- From: Steve Deach <sdeach@adobe.com>
- Date: Fri, 31 Oct 2008 13:50:26 -0700
- To: Asmus Freytag <asmusf@ix.netcom.com>
- CC: Martin Duerst <duerst@it.aoyama.ac.jp>, "KOBAYASHI Tatsuo(FAMILY Given)" <tlk@kobysh.com>, fantasai <fantasai.lists@inkedblade.net>, WWW International <www-international@w3.org>, Paul Nelson <paulnel@winse.microsoft.com>, Michel Suignard <michel@unicode.org>
- Message-ID: <APACMAILAX7Ur5qWn3G00000d92@apacmail.pac.adobe.com>
Exactly what I said under WSA/WSR. In some languages, this is used for emphasis. There are ³country² differences, ³language² differences, ³script², and ³wild hare² (random designer-/instance-specific) differences in everything related to text composition (styling & layout). (However, 20+ years ago, no one was very careful about those distinctions; so I think I used [or intended to use] script/language in the message below to indicate the distinctions were fuzzy. The same comment applies to ³letter², ²character², vs. ³glyph²; so read my email using the traditional ³fuzzy² definitions vs. the current ones.) On 2008.10.31 12:46, "Asmus Freytag" <asmusf@ix.netcom.com> wrote: > An aside on "letterspacing": > > The use of this is language dependent! (Not just script dependent). > > In German, it the use of increased letterspace for e m p h a s i s > (like this) has traditionally been used with both Fraktur and roman > style fonts. The practice is apparently still alive and well, because > you find it use in electronic forums on the web - a rather modern use of > text. Letterspacing, unless kept below very tight thresholds, is > therefore c o n f u s i n g to readers expecting it to denote emphasis. > > Other Northern European languages may have similar issues, but I don't > have first hand knowledge of current practices. > > A./ > > On 10/31/2008 12:04 PM, Steve Deach wrote: >> Every few years this issues comes back up. Unfortunately, I can't find the >> rather long treatise I wrote the last time. >> >> In general, I agree with Martin, that one should use styling properties as a >> replacement for most of the "layout" uses of space characters (just as one >> should use tables in place of most uses of tabs). That said, I would like to >> briefly summarize the traditional (pre-DTP) handling of spaces and spacing, >> and comment on "what I believe" to be the correct handling. >> >> Second, I agree that the handling of letterspacing and wordspacing varies by >> script and in some cases usage within a script, due to historic/cultural >> differences in preferences/aesthetics, or specific readability requirements >> for the usage, and the aesthetic desires of the designer. >> >> >> >> This is a partial reconstruction of my prior emails on this topic. >> >> My terminology: >> "Spacing" an adjustment to the distance between 2 glyphs/characters. >> "Space" a character which has a width but no visible inked representation. >> "Letterspacing" an adjustment to the intercharacter spacing used for >> line justification. [This definintion differs from CSS's.] >> "Wordspacing" an adjustment to the width of an interword space, also >> used for line justification. >> "WhiteSpaceAddition/Reduction (WSA/WSR)" a uniform adjustment to >> intercharacter spacing that is applied for design purposes or >> emphasis. [This corresponds most closely to the CSS-2.0 definition >> of letterspacing. Most DTP applications call this "Tracking".] >> "Tracking" and adjustment to intercharacter spacing which varies by >> fontsize/pointsize that is used to increase readability when >> optical sizing is not provided by the font. [This traditional >> definition differs from that used in most DTP applications.] >> >> >> In setting Roman text: >> Letterspacing is not generally applied to Arabic (and other >> connected-letter scripts/languages, nor to connected letter ("script") faces >> in Roman-derivative scripts) >> Letterspacing is not generally applied to ideographic or similar >> monospaced scripts, nor to monospaced text in Roman-derivative environments. >> Traditional applications varied widely in the algorithms used for >> weighting how much of a justification adjustment was applied to wordspacing >> vs to letterspacing. Most modern systems treat them as linear-proportional. >> Traditional publishing applications were also at odds over whether the >> letterspacing adjustment AND the wordspacing adjustment should both be >> applied to the space/NbSp characters, but most modern systems apply both. >> The Unicode NbSp (u+00a0) character should be treated the same as the >> Unicode Space (u+0020). [In traditional publishing systems, these are >> variable width in justified lines and fixed width in "aligned", tabular, and >> math uses. However, some traditional publishing systems treat all space >> characters prior to the first non-space in a line as fixed width.] >> The FigureSpace (u+2007), and PunctuationSpace (u+2008) are treated the >> same way the corresponding figure '0' and punctuation period/full stop would >> be treated in the current layout context (justified vs >> aligned/tabular/math). >> Some traditional publishing systems had a quad-space and a >> justifying-space (sometimes called a 'spaceband' rather than 'justifying >> space'). Use of the quad-space within justified text would force the fixed >> nominal-width of the normal interword space character, disabling >> justification adjustments. This encoding concept has no analogy in Unicode. >> All other space characters {EM-space, EN, EM-quad, EN-quad, 3/EM, 4/EM, >> 6/EM, Thin, & Hair} are treated as fixed width and are not adjusted for >> letterspacing nor for wordspacing. (Traditional publishing systems used >> these for alignment/layout and did not generally apply tracking nor WSA/WSR >> either.) >> >> Ideographic languages/scripts do not generally use wordspacing or >> letterspacing to adjust justification; instead they typically use rules akin >> to those described in JIS-4051 (latest). This algorithm involves trimming >> some characters to half-width, then reinserting 1/2 & 1/4-em spacing >> adjustments at selected points within the line. >> Under these rules, Ideographic-space is treated as an ideographic letter >> [generally fixed-fullwidth, but has some specific additional rules], and not >> as a roman variable space. >> It should be a styling option of whether Roman text embedded in >> Ideographic text is set using Roman algorithms or Japanese/Chinese >> algorithms. Depending on the publication and the publisher, Roman text may >> be set proportional (using Roman or Asian justification rules), halfwidth, >> or fullwidth. (Similarly, they may choose Asian or Roman word-breaking and >> hyphenation rules.) >> >> I have not covered any specifics in the handling of ancient languages that >> are generally only of academic interest; nor the handling of Arabic and >> Arabic-dervative scripts; nor Indic; nor certain other language-specific >> differences (such as adjustments to spaces on sentence boundaries in some >> uses, nor after certain punctuation characters in French and other >> languages). >> >> I have also not addressed the handling of "hanging punctuation" and "hanging >> spaces"; though there are different philosophies/algorithm for handling >> these across the various script families. >> >> -- S.Deach >> sdeach@adobe.com >> >> >> >> >> >> >> On 2008.10.31 02:43, "Martin Duerst" <duerst@it.aoyama.ac.jp> wrote: >> >> >>> Hello everybody, >>> >>> Just a bit of a wider background on full-width space. >>> >>> It should be remembered that in contrast to the usual space (U+0020), >>> which occurs all over the place in texts in most languages, the >>> full-width space doesn't occur AT ALL in typical Japanese (or Chinese) >>> texts. That's why it also barely occurs in the document written >>> by the Japanese Layout TF, as well as in JIS 4501. >>> >>> The full-width space is more used for layout than inside the actual >>> text. In this respect, what CSS should do is to mainly look at >>> Japanese typography and try to come up with properties that allow >>> to get rid of full-width spaces in the text, rather than spending >>> too much time on how to treat full-width space. >>> >>> As a typical example, I guess lead typesetting and also definitely >>> simple approaches to typesetting on the computer, such as plain >>> text or old "word-processors" (which were not very much above >>> plain text in their capabilities) use a full-width space to produce >>> a start-of-paragraph indent (which is very often one full-width >>> character wide). CSS should make sure that there is no need to >>> insert such full-width spaces, because an exact one-full-width- >>> character start-of-paragraph indent can be produced with an >>> appropriate CSS property setting. >>> >>> Another typical use of full-width space was to center text, >>> and to insert spaces into text for headlines (to a large >>> extent a crude backup for increasing text size, which wasn't >>> possible when technology was limited to one or two bit-mapped >>> font sizes. In this case, inter-character spacing property(/ies) >>> may be important for 'facsimile' layouts, but with modern >>> technology, such layout isn't much used anymore anyway. >>> >>> Regards, Martin. >>> >>> At 18:31 08/10/30, KOBAYASHI Tatsuo(FAMILY Given) wrote: >>> >>>> Hi, Erica, >>>> >>>> In Japanese Layout, "spacing issue" is one of the most difficult issues to >>>> treat. >>>> We intended to carefully eliminate concrete character name like IDEOGRAPHIC >>>> SPACE(U+3000) and SPACE(U+0002) from our requirement. Rather introduced >>>> three >>>> different types of abstract space concepts as follows: >>>> >>>> inter character space: usulal 1/2 em fixed space. >>>> conditional space: 1/2 em fixed space to be inserted or pulled off between >>>> characters and punctuation marks. >>>> adjustable space: variable width space, behaves like usual western variable >>>> space. >>>> >>>> Note that, usual Japanese punctuation marks have 1/2 em width in our >>>> requirement, even if the character name might include "FULLWIDTH ~~~" >>>> >>>> Anyway, the disition how to deal with these spaces in CSS recommendation >>>> and >>>> in actual implementation is up to your side:-) >>>> >>>> regards, >>>> Tatsuo >>>> >>>> 2008/10/30 Steve Deach <<mailto:sdeach@adobe.com>sdeach@adobe.com> >>>> >>>>> No, in my personal opinion, it should not. >>>>> The 2 differences between normal space/nbsp vs ideographic space are: >>>>> 1.) The normal width is different, and >>>>> 2.) The normal space/nbsp is treated as justifying >>>>> (adjusted by both wordspacing and letterspacing), >>>>> whereas the Ideographic space should only be adjusted by >>>>> letterspacing (only if ideographic letters are also so adjusted). >>>>> >>>>> However, I will re-confirm this with our CJK experts, before claiming this >>>>> is an Adobe opinion. >>>>> >>>>> >>>>> >>>>> On 2008.10.29 15:13, "fantasai" >>>>> <<mailto:fantasai.lists@inkedblade.net>fantasai.lists@inkedblade.net> >>>>> wrote: >>>>> >>>>> >>>>>> Hello, >>>>>> >>>>>> The CSSWG would like to know whether the IDEOGRAPHIC SPACE U+3000 >>>>>> should be affected by 'word-spacing', and whether it should be >>>>>> treated as a space during spaces-only justification or treated as >>>>>> a typical ideographic punctuation character. >>>>>> >>>>>> ~fantasai >>>>>> >>>>>> >>>>> >>>> >>>> -- >>>> KOBAYASHI Tatsuo >>>> Scholex Co., Ltd. Yokohama >>>> JUSTSYSTEM Digital Culture Research Center >>>> >>> #-#-# Martin J. Du"rst, Assoc. Professor, Aoyama Gakuin University >>> #-#-# http://www.sw.it.aoyama.ac.jp mailto:duerst@it.aoyama.ac.jp >>> >>> >> >> >> >> >> >
Received on Friday, 31 October 2008 20:51:43 UTC