Цифрлық типография жүйелері мен қаріптік мүмкіндіктер

None
Typographic features made possible using digital typographic systems have solved many of the demands placed on computer systems to replicate traditional typography and have expanded the possibilities with many new features. Three systems are in common use: OpenType, devised by Microsoft and Adobe, Apple's Apple Advanced Typography (AAT), and SIL's Graphite. The lists below provide information about OpenType and AAT features. Graphite does not have a fixed set of features; instead it provides a way for fonts to define their own features.

The OpenType format defines a number of typographic features that a particular font may support. Some software, such as Adobe InDesign, LibreOffice/OpenOffice, or recent versions of Lua/XeTeX, gives users control of these features, for example to enable fancy stylistic capital letters (swash caps) or to choose between ranging (full height) and non ranging (old style, or lower case) digits. Some web browsers also support OpenType features in accordance with the CSS Fonts Module Level 3 specification, which allows OpenType features to be set directly via the property, or indirectly by means of higher level mechanisms. The following tables list the features defined in version 1.8.1 of the OpenType specification. The codes in the "type" column are explained after the tables. OpenType features may be applicable only to certain language scripts or specific languages, or in certain writing modes. The features are split into several tables accordingly.

Long name tag type DescriptionAbove base Formsabvf S1 Replaces the above base part of a vowel sign. For Khmer and similar scripts. Above base Mark Positioningabvm P4,5 Positions a mark glyph above a base glyph. Above base Substitutionsabvs S4 Ligates a consonant with an above mark. Below base Formsblwf S4 Replaces halant+consonant combination with a subscript form. Below base Mark Positioningblwm P4,5 Positions a mark glyph below a base glyphBelow base Substitutionsblws S4 Ligates a consonant with a below mark. Pre base Formspref S4 Replaces halant+consonant at the end of a consonant cluster with a glyph at the beginning. Khmer, Myanmar, Malayalam, TeluguPre base Substitutionspres S4,5 Ligates consonant combinations. Post base Substitutionspsts S4 Ligates a final consonant+consonant. Post base Formspstf S4 Substitutes final halant+consonant with special form. Khmer and Gurmukhi, MalayalamDistancedist P2 Adjusts horizontal positioning between glyphs. (Always enabled, as opposed to 'kern'. )Akhandakhn S4 Hindi for unbreakable. Ligates consonant+halant+consonant, usually only for k ss and j ny combinations. Halant Formshaln S4 Replaces a glyph for final consonant+halant. Half Formhalf S4 Replaces consonant+halant with a half form, indicating it is part of a conjunct. Nukta Formsnukt S4 Replace consonant+nukta (dot mark) with single glyph. Rakar Formsrkrf S4 Replaces halant+ra with a rakar glyph, indicating it is part of a conjunct. Reph Formrphf S4 Replaces initial ra+halant with a final reph mark, indicating part of a conjunct. Vattu Variantsvatu S4 Replaces consonant+rakar combinations with a vattu variant ligature. Conjunct Formscjct S4 Ligates consonant+halant+consonant, indicates part of a conjunct. Conjunct Form After Rocfar S1 Khmer

Long name tag type DescriptionSimplified Formssmpl S1 Replaces sinograms with their simplified versions, may be language dependentTraditional Formstrad S1,3 Replaces Chinese characters with their traditional versions Traditional Name Formstnam S1Japanese alternates for proper namesExpert Formsexpt S1 Typographic alternatives for some Japanese tetragramsHojo Kanji Formshojo Hojo alternates for Japanese tetragramsNLC Kanji Formsnlck NLC alternates for Japanese tetragramsJIS 78 Formsjp78 S1,3 JIS C 6226 1978 alternates for Japanese tetragrams, not accessible per UnicodeJIS 83 Formsjp83 S1JIS X 0208 1983 alternates for Japanese tetragrams, not accessible per UnicodeJIS 90 Formsjp90 S1 JIS X 0208 1990 alternates for Japanese tetragrams, not accessible per UnicodeJIS 04 Formsjp04 JIS 2004 alternates for Japanese tetragrams, not accessible per UnicodeHangulhngl S1,3 Transliterates Chinese style characters with Korean HangulLeading Jamo Formsljmo S4 Initial group of consonants for a synthesized Korean Hangul tetragramTrailing Jamo Formstjmo S4 Final group of consonants for a synthesized Korean Hangul tetragramVowel Jamo Formsvjmo S4 Medial group of vowels for a synthesized Korean Hangul tetragramFull Widthsfwid S1 Substitutes proportionally spaced character with full width versions (esp. for Latin letters within Chinese)Half Widthshwid S1,P1 Substitutes uniformly spaced characters with half width versionAlternate Half Widthshalt P1 Re positions full width glyphs on half width spacesThird Widthstwid S1,P1 Substitutes uniformly spaced character with a version of 1/3 width (punctuation, etc. )Quarter Widthsqwid S1 Replaces uniformly spaced glyphs with quarter width ones (punctuation etc. )Proportional Widthspwid S1 Replaces uniformly spaced glyphs with proportional onesProportional Alternatespalt P1 Re positions otherwise monospace characters according to glyph widthProportional Kanapkna S1 Kana for use alongside alphabets, without grid typographyRuby Notation Formsruby S1 Ruby characters, small printHorizontal Kana Alternateshkna S1 Alternate forms for horizontal kana text, e. g. ー for chōonpu instead of ｜, cf. vknaVertical Kanavkna S1 Alternate Japanese kana forms for vertical text, e. g. ｜ for chōonpu instead of ー, cf. hknaCentered CJK Punctuationcpct P1 Positions punctuation marks vertically and horizontally

Long name tag type DescriptionSmall Capssmcp S1 Substitutes lower case letters with small caps versionsCapitals to Small Capsc2sc S1 Substitutes capital letters with small capsPetite Capspcap S1 Substitute lower case letters with their petite caps analogsCapitals to Petite Capsc2pc S1 Substitutes capital letters with petite capsUnicaseunic S1 Replaces lowercase and uppercase letters with a set of single case glyphsCapital Spacingcpsp P1 Adjusts spacing between letters in all capitals textCase Sensitive Formscase P1 Replace characters, especially punctuation, with forms better suited for all capital text, cf. titlItalicsital S1 Replaces letter with corresponding italic glyphOrdinalsordn S6,4 Replaces characters with ordinal forms for use after numbers

Long name tag type DescriptionLining Figureslnum S1 Replaces numerals with glyphs meant to fit better in all capitals text, often also tnumOldstyle Figuresonum S1 Replaces numerals with cased old style numerals, often also pnumProportional Figurespnum S1 Replaces numerals with glyphs of proportional width, often also onumTabular Figurestnum S1 Replaces numerals with glyphs of uniform width, often also lnumFractionsfrac S4 Converts figures separated by slash with diagonal fractionAlternative Fractionsafrc S4 Converts figures separated by slash with alternative stacked fraction formDenominatordnom S1 Converts to appropriate fraction denominator form, invoked by fracNumeratornumr S1 Converts to appropriate fraction numerator form, invoked by fracScientific Inferiorssinf S1 as in "H2O", "SOx" or "YCbCr" (but using the same font weight and predefined position in contrast these plain HTML subs and sups)Slashed Zerozero S1 Replaces 0 figure with slashed 0Mathematical Greekmgrk S1 Replaces Greek characters with special forms for use in mathematicsFlattened accent formsflac This feature is applied to individual glyphs during layout of math formula. Dotless Formsdtls The dotless forms are to be used as base forms for placing mathematical accents over them. Math script style alternatesssty This feature can have a parameter indicating the script level: 1 for simple subscripts and superscripts, 2 for second level subscripts and superscripts (that is, scripts on scripts), and so on. (Currently, only the first two alternates are used). For glyphs that are not covered by this feature, the original glyph is used in subscripts and superscripts.

Long name tag type DescriptionAccess All Alternatesaalt S1,3 Special feature: used to present user with choice all alternate forms of the characterSwashswsh S1,3 Either replaces character with or displays multiple swashed versionsContextual Swashcswh S8 Converts letter to a swashed version based on characters around the letterContextual Alternatescalt S6 Applies a second substitution feature based on a match of a character pattern within a context of surrounding patternsHistorical Formshist S1 Obsolete forms of characters to be applied at the user's discretion, cf. hligLocalized Formslocl S1 Substitutes character with the preferred form based on script languageRandomizerand S3 Replaces character with random forms (meant to simulate handwriting)Alternate Annotation Formsnalt S1,3 Provides user access to circled digits, inverse letters etc. Character Variant 1–99cv01–cv99 S3 Multiple variants of a single character, which may not apply to many other characters, see references for voluminous documentationStylistic Alternatessalt S1,3 Either replaces with, or displays list of, stylistic alternatives for a characterStylistic Set 1 – 20ss01 ss20 S1 Replaces character with one from a font specific set of stylistic alternativesSubscriptsubs S1 Replaces character with subscript version, cf. numrSuperscriptsups S1 Replaces character with superscript version, cf. dnomTitling Alternatestitl S1 Replaces characters with forms suited for large type, as in titlesRequired Variation Alternatesrvrn S1 Special variants of a single character, which need apply to specific font variation, required by variable fontsContextual Ligaturesclig S8 Applies a second ligature feature based on a match of a character pattern within a context of surrounding patternsDiscretionary Ligaturesdlig S4 Ligatures to be applied at the user's discretionHistorical Ligatureshlig S1 Obsolete ligatures to be applied at the user's discretionStandard Ligaturesliga S4 Replaces (by default) sequence of characters with a single ligature glyph

Long name tag type DescriptionGlyph Composition/Decompositionccmp S4,2 Either calls a ligature replacement on a sequence of characters or replaces a character with a sequence of glyphs. Provides logic that can for example effectively alter the order of input characters. Kerningkern P2,8 Fine horizontal positioning of one glyph to the next, based on the shapes of the glyphsMark Positioningmark P4,5 Fine positioning of a mark glyph to a base characterMark to mark Positioningmkmk P6 Fine positioning of a mark glyph to another mark characterOptical Boundsopbd P1 Re positions glyphs at beginning and end of line, for precise justification of text. Left Boundslfbd P1 Re positions glyphs at end of line. Called by opbd. Right Boundsrtbd P1 Re positions glyphs at beginning of line. Called by opbd.

Long name tag type DescriptionOptical sizesize Not a lookup: feature's table provides to applications information about the appearance and intent of the font, to aid in font selection. Ornamentsornm S3,1 Decorative alternates for the bullet character •

Below are listed the OpenType lookup table types, as used in the "type" column in the above tables. S stands for substitution, and P stands for positioning. Note that often a feature can be implemented by more than one type of table, and that sometimes the specification fails to explicitly indicate the table type. abbrev. type description S1 GSUB 1 simple substitution of one glyph with another S2 GSUB 2 multiple substitution of one character by several glyphs S3 GSUB 3 variant selection S4 GSUB 4 ligatures S5 GSUB 5 contextual substitution S6 GSUB 6 chained contextual substitution S7 GSUB 7 extension for GSUB tables past 64kB S8 GSUB 8 reverse chained contextual substitution P1 GPOS 1 positioning of single glyph P2 GPOS 2 positioning of pair of glyphs P3 GPOS 3 cursive attachment P4 GPOS 4 positioning of mark glyphs relative to base P5 GPOS 5 positioning of mark glyphs relative to ligature P6 GPOS 6 positioning of mark glyphs relative to another mark glyph P7 GPOS 7 contextual positioning P8 GPOS 8 extended contextual positioning P9 GPOS 9 extension for GPOS tables past 64kB