+
+<pre class="prod"><dfn id="east-asian-width-values"><var>&lt;east-asian-width-values&gt;</var></dfn>   = [ <span>full-width</span> | <span>proportional-width</span> ]</pre>
+
+<p>Individual values have the following meanings:</p>
+
+
+<dl dfn-for="font-variant-east-asian" dfn-type="value">
+	<dt><dfn id="font-variant-east-asian-normal-value" title="normal!!font-variant-east-asian">normal</dfn>
+	<dd>None of the features listed below are enabled.</dd>
+
+	<dt><dfn>jis78</dfn>
+	<dd>Enables rendering of JIS78 forms
+	(OpenType feature: <span class="tag">jp78</span>).</dd>
+
+	<div class="featex"><img alt="JIS78 form example" src="images/jp78.png"></div>
+
+	<dt><dfn>jis83</dfn>
+	<dd>Enables rendering of JIS83 forms
+	(OpenType feature: <span class="tag">jp83</span>).</dd>
+
+	<dt><dfn>jis90</dfn>
+	<dd>Enables rendering of JIS90 forms
+	(OpenType feature: <span class="tag">jp90</span>).</dd>
+
+	<dt><dfn>jis04</dfn>
+	<dd>Enables rendering of JIS2004 forms
+	(OpenType feature: <span class="tag">jp04</span>).
+
+	<p>The various JIS variants reflect
+	the glyph forms defined in different Japanese national standards.
+	Fonts generally include glyphs
+	defined by the most recent national standard,
+	but it's sometimes necessary
+	to use older variants,
+	to match signage for example.</p>
+	</dd>
+
+	<dt><dfn>simplified</dfn>
+	<dd>Enables rendering of simplified forms
+	(OpenType feature: <span class="tag">smpl</span>).
+
+	<dt><dfn>traditional</dfn>
+	<dd>Enables rendering of traditional forms
+	(OpenType feature: <span class="tag">trad</span>).</dd>
+
+	<p>The 'simplified' and 'traditional' values
+	allow control over the glyph forms
+	for characters which have been simplified over time
+	but for which the older, traditional form
+	is still used in some contexts.
+	The exact set of characters and glyph forms
+	will vary to some degree
+	by the context for which a given font was designed.</p>
+	</dd>
+
+	<div class="featex"><img alt="tradtional form example" src="images/trad.png"></div>
+
+	<dt><dfn>full-width</dfn>
+	<dd>Enables rendering of full-width variants
+	(OpenType feature: <span class="tag">fwid</span>).</dd>
+
+	<dt><dfn>proportional-width</dfn>
+	<dd>Enables rendering of proportionally-spaced variants
+	(OpenType feature: <span class="tag">pwid</span>).</dd>
+
+	<div class="featex"><img alt="proportionally spaced Japanese example" src="images/pwid.png"></div>
+
+	<dt><dfn>ruby</dfn>
+	<dd>Enables display of ruby variant glyphs
+	(OpenType feature: <span class="tag">&#x0072;uby</span>).
+		Since ruby text is generally smaller
+		than the associated body text,
+		font designers can design special glyphs for use with ruby
+		that are more readable than scaled down versions
+		of the default glyphs.
+		Only glyph selection is affected,
+		there is no associated font scaling
+		or other change that affects line layout.
+
+		The red ruby text below
+		is shown with default glyphs (top)
+		and with ruby variant glyphs (bottom).
+		Note the slight difference
+		in stroke thickness.</dd>
+
+	<div class="featex"><img alt="ruby variant example" src="images/rubyshinkansen.png"></div>
+
+</dl>
+
 <h3 id="font-variant-prop">
 Overall shorthand for font rendering: the 'font-variant!!property' property</h3>