- From: Asmus Freytag <asmusf@ix.netcom.com>
- Date: Fri, 31 Oct 2008 14:30:07 -0700
- To: Steve Deach <sdeach@adobe.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>
On 10/31/2008 1:50 PM, Steve Deach wrote: > Exactly what I said under WSA/WSR. In some languages, this is used for > emphasis . My point was that because they conflict visually, when WSA is used, letterspacing should either not be permitted, should be contraction only, or should be kept below a threshold that prevents it from being confused with WSA. > > There are “country” differences, “language” differences, “script”, and > “wild hare” (random designer-/instance-specific) differences in > everything related to text composition (styling & layout). Agreed - it is helpful, though, to amass as much detailed input on known systematic differences in typical text usage conventions. I find that much more helpful than merely saying "watch out - something may depend on something". A./ > (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 “letter”, ”character”, vs. “glyph”; so read my > email using the traditional “fuzzy” 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 > <mailto:sdeach@adobe.com%3Esdeach@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 > <mailto:fantasai.lists@inkedblade.net%3Efantasai.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 21:30:56 UTC