The Tao of Fonts - TeX Users Group
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1. Fig 19 shows a piece of text typeset with a computer replica of the font used in the Polish Alphabet Primer by Falski I learned to write letters with the help of Falski s primer as did my wife and my daughter In fact all children in Poland learn Falski s letters DIALOGS ARE REWRITTEN AGAIN JO SPARE JHE AUTHOR AND JHE OTHER CHARACTERS JHE SHAME OF SOUNDING AS INARTICULATE AS THEY INVARIABLY DO OR WOULD IF JHEIR SENTENCES ALMOST INVARIABLY BEGUN WITH JHE WORD DUDE AS IN FOR EXAMPLE DUDE SHE DIED WERE MERELY TRANSCRIBED Fig 19 Ala font 27 The characteristic features of this font are listed below size of characters BIG width PROPORTIONAL slanting UPRIGHT interletter spacing BIG uniformity of pressure CONSTANT strength of pressure AVERAGE interword spacing BIG overall appearance OVAL readability CLEAR Handwriting can reveal the personality of the writer The writer in this case is my computer so we can get his psychological portrait easily A person which writes this way is well wishing Easy to cooperate with and friendly Usage of uppercase letters and big interletter spacing indicates this Constant pressure means emotional maturity Oval appearance might mean uncertainty and submissiveness Finally constant and average pressure and wide characters indicate an uneasy and over excitable person The most important thing about this example is how easy it is to make this font to look diffe2. The Tao of Fonts o W odzimierz Bzyl e matwb univ gda pl M Abstract Fonts are collections of symbols which allow people to express what they want to say what they think or feel Writing is a technique and as each technique has something to offer and has limitations For example the shapes of symbols depend on the tools and materials used for writing In the first part I illustrate some writing techniques with examples In the second part I present a new technique for creating fonts and illustrate it with several examples It is based on the METAPOST language 1 and could be viewed as Knuth s method 2 5 adapted to METRPOST Knuth uses METRFONT to program fonts and an mf compiler to translate programs into bitmap fonts Unfortunately today s standards are based on PostScript fonts 6 9 So to keep the Knuth s idea of programmable shapes alive fonts should be programmed in PostScript This is difficult because PostScript is a low level language The approach presented here is to program fonts in METAPOST Although the mpost compiler is not able to output a font directly its output can be assembled into a PostScript font 10 13 A font programming environment is based on a revised version of the mft pretty printer The original mft understands only METAFONT but changed mft understands METAPOST too In the third part I present a simple font programmed as a Type 3 and as a Type 1 font These examples will give an idea of font pro
3. doc plus yellow change name plus b00 plus 000 mp To test the font create a file named doc tex with the following content NfontlY plus b00 at 10pt centerline Y quad quad typeset it and convert to PostScript tex doc tex dvips u plus b00 map doc dvi o doc ps This should generate file named doc ps which may be viewed and printed for example with the Ghostscript program The programmed yellow plus is printed below H Generating hardcopy proofs compiling fonts typesetting documents requires remembering and executing a lot of shell commands Here the make utility helps a lot 20 Type 1 font example Type 1 font programming differs from Type 3 font programming Type 3 glyphs can use any Post Script command but Type 1 glyphs use a subset of PostScript Moreover we must construct an outline of glyph instead of drawing it The outline is filled when the glyph is printed Each METAPOST font should input the META POST Typel library The library contains macros which help to compute outlines and to output TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting 35 W odzimierz Bzyl various font data to several files These data are used by the mkfont1 script which assembles Type 1 font and mkproof1 script which typesets hardcopy proofs ooo The Type 1 font programmed below contains noth ing but a plus symbol Let s start with reading basic macros input typel Next f
4. i idko poggdny do ojkitne z wzdy ym zn kiem zn czy treba dwoie pi rwp ieno w ten cz s kiedy slowo iedn ko ie pife 4 zd r znym t y iftey li TAO tery myma rmi nim r zny ma y wyklad i ko fie t m S Fig 7 New Polish Character Jan Januszowski 1594 Cracow f THE GLICCERI HND Of LIYINC EZ Chapter L Of those Threewh to the Dousc of the Raven EA DAS been told that there was once a Li II young man of free kindred and whose BM name was Dallblithe he was fair strong f and not untried in battle bc was of the Kelmscott Press 1891 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting 29 W odzimierz Bzyl Fig 9 Playboy Polish edition 2001 newpath e 5 i 487 499 moveto a C40 RZ 451 499 lineto 423 616 363 661 299 661 curveto 239 661 195 621 195 559 curveto 195 483 278 447 344 420 curveto 435 382 533 331 533 199 curveto 533 95 473 13 273 15 curveto 207 15 108 0 57 47 curveto 42 226 lineto 79 226 lineto 117 101 193 31 269 31 curveto 334 31 382 66 383 140 curveto 383 204 341 249 250 287 curveto 162 324 51 378 51 502 curveto 51 620 132 707 300 707 curveto 361 707 435 695 487 663 curveto 487 499 lineto mecze closepath fill Fig 10 redraws the shape see Fig 10 We have replaced a chisel by a mouse and wood metal by the computer screen With these tools we ca
5. non letter shaped symbols are better served by the Type 3 font program which defines shapes with ordinary PostScript procedures including those which produce color Other font types are used infrequently TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting 33 W odzimierz Bzyl Although Type 3 fonts are PostScript pro grams I prefer to program shapes in the META POST language and convert the mpost output into a Type 3 font because METAPOST simplifies the programming due to its declarative nature In PostScript each curve is built from lines arcs of circle and Bezi r curves p 393 9 For complicated shapes this requires a lot of nontrivial program ming METAPOST implements a magic recipe 10 for joining points in a pleasing way which helps a lot Even if you are not satisfied with the shape you can give the program various hints about what you have in mind therefore improving upon the automatically generated curve To use a font with TEX the font metric file is required It contains data about width height and depth of each shape from the font Because mpost could generate metric file on demand fonts prepared with METAPOST are immediately usable with TEX GGO Creation of a Type 3 font is a multi step process 1 A font must be imagined and designed 2 The design must be programmed This step is supported by a specially created library 3 The METAPOST font program must be com piled 4
6. type was cut in metal Finally we get to Fig 9 showing what com puters are good at The shapes drawn by a computer are almost ideal Typographical embel lishments are not present instead the letters are colored and a background photo is used to improve the typography of the page GGO Fach new technique starts from the point where the old one ends When we make a letter with a computer the mouse is used to put points on an imaginary sheet As the points are laid down the computer joins them with curves Next the inflexion points red and the endings of tangents green lines are adjusted by hand At the same time the computer Koo dr zniey by o A s tym t 3 ius drugim chegli wolno bedie przyi chwali gani abo y fwo ie myd c Plalmow kilka Stomienfkich Orthogni phia Te M P n G rnicki go piftinych kt re mi potym poftal na ko cu przy Ortographiity iego poto gone kosdy snay ie ORTHOGRAPHIA tedy Polfka rzedem obiec dl prow dzi fie tym fpofobem k r kterem vko nym y proftym A Ko cuaNowsxr A troidki Polacy m ig Pi r we soe Leo ktor ma fiv y snak n d oba kr ke zg ry n dol wiedjion od pr w y r ki ku lew y i ko uud to yid niecudny Drugi zowg woim to ieft Pol kim kt r go zn k ie tkr k t kze n d nim dle od few y ku pr mey r ce i ko zadny to ieft mkt drecie zowiemy ciegkimy kt r m kr ke pres
7. u isFixedPitch if true indicates that the font is a monospaced font otherwise set false u UnderlinePosition recommended distance from the baseline for positioning underlining strokes y coordinate u UnderlineThickness recommended stroke width for underlining in units of the char acter coordinate system FontInfo FamilyName Geometric FullName Square Notice Type 3 Repository Copyright C 2001 Anonymous All Rights Reserved Weight Medium version 1 0 ItalicAngle O isFixedPitch true UnderlinePosition 0 0 UnderlineThickness 1 0 gt gt def The Encoding array maps character codes integers to character names All unused positions in the encoding vector must be filled with the name notdef It is special in only one regard if some encoding maps to a character name that does not exist in the font notdef is substituted The effect produced by executing notdef character is at the discretion of the font designer but most often it is the same as space Encoding 256 array def O 1 255 Encoding exch notdef put for The CharacterProcedures dictionary contains in dividual character definitions The name is not special any name could be used but this name is assumed by the BuildGlyph procedure below CharacterProcedures 256 dict def Each character must invoke one of the setcachede vice and setcharwidth operators before executing graphics operators to define and paint t
8. AILR DAIL ES f tQ 52 4XT57 Listen sons of Kahless Listen his daughters Fig 15 Klingon font 23 We can also send our classic love poems to elves The elves write vowels over the preceding letter unless it is also a vowel This case and the case when a vowel starts a word are handled by other rules 18 p r isl pg 5 pedo mols od r po nj p o sb gd you Fig 16 Tengwar font 24 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting 31 W odzimierz Bzyl It appears that that all these rules can be imple mented with an appropriate ligature and kerning table What was considered unreadable yesterday is readable today People are more visually sophisti cated and typographically savvy than ever before so my next font contains ideograms for love and for some other emotions as well as letters iG OS S gt gt Y 8 VETAPOST f Fig 17 Redis font see also 28 Special math fonts can be useful too We could use them on title pages or on slides In the example below math characters are colored according to their math class as defined in plain format Below binary operators are painted in green large operators in magenta etc In the pdf version not on paper C C 1 0 0 M l B 1 8 0 CLO E def 00 9 2 CO CO 9 9 i a az elf v qxdy 00 00 00 r 00 Jae r 0 j 7 8 Fig 18 New Punk Math font see also 19
9. The files thus created must be assembled into a font This task is done by the mkfont3 Perl script Additionally the font must be made available to TEX and instructions must be given to tell TEX how to switch to this font GGO Let s create a font which contain one character named plus Use an ascii text editor it does not have to be your favorite any such editor works to create a file called plus 000 mp that contains the following lines of text Fach font program should name the font it creates font name Plus 000 These names are merely comments which help to understand large collections of PostScript fonts family name Plus font version O Ofinal is fixed pitch true and following names play similar r le in the TEX world font identifier PLUS 000 font coding scheme FONT SPECIFIC The mpost program does all its drawing on its internal graph paper We establish a 100 x 100 coordinate space on it grid_size 100 The font matrix array is used to map all glyphs to PostScript s 1 x 1 coordinate space This convention allows consistent scaling of characters which come from different fonts font_matrix 1 grid_size 0 0 1 grid_size 0 0 This particular font matrix will scale a plus shape by the factor 1 100 in the x dimensions and by the same factor in the y dimension If we had choosen scaling by the factor 1 50 then the plus shape would have appeared twice as large as characters from other fonts T
10. board clearxy the dangerous bend numeric heavyline heavyline 27 X5 w Xo X5 Xo 80 ri T2 T5 To T3 T4 Vo ys loh y ya sh ya ys 1u h pickup pencircle scaled heavyline interim linecap butt draw zo 21 21 20 za za Z f 25 Z4 25 withcolor c Dangerous Bend labelcolor white dotcolor white labels ft 1 2 3 4 5 labels rt 0 endpic 11 57 11 VII 2001 RI Fig 13 Hardcopy proof of the dangerous bend TAO In font programming two type of errors appear bugs in font program and design errors Bugs are treated in an ordinary way To catch design errors I use hardcopy produced by the mft program We have the tools so it s high time to start programming Let s start from the beginning The Phoenician font lacks vowels There are three ways of writing with this font Lines may be written from left to right right to left or left to right right to left etc with letters on every other line reflected vertically It could be a real challenge to typeset a Phoenician script with TEX It gt TII IT gt T BE P F FEFIETIE To our Lady Ishtar This is the holy place Fig 14 Phoenician font 26 TEX could be used to communicate with the STAR TREK crew we only need their font No problem there is nothing special about this font except the extraordinary shapes of the symbols and the use of few ligatures f tQ M
11. bove and stores it in the array named in the second argument find outlines vertical stem horizontal stem glyph Now we are ready to draw the plus symbol fill outline glyph Finally we fix the width of the glyph to w and its left and right sidebearings to 0 fix hsbw w 0 0 36 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting Each symbol should include so called hints 8 p 56 57 that make it render better on a wide variety of devices fix hstem py horizontal stem fix vstem px vertical stem To make our hardcopy proofs more readable we define some construction points see the figure below dotlabels 0 1 2 3 The last two macros end the subprogram for plus symbol and the whole font program endglyph endfont Now we can create a TFM file Type 1 font and dvips fontmap file with the command mkfonti plus mp The plus character just constructed is used to print the divider line below H The hardcopy proof below was typeset with the command mkproofi u plus map plus mp def fill_outline suffix s for i 1 upto Spum if turningnumber s i gt 0 Fill else unFill fi s i endfor enddef def butt end text nodes cut rel 90 nodes enddef numeric pz pr 100 numeric py py 90 default nib fix nib pz py 0 path vertical stem horizontal stem glyph beginfont encode p
12. e color of plus to yellow and the pen width to 5 units The code to be executed could be read from a separate file see below on how to prepare and use such a 34 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting file Thus we can make a variation of this design or re parameterize the font without changing the master plus 000 mp file Such a mechanism is required to avoid populating our hard disks with similar files mode setup The Type3 library makes it convenient to define glyphs by starting each one with beginpic code width height depth where code is either a quoted single character like or a number that represents the glyph position in the font The other three numbers say how the big the glyph bounding box is The command endpic finishes the plus glyph Each beginpic operation assigns values to special variables called w h and d which represent respective width height and depth of the current glyph bounding box Other pseudo words are part of METAPOST language and are explained in 6 beginpic 100u 100 0 plus interim linecap butt drawoptions withcolor stem color pickup pencircle scaled stem width draw w 2 d w 2 h draw 0 h d 2 w h d 2 endpic Finally each font program should end with the endfont command endfont Now we are ready to compile the font with mpost and assemble generated glyphs into Type 3 font with one command mkfon
13. echniques have been used to write carve cut and print symbols Handwriting used to be the most common technique The Phoenicians invented an alphabetic font which is a precursor of the Greek Latin and Cyrillic fonts The inscription of Fig 3 was originally written on papyrus Ksk AY55FSGN TJ 442 31 2o HH OADEL Ay IKI KIC KYAT IA O39 Fig 3 Phoenician inscription Byblos 1100 B C Handwriting can reveal the author s personality which makes this technique interesting Wouldn t it be nice to have a psychological portrait of this author Fig 4 shows a fragment of a poem written by probably the greatest Polish poet Cyprian Kamil Norwid This poem seems to move every Pole who reads it I think that the same poem printed along with several others in Computer Modern Garamond Times or Palatino would not have the manuscript in Polish 1865 1866 Sa s gs Im e eaa me rapa sio o cu s Bipajeszeczyj sz ge ane y m E t rom LJ ES my t LE Niemm mis A ssgess ge m BE feinem ul Sitominmiatin rete r 1 CES 3 LN a eth p k eg La ao o oou0 Fig 5 Calendarium Parisiense manuscript Latin ca 1425 same impact on readers Maybe this is why I don t like reading poems which all look the same 1 But the main problem caused by handwriting and computer typesetting too is the appearance of overfull and underfull lines These in some cases can not be eliminated F
14. ference Manual Ad dison Wesley 10 Bogus aw Jackowski et al 1999 Antykwa P tawskiego a parameterized outline font Eu ro TEX 99 Proceedings Ruprecht Karls Univerit t Heidelberg 117 141 11 Bogustaw Jackowski Janusz M Nowacki and Piotr Strzelczyk 2001 METATYPE1 A Meta Post based engine for generating Type 1 fonts EuroTEX 2001 Proceedings Kerkrade the Nether lands 111 119 12 W odzimierz Bzyl 2001 Re introducing Type 3 fonts to the world of TEX EurolEX 2001 Pro ceedings Kerkrade the Netherlands 219 243 13 Apostolos Syropoulos 2000 The MF2PT3 tool Available online from www obelix ee duth gr apostolo 14 Rob Carter 1997 Experimental Typography A RotoVision Book Watson Guptill Publications 15 Frantisek Muzika 1965 Die Sch ne Schrift Verlag Werner Dausien Hanau Main Vol I amp II 16 Halina Th rzewska Ed 2000 More Precious Than Gold Treasures of the Polish National Li brary Biblioteka Narodowa Warszawa 17 Charlotte amp Peter Fiell 1999 William Morris 1834 1896 Benedikt Taschen Verlag GmbH 18 J R R Tolkien 1981 The Fellowship of the Ring Spldzielnia Wydawnicza Czytelnik Warszawa 19 Donald E Knuth 1988 A Punk Meta Font TUGboat 9 152 168 20 Richard M Stallman and Roland McGrath GNU Make Available online as a part of GNU MAKE package 21 Per Cederqvist et al Version Management with CVS Available o
15. gramming In the Appendix I present a detailed description of Type 3 fonts 6 9 Typographical journey Exploring type with computer is fun and ultimately it changes the way you think about type and work with it ROB CARTER Experimental Typography Throughout history people used have symbols to visually encode thoughts and feelings The oldest example I was able to find in the literature is an inscription from La Pasiega cave UL W I Fig 1 Inscription from La Pasiega cave Spain ca 10000 B C Unfortunately the meaning of the symbols was lost in the past so that we don t know how to decode this inscription As a result we don t know exactly what it means we can only guess Other Fig 2 Magical stamps ancient symbols are found on pikes and bows It is assumed that they are some kind of owner s signature or that they have a magical value so that they bring luck to the owner etc Nowadays we still use symbols in similar way Probably everyone has at least once received a mail overprinted with CONFIDENTIAL you have been chosen to be rich You can take part in our lottery draw All you have to do is to subscribe our magazine Pictographs ideograms and alphabets have been written and reproduced on papyrus stones wood clay tablets paper and computer displays TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting 27 W odzimierz Bzyl and different t
16. he char acter The setcachedevice operator stores the bitmapped image of the character in the font cache However caching will not work if color or gray is used In such cases the setcharwidth operator should be used which is similar to setcachede vice but declares that the character being defined is not to be placed in the font cache Wy Wy ly ly Uz Uy setcachedevice Wz Wy comprise the basic width vector i e the normal position of the origin of the next character relative to origin of this one lz ly us uy are the coordinates of this character bounding box Wz Wy setcharwidth Wz Wy comprise the basic width vector of this character CharacterProcedures notdef 1000 0 0 0 1000 1000 setcachedevice 1000 O moveto put Encoding 32 space put CharacterProcedures space 1000 O O O 1000 1000 setcachedevice 1000 O moveto put Encoding 83 square put ASCII S CharacterProcedures square 1000 0 setcharwidth O 1 10 setcmykcolor red 0 0 1000 1000 rectfill put The BuildGlyph procedure is called within the confines of a gsave and a grestore so any changes BuildGlyph makes to the graphics state do not persist after it finishes BuildGlyph should describe the character in terms of absolute coordinates in the character coordinate system placing the character origin at 0 0 in this space The Current Transformation Matrix CTM and the graphics state are inherited from the envi ron
17. he data below provides information about how to typeset with this font A font quad is the unit of measure that a TEX user calls one em when this font is selected The normal space stretch and shrink parameters define the interword spacing when text is being typeset in this font A font like this is hardly ever used to typeset anything apart from the plus but the spacing parameters have been included just in case somebody wants to typeset several pluses separated by quads or spaces font_quad 100 font_normal_space 33 font_normal_stretch 17 font_normal_shrink 11 Another more or less ad hoc unit of measure is x height In TEX this unit is available under the name ex It it used for vertical measurements that depend on the current font for example for accent positioning font x height 100 The plus font is an example of a parameterized font A single program like this could be used to produce infinite variations of one design For example by changing the parameters below we could make the plus character paint in a different color or make it thicker color plus color pius color red u 1 unit width pen_width 10 The mode_setup macro could be used to over ride all the settings done above Typically it is used to tell the mpost program to generate a font metric file or proofsheets Additionally mode_setup could execute any piece of valid METAPOST code at this point For example we could change th
18. ig 5 shows the earliest example I was able to find Another technique is cutting in stone The shapes in Fig 6 are more regular partly because bigger letters were sketched beforehand This picture shows the earliest example of serifs ever found The serifs are functioning here as a way of finishing letters which otherwise would be irregular and wiggly ended Nowadays we think that serif fonts are easier and quicker to read This is generally true because letters without serifs in some cases looks similar to each other for example I I1 L T But I would be very grateful if my doctor chose to use Computer Modern on my prescriptions cannot imagine books or newspapers carved in stone Nevertheless there was once an exception I have seen Fred Flintstone reading newspapers But this was a long time ago down in the Bed Rock 28 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting ABCCD EFGHIK LAANO KOLS TVX Fig 6 Rome ca 200 B C Fig 7 shows the 32nd page of one of the first printed books in Poland This book is very important because it contains designs for Polish diacritics aogonek eogonek etc The borders were cut in wood and letters in metal The printed letters are much smaller than carved ones so cutting them was a real challenge yet even tiny serifs are present This technique was perfected over the years The results are seen on Fig 8 Here borders were cut in wood and the
19. lus 43 standard introduce plus beginglyph plus w 760 h 760 d 0 29 w 2 d iz w 2 h 22 0 h d 2 23 w h d 2 pen stroke butt_end 0 1 zo 21 vertical_stem pen stroke butt_end 0 1 za 2g horizontal_stem find_outlines vertical_stem horizontal stem glyph fill outline glyph fix hsbw w 0 0 fix hstem py horizontal stem fix vstem pz vertical_stem dotlabels 0 1 2 3 endglyph endfont 21 05 17 X 2002 PLUS 3 TAO Appendix This description is somewhat simplified in respect to the examples to be found in 6 9 Each Type 3 font should begin with two lines of comments PS AdobeFont 1 0 Square 1 00 A CreationDate 1 May 2001 A Type 3 font consists of a single dictionary possibly containing other dictionaries with certain required entries The dictionary of size 99 should suffice for fonts which consists of several characters 99 dict begin This dictionary should include following entries Variable FontType indicates how the character information is organized for Type 3 fonts it has to be set 3 u Variable LanguageLevel is set to the minimum PostScript language level required for correct behavior of the font Array FontMatrix transforms the character coordinate system into the user coordinate system This matrix maps font characters to one unit coordinate space which enables the PostScript interpre
20. ment To ensure predictable results despite font caching BuildGlyph must initialize any graphics state parameter on which it depends In particular if BuildGlyph executes the stroke operator it should explicitly set dash parameters line cap line join line width These initializations are unneces sary if characters are not cached for example if the setcachedevice operator is not used When a PostScript language interpreter tries to show a character from a font and the character is not already present in the font cache it pushes current font dictionary and character name onto the operand stack The BuildGlyph procedure must remove these two objects from the operand 38 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting stack and use this information to render the re quested character This typically involves finding the character procedure and executing it BuildGlyph stack font charname exch begin initialize graphics state parameters turn dashing off solid lines 0 setdash projecting square cap 2 setlinecap miter join O setlinejoin thickness of lines rendered by 4 execution of the stroke operator 50 setlinewidth the miter limit controls the stroke operator s treatment of corners this is the default value and it causes cuts off mitters at 22 23 gt USN 22 23 23 23 22 angles less than 11 degrees 10 setmiterlimit CharacterProcedures exch get exec end bind def cur
21. n polish the shape as long as we wish and we can not ruin the shape with the one wrong decision as can happen with traditional tools and materials One of the limitations of this technique is shown in Fig 11 Printing a symbol by computer means putting the imaginary sheet on the screen This sheet can be expanded contracted or skewed we can apply any geometrical transformation to it Unfortunately the results may not be satisfactory 94 o 9424 9444 9444 Fig 11 for example the stop sign in the third row has lost its white border and the inscription is hardly readable We could repair this if it would be possible to drop the border and scale the inscription less but the operation is unfeasible because the computer does not know which numbers in the character design are responsible for the border and which for the inscription So the only way to produce a better font at small sizes is to make it from scratch Since some will inevitably use an enlarged version of this font instead of the original one and chaos will ensue Imagine a country where each town has slightly different traffic signs Programming fonts Typographic standards make type more readable but readability has become a relative concept The immediacy of personal computers and the World Wide Web has raised the level of typographic literacy computers are used to stretch typographic boundaries 14 Before we start to explore type with com
22. nline with the CVS package Signum Support AB 22 Mark Shoulson 1994 Okuda Font METRFONT source available online from CTAN fonts okuda 23 Karol Jarmakiewicz 2002 Czcionka Klingonska Instytut Matematyki Uniwersytet Gda ski Su D I oo e TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting 39 W odzimierz Bzyl 24 Mieszko Zieli ski 2002 Kto i dlaczego wymy li 29 Alan M Stanier 1994 METRFONT source Tengwar Instytut Matematyki Uniwersytet Gda available online from CTAN fonts iching ski 30 Les aw Furmaga 1999 Ortofrajda Pamieciowo 26 Wojciech G rski 2002 Font Fenicki Instytut wzrokowy s ownik ortograficzny dla dzieci INTE Matematyki Uniwersytet Gda ski GRAF Sopot 27 S awomir Lis 2002 Pismo R czne Instytut 31 Jan Jelinek 1977 Wielki Atlas Prahistorii Matematyki Uniwersytet Gda ski Cz owieka Pa stwowe Wydawnictwo Rolnicze 28 Jacek Neuman 2002 Just Smiley Instytut i Le ne Warszawa Matematyki Uniwersytet Gda ski 40 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting
23. ollows the usual font administration stuff Each font should define several variables 9 Tables 5 14 pf info familyname Plus pf_info_fontname Plus Regular pf info weight Normal pf info version 1 0 pf_info_fixedpitch true pf info author Anonymous 2002 pf info creationdate The mpost program does all its drawing on its internal graph paper with 1000 x 1000 coordinate space on it The data below provides information about how to typeset with this font pf info quad 760 pf info capheight 760 pf info xheight 760 pf info space 333 The adl suffix here is a mnemonic for Ascender Descender and Lineskip pf_info_adl 750 250 0 The PostScript fill operator is used to paint the entire region closed by the current path For each path the non zero winding number rule 9 p 161 determines whether a given point is inside a path This behaviour is simulated by the Fill and unFill macros The fill_outline macro for each closed path stored in the array s 1 s num fills or unfills it based on its turning number 4 p 111 def fill outline suffix s for i 1 upto s num if turningnumber s i gt 0 Fill else unFill fi s il endfor enddef The plus sign has squared off ends Macro butt end simplifies the task of cutting of ends of paths def butt end text nodes cut rel 90 nodes enddef A horizontal line of the same width as a vertical line seems thicker To avoid this optical illusion
24. ped to a crayon with different colors corresponding to different letters Instead of writing a problematic letter the child uses the appropriate crayon to draw a rectangle After a while the crayons are removed This method is supplemented by appropriate books and dictionaries The following text demonstrates the extreme case in which every letter is problematic TAO Ilike this kind of writing so why take off crayons TYPE DESIGN BAN BE HAZARDOUR TO YOUR OTHER INTERES TR ONE YOW GET HOOKED YOU WILL DEVELOP INTENSE FEELINGS ABOWT LETTERFOR R THE EDIB WILL INTRSDE ON THE BRAGRi THAT YOW READ AND YOW WILL PERPETWA LY BE THINKING OF I PRO E ENIE TO THE FONTS THAT YOU SEE EVERYWHERE ESPEWIA Y THOSE OF YOUR OWN DESIGN DONALD E KNUTH The METAFONTbook Type 3 font example Fonts are collections of programmed shapes There are several kinds of fonts Each type of font has its own convention for organizing and representing the information within it The PostScript language defines the following types of fonts 8 p 322 0 1 2 3 9 10 11 14 32 42 Text fonts are mostly of Type 1 which are programmed with special procedures To execute efficiently and to produce more legible output these procedures use features common to collections of black amp white letter like shapes The procedures may not be used outside a Type 1 font While any graphics symbol may be programmed as a character in a Type 1 font
25. puters we should ask What is the right way to create digitized patterns for printing or displaying In this section I will try to convey some of my excitement about experiments with the tools I have created since I think that I am going in the right direction see also 3 To play with and to explore fonts I use a set of UNIX tools To this set I added the DOS batch files forming the METATYPE1 package by the JNS team 11 which I converted to UNIX scripts The language for font programming is METR POST To make a METRPOST font usable we must convert it into something that printing and type setting systems can understand I chose PostScript Type 1 or Type 3 font programs mainly be cause Ghostscript a free PostScript interpreter is available on almost every computer platform The Linux version of the tools consists of METAPOST font libraries and four scripts 30 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting Fig 12 Fonts programming mkfonti converts METRPOST font sources to Type 1 font a shell script that uses programs mpost tiasm from the tlutils package and awk mkfont3 converts METRPOST font sources to Type 3 font a perl script that calls mpost mkproofi and mkproof3 scripts that produce hardcopy proofs and are used as debugging tools they call mpost and the mft pretty printer SIGN 000 MP beginpic 127 250 125 0 Dangerous bend draw post draw info sign
26. rentdict end of font dictionary Finally we register the font name as a font dic tionary defined above and associate it with the key Square Additionally the definefont operator checks if the font dictionary is a well formed Square exch definefont pop If the following lines are not commented out the Ghostscript program a public domain PostScript interpreter will show the text below online Obvi ously these lines should be commented out in the final version of the font program Square findfont 72 scalefont setfont O 72 moveto S show showpage References 1 John D Hobby 1992 A User s Manual for Meta Post Technical Report 162 AT amp T Bell Labora tories Murray Hill New Jersey Available online as a part of METAPOST distribution 2 Donald E Knuth 1982 The Concept of a Meta Font Visible Language 16 3 27 3 Donald E Knuth 1985 Lessons Learned from METAFONT Visible Language 19 35 53 TAO 4 Donald E Knuth 1986 The METAFONTbook American Mathematical Society and Addison Wesley Donald E Knuth 1992 Computer Modern Typefaces Addison Wesley Adobe Systems Incorporated 1985 Tutorial and Cookbook Addison Wesley Adobe Systems Incorporated 1992 The Post Script Font Handbook Addison Wesley Adobe Systems Incorporated 1993 3rd print ing Version 1 1 Adobe Type 1 Font Format Addison Wesley Adobe Systems Incorporated 1999 3rd print ing PostScript Language Re
27. rently for example more technical It suffices to change few numbers which define this font But it would be difficult to simulate other important features of handwritten scripts such as variable baseline variable letters shape pressure of script The next example shows the I Ching font see also 29 The I Ching or The Book of Changes is an old Chinese oracle This font could be used to do divinations With computers it is easy Ask a question press Enter key and your computer will do the rest On the next page I put results obtained 32 TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting LI To Shine Brightly to Part NS PO WS lt A A My Ss ly OD DA 7 NS D Ss et SS PO id SS Pek xk INTERPRETATION To Part It is useful to stand firm and behave well This will bring success Take care of the cows There will be good fortune Interpretation of the 4th change line It comes unexpectedly It is like a fire which dies down and is discarded during my presentation at the TUG 2002 meeting in Trivandrum Nowadays children in Poland have more and more problems with orthography There are many pairs of letters which cause them problems For example the letters oacute and u are pronounced the same way b and p are pronounced almost the same way etc The following trick is used to teach orthography to children with dyslexia 22 Each problematic letter is map
28. t3 plus 000 To use Plus 000 font in a TEX document it suffices to insert these lines font X plus 000 at 10pt centerline X quad quad This code produces the seven red pluses below H A font cannot be proved faultless If some glyphs are defective the best way to correct them is to look at a big hardcopy proof that shows what went wrong The hardcopy for the Plus 000 font could be generated with the following shell command mkproof3 u plus 000 map plus 000 mp To see characters from a PostScript Plus 000 font the DVI file must be processed by DVIPS see the explanations at the end of this section TAO ooo As mentioned above it is not wise to make one time only variation of a font by changing the font source To change font parameters mode setup is used in conjuction with the change mode macro used I will explain this last sentence with an example Assume that fictitious document doc tex uses Plus 000 font and the font program reside in the file plus 000 mp The default color of the plus symbol is red To create a variation of the font with the plus symbol painted in yellow we re parameterize it using a file named doc mp with the following content mode def plus yellow message yellow final create metric file font name Plus b00 plus color 1 1 0 enddef Now we can create a TFM file Type 3 font and dvips fontmap file with the command mkfont3 change mode
29. ter to scale font characters properly This font uses a 1000 unit grid Array of four numbers FontBBox gives lower left lz ly and upper right uz uy coordinates of the smallest rectangle enclosing the shape that would result if all characters of the font were placed with their origins coincident and then painted This information is used in making decisions about character caching and clipping If all four values are zero no as sumptions about character bounding box are made FontType 3 def LanguageLevel 2 def FontMatrix 0 001 O 0 0 001 0 0 def FontBBox O O 1000 1000 def The FontInfo dictionary is optional All infor mation stored there is entirely for the benefit of PostScript language programs using the font or for documentation FamilyName a human readable name for a group of fonts All fonts that are members of such a group should have exactly the same FamilyName FullName unique human readable name for an individual font Should be the same name as one used when registering the font with the definefont operator below u Notice copyright if applicable TUGboat Volume 23 2002 No 1 Proceedings of the 2002 Annual Meeting 37 W odzimierz Bzyl u Weight name for the boldness attribute of a font u version version number of the font program u ItalicAngle angle in degrees counterclock wise from the vertical of the dominant vertical strokes of the font
30. we use an elliptical pen numeric px px 100 numeric py py 90 default_nib fix_nib px py 0 These names are intended to make the code more readable path vertical_stem horizontal_stem path glyph Fach glyph should be defined within a block defined by beginfont and endfont commands beginfont Programmed symbols must be given names as well as positions in the font encode plus 43 Each glyph starts with beginglyph and ends with endglyph macro The following macros initialize several variables used for the glyph data bookkeep ing standard introduce plus beginglyph plus For convenience the width height and depth of the character are assigned to variables w h and d w 760 h 760 d 0 The horizontal and vertical bars of the plus glyph are centered with respect its bounding box z0 w 2 d zi w 2 h z2 0 h d 2 z3 w h d 2 To draw paths z0 zi and z2 z3 the pen with a default nib shaped nib is used The macro pen stroke finds the outline of each path Out lines are assigned to the paths vertical stem and horizontal stem lhe macro butt end cuts off the ends of these paths at times 0 beginning and 1 end pen stroke butt end 0 1 z0 z1 vertical stem pen stroke butt end 0 1 z2 z3 horizontal stem Programming a Type 1 glyph means constructing its outline which could be made up of several cyclic paths The macro below finds the outline of the paths constructed a
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