[css3-transitions] Make interpolation of integers round to nearest rather than floor, and make interpolation of integers and font weights round the halfway points towards positive infinity, to match SMIL.

Tue, 05 Feb 2013 09:42:17 -0700

author
L. David Baron <dbaron@dbaron.org>
date
Tue, 05 Feb 2013 09:42:17 -0700
changeset 7335
54cd45623730
parent 7334
53c820ccb51c
child 7336
aa7d9efd6fb3

[css3-transitions] Make interpolation of integers round to nearest rather than floor, and make interpolation of integers and font weights round the halfway points towards positive infinity, to match SMIL.

As resolved at Tucson face-to-face, 2013-02-04 11:59:32 -0700.

And with details of SMIL rounding behavior clarified in
http://lists.w3.org/Archives/Public/public-fx/2013JanMar/0034.html

css3-transitions/Overview.html file | annotate | diff | comparison | revisions
css3-transitions/Overview.src.html file | annotate | diff | comparison | revisions
     1.1 --- a/css3-transitions/Overview.html	Tue Feb 05 08:02:40 2013 -0700
     1.2 +++ b/css3-transitions/Overview.html	Tue Feb 05 09:42:17 2013 -0700
     1.3 @@ -10,11 +10,11 @@
     1.4     rel=dcterms.rights>
     1.5    <meta content="CSS Transitions" name=dcterms.title>
     1.6    <meta content=text name=dcterms.type>
     1.7 -  <meta content=2013-02-04 name=dcterms.issued>
     1.8 +  <meta content=2013-02-05 name=dcterms.issued>
     1.9    <meta content="http://dev.w3.org/csswg/css3-transitions/"
    1.10     name=dcterms.creator>
    1.11    <meta content=W3C name=dcterms.publisher>
    1.12 -  <meta content="http://www.w3.org/TR/2013/ED-css3-transitions-20130204/"
    1.13 +  <meta content="http://www.w3.org/TR/2013/ED-css3-transitions-20130205/"
    1.14     name=dcterms.identifier>
    1.15    <meta content="text/html; charset=utf-8" http-equiv=Content-Type>
    1.16    <link href="../default.css" rel=stylesheet type="text/css">
    1.17 @@ -38,15 +38,15 @@
    1.18  
    1.19     <h1>CSS Transitions</h1>
    1.20  
    1.21 -   <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 4 February
    1.22 +   <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 5 February
    1.23      2013</h2>
    1.24  
    1.25     <dl>
    1.26      <dt>This version:
    1.27  
    1.28 -    <dd> <a href="http://www.w3.org/TR/2013/ED-css3-transitions-20130204/">
    1.29 +    <dd> <a href="http://www.w3.org/TR/2013/ED-css3-transitions-20130205/">
    1.30       http://dev.w3.org/csswg/css3-transitions/</a>
    1.31 -     <!--http://www.w3.org/TR/2013/WD-css3-transitions-20130204/-->
    1.32 +     <!--http://www.w3.org/TR/2013/WD-css3-transitions-20130205/-->
    1.33  
    1.34      <dt>Latest version:
    1.35  
    1.36 @@ -1197,16 +1197,15 @@
    1.37  
    1.38     <li id=animtype-integer> <strong>integer</strong>: interpolated via
    1.39      discrete steps (whole numbers). The interpolation happens in real number
    1.40 -    space and is converted to an integer using <code>floor()</code>. <span
    1.41 -    class=issue> This floor behavior is inconsistent with SMIL Animation /
    1.42 -    SVG Animation. </span>
    1.43 +    space and is converted to an integer by rounding to the nearest integer,
    1.44 +    with values halfway between a pair of integers rounded towards positive
    1.45 +    infinity.
    1.46  
    1.47     <li id=animtype-font-weight> <strong>font weight</strong>: interpolated
    1.48      via discrete steps (multiples of 100). The interpolation happens in real
    1.49      number space and is converted to an integer by rounding to the nearest
    1.50 -    multiple of 100. <span class=issue> This round-to-nearest behavior is
    1.51 -    inconsistent with the floor behavior used for integer types, but probably
    1.52 -    should be consistent (one way or the other). </span>
    1.53 +    multiple of 100, with values halfway between multiples of 100 rounded
    1.54 +    towards positive infinity.
    1.55  
    1.56     <li id=animtype-number> <strong>number</strong>: interpolated as real
    1.57      (floating point) numbers.
     2.1 --- a/css3-transitions/Overview.src.html	Tue Feb 05 08:02:40 2013 -0700
     2.2 +++ b/css3-transitions/Overview.src.html	Tue Feb 05 09:42:17 2013 -0700
     2.3 @@ -1203,22 +1203,16 @@
     2.4          <li id="animtype-integer">
     2.5            <strong>integer</strong>: interpolated via discrete steps (whole
     2.6            numbers). The interpolation happens in real number space and is
     2.7 -          converted to an integer using <code>floor()</code>.
     2.8 -          <span class="issue">
     2.9 -            This floor behavior is inconsistent with SMIL Animation /
    2.10 -            SVG Animation.
    2.11 -          </span>
    2.12 +          converted to an integer by rounding to the nearest integer, with
    2.13 +          values halfway between a pair of integers rounded towards
    2.14 +          positive infinity.
    2.15          </li>
    2.16          <li id="animtype-font-weight">
    2.17            <strong>font weight</strong>: interpolated via discrete steps
    2.18            (multiples of 100). The interpolation happens in real number
    2.19            space and is converted to an integer by rounding to the
    2.20 -          nearest multiple of 100.
    2.21 -          <span class="issue">
    2.22 -            This round-to-nearest behavior is inconsistent with the
    2.23 -            floor behavior used for integer types, but probably should
    2.24 -            be consistent (one way or the other).
    2.25 -          </span>
    2.26 +          nearest multiple of 100, with values halfway between multiples
    2.27 +          of 100 rounded towards positive infinity.
    2.28          </li>
    2.29          <li id="animtype-number">
    2.30            <strong>number</strong>: interpolated as real (floating point)

mercurial