[ttml10se] clarify meaning of #length* features (D.1.42 to D.1.50)
authorGlenn Adams <glenn@skynav.com>
Tue, 07 May 2013 17:50:55 -0600
changeset 360 e07a3abea1ea
parent 359 a985d825a4fa
child 361 420c6d83ebef
[ttml10se] clarify meaning of #length* features (D.1.42 to D.1.50)
ttml10/spec/ttaf1-dfxp.xml
--- a/ttml10/spec/ttaf1-dfxp.xml	Thu May 02 22:33:43 2013 -0700
+++ b/ttml10/spec/ttaf1-dfxp.xml	Tue May 07 17:50:55 2013 -0600
@@ -2170,7 +2170,7 @@
 matches the cell size.</p>
 </note>
 <note role="elaboration">
-<p>Except when indicated otherwise, when a <loc href="#style-value-length">&lt;length&gt;</loc> expressed in
+<p>Except where indicated otherwise, when a <loc href="#style-value-length">&lt;length&gt;</loc> expressed in
 cells expresses a dimension parallel to the inline or block progression dimension,
 the cell's dimension in the inline or block progression dimension applies, respectively.
 For example, if padding (on all four edges) is specified as 0.1c, the cell resolution
@@ -2429,7 +2429,7 @@
 choice was incorrect, and that the most common default is <code>discontinuous</code>.</p>
 </note>
 <note role="recommendation">
-<p>Due to lack of industry consensus on the utility and interpretation of 
+<p>Due to lack of industry consensus on the utility and interpretation of the
 <code>continuous</code> marker mode, authors are advised to avoid its use. Furthermore, the
 <att>ttp:markerMode</att> is being considered for deprecation in the next revision of this
 specification.</p>
@@ -2753,8 +2753,7 @@
 which content regions are located and presented. If no <att>tts:extent</att>
 attribute is specified, then the spatial extent of the root container region is
 considered to be determined by the external authoring or presentation
-context. The root container origin is determined by the external
-authoring (or presentation) context.</p>
+context. The root container origin is determined by the <emph>Document Processing Context</emph>.</p>
 <note>
 <p>If an author desires to signal the (storage or image) aspect ratio of the root container
 region without specifying its resolution, then this may be accomplished by using metadata specified
@@ -3023,7 +3022,7 @@
 be considered to be an <emph>anonymous span</emph> for the purpose of
 applying style properties that apply to <el>span</el> elements.</p>
 <note role="elaboration"><p>The presentation semantics of TTML effectively
-imply that a <el>p</el> element constitutes a line break. In particular,
+implies that a <el>p</el> element constitutes a line break. In particular,
 it is associated with a block-stacking constraint both before the first
 generated line area and after the last generated line area. See
 <specref ref="semantics-region-layout-step-2"/> for further details.</p>
@@ -9478,6 +9477,17 @@
 feature if it implements presentation semantic support for all defined values of
 the <loc href="#style-value-length">&lt;length&gt;</loc> style value
 expression.</p>
+<note role="clarification">
+<p>Support for <code>#length</code> is intended to imply support for the following features:
+<code>#length-integer</code>,
+<code>#length-real</code>,
+<code>#length-positive</code>,
+<code>#length-negative</code>,
+<code>#length-cell</code>,
+<code>#length-em</code>,
+<code>#length-percentage</code>, and
+<code>#length-pixel</code>.</p>
+</note>
 </div3>
 <div3 id="feature-length-cell">
 <head>#length-cell</head>
@@ -9491,6 +9501,13 @@
 for scalar values of the <loc
 href="#style-value-length">&lt;length&gt;</loc> style value expression
 that use <code>c</code> (cell) units.</p>
+<note role="clarification">
+<p>Support for <code>#length-cell</code> does not, by itself, imply support for
+<code>#length-integer</code>,
+<code>#length-real</code>,
+<code>#length-positive</code>, or
+<code>#length-negative</code> features.</p>
+</note>
 </div3>
 <div3 id="feature-length-em">
 <head>#length-em</head>
@@ -9504,6 +9521,13 @@
 for scalar values of the <loc
 href="#style-value-length">&lt;length&gt;</loc> style value expression
 that use <code>em</code> (EM) units.</p>
+<note role="clarification">
+<p>Support for <code>#length-em</code> does not, by itself, imply support for
+<code>#length-integer</code>,
+<code>#length-real</code>,
+<code>#length-positive</code>, or
+<code>#length-negative</code> features.</p>
+</note>
 </div3>
 <div3 id="feature-length-integer">
 <head>#length-integer</head>
@@ -9518,6 +9542,11 @@
 href="#style-value-length">&lt;length&gt;</loc> style value
 expression.
 </p>
+<note role="clarification">
+<p>Support for <code>#length-positive</code> does not, by itself, imply support for
+<code>#length-negative</code> or
+<code>#length-positive</code> features.</p>
+</note>
 </div3>
 <div3 id="feature-length-negative">
 <head>#length-negative</head>
@@ -9532,6 +9561,11 @@
 href="#style-value-length">&lt;length&gt;</loc> style value
 expression.
 </p>
+<note role="clarification">
+<p>Support for <code>#length-positive</code> does not, by itself, imply support for
+<code>#length-integer</code> or
+<code>#length-real</code> features.</p>
+</note>
 </div3>
 <div3 id="feature-length-percentage">
 <head>#length-percentage</head>
@@ -9546,6 +9580,13 @@
 href="#style-value-length">&lt;length&gt;</loc> style value
 expression.
 </p>
+<note role="clarification">
+<p>Support for <code>#length-percentage</code> does not, by itself, imply support for
+<code>#length-integer</code>,
+<code>#length-real</code>,
+<code>#length-positive</code>, or
+<code>#length-negative</code> features.</p>
+</note>
 </div3>
 <div3 id="feature-length-pixel">
 <head>#length-pixel</head>
@@ -9559,6 +9600,13 @@
 for scalar values of the <loc
 href="#style-value-length">&lt;length&gt;</loc> style value expression
 that use <code>px</code> (pixel) units.</p>
+<note role="clarification">
+<p>Support for <code>#length-pixel</code> does not, by itself, imply support for
+<code>#length-integer</code>,
+<code>#length-real</code>,
+<code>#length-positive</code>, or
+<code>#length-negative</code> features.</p>
+</note>
 </div3>
 <div3 id="feature-length-positive">
 <head>#length-positive</head>
@@ -9573,6 +9621,20 @@
 href="#style-value-length">&lt;length&gt;</loc> style value
 expression.
 </p>
+<note role="clarification">
+<p>Support for <code>#length-positive</code> is intended to imply support for zero valued
+<loc
+href="#style-value-length">&lt;length&gt;</loc> style value
+expressions.</p>
+</note>
+<note role="clarification">
+<p>Support for <code>#length-positive</code> does not, by itself, imply support for
+<code>#length-integer</code> or
+<code>#length-real</code> features; however, as a concession to existing practice,
+a profile that requires support for <code>#length-positive</code> but does not require
+support for <code>#length-integer</code> or <code>#length-real</code> is recommended
+to be considered as additionally requiring support for <code>#length-real</code>.</p>
+</note>
 </div3>
 <div3 id="feature-length-real">
 <head>#length-real</head>
@@ -9587,6 +9649,17 @@
 href="#style-value-length">&lt;length&gt;</loc> style value
 expression.
 </p>
+<note role="clarification">
+<p>Support for <code>#length-real</code> is intended to imply support for
+integer valued <loc
+href="#style-value-length">&lt;length&gt;</loc> style value
+expressions as well as real valued expressions.</p>
+</note>
+<note role="clarification">
+<p>Support for <code>#length-real</code> does not, by itself, imply support for
+<code>#length-negative</code> or
+<code>#length-positive</code> features.</p>
+</note>
 </div3>
 <div3 id="feature-lineBreak-uax14">
 <head>#lineBreak-uax14</head>