1.1 --- a/css-fonts/Fonts.html Thu May 30 16:25:34 2013 +0900
1.2 +++ b/css-fonts/Fonts.html Thu May 30 16:51:03 2013 +0900
1.3 @@ -1906,18 +1906,19 @@
1.4 class=property>font-variant</code>’</a> and <a
1.5 href="#propdef-font-weight" title="font-weight!!property">‘<code
1.6 class=property>font-weight</code>’</a> explicitly, so these properties
1.7 - receive their initial values (‘<code class=property>normal</code>’).
1.8 - Notice that the font family name "new century schoolbook", which contains
1.9 - spaces, is enclosed in quotes. The fourth rule sets the <a
1.10 - href="#propdef-font-weight" title="font-weight!!property">‘<code
1.11 + receive their initial values (‘<a href="#normal"><code
1.12 + class=property>normal</code></a>’). Notice that the font family name
1.13 + "new century schoolbook", which contains spaces, is enclosed in quotes.
1.14 + The fourth rule sets the <a href="#propdef-font-weight"
1.15 + title="font-weight!!property">‘<code
1.16 class=property>font-weight</code>’</a> to ‘<a href="#bold"><code
1.17 class=property>bold</code></a>’, the <a href="#propdef-font-style"
1.18 title="font-style!!property">‘<code
1.19 class=property>font-style</code>’</a> to ‘<a href="#italic"><code
1.20 class=property>italic</code></a>’, and implicitly sets <a
1.21 href="#propdef-font-variant" title="font-variant!!property">‘<code
1.22 - class=property>font-variant</code>’</a> to ‘<code
1.23 - class=property>normal</code>’.
1.24 + class=property>font-variant</code>’</a> to ‘<a href="#normal"><code
1.25 + class=property>normal</code></a>’.
1.26
1.27 <p> The fifth rule sets the <a href="#propdef-font-variant"
1.28 title="font-variant!!property">‘<code
1.29 @@ -1930,9 +1931,9 @@
1.30 class=property>line-height</code>’</a> (120% of the font size) and the
1.31 <a href="#propdef-font-family" title="font-family!!property">‘<code
1.32 class=property>font-family</code>’</a> (‘<a href="#fantasy"><code
1.33 - class=property>fantasy</code></a>’). It follows that the keyword
1.34 - ‘<code class=property>normal</code>’ applies to the two remaining
1.35 - properties: <a href="#propdef-font-style"
1.36 + class=property>fantasy</code></a>’). It follows that the keyword ‘<a
1.37 + href="#normal"><code class=property>normal</code></a>’ applies to the
1.38 + two remaining properties: <a href="#propdef-font-style"
1.39 title="font-style!!property">‘<code
1.40 class=property>font-style</code>’</a> and <a
1.41 href="#propdef-font-weight" title="font-weight!!property">‘<code
1.42 @@ -2923,14 +2924,13 @@
1.43 font selection. Values are identical to those defined for the
1.44 corresponding <a href="#propdef-font-variant"
1.45 title="font-variant!!property">‘<code
1.46 - class=property>font-variant</code>’</a> and <span
1.47 - title="font-feature-settings!!property">‘<a
1.48 - href="#propdef-font-feature-settings"><code
1.49 - class=property>font-feature-settings</code></a>’</span> properties
1.50 - defined below except that the value ‘<code
1.51 - class=property>inherit</code>’ is omitted. When multiple font feature
1.52 - descriptors or properties are used, the cumulative effect on text
1.53 - rendering is detailed in the section <a
1.54 + class=property>font-variant</code>’</a> and <a
1.55 + href="#propdef-font-feature-settings"
1.56 + title="font-feature-settings!!property">‘<code
1.57 + class=property>font-feature-settings</code>’</a> properties defined
1.58 + below except that the value ‘<code class=property>inherit</code>’ is
1.59 + omitted. When multiple font feature descriptors or properties are used,
1.60 + the cumulative effect on text rendering is detailed in the section <a
1.61 href="#font-feature-resolution">Font Feature Resolution</a> below. In
1.62 cases where specific values define synthesized fallback for certain <a
1.63 href="#propdef-font-variant" title="font-variant!!property">‘<code
1.64 @@ -3151,8 +3151,8 @@
1.65 exactly matches the width value the nearest width is used instead. If
1.66 the value of <a href="#propdef-font-stretch"
1.67 title="font-stretch!!property">‘<code
1.68 - class=property>font-stretch</code>’</a> is ‘<code
1.69 - class=property>normal</code>’ or one of the condensed values,
1.70 + class=property>font-stretch</code>’</a> is ‘<a href="#normal"><code
1.71 + class=property>normal</code></a>’ or one of the condensed values,
1.72 narrower width values are checked first, then wider values. If the
1.73 value of <a href="#propdef-font-stretch"
1.74 title="font-stretch!!property">‘<code
1.75 @@ -3169,15 +3169,16 @@
1.76 then oblique, then normal faces. If the value is ‘<a
1.77 href="#oblique"><code class=property>oblique</code></a>’, oblique
1.78 faces are checked first, then italic faces and then normal faces. If
1.79 - the value is ‘<code class=property>normal</code>’, normal faces are
1.80 - checked first, then oblique faces, then italic faces. Faces with other
1.81 - style values are excluded from the matching set. User agents are
1.82 - permitted to distinguish between italic and oblique faces within
1.83 - platform font families but this is not required, they may treat all
1.84 - italic or oblique faces as italic faces. However, within font families
1.85 - defined via <code>@font-face</code> rules, italic and oblique faces
1.86 - must be distinguished using the value of the <a
1.87 - href="#descdef-font-style" title="font-style!!descriptor">‘<code
1.88 + the value is ‘<a href="#normal"><code
1.89 + class=property>normal</code></a>’, normal faces are checked first,
1.90 + then oblique faces, then italic faces. Faces with other style values
1.91 + are excluded from the matching set. User agents are permitted to
1.92 + distinguish between italic and oblique faces within platform font
1.93 + families but this is not required, they may treat all italic or oblique
1.94 + faces as italic faces. However, within font families defined via
1.95 + <code>@font-face</code> rules, italic and oblique faces must be
1.96 + distinguished using the value of the <a href="#descdef-font-style"
1.97 + title="font-style!!descriptor">‘<code
1.98 class=property>font-style</code>’</a> descriptor.
1.99
1.100 <li><a href="#propdef-font-weight"
1.101 @@ -3578,12 +3579,12 @@
1.102 <p>When set to ‘<code class=property>auto</code>’, user agents can
1.103 determine whether to apply kerning or not based on a number of factors:
1.104 text size, script, or other factors that influence text processing speed.
1.105 - Authors who want proper kerning should use ‘<code
1.106 - class=property>normal</code>’ to explicitly enable kerning. Likewise,
1.107 - some authors may prefer to disable kerning in situations where performance
1.108 - is more important than precise appearance. However, in well-designed
1.109 - modern implementations the use of kerning generally does not have a large
1.110 - impact on text rendering speed.</p>
1.111 + Authors who want proper kerning should use ‘<a href="#normal"><code
1.112 + class=property>normal</code></a>’ to explicitly enable kerning.
1.113 + Likewise, some authors may prefer to disable kerning in situations where
1.114 + performance is more important than precise appearance. However, in
1.115 + well-designed modern implementations the use of kerning generally does not
1.116 + have a large impact on text rendering speed.</p>
1.117 <!-- prop: font-variant-ligatures -->
1.118
1.119 <h3 id=font-variant-ligatures-prop><span class=secno>6.4 </span>Ligatures:
1.120 @@ -3670,11 +3671,12 @@
1.121 <dt><dfn id=font-variant-ligatures-normal-value
1.122 title="normal!!font-variant-ligatures">normal</dfn>
1.123
1.124 - <dd>A value of ‘<code class=property>normal</code>’ specifies that
1.125 - common default features are enabled, <a
1.126 - href="#font-feature-resolution">as described in detail in the next
1.127 - section</a>. For OpenType fonts, common ligatures and contextual forms
1.128 - are on by default, discretionary and historical ligatures are not.
1.129 + <dd>A value of ‘<a href="#normal"><code
1.130 + class=property>normal</code></a>’ specifies that common default
1.131 + features are enabled, <a href="#font-feature-resolution">as described in
1.132 + detail in the next section</a>. For OpenType fonts, common ligatures and
1.133 + contextual forms are on by default, discretionary and historical
1.134 + ligatures are not.
1.135
1.136 <dt><dfn id=font-variant-ligatures-none-value
1.137 title="none!!font-variant-ligatures">none</dfn>
1.138 @@ -3767,8 +3769,8 @@
1.139 <tr>
1.140 <td>Value:
1.141
1.142 - <td><span title="normal!!font-variant-position">normal</span> |
1.143 - <span>sub</span> | <span>super</span>
1.144 + <td><span title="normal!!font-variant-position">normal</span> | <a
1.145 + href="#sub">sub</a> | <a href="#super">super</a>
1.146
1.147 <tr>
1.148 <td>Initial:
1.149 @@ -3819,21 +3821,32 @@
1.150 (bottom)
1.151 </div>
1.152
1.153 - <p>The values ‘<code class=property>sub</code>’ and ‘<code
1.154 - class=property>super</code>’ imply the appropriate variant glyph is
1.155 - displayed when available in the font (OpenType features: <span
1.156 - class=tag>subs, sups</span>). A value of ‘<code
1.157 - class=property>normal</code>’ specifies neither of these alternate
1.158 - glyphs are substituted.
1.159 + <p>Individual values have the following meanings:
1.160 +
1.161 + <dl>
1.162 + <dt><dfn id=normal>normal</dfn>
1.163 +
1.164 + <dd>None of the features listed below are enabled.
1.165 +
1.166 + <dt><dfn id=sub>sub</dfn>
1.167 +
1.168 + <dd>Enables display of subscript variants (OpenType feature: <span
1.169 + class=tag>subs</span>).
1.170 +
1.171 + <dt><dfn id=super>super</dfn>
1.172 +
1.173 + <dd>Enables display of superscript variants (OpenType feature: <span
1.174 + class=tag>sups</span>).
1.175 + </dl>
1.176
1.177 <p>Because of the semantic nature of subscripts and superscripts, when the
1.178 - value is either ‘<code class=property>sub</code>’ or ‘<code
1.179 - class=property>super</code>’ for a given contiguous run of text, if a
1.180 - variant glyph is not available for all the characters in the run,
1.181 - simulated glyphs must be synthesized for all characters using reduced
1.182 - forms of the glyphs that would be used without this feature applied. This
1.183 - is done to avoid a mixture of variant glyphs and synthesized ones that
1.184 - would not align correctly.
1.185 + value is either ‘<a href="#sub"><code class=property>sub</code></a>’
1.186 + or ‘<a href="#super"><code class=property>super</code></a>’ for a
1.187 + given contiguous run of text, if a variant glyph is not available for all
1.188 + the characters in the run, simulated glyphs must be synthesized for all
1.189 + characters using reduced forms of the glyphs that would be used without
1.190 + this feature applied. This is done to avoid a mixture of variant glyphs
1.191 + and synthesized ones that would not align correctly.
1.192
1.193 <p>In the case of OpenType fonts that lack subscript or superscript glyphs
1.194 for a given character, user agents must use the appropriate subscript and
1.195 @@ -3844,10 +3857,10 @@
1.196 and offset of the synthesized substitutes.
1.197
1.198 <p>In the past, user agents have used font-size and vertical-align to
1.199 - simulate subscripts and superscripts for the <span class=tag>sub</span>
1.200 - and <span class=tag>sup</span> elements. To allow a backwards compatible
1.201 - way of defining subscripts and superscripts, it is recommended that
1.202 - authors use conditional rules <a href="#CSS3-CONDITIONAL"
1.203 + simulate subscripts and superscripts for the <a class=tag
1.204 + href="#sub">sub</a> and <span class=tag>sup</span> elements. To allow a
1.205 + backwards compatible way of defining subscripts and superscripts, it is
1.206 + recommended that authors use conditional rules <a href="#CSS3-CONDITIONAL"
1.207 rel=biblioentry>[CSS3-CONDITIONAL]<!--{{CSS3-CONDITIONAL}}--></a> so that
1.208 older user agents will still render subscripts and superscripts via the
1.209 older mechanism.
1.210 @@ -3871,12 +3884,13 @@
1.211 <p>This property is not cumulative, applying it to subelements within a
1.212 subscript or superscript won't nest the placement of a subscript or
1.213 superscript glyph. Images contained within text runs where the value of
1.214 - this property is ‘<code class=property>sub</code>’ or ‘<code
1.215 - class=property>super</code>’ will be drawn just as they would if the
1.216 - value was ‘<code class=property>normal</code>’. Likewise, text
1.217 - decorations such as underlines or emphasis marks will render in the same
1.218 - position as they would for the default glyphs, since this property does
1.219 - not affect the baseline position.
1.220 + this property is ‘<a href="#sub"><code class=property>sub</code></a>’
1.221 + or ‘<a href="#super"><code class=property>super</code></a>’ will be
1.222 + drawn just as they would if the value was ‘<a href="#normal"><code
1.223 + class=property>normal</code></a>’. Likewise, text decorations such as
1.224 + underlines or emphasis marks will render in the same position as they
1.225 + would for the default glyphs, since this property does not affect the
1.226 + baseline position.
1.227
1.228 <p>Because of these limitations, font-variant-position is not recommended
1.229 for use in user agent stylesheets. Authors should use it in cases where
1.230 @@ -3884,8 +3898,8 @@
1.231 characters supported by the fonts specified.
1.232
1.233 <div class=example>
1.234 - <p>A typical user agent default style for the <span class=tag>sub</span>
1.235 - element:</p>
1.236 + <p>A typical user agent default style for the <a class=tag
1.237 + href="#sub">sub</a> element:</p>
1.238
1.239 <pre>sub {
1.240 vertical-align: sub;
1.241 @@ -5050,10 +5064,10 @@
1.242 class=property>font-variant</code>’</a> resets unspecified font-variant
1.243 subproperties to their initial values. It does not reset the values of
1.244 either ‘<a href="#propdef-font-language-override"><code
1.245 - class=property>font-language-override</code></a>’ or <span
1.246 - title="font-feature-settings!!property">‘<a
1.247 - href="#propdef-font-feature-settings"><code
1.248 - class=property>font-feature-settings</code></a>’</span>.
1.249 + class=property>font-language-override</code></a>’ or <a
1.250 + href="#propdef-font-feature-settings"
1.251 + title="font-feature-settings!!property">‘<code
1.252 + class=property>font-feature-settings</code>’</a>.
1.253
1.254 <h3 id=font-feature-settings-prop><span class=secno>6.12 </span>Low-level
1.255 font feature settings control: the <a
1.256 @@ -5064,7 +5078,8 @@
1.257 <tr>
1.258 <td>Name:
1.259
1.260 - <td><dfn id=propdef-font-feature-settings>font-feature-settings</dfn>
1.261 + <td><dfn id=propdef-font-feature-settings
1.262 + title="font-feature-settings!!property">font-feature-settings</dfn>
1.263
1.264 <tr>
1.265 <td>Value:
1.266 @@ -5335,13 +5350,13 @@
1.267 <p>As described in the previous section, font features can be enabled in a
1.268 variety of ways, either via the use of <a href="#propdef-font-variant"
1.269 title="font-variant!!property">‘<code
1.270 - class=property>font-variant</code>’</a> or <span
1.271 - title="font-feature-settings!!property">‘<a
1.272 - href="#propdef-font-feature-settings"><code
1.273 - class=property>font-feature-settings</code></a>’</span> in a style rule
1.274 - or within an <code>@font-face</code> rule. The resolution order for the
1.275 - union of these settings is defined below. Features defined via CSS
1.276 - properties are applied on top of layout engine default features.
1.277 + class=property>font-variant</code>’</a> or <a
1.278 + href="#propdef-font-feature-settings"
1.279 + title="font-feature-settings!!property">‘<code
1.280 + class=property>font-feature-settings</code>’</a> in a style rule or
1.281 + within an <code>@font-face</code> rule. The resolution order for the union
1.282 + of these settings is defined below. Features defined via CSS properties
1.283 + are applied on top of layout engine default features.
1.284
1.285 <h3 id=default-features><span class=secno>7.1 </span>Default features</h3>
1.286
1.287 @@ -5355,13 +5370,13 @@
1.288 mark, mkmk</span>). These features must always be enabled, even when the
1.289 value of the <a href="#propdef-font-variant"
1.290 title="font-variant!!property">‘<code
1.291 - class=property>font-variant</code>’</a> and <span
1.292 - title="font-feature-settings!!property">‘<a
1.293 - href="#propdef-font-feature-settings"><code
1.294 - class=property>font-feature-settings</code></a>’</span> properties is
1.295 - ‘<code class=property>normal</code>’. Individual features are only
1.296 - disabled when explicitly overridden by the author, as when ‘<a
1.297 - href="#propdef-font-variant-ligatures"><code
1.298 + class=property>font-variant</code>’</a> and <a
1.299 + href="#propdef-font-feature-settings"
1.300 + title="font-feature-settings!!property">‘<code
1.301 + class=property>font-feature-settings</code>’</a> properties is ‘<a
1.302 + href="#normal"><code class=property>normal</code></a>’. Individual
1.303 + features are only disabled when explicitly overridden by the author, as
1.304 + when ‘<a href="#propdef-font-variant-ligatures"><code
1.305 class=property>font-variant-ligatures</code></a>’ is set to ‘<a
1.306 href="#no-common-ligatures"><code
1.307 class=property>no-common-ligatures</code></a>’. For handling complex
1.308 @@ -5395,11 +5410,11 @@
1.309
1.310 <li>Feature settings determined by properties other than <a
1.311 href="#propdef-font-variant" title="font-variant!!property">‘<code
1.312 - class=property>font-variant</code>’</a> or <span
1.313 - title="font-feature-settings!!property">‘<a
1.314 - href="#propdef-font-feature-settings"><code
1.315 - class=property>font-feature-settings</code></a>’</span>. For example,
1.316 - setting a non-default value for the ‘<code
1.317 + class=property>font-variant</code>’</a> or <a
1.318 + href="#propdef-font-feature-settings"
1.319 + title="font-feature-settings!!property">‘<code
1.320 + class=property>font-feature-settings</code>’</a>. For example, setting
1.321 + a non-default value for the ‘<code
1.322 class=property>letter-spacing</code>’ property disables ligatures.
1.323
1.324 <li>Font features implied by the value of the <a
1.325 @@ -5409,10 +5424,10 @@
1.326 OpenType features (e.g. the ‘<a href="#propdef-font-kerning"><code
1.327 class=property>font-kerning</code></a>’ property).
1.328
1.329 - <li>Font features implied by the value of <span
1.330 - title="font-feature-settings!!property">‘<a
1.331 - href="#propdef-font-feature-settings"><code
1.332 - class=property>font-feature-settings</code></a>’</span> property.
1.333 + <li>Font features implied by the value of <a
1.334 + href="#propdef-font-feature-settings"
1.335 + title="font-feature-settings!!property">‘<code
1.336 + class=property>font-feature-settings</code>’</a> property.
1.337 </ol>
1.338
1.339 <p>This ordering allows authors to set up a general set of defaults for
1.340 @@ -5522,21 +5537,21 @@
1.341 </pre>
1.342
1.343 <p>Within spans of class "special", discretionary ligatures <em>will</em>
1.344 - be rendered. This is because both the <span
1.345 - title="font-feature-settings!!property">‘<a
1.346 - href="#propdef-font-feature-settings"><code
1.347 - class=property>font-feature-settings</code></a>’</span> and ‘<a
1.348 + be rendered. This is because both the <a
1.349 + href="#propdef-font-feature-settings"
1.350 + title="font-feature-settings!!property">‘<code
1.351 + class=property>font-feature-settings</code>’</a> and ‘<a
1.352 href="#propdef-font-variant-ligatures"><code
1.353 class=property>font-variant-ligatures</code></a>’ properties apply to
1.354 these spans. Although the ‘<code class=css>no-discretionary
1.355 ligatures</code>’ setting of ‘<a
1.356 href="#propdef-font-variant-ligatures"><code
1.357 class=property>font-variant-ligatures</code></a>’ effectively disables
1.358 - the OpenType <span class=tag>dlig</span> feature, because the <span
1.359 - title="font-feature-settings!!property">‘<a
1.360 - href="#propdef-font-feature-settings"><code
1.361 - class=property>font-feature-settings</code></a>’</span> is resolved
1.362 - after that, the ‘<code class=property>dlig</code>’ value reenables
1.363 + the OpenType <span class=tag>dlig</span> feature, because the <a
1.364 + href="#propdef-font-feature-settings"
1.365 + title="font-feature-settings!!property">‘<code
1.366 + class=property>font-feature-settings</code>’</a> is resolved after
1.367 + that, the ‘<code class=property>dlig</code>’ value reenables
1.368 discretionary ligatures.</p>
1.369 </div>
1.370
1.371 @@ -5598,6 +5613,11 @@
1.372 <dd>Serialized set of feature values.
1.373 </dl>
1.374
1.375 + <p class=issue>Should this be extended to make <a
1.376 + href="#cssfontfeaturevaluesrule"><code>CSSFontFeatureValuesRule</code></a>
1.377 + be a subclass of <code>CSSGroupingRule</code> with other CSSRule
1.378 + subclasses for each value definition block?
1.379 +
1.380 <h2 class=no-num id=platform-props-to-css>Appendix A: Mapping platform font
1.381 properties to CSS properties</h2>
1.382
1.383 @@ -6280,11 +6300,13 @@
1.384 property"><strong>3.1</strong></a>
1.385 </ul>
1.386
1.387 - <li>font-feature-settings, <a href="#propdef-font-feature-settings"
1.388 - title=font-feature-settings><strong>6.12</strong></a>
1.389 + <li>font-feature-settings
1.390 <ul>
1.391 <li>descriptor, <a href="#descdef-font-feature-settings"
1.392 title="font-feature-settings, descriptor"><strong>4.7</strong></a>
1.393 +
1.394 + <li>property, <a href="#propdef-font-feature-settings"
1.395 + title="font-feature-settings, property"><strong>6.12</strong></a>
1.396 </ul>
1.397
1.398 <li>font-kerning, <a href="#propdef-font-kerning"
1.399 @@ -6428,7 +6450,7 @@
1.400 title="none, font-variant-ligatures"><strong>6.4</strong></a>
1.401 </ul>
1.402
1.403 - <li>normal
1.404 + <li>normal, <a href="#normal" title=normal><strong>6.5</strong></a>
1.405 <ul>
1.406 <li>font-feature-settings, <a href="#font-feature-settings-normal-value"
1.407 title="normal, font-feature-settings"><strong>6.12</strong></a>
1.408 @@ -6531,6 +6553,10 @@
1.409 <li>stylistic, <a href="#stylistic"
1.410 title=stylistic><strong>6.8</strong></a>
1.411
1.412 + <li>sub, <a href="#sub" title=sub><strong>6.5</strong></a>
1.413 +
1.414 + <li>super, <a href="#super" title=super><strong>6.5</strong></a>
1.415 +
1.416 <li>swash, <a href="#swash" title=swash><strong>6.8</strong></a>
1.417
1.418 <li>tabular-nums, <a href="#tabular-nums"
1.419 @@ -6615,8 +6641,7 @@
1.420 <td>visual
1.421
1.422 <tr>
1.423 - <th><a class=property
1.424 - href="#propdef-font-feature-settings">font-feature-settings</a>
1.425 + <th><span class=property>font-feature-settings</span>
1.426
1.427 <td>normal | <feature-tag-value> #
1.428
1.429 @@ -6915,8 +6940,7 @@
1.430 <td>N/A
1.431
1.432 <tr>
1.433 - <th><a class=property
1.434 - href="#propdef-font-feature-settings">font-feature-settings</a>
1.435 + <th><span class=property>font-feature-settings</span>
1.436
1.437 <td>normal | <feature-tag-value> #
1.438
