Improved Unicode Support in FontLab Studio 5
Contents
1. Layout fea tures registry for details 13 4 Designing Glyphs 4 1 Glyph Window The Glyph Window is the place where the designer creates the letterforms This is where you see the glyph outline built from nodes sometimes called points as well as straight and curve segments between them hints glyph and font metrics guide lines A number of different toolbars and panels are available to the user the Tools and Paint toolbars hold various tools for creating editing and modifying outlines the meter toolbar displays the position of the currently selected node and the cursor po sition in relation to the 0 0 point and optionally in relation to a special reference point that the designer can put anywhere within the drawing space The Transformation panel available from the Window Panels submenu allows for precise geometric transformation scaling shifting slanting rotating When you re doing free transformations by just dragging parts of the outline with your mouse the Transformation will detect if you re scaling slanting or rotating and will automati cally display the numerical value of what you are currently doing The Editing Layers panel allows the designer to edit different elements of the glyph its outline the metrics the left and the right sidebearing the guidelines the hints and the mask that is a second outline layer placed in the background In the past type designers used many different tools Ik2. Studio has the ability to create and mod ify CID keyed PostScript and OpenType fonts A general introduction for using Font Lab Studio and other FontLab applications can be found in the book Learn FontLab Fast 3 and in the application s reference guide 4 Whenever we speak of a font in this paper a TrueType or OpenType font is assumed This paper will not discuss the OpenType font format in detail For technical details regarding the OpenType format please consult the OpenType specification 5 and other cited reference works One terminological remark needs to be made upfront The TrueType font format 6 was defined by Apple Computer and further extended by Microsoft Corporation Subsequently Adobe Systems contributed some extensions to the format already extended by Microsoft and the format was renamed to OpenType In the same time Apple Computer developed their own extensions independently retaining the name TrueType This paper uses the term OpenType to collectively refer to all fonts that are compatible with either the OpenType specification or the TrueType specifica 27th Internationalization and Unicode Conference 2 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 tion When referring only to the OpenType fonts with PostScript outlines stored in the CFF table we use the term OpenType PS When referring only to the TrueType fonts and OpenType fonts with TrueType outlines stored in the glyf table we u
3. The new glyph template font Andale Mono provided by Monotype Imaging covers the entire Unicode 3 2 character range and provides small scale thumbnails for characters that are not included in the current font When adding glyphs to your font you can use the thumbnail images from the glyph template as guidance Note that the provided thumbnail templates do not necessarily reflect all the typographical finesse of the respective characters they should be used as orientation only Of course as with most elements of the user interface this glyph template font can be customized the user can specify a different font to be displayed as the glyph template font FontLab Studio 5 has a new handy tool that allows the designer to quickly create a set of accented characters Select certain Unicode range such as Latin Extended A right click on any glyph and choose Select Encoding from the context menu and fi nally choose Glyph Create Glyphs if Empty A set of stub accented characters will be automatically created from elements that are present in the font FontLab Studio 5 comes with a large set of recipes on how accented characters should be built which composites to use and how to place them The user can modify and extend these recipes 27th Internationalization and Unicode Conference 15 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 Fonli ih Shuck fl ud x Eile Edit View Contour Glyph T
4. glyphs according to a so called encoding Encoding is a list of glyph names ordered in a particular sequence The term encoding is a bit misleading when developing a Unicode font the encoding selected in the Names mode does not represent the actual encoding of the font The Names mode is used to help the designer navigate through the glyph repertoire of a font When a certain encoding is selected the glyphs covered by that encoding are presented at the top of the window highlighted in yellow color The designer can easily create custom encodings and use them to switch between different views of the entire glyph repertoire of the font 27th Internationalization and Unicode Conference 4 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 Kg Font Myriad Condensed DA XAdobe SystemsXMyriadCondensedA v b zh wn UN Em IER d ABCD Pe eee eee ee ee eee ees Eee eee ee anunngnmman is 20 mee x m pz e 2 9 a ING oM uz 38 az wet 0024 sa ss eo amp ez ez w 20 mh 1 A 0 P Q R m 5 T 51 d e ann L m Tod Figure 2 Index mode of the Font Window A font is just a sequence of enumerated glyphs each glyph has a name and often a Unicode codepoint assigned Eth eth Lslash Islash Scaren scaron Yacute yacute HT LF Thorn thom sata TUTTI DLE BEER MMURE space jexclam g uotedlinumber dollar percentlampers quatezi pa
5. panel The variant glyphs should different names constructed according to guidelines outlined below An appropriate OpenType Layout feature 8 should allow the font user to produce the particular variant on the screen the use of an application and operating system that supports OpenType Layout features is a prerequisite To allow the user access to the variant glyphs in applications that support Unicode but do not support OpenType Layout features each of the glyphs may have a PUA Private Use Area Unicode codepoint assigned but they may also remain unencoded A glyph in a font can represent the default form of more than one character Here several cases need to be differentiated First several characters can have identical appearance so the same glyph could serve as the default representation of each of those characters In such case the Unicode codepoints of all the represented characters are entered in the Unicode field of the Properties panel separated by spaces For example the glyph with the cip 66 with the shape of the letter a could represent two characters U 0061 LATIN SMALL LETTER A and U 0430 CYRILLIC SMALL LETTER A In this case the Unicode field in the Prop erties panel would have the entry 0061 0430 The glyph name is a Generally how ever assigning multiple Unicode codepoints to one glyph is not recommended in particular when creating OpenType PS fonts The designer should rather duplicate the glyphs assigni
6. plays fonts using the system font mechanism so on Windows XP Service Pack 2 with complex script support enabled in Control Panel Regional and Language Options Lan guages the user can test OpenType layout features such as ligatures or contextual alternates The Font Info dialog that acts as the command central of the font has several new handy features With the Copy feature the user can quickly copy family names copy right strings licensing information metric and encoding information from one font to all the other fonts in a family A new Verify names button in the Names and Copyright section will check for common name problems like too long names or PostScript font 27th Internationalization and Unicode Conference 19 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 names with two hyphens The Embedding settings have been updated to reflect the recent OpenType specification The algorithm that automatically checks codepages and Unicode ranges included in the font has been improved A new cmap editor has been added so OpenType and TrueType fonts with very complex encodings can be created 8 Closing remarks This paper only covers a small subset of issues regarding the process of creation of Unicode compatible fonts A detailed discussion on specific aspects would have not fit in the scope We shall however mention some of the most important points and limitations FontLab Studio 5 does not offer a full bidirec
7. turn of the millennium brought about OpenType a significant initiative that unified Post Script TrueType and Unicode and added a sophisticated system of advanced typo graphic features The year 2005 marks an unusual anniversary 30 years of digital font technology The development of the digital font technology makes it easier for end users to do text processing typesetting and layout without sacrificing the typographic quality and logical correctness of the text But nothing gets lost in Nature using fonts is getting easier but developing them is more complex Apart from just drawing letters a type designer needs to know about encoding hinting layout features and various parame ters that need to be set inside of a font FontLab Studio is an application that assists the font developer in all that a digital font editor for Mac and Windows that allows the designer to create professional level fonts from start to end In 2005 Fontlab Ltd releases FontLab Studio 5 a new ver sion of the application This new release of FontLab Studio 5 brings some major im provements that should facilitate the creation of fonts that conform to the Unicode Standard In this paper we will only discuss the issues of creating Unicode compatible fonts in the TrueType and OpenType format It should be noted however that FontLab Stu dio also has the ability to create and modify Type 1 and Multiple Master fonts and legacy encoded fonts In addition AsiaFont
8. 328 s5 03 udA b e 321 2 pz asp uonoeg aj ispjooraz pz d y p ayoeqg pz jews uo1o1uu jews euer NI Burua 32eduuo2 pue sasse h seu og Sasse 37243039 Bojeip aaueqsisse buius ayy e30p3sissy Bojeip ogu Burussy pjo eua Buiudax 3Ip3 anjen uje3492 e mojag sared Bulusay e3s sp 03 s2u amp 3sur4oj GUILUAY Jasay 7 ss j34He3ssn s403 SIleg PPY tc begdiun 3 34 un tc H bz use s bz ysels Tayo OW ZIUOAYIUAS A g R 433jse A 7 ooz lt gt bo 3UBte bo 6 z xR O amp G 2 E 2 2 2 2 2 2 m 5 5 5 5 5 5 5 5 5 5 u gt gt gt gt F V w ubi g any B Buiu485 03n amp 3504 49 3 M ony uuaa AY 4 samu iyi sixy woyog 40 doz ye Wi LJ 003 9g suondo seijunf aul s3usu A manad N Sc EWS peporun ews y Lporun a gt epayzu sbueys aajn poa ANSES pomi lays Gz ews gzpoun ews z grun aplysmoys asn d am T puz ii S il T aM PE lui m me pBJ E We Pu BAZU daH opui soor udA A4noqu05 ma 3p3 ag LU suesau SIJAA 81A984d o1pn3s qe131u04 paa ps4o o2 pue ysl 843 jo Woyog ay 3e se suoInde2us anjer Ag papos ua ANTA a gue net Aa se 2n T o Jenuew uay 13 351 243 HOS 03 3431 421 9 id 9 Berlin Germany April 2005 17 27th Internationalization and Unicode Conference Improved Unicode support in FontLab Studio 5 In place of the old Metrics Window w
9. Improved Unicode support in FontLab Studio 5 Adam Twardoch Improved Unicode support in FontLab Studio 5 Frankfurt Oder April 2005 Version 1 0 he new generation of FontLab s professional font editors FontLab Studio 5 and AsiaFont Studio 5 includes numerous improvements relevant for Unicode font developers We present some of the feature highlights better support for Unicode 4 1 support for advanced layout technologies improved OpenType Layout support and new AAT support greatly improved class based kerning and metrics We discuss the key improvements in FontLab Studio 5 that are helpful in the process of designing and developing fonts for Unicode environments We focus on the issues of glyph naming and encoding as the crucial prerequisite for creating a functioning Uni code compatible font We present guidelines for glyph naming and encoding and discuss two specific case studies that demonstrate their practical application Fontlab Ltd 1 is an international software vendor that has stayed at the forefront of digital font management by remaining devoted to developing font editors and typography products Their full line of products is dedicated to solving the most com plex typography issues These products include FontLab AsiaFont Studio ScanFont TypeTool SigMaker TransType CompoCompiler BitFonter and FONmaker The Font lab Ltd team works in offices in Canada Germany Panama Russia and USA With FontLab Studio 5 and A
10. Preview panel that opens activate the ccmp feature and type in the following u0045 uU0323 U0301 U0045 U0301 U0323 Nu00C9Nu0323 Nu1EB8Nu0301 to test your new character Generate the font as Win TrueType OpenType TT ttf or as OpenType PS otf in stall it in the system and in Microsoft Word 2003 for Windows or newer and test your new character type in the hexadecimal codes of the composite codepoints and press Alt X after each of them Alternatively use the Character Map application or a custom keyboard driver x ay EOE kv l feature liga Standard Ligatures Latin ail dnom lookup ligaZ4 ssl et ei NETECIS ssl ounb fa Bero salt ligaz4 lookup ligaZ5 sub T h by T h sub f tb by f bri sub f f hoby f ru auh f Ff a hs f f A Figure 5 The OpenType layout feature definitions are stored in the OpenType panel us ing the Adobe FDK for OpenType notation 27th Internationalization and Unicode Conference 12 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 The technique described above should be applied accordingly to other glyphs that represent characters that do not have precomposed codepoints The same technique should be applied to building ligatures except that the mapping of the component glyphs to the ligature glyphs should not be done in the ccmp feature but in the ap propriate ligature features liga dlig hlig Please refer to the OpenType
11. arus Font Studio Fontogra pher and previous versions of FontLab Many of these users developed very strong habits as for how certain things should work Since most of these tools are no longer being developed FontLab Studio 5 includes options that make the look and feel more familiar for users of other tools The user can control many aspects of what the Glyph Window looks like control the size and color of nodes the smoothing of out lines decide whether to show connection marks or to fill the outlines Something completely new to FontLab Studio 5 is in context editing FontLab 4 6 users know the mask layer where the designer can place an additional outline for reference In FontLab Studio 5 a new kind of dynamic masks are introduced shape groups and neighbors The shape groups layer displays a number of semi transparent glyphs stacked behind the outline of the current glyph The neighbors layer shows glyphs left and right of the current outline The composition of shape groups and neighbors changes automatically for each glyph that you edit and naturally this composition can be fully customized 27th Internationalization and Unicode Conference 13 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 S Fon zh Shutin Glyph m inom Utopia Pasgalar I DX G Eile Edit View Contour Glyph Tools Window Help amp l x 1090 ms Tid 1H Tad OY alt citing Layers e e Cutline m n Metrics E 7 Guide
12. as glyph name For a ligature of longs and i use longs i as glyph name For a ligature of the glyphs Esmcp Esmcp and I smcp use F_F_l smcp as glyph name For a ligature of the glyphs R salt and s sups use R s salt sups as glyph name For the African E character use the glyph name E dotbelowcomb acutecomb If each element of a compound glyph name represents a BMP character you can use an alternative way of building the basename which can potentially produce a shorter glyph name The glyph name starts with uni and must be followed by unseparated groups of four uppercase hexadecimal digits representing the BMP codepoint of each element So instead of E dotbelowcomb acutecomb you can use the name uni004503230301 Remember that a glyph name should be no longer than 31 characters so you may need to abbreviate the name if needed 3 6 Symbol glyph names If a glyph does not represent a Unicode character but rather is an ornament a non textual symbol etc you can use a glyph name of your liking but adhering to the limitations outlined in 3 2 If you assign PUA codepoints to these glyphs you can create the glyph names using the uniXXXX scheme where XXXX represents the PUA codepoint 3 7 Additional naming guidelines Refer to the Adobe guidelines 9 for additional guidelines on making glyph names especially for creating complex glyph names that involve uniXXXX and uXXXXX glyph names a
13. ase English letters a z European digits 0 9 and underscore Other char acters such as spaces are not permitted A glyph name must start with a letter or the underscore character with the exception of the special glyph name notdef that starts with the period For example twocents al and are valid glyph names while 2cents and twocents are not 3 3 Simple glyph names Review the Adobe Glyph List for New Fonts AGLFN 10 If your glyph represents a character listed in AGLFN use the glyph name listed there Instead of using arbitrary names e g middot use standardized names listed in AGLEN periodcentered Review the Unicode Standard code charts If your glyph represents a default form of a character encoded in the Unicode Standard but not listed in AGLFN a for BMP codepoints use the name uniXXXX that is lowercase uni followed by a four digit Unicode codepoint written using uppercase hexadecimal digits Note that uni must be lowercase and XXXX must use uppercase letters for hexadecimal digits so uniO1EB is a vaild glyph name but uniOleb or UniO1Eb are not b for smp codepoints use the name uXXXXX or UXXXXXX that is lowercase u followed by 5 or 6 uppercase hexadecimal digits representing the codepoint 3 4 Glyph names with suffix If your glyph represents an alternate form of a character that is encoded in the Uni code Standard
14. e glyphs Tcommaaccent uniO21A and tcommaaccent uniO21B with mappings listed below Use T t with disconnected undercomma accent for Romanian in both these cases Glyph name Tcommaaccent Unicode 0162 LATIN CAPITAL LETTER T WITH CEDILLA Glyph name uni021A Unicode 021A LATIN CAPITAL LETTER T WITH COMMA BELOW 27th Internationalization and Unicode Conference 10 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 Glyph name tcommaaccent Unicode 0163 LATIN SMALL LETTER T WITH CEDILLA Glyph name uni021B Unicode 021B LATIN SMALL LETTER T WITH COMMA BELOW Alternatively create Tcommaaccent with two Unicode codepoints assigned 0162 021A and tcommaaccent with two Unicode codepoints assigned 0163 021B As an alternative approach you may choose to design a hybrid disconnected accent that serves as both cedilla and commaaccent Please refer to the Microsoft Diacritics Design Standards document 11 Short call your glyphs something cedilla when they use cedilla and something commaaccent when they use commaaccent Supply C and S with cedilla for Western and Turkish and G K L N R S T with commaaccent for Romanian and the Baltic languages 3 11 Case study II No precomposed Unicode codepoints As explained in 3 1 characters such as LATIN CAPITAL LETTER E WITH DOT BELOW AND COMBINING ACUTE ACCENT E do not have a precomposed Unicode value The glyph that represents such a character needs spec
15. edded in electronic documents or sent to a printer under some circumstances only the information about the glyphs their Gips names and outlines are retained while the encoding information the associated Unicode codepoints is lost The electronic document looks right but the underlying text streams are ob scured or not available In such cases meaningfully constructed glyph names can be used as a help to rebuild or at least approximate the original text A practical exam ple the user creates a text document that uses an OpenType PS font The document is printed to a PostScript file Since PostScript does not support OpenType PS the font is embedded in the print stream as Type 1 The OpenType information such as layout tables or Unicode codepoints is lost If Acrobat Distiller is used to convert the Post Script file to a PDF document the application first tries to locate the original Open Type PS font on the user s system if the font is found Distiller is able to use its origi nal Unicode codepoints and embed them in the PDF document But if the original OpenType PS font is not available to Distiller for example because the PS to PDF conversion happens on a different machine Distiller embeds the Type 1 font found in the PostScript stream with no Unicode information Now when the text in the PDF document is being searched copy pasted or otherwise extracted by an application such as Acrobat or Google the application can attempt to rebui
16. equired using a bunch of command line tools running only on Microsoft Windows FontLab Studio 5 has built in support for digital signatures so the font developer only needs to buy a code sign ing digital certificate from a company such as Thawte or Verisign starting at 200 USD year 27th Internationalization and Unicode Conference 18 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 FontLab Studio 5 also includes another innovative feature it can convert selected Apple GX AAT typographic features if present in the font to OpenType Layout fea tures 15 FontLab Studio s abilities to create OpenType Layout features are currently limited to GSUB substitution features and kerning Advanced GPOS positioning used in complex scripts Arabic Indic scripts is not directly supported However FontLab Studio 5 provides convenient integration with Microsoft Visual OpenType Layout Tool vorT 16 a free application that can be used to create complex OpenType Layout fea tures The designer can use FontLab Studio to design the glyphs assign Unicode co depoints and generate the font later he can open the font in vorr and add the OpenType features there For more information about creating OpenType features for complex scripts please consult the specifications published at the Microsoft Typogra phy website 17 7 Other features A common scenario for creating multilingual OpenType fonts is that the user has sev e
17. ial treatment the font must include an OpenType Layout feature that maps the composite codepoints to the actual glyph To include such a font in your OpenType font you will need to create the Canonical Composition Decomposition OpenType feature ccmp 12 First the ingredients of the character must be identified LATIN CAPITAL LETTER E WITH ACUTE AND DOT BELOW consists of the LATIN CAPITAL LETTER E COMBINING DOT BELOW and COMBINING ACUTE AC CENT U 0045 LATIN CAPITAL LETTER E glyph name E U 0323 COMBINING DOT BELOW glyph name dotbelowcomb U 0301 COMBINING ACUTE ACCENT glyph name acutecomb The canonical decomposition of the character i e the Unicode Normalization Form D NFD of the character is U 0045 U 0323 U 0301 This is the default form in which the character should be represented in the text According to the glyph naming guidelines detailed above the name of the glyph E could be uni004503230301 or E dotbelowcomb acutecomb We will choose the first one for brevity In addition to the canonical components of the character we should consider that parts of the character do exist in the Unicode standard in precomposed form U 00C9 LATIN CAPITAL LETTER E WITH ACUTE glyph name Eacute U 1EB8 LATIN CAPITAL LETTER E WITH DOT BELOW glyph name uni1EB8 We should not assume that all Unicode texts in which we want to use our character will exist in canonically decomposed wrp form Therefore
18. ith just one line of text the new Metrics Win dow is a multiline text editor so the user can see the whitespace distribution not only between characters but also between lines of text The Metrics Window has four modes that you choose using the four buttons on the top left of the window Text Preview Metrics and Kerning The Text mode works like a little text editor you can type any text select copy and paste The Preview mode removes all unnecessary lines and marks so you can look at your typeface and print a sample from the win dow 6 OpenType Layout support To create OpenType layout features in FontLab the user puts the feature definitions in FontLab s OpenType panel using source notation defined by Adobe Systems When FontLab generates an OpenType PS or OpenType TT it compiles the notation into binary OpenType tables using programming code licensed from Adobe Systems the same code that is included in the Adobe FDK for OpenType Unlike the Adobe FDK FontLab is able to do the reverse to open an OpenType font containing the binary OpenType layout tables and to decompile them into the source notation When FontLab 4 6 opens an OpenType it always decompiles the features which has turned out to be a limitation The Adobe FDK for OpenType code does not support certain aspects of the OpenType specification such as the mark to base and mark to mark GPOS positioning lookups that are extensively used in Arabic Hebrew and Indic OpenType fo
19. ld the Unicode code points basing on glyph names included in the embedded Type 1 font For Latin or Cyrillic scripts the recreated text will likely be a very close match of the original for Thai or Hindi the text recreated that way will probably be only a crude approxima tion with letters arranged in incorrect sequence and some information missing But yet some is often better than nothing Users of the Unicode Standard familiar with the character glyph model know that the relationship between glyphs and characters is not a simple one to one mapping A glyph in a font can represent the default form of a character Such glyph needs to have the Unicode codepoint of the represented character assigned For example the glyph with the cip 4 representing the character U 0024 DOLLAR SIGN has the Unicode codepoint 0024 assigned in the Unicode field of the Properties panel The glyph s name is dollar 27th Internationalization and Unicode Conference 6 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 A glyph in a font can also represent a variant form of a character For example a font can include a glyph that represents the default form of the character a U 0061 LATIN SMALL LETTER A as well as glyphs that depict stylistic variants of that character a small cap variant a swash variant etc The glyph that represents the default form should have the name a and the Unicode codepoint 0061 assigned in the Properties
20. m for you 5 Letterspacing and Kerning The Metrics Window probably includes the most important changes in FontLab Stu dio 5 In the Classes panel the user can associate similar glyphs into classes Kerning classes are used to associate glyphs that can share the same kerning values FontLab Studio 5 includes a brand new automatic class builder the software analyzes the shapes of the glyphs included in the font and finds glyphs that are similar on the left side or on the right side These glyphs are automatically associated into classes For example a kerning class B can include a number of glyphs that are similar in shape on their left side B D F H I etc They can use the same kerning value if one of them appears as the second glyph in a kerning pair With such kerning class in place the user only needs to define kerning pairs for one of the glyphs for example B which is the so called key glyph The other glyphs will automatically receive the same kerning values on their left side Next page Figure 9 New Metrics and Kerning editing in FontLab Studio 5 illustration by Luc as de Groot 27th Internationalization and Unicode Conference 16 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 P289 Sed v6t6l P WHO HIO Z IXIHIXPNDID OI0 2 0 0 0 H HIHIO Z IHIH HINHIOIH O ZIHIO H a ster a suendo pP 7 c sued emo amp juo s udA D sels E 0422 JEWs pe323 9 49 BABY saj 3493
21. n a font is uniquely identified by a glyph index GID FontLab Studio also requires that every glyph in the font has a glyph name The glyph name is visible and can be modified in the glyph s Properties panel To open the Properties panel click on a glyph and choose from the menu Edit Properties Note that the glyph name must not be confused with the Unicode character name A de tailed discussion of glyph naming is included later in this paper FontLab Studio follows the character glyph model defined by the Unicode Standard 7 Each glyph may be associated with one or more Unicode codepoints The Unicode codepoints are also visible and can be modified in the Properties panel In FontLab Studio 5 the Unicode codepoints are expressed using hexadecimal digits In FontLab 3 0 the Unicode support was limited to the first 65 535 codepoints the Basic Multilingual Plane Bmp or to four digit Unicodes In FontLab 4 6 experimen tal support for higher Unicodes smp Supplementary Multilingual Planes was added but it never worked correctly FontLab Studio 5 can finally create fonts that are fully compatible with the Unicode Standard version 4 1 Unicode codepoints with 4 5 or 6 digits are equally well supported The glyphs in the Font Window can be presented in different arrangements depend ing on the Font Window mode selected The Index mode displays the physical se quence of the glyphs in the font ordered by cips The Names mode arranges
22. ng no more than one Unicode index to each of them note that one of the glyphs can refer to the other one as a component Another case is that one glyph represents several Unicode characters at a time For example the glyph E represents an accented character LATIN CAPITAL LETTER E WITH ACUTE AND DOT BELOW used in African languages such as Yoruba This character does not have its own codepoint in the Unicode Standard so it needs to be encoded as a series of characters It is encoded as E followed by dot below followed by acute U 0045 U 0323 U 0301 Another example is the glyph ffk which is a ligature of f followed by f followed by k U 0066 U 4 0066 U 006B In such cases again the appropriate OpenType Layout features must be used to produce the glyphs The glyph name should be constructed accordingly and the glyph may have a PUA Uni code codepoint assigned The following sections present a summary of the Adobe FontLab glyph naming guide lines There guidelines unify recommendations by Adobe Systems 9 and those by Fontlab Ltd 3 2 Glyph name limitations A glyph name must not be longer than 31 characters The glyph name consists of a basename optionally followed by a period which is then followed by a suffix Both the basename and the suffix may only include uppercase English letters A Z 27th Internationalization and Unicode Conference 7 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 lowerc
23. ns names and Unicode codepoints to glyphs views the glyphs in various arrangements and changes their physical arrangement within the font In 27th Internationalization and Unicode Conference 3 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 the Glyph Window the user creates and modifies the appearance of a glyph by drawing the glyph s outlines or assembling the glyph from existing parts In the Met rics Window the user specifies the appearance of the glyphs when they are arranged on a page that is modifies the glyphs metrics and defines kerning In additional FontLab Studio includes a number of panels and toolbars that provide additional functionality FontLab Studio s Font Window is the table of contents of a font All the glyphs in cluded in the font are displayed in a cell grid Each font is a sequence of glyphs numbered with consecutive indexes Gips O 1 2 3 etc The number of glyphs in a font and their ordering may differ from font to font A typical Western font contains between 200 and 300 glyphs an Asian font can have 50 000 glyphs or more note that such large fonts can only be processed with AsiaFont Studio not FontLab Stu dio Glyphs in digital fonts are constructed out of outlines curves and straight seg ments A glyph can also include components a closed portion of the outline can be constructed as a reference to another glyph present in the same font As mentioned above each glyph i
24. nts When a user opens such font in FontLab 4 6 performs some mini mal modifications and tries to generate a new font FontLab will fail It cannot re compile the features since they include unsupported lookup types There is no easy workaround for that problem but fortunately it is fixed in FontLab Studio 5 The new FontLab version has options that control whether to store the OpenType binary tables and whether to interpret them when opening an OpenType font With both options enabled FontLab will decompile the feature definitions and also store their binary form When the user re generates the font FontLab Studio asks him which version of the tables binary or compiled to include The user can also enable just one of the options in this case he will not be asked when generating the final font In Microsoft Windows XP OpenType PS fonts with the otf extension are always dis played using the green OpenType icon O OpenType TT fonts with the ttf exten sion are shown using the blue TrueType icon TT by default Windows will only display the green OpenType icon for a ttf font if the font includes a digital signature Font developers should add digital signatures to their font to certify the authorship of the font A user of an OpenType font by for instance Linotype Library can be sure that the font is a genuine Linotype font if it contains a Linotype digital signature Un til now adding digital signatures was cumbersome it r
25. ools Window Help l l Ene POESIE a ZIP XT IEE E DD ae S hi Me uli u eae ea b AEE GQ ront utopia Regular DA Adobe systemslutopiz z H B sarmpuarert ome 2 A al A amp Amice moms 2 A a A Ala 3 pip jJ 2 mor evan 033 or 01 57 Decompose IA A q Ba Rename Glyph UCirisCircumflex accent E Mie a a a ey Ee Ee eG g fe uj DHE 6141F 6120 8121 ote Generale Glyphs Clrl 4G orc HHBBE ae ee oalele e lelea n w n n n o w T ANN Am sacaacavaanarsnsrceeomseues JE fjr I s 8 5 5s nn E sjofofops u o uo vie w w v v Jao oadaoauy wets YIzIzIz z lz s t Y JE BEI 3 n ee ee to me oazo oae mar ooma oos uozz uasa eas uaa woz amp L A NE 4 amp ELT pex BODEN Az je ziela B C 5 6 O08 A555 eA BoC 5 E TIriciHiTliKIL MINOT OLR cai cow oom oor ES 8E EST coc DGETA vaga EIN STE ZISsITIUIVIWIXIYI Z S U n Saas bas OR CAEN AES ON man aA en MI al 8 id E poo mrgirisijtiu vIiwIx y giri Sa 7 seg _ _ _ MEET ona OA ansa wi ETTE DAR mam munumnuux TT RN dde bt d TUBE TEF 4 2 L LE d E M l RA 6 i Figure 8 If your font is missing some accented characters FontLab Studio 5 will at tempt to create the
26. or is listed in AGLFN use the glyph name of the basic form as the basename followed by a period followed by a suffix For the suffix use the name of the OpenType Layout feature that you would most likely access that glyph through For example for a small caps A use A smcp for a stylistic alternate R use R salt for a swash Q use Q swsh for a superior m use m sups for a tabular 5 use five tnum etc If there are multiple OpenType Layout features that can be used to access a glyph pick one of your likings 3 5 Compound glyph names If your glyph represents a compound character i e a ligature or an accented char acter that does not have a precomposed Unicode codepoint and if the character is not explicitly listed in AGLFN or the Unicode Standard construct the compound glyph name as follows For each element of the compound character take the basename or the entire glyph name if there is no suffix Concatenate these using underscore to make the com pound basename 27th Internationalization and Unicode Conference 8 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 For each element of the compound glyph that has a suffix concatenate the suffixes using underscore to make the compund suffix You may eliminate duplicate suffix elements For example for a ligature of the glyphs c and t use c t as glyph name For a ligature of the glyphs f f and i use f f i
27. pography developers fdsspec 12 Microsoft Corp ccmp OpenType Layout feature http www microsoft com typography otspec features ae htm ccmp 13 Microsoft Corp OpenType Layout features registry http www microsoft com typography otspec featurelist htm 14 Monotype Imaging http www monotypeimaging com 15 Apple Computer Comparing GX Line Layout and OpenType layout http developer apple com fonts WhitePapers GXvsOTLayout html 16 Microsoft Corp Microsoft VOLT http www microsoft com typography developers volt 17 Microsoft Corp Typography Specifications http www microsoft com typography SpecificationsOverview mspx 27th Internationalization and Unicode Conference 2 Berlin Germany April 2005
28. ral Type 1 fonts designed in the past each of them including a part of the desired character set For example there can be a Roman font a Central European font a Cyrillic font a small caps font and a font with old style numerals FontLab Studio includes some new features useful in such a conversion process In your Type 1 small cap font the small cap glyphs are probably named a b c but in the OpenType font such glyph names already exist for lowercase letters so your small caps should get different names e g a smcp b smcp c smcp etc With Add Suffix to Name the user can append a particular name suffix to selected glyphs With Tools Merge Fonts the user can copy all glyphs or just the ones with the unique names from one font to an other including kerning pairs A feature often requested by users of the 4 6 version was improved font proofing FontLab Studio 5 has greatly extended printing capabilities The user can print vari ous samples of single glyphs or the entire font including metric information There is also a new Quick Test feature FontLab Studio generates the current font in OpenType PS or OpenType TT format taking the current export Options into account installs it temporarily and shows a little text editor window The user can populate the contents of selected codepages or the entire font character set into the Quick Test window but can also paste arbitrarily long texts from the clipboard The Quick Test window dis
29. renle parenridasterisk plus romma hyphen periad slash three em five seven eight nine mm semicol less EMI reater questio Figure 3 Names mode of the Font Window For Type 1 fonts it represents the font s encoding For TrueType and OpenType fonts it s just a handy glyph browser 2018 2018 201c 2010 2022 2013 2014 2122 0161 203a 0158 M65 017E 017A gud dub B H ozc7 B2D8 0141 oad 0104 DDAE oo ODa8 Ooms 015E DOAB DOAC OOAD OOAE 017B u00 Nagg nE my Tey rs let ad EN O 0154 elei en fan fr re ra e we E mj r Figure 4 Codepage mode of the Font Window When a glyph is missing a template image is displayed 27th Internationalization and Unicode Conference 5 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 The Font Window has two more modes the Unicode mode and the Codepage mode that work analogically to the Names mode The Unicode mode can filter glyphs by Unicode range the Codepage holds a huge number of legacy codepages that can be used to view glyphs in a particular arrangement 3 Glyph Naming and Encoding 3 1 General provisions Theoretically the OpenType specification permits the designer not to supply any glyph names at all at least in case of OpenType TT fonts However realistically it is essential to create fonts with glyph names that fulfill the recommendations detailed below When fonts are emb
30. s LI Hirit Mask d gt Auto select layer o bu E Fa FAF ns E x i E E eat Center Sr 3 gt 2 analy Mode Properties xi Straight lina 31 36 1 oe es at fo a s alr iem 4 ET mE gt I secos z eo I 4 kh iad x T Ee cio Laban s ec iie nl r P amp T XH ENS w x Beet i eerie B f g 1 JAN bi pu I T Of p L L WEA ee eS Jalb c d e fi igi h ij i ik Bs o lpq risit ujv B Figure 6 The Glyph Window is the heart of FontLab Studio 5 4 2 Alternative ways to add glyphs Until now autotracing was a feature unique to Fontlab Ltd s separate product Scan Font While ScanFont still remains useful as it can quickly and automatically separate an entire scanned alphabet into single characters FontLab Studio 5 has a built in Trace feature The user can place a black and white bitmap of a character into the Background layer and FontLab Studio 5 will convert it into an outline with custom izable precision FontLab Studio 5 can also import illustrations saved in EPS format If you prefer to draw in Illustrator or Freehand remember to save your EPS in Illustra tor 6 or Illustrator 8 format rather than any of the newest formats FontLab will then have less trouble in importing the EPS The cells that represent glyphs missing from your font have a gray background and a glyph template image that you can use as orien
31. s elements 3 8 Proper Unicode codepoints Refer to the Unicode Standard code charts and assign proper Unicode codepoints to the glyphs discussed in 3 3 As discussed above if the more than one Unicode character share the same glyph shape two approaches are theoretically possible a create multiple glyphs with identical content but different names and assign one Unicode codepoint per glyph for example create a periodcentered glyph and en code it as U 00B7 and create a uni2219 glyph and encode it as U 2219 One of 27th Internationalization and Unicode Conference 9 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 the glyphs can refer to the other one as a component This is the approach recom mended by Fontlab Ltd for OpenType fonts in particular for OpenType PS fonts b alternatively either assign multiple Unicode codepoints to your glyph for exam ple for periodcentered assign U 00B7 and U 2219 3 9 Private Use Area codepoints For glyphs discussed in 3 4 3 6 you may assign custom codepoints from the Uni code Private Use Area Pua from U E000 to U F8FF However you also may choose to leave these glyphs unencoded not assign any codepoints For some applications e g Microsoft Word 2003 for Windows assigning PUA code points may be the only way to display such glyphs in your font so it is practical to assign PUA codepoints On the other hand Pua codepoints are comple
32. se the term OpenType TT When we refer to the advanced typographic features of OpenType we use the term OpenType Layout At the time of writing FontLab Studio 5 has not been released yet However the key concepts presented in this paper equally apply to the currently available version FontLab 4 6 Whenever we refer to FontLab Studio the same remarks usually apply to the application s high end cousin AsiaFont Studio The main difference between FontLab Studio and AsiaFont Studio is that the former can only produce fonts that include less than 6 400 glyphs AsiaFont Studio can produce fonts with up to 65 535 glyphs S Font ah Sludin E i igj xj Eile Edit eee DNE Glyph Jools Window Help josag bO loo S Hale eee ep Fle as mnanaa nla Si go b oa b d I x 3 mee Mza snol Neu T Figure 1 Three main elements of the FontLab Studio 5 user interface the Font Window showing the character set of a font the Glyph Window for designing the glyph shapes and the Metrics Window for setting metrics and kerning 5 IT eiHR 74 0 8 8 GAO 3 0 ae aru Yaua l A K I LE E u E U E INO 2 Building Blocks of a Font The three main elements of FontLab Studio s user interface are the Font Window the Glyph Window and the Metrics Window In the Font Window the user navigates through the font assig
33. siaFont Studio 5 software developers and type designers are able to create professional quality Unicode savvy OpenType fonts either from new artwork or by converting their existing font libraries from legacy formats Adam Twardoch 2 is Scripting Products and Marketing Manager at Fontlab Ltd In addition Adam serves as typographic consultant to MyFonts com as OpenType con sultant to Linotype Library and provides consulting services in font tool develop ment font technology and multilingual typography to other clients worldwide He regularly writes and lectures about fonts and typography He is member of the ATypl Board and ATypl country delegate for Poland Born 1975 in Poland Adam now lives in Frankfurt Oder approximately 80 km east of Berlin 27th Internationalization and Unicode Conference 1 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 1 Introduction In 1975 at the ATypl conference in Warsaw Peter Karow from the Hamburg based company URW introduced Ikarus the world s first digital type design system that worked with outline fonts Ten years later Adobe created PostScript and the Type 1 font format which both became standards in publishing In the early 1990s Apple introduced the TrueType font format and the Unicode Consortium published the Uni code Standard Both initiatives laid the foundations for multilingual text processing and were subsequently implemented in Microsoft Windows and Mac OS The
34. tation for your design FontLab Stu dio 5 includes a new very extensive glyph template font provided by Monotype Im aging 14 It is a one size bitmap version of Andale Mono wro that provides low resolution character previews for the entire Unicode 3 2 character range 27th Internationalization and Unicode Conference 14 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 S FontLab Studio O x File Edit View Contour Glyph Tools Window Help Euer e eae GS A Hm sm m mw rs JE IEE Ld Font Minion Pro DA m MinionPro R E x z Glyph uni03E0 from Minion Pro m Glyph unio3E0 fromMinionPro IC xi al EX EI Jj iz EET and oe A H gq 100 96 amp A Rhos HAAN Eel de Fes ESAE 3 B 100 of 100 200 300 400 500 600 700 Seng Hm S nanngnnmdn 0389 03BA 03BB 03BC O3BD O3BE O3BF 03CO 03C1 03C2 03C3 AAEE RTRS ahy o 03D0 0 fina s c e nos bon B O 2 L ies 8 e a Es ET o eB N D amp 2 le me m uU mw TI oJ J O3DC 03DD 03DE 03DF esl cepe pes C ea rpg TERCIO 5 62 0022 0023 0024 0025 0026 0027 0028 008 TER ananaownm E 8 GJ m Cn Lo elitri i 678 68 x 100 EE P M Py P u oO 400 1 l 0037 0038 0039 003A 003B 003C 003D 003E OO3F 0040 0041 0042 x a z 100z lt Ej 2 N 496 173 X 6 8 Y 68 A Figure 7
35. tely custom so there is no way that exchangeability of documents can be guaranteed Also the text that is set using PUA codepoints is garbled spelling hyphenation search amp replace won t work So this is only a short sighted interim measure Some font developers e g Adobe assign PUA codepoints to glyphs that do not have proper Unicode codepoints while others Microsoft Bitstream Linotype Tiro Type works leave the glyphs unencoded 3 10 Case study I The tcedilla vs tcommaaccent confusion During the development of the Unicode Standard some confusion was introduced with regard to glyphs that involve the cedilla and the commaaccent acccents The case study below illustrates the relation between Unicode codepoints Unicode char acter names glyph names and the actual glyph design Use C c with a connecting cedilla accent below for Turkish Glyph name Ccedilla Unicode OOC7 LATIN CAPITAL LETTER C WITH CEDILLA Glyph name ccedilla Unicode OOE7 LATIN SMALL LETTER C WITH CEDILLA Use S s with a connecting cedilla accent below for Turkish Glyph name Scedilla Unicode 015E LATIN CAPITAL LETTER S WITH CEDILLA Glyph name scedilla Unicode 015F LATIN SMALL LETTER S WITH CEDILLA Use S s with disconnected undercomma accent for Romanian Glyph name Scommaaccent Unicode 0218 LATIN CAPITAL LETTER S WITH COMMA BE LOW Glyph name scommaaccent Unicode 0219 LATIN SMALL LETTER S WITH COMMA BELOW Make duplicat
36. tional support However the key elements of the user interface such as the Metrics Window support right to left rendering as well as to some extent vertical rendering The final Windows version of FontLab Studio 5 is expected to be released in the spring of 2005 with the Mac version to follow a few months later The information will be announced on http www fontlab com 27th Internationalization and Unicode Conference 20 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 9 References 1 Fontlab Ltd http www fontlab com 2 Adam Twardoch http www twardoch com adam 3 Leslie Cabarga Learn FontLab Fast Iconoclassics Los Angeles 2004 http www Logofontandlettering com 4 Fontlab Ltd FontLab Studio User s Manual http www fontlab com 5 Adobe Systems Microsoft Corp The OpenType specification http www microsoft com typography otspec 6 Apple Computer TrueType Reference Manual http developer apple com fonts TTRefMan 7 The Unicode Standard http www unicode org 8 Adobe Systems OpenType Advanced Typography http store adobe com type opentype adv 9 Adobe Systems Unicode and Glyph Names http partners adobe com public developer opentype index glyph ht ml 10 Adobe Systems Adobe Glyph List For New Fonts http partners adobe com public developer en opentype aglfni13 txt 11 Microsoft Corp Microsoft Character Design Standards http www microsoft com ty
37. usay udo j 3nouit 3 saed moys BADUE Y saied auno 4Eq 003 34 W04 apow quo oaz E 0 s 003 pue suondo suondo azis yoyims Yams yan uses Buxous BUI MaU 40 spue3s us unod ou eddey addy 3423 aysed 40 ady 37 eddey elay eydi ewbis ne pouad oui eydje 1yo uojisda 143 E uayddy ied ued aed jnejunieBunun uonda2ss sse Hn apung Bull Bull ls sissleip pad Aeab I3 uo1oeui oen apno Yseiso aseo s eIq anoen neg SsE 2 BYR 895 03 821331 ADD z saed papuedua aas o3 sienbs anyjg aya 4215 c ye leuis sen e Bulusay abuey gt o3 J POP P POP NNN NNN PS OP PM a c OYE EWS 043u02 40 44S yum yy pue yaj moe asn z 634 c 2694 un 483 s21438 4 UI pe3e ndiue ur eq uen 34233002 igdA B 425 40 321 5 432 oul ss amp 2 404 uo21 321 2 z J euis o 243 ay uo papajas aq pynoys aired ou 0 ajed e urasay oz leuis 35s3u02 3euw03ne Ul UMOYS 34e sJled 27 4 ssepuludAD Aay Sueaul Uo 3s 5143 ubnoa4us o42s 03 Ww i ee feuis umop modde pue dn modde asm c f d c x 0 z anelli 4 Ez d d z inejunieBunuqo 3 c aunso 3 c SIS9IaIpo 3 ZHZ ssuo2sqzH im poi 2 ud b 3s T ayy jo apis ya tc oen 3 au uo dn moys y ayeu z aping 3 03 udA B puo ss eui uo c use so 3 A212 qnop 3 o43u052 z s EIb 3 c 33190 3 c anoen 3 d aed e c 30 3 yoajasap c a 3 03 tz 0 3 aaay mopuim qud B ui TU uado o 1 el pz aj ispjosuo aj fispjo uses 321 2 aed e
38. we should make provisions for all possible combinations of Unicode characters that can represent our LATIN CAPI TAL LETTER E WITH DOT BELOW AND COMBINING ACUTE ACCENT character This means that our font should contain all of the following glyphs E dotbelowcomb acutecomb Ea cute uniEB8 27th Internationalization and Unicode Conference 11 Berlin Germany April 2005 Improved Unicode support in FontLab Studio 5 This also means that the final character can be a combination of the following U 0045 U 0323 U 0301 glyphs E dotbelowcomb acutecomb U 0045 U 0301 U 0323 glyphs E acutecomb dotbelowcomb U 00C9 U 0323 glyphs Eacute dotbelowcomb U 1EB8 U 0301 glyphs uniT EB8 acutecomb To create the glyph for the character LATIN CAPITAL LETTER E WITH DOT BELOW AND COM BINING ACUTE ACCENT in FontLab Studio 5 choose Glyph Generate Glyphs and type in the following E dotbelLowcombt acutecomb uni 004503230301 Finally refine the design of the glyph adjust the positioning of the diacritics as re quired Open the OpenType panel Window menu add a new feature and in the feature definition code field type in the following feature ccmp sub E dotbelowcomb acutecomb by uni004503230301 sub E acutecomb dotbelowcomb by uni004503230301 sub Eacute dotbelowcomb by uni004503230301 sub unilEB8 acutecomb by uni004503230301 ccmp Click on the Compile button then on the Open Preview Panel button In the OpenType
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