# HG changeset patch # User fantasai # Date 1374017392 25200 # Node ID 9a46d52c3a862bc265c060a30b955de9096a0f2f # Parent e957d5e490dfb00dae58d6dd085cb3cfdcb8754c [css-writing-modes] Require hwid/twid/qwid for OT implementations of TCY compression when they are available for all characters in the composition diff -r e957d5e490df -r 9a46d52c3a86 css-writing-modes/Overview.html --- a/css-writing-modes/Overview.html Tue Jul 16 16:24:23 2013 -0700 +++ b/css-writing-modes/Overview.html Tue Jul 16 16:29:52 2013 -0700 @@ -10,7 +10,7 @@ rel=dcterms.rights> - + @@ -46,7 +46,7 @@

CSS Writing Modes Module Level 3

-

Editor's Draft 10 July 2013

+

Editor's Draft 16 July 2013

This version: @@ -54,7 +54,7 @@
http://dev.w3.org/csswg/css3-writing-modes/
Latest version: @@ -3438,10 +3438,15 @@

The UA must ensure that the combined advance width of the composition fits within 1em by compressing the combined text if necessary. (This does not necessarily mean that the glyphs will fit within 1em, as some glyphs - are designed to draw outside their geometric boundaries.) The UA may use - any means to do so, including substituting half-width, third-width, and/or - quarter-width glyphs provided by the font or using other font features - designed to compress text horizontally. + are designed to draw outside their geometric boundaries.) OpenType + implementations must use width-specific variants + (hwid/twid/qwid) to compress text in + cases where those variants are available for all characters in the composition. Otherwise, the + UA may use any means to compress the text, including substituting + half-width, third-width, and/or quarter-width glyphs provided by the font, + using other font features designed to compress text horizontally, scaling + the text geometrically, or any combination thereof.

For example, a simple OpenType-based implementation might compress the diff -r e957d5e490df -r 9a46d52c3a86 css-writing-modes/Overview.src.html --- a/css-writing-modes/Overview.src.html Tue Jul 16 16:24:23 2013 -0700 +++ b/css-writing-modes/Overview.src.html Tue Jul 16 16:29:52 2013 -0700 @@ -2563,9 +2563,15 @@ fits within 1em by compressing the combined text if necessary. (This does not necessarily mean that the glyphs will fit within 1em, as some glyphs are designed to draw outside their geometric boundaries.) - The UA may use any means to do so, - including substituting half-width, third-width, and/or quarter-width glyphs provided by the font - or using other font features designed to compress text horizontally. + OpenType implementations must use width-specific variants + (hwid/twid/qwid) + to compress text + in cases where those variants are available for all characters in the composition. + Otherwise, the UA may use any means to compress the text, + including substituting half-width, third-width, and/or quarter-width glyphs provided by the font, + using other font features designed to compress text horizontally, + scaling the text geometrically, + or any combination thereof.

For example, a simple OpenType-based implementation might compress the text as follows: