I will open this article by stating that OpenType features are almost always GSUB (Glyph SUBstitution) or GPOS (Glyph POSitioning). The former table specifies features that substitute glyphs with other glyphs, usually in a 1:1 fashion, but not always. The latter table specifies features that alter the metrics of glyphs, or the inter-glyph metrics (aka kerning).
The focus of this particular article will be the 'vert' (Vertical Alternates) feature, which substitutes a glyph with the appropriate glyph for vertical writing, and is invoked when in vertical writing mode. In other words, it’s a GSUB feature, and one that needs to be invoked for proper vertical writing. Current implementations that support the 'vert' GSUB feature, which tend to be CJK fonts, substitute glyphs with their vertical forms on a 1:1 basis, though language-tagging may affect the outcome for Pan-CJK fonts, such as the Adobe-branded Source Han Sans and the Google-branded Noto Sans CJK, which support multiple languages.
This article is largely a test, but also serves to start the process of resurrecting L2/14-006 (Proposal to add standardized variation sequences for nine characters) for discussion at UTC #151 in early May.
Liang Hai (梁海) brought up this document for discussion at UTC #150 last week, and while I had an opportunity to have it accepted by the UTC, to be included in Unicode Version 10.0 (June, 2017), I decided that it was prudent to instead prepare a revised proposal that is more complete, mainly because L2/14-006 was submitted and discussed prior to the first release of the Adobe-branded Source Han Sans and Google-branded Noto Sans CJK Pan-CJK typeface families. This functionality was implemented in those typeface families via the 'locl' GSUB feature, which requires the text to be language-tagged. In other words, I learned a lot since L2/14-006 was discussed, and prefer to submit a more complete proposal, even if it means waiting for Unicode Version 11.0 (June, 2018).
As recorded on the very first page of Adobe Tech Note #5078, Adobe-Japan1-6 was released on 2004-03-05, and one of the glyphs that was added was CID+20958. According to the Adobe-Japan1-6 ordering file, its glyph name is freedial, and is assigned to the Dingbats FDArray element for the purpose of hinting. Of course, if you look for CID+20958 in Adobe Tech Note #5078, you can find it on the bottom of page 54, immediately to the right of CID+20957 that maps from U+26BD ⚽ SOCCER BALL, though it is blank. This is simply because Adobe does not have the rights to use NTT’s trademarked FreeDial mark. CID+20958 was included in Adobe-Japan1-6 for the benefit of font developers who do have the rights to use this mark, and can thus include the glyph in their fonts.
Unlike the first and second similarly-titled articles that I published last month, this article will focus on a minor efficiency for the combining jamo feature of the Adobe-branded Source Han Sans and Google-branded Noto Sans CJK Pan-CJK typeface families.
Again. I arrived on the afternoon of 2016-10-16.
This month provided to me yet another opportunity to visit Japan, the Land of the Rising Sun and my wife’s home country, thanks to IRG #47 (Ideographic Rapporteur Group Meeting #47) being hosted there. This trip was also the first time for me to visit an island of Japan other than Honshū (本州), specifically Shikoku (四国).
As a follow on to our seven-year-old May of 2009 article of the same name, several things have happened with the Adobe Clean family that have yet to be reported, and which have CJK implications. Hence the reason for spending my Sunday morning writing this article.
In the following year, 2010, I developed and deployed a Japanese version of Adobe Clean named Ryo Clean PlusN (りょう Clean PlusN in Japanese), and then in 2015, I developed and deployed a Pan-CJK version named Adobe Clean Han (Adobe Clean 黑体 in Simplified Chinese, Adobe Clean 黑體 in Traditional Chinese, Adobe Clean 角ゴシック in Japanese, and Adobe Clean 고딕 in Korean). These typeface families are Adobe corporate fonts that are meant to be used for product literature, for serving to Adobe websites, and for use by Adobe apps. They are not meant to be used by our customers, but I suspect that the readership of this blog may be interested in some of the development details. If this interests you, please continue reading.
Attention, students! Class is in session.
In my experience, the following two statements about standards are seemingly conflicting yet accurate:
- Standards are incredibly useful—and required—for product development.
- Standards cannot be completely trusted.
On one hand, developing products, such as typeface designs and their fonts, depends on standards.
On the other hand, standards themselves are developed by humans, meaning that they are prone to error, especially when they happen to be character set or glyph standards that include thousands or tens of thousands of representative glyphs.
August 2, 2016 is the official release date for Microsoft’s Windows 10 Anniversary Update (aka Redstone or RS1). Although I do not use Windows OS, I am jumping for joy, for the benefit of those who do use this modern and world-class OS.
Thanks to our friends at Microsoft, the DirectWrite that ships with the Windows 10 Anniversary Update supports OpenType/CFF Collections (aka OTCs), such as those deployed as part of the Adobe-branded Source Han Sans and Google-branded Noto Sans CJK open source projects, to include their all-inclusive “one font to rule them all” Super OTCs.
This will be a short, sweet, and to-the-point article. Sorry, no graphics nor photos.
When developing name-keyed fonts, glyph names matter. They matter a lot. When developing new fonts, the glyph names should either be explicitly listed in AGLFN (Adobe Glyph List For New Fonts) or derivable via the AGL Specification. Glyph names that adhere to AGLFN or the AGL Specification result in fonts with well-formed 'cmap' tables, which means that their glyphs will behave better in a broader range of environments. I cannot stress the importance of this.
CIDs (Character IDs), on the other hand, represent a completely different beast. If a font is genuinely CID-keyed, it means that there are absolutely no glyph names, regardless of whether the source font or fonts that were used to build the CID-keyed font were named-keyed. Once a font resource becomes CID-keyed, the original glyph names are literally jettisoned, and the only way in which to map Unicode values to glyphs is via the 'cmap' table, which is usually done using a UTF-32 CMap resource. In other words, when developing fonts that are intended to be deployed in a CID-keyed fashion, the source glyph names play absolutely no role in how such fonts are processed.
By ESO/José Francisco Salgado (josefrancisco.org) — ALMA antennas under the Milky Way
Five years ago, I wrote this article that described how to manage XUID arrays. Then last year, I wrote this article that suggested that XUID arrays are no longer necessary.
Anyway, there are two messages that are being conveyed in today’s article.
The first message is short and sweet, and meant to be strong: Adobe advises against including XUID arrays in all new and updated font-related resources, meaning fonts themselves and their corresponding CMap resources. The good news is that omitting the XUID array represents one less thing to worry about during font development.
The second message is longer, meant to provide some background information, and describes why Adobe advises against including XUID arrays in font-related resources.
One of my more popular open source fonts is Adobe Blank, and to a less extent the related Adobe Blank 2 because it uses a 'cmap' table format, Format 13, that is not broadly supported. Actually, Adobe Blank provides absolutely nothing, because it maps all 1,111,998 Unicode code points to a range of 2,048 non-spacing and non-marking glyphs, yet such a font is useful for particular scenarios, such as addressing the FOUT (Flash Of Unstyled Text) problem.
Allow me to introduce Adobe NotDef, which is modeled after Adobe Blank in that it covers all of Unicode and maps to a range of 2,048 glyphs, but differs in that the functional glyphs are spacing and marking. The original suggestion for Adobe NotDef came from Dave Crossland. The glyphs match the shape and advance width of the standard Adobe .notdef glyph that is invoked in environments that do not support font fallback when the selected font does not include a glyph for a particular character, and as Dave wrote, Adobe NotDef is useful for font fallback purposes in that it can be used to prevent the display of non-standard .notdef glyphs that may be present in some fonts in the font fallback chain.
It seems that I am on roll, having released two new open source fonts on GitHub within the past week. The previous—and brief—article that was about the LOCL Test OpenType/CFF font simply pointed to the repository. This article will be longer. I promise.
Inspired by the font that I prepared for and referenced in the previous article, I decided to launch a dedicated open source project for this useful test font, LOCL Test.
Although this article shares its title with an article from four years ago that was about the excitement associated with attending ATypI Hong Kong 2012, this particular one will focus on efforts to properly support Hong Kong SAR (aka HK or Hong Kong) in the Adobe-branded Source Han Sans and Google-branded Noto Sans CJK typeface families, but also in infrastructure, such as OSes and apps.
In other words, this article is not about traveling to Hong Kong, but rather about properly supporting Hong Kong in OSes, apps, and fonts.
A peculiar series of events that took place on April 1st (no joke) and 2nd of this year led to the discovery of what can only be described as somewhat of a revelation: A small number of CJK Compatibility Ideographs are necessary for China. This is important, because I made the following statement on page 168 of CJKV Information Processing, Second Edition:
One of the most powerful font-development tools available today is tx (Type eXchange), which is included in AFDKO (Adobe Font Development Kit for OpenType) and whose sources are available on GitHub. Despite its two-letter name, this command-line utility is packed with an enormous amount of features and functionality.
Four years ago I wrote a similar article, but it seems like a good time to revisit tx and the useful things that it can do. I still recommend that its “-u” and -h” command-line options be used to explore its vast capabilities.
—Humans make mistakes—
—Anything made by humans has the potential to include mistakes—
The most important things about mistakes are that 1) we recognize them, lest they propagate; 2) we learn from them; 3) we make an effort not to repeat them; and 4) we try to fix them, if possible.
Some mistakes are more easily fixed than others. Mistakes that cannot be fixed must be worked around.
With that said, an interesting event of historical significance occurred in June of 2000:
The first version of the IVD (Ideographic Variation Database) was issued on 2007-12-14, meaning over eight years ago, and there have been three subsequent revisions, the latest being issued on 2014-05-16. There are currently three registered IVD collections: Adobe-Japan1, Hanyo-Denshi, and Moji_Joho. A significant number of IVSes are shared between the latter two IVD collections, 9,685 to be exact. While I cannot speak to the latter two IVD collections, the Adobe-Japan1 one is supported by hundreds of OpenType fonts via the Format 14 (Unicode Variation Sequences) ‘cmap‘ subtable. Furthermore, the number of apps and OSes that support UVSes has reached critical mass.
With all that said, there is a rather substantial missing link in terms of IVD support infrastructure: the all-important input method.
The next UTC (Unicode Technical Committee) meeting, the 147th one, takes place during the week of May 9th, and will be hosted at the Adobe headquarters in San José, California. All members of the Unicode Consortium, especially voting members, are encouraged to attend.
Much of the thinking that I did with regard to this unregistered—but hopefully soon-to-be-registered—IVD (Ideographic Variation Database) collection was done while visiting my parents in South Dakota, with one of the highlights of that trip being a scenic drive through Badlands National Park.
First and foremost, please forget, or at least ignore, most everything that was written in the 2016-02-13 and 2016-02-20 articles (which makes one wonder why I am linking to them, but I digress). Far too many things have changed, and what I present in this article represents the IVD collection that I hope will be registered later this year.