SUPPORT_FEATURE.md

对于 OpenType Feature 的支持情况

｜2023 年 11 月 02 日｜

为了检测 cn-font-split 和最先进的浏览器对于各种 Opentype Feature 的支持程度，我们对非常多款字体进行了相应的视觉测试，保证其实现的严谨性。

下表来源为 Registered Features，我们用于记录测试进度。

我们的测试浏览器核心为 Webkit。它对 OpenType 的支持是最为全面和可靠的，Chromium 和 FireFox 都在不同程度上对字体排版的渲染进行了一些自定义的变更导致测试失败。

状态解释

1. ✅ 支持，并通过测试
2. ❌ 未进行测试，可能不支持
3. ⏺️ 部分支持，待验证
4. ⭕ 浏览器不支持

Status	Feature Tag	Friendly Name	测试说明
✅	aalt	Access All Alternates
✅	abvf	Above-base Forms
✅	abvm	Above-base Mark Positioning
✅	abvs	Above-base Substitutions
✅	afrc	Alternative Fractions
✅	akhn	Akhand
⏺️	blwf	Below-base Forms	harfbuzz 部分解析失效，部分成功
✅	blwm	Below-base Mark Positioning
✅	blws	Below-base Substitutions
✅	calt	Contextual Alternates
✅	case	Case-Sensitive Forms
✅	ccmp	Glyph Composition / Decomposition
❌	cfar	Conjunct Form After Ro
❌	chws	Contextual Half-width Spacing
✅	cjct	Conjunct Forms
✅	clig	Contextual Ligatures
⏺️	cpct	Centered CJK Punctuation	浏览器 unicode-range 部分形态位移
✅	cpsp	Capital Spacing
✅	cswh	Contextual Swash
✅	curs	Cursive Positioning
✅	cv01 –cv99	Character Variants
✅	c2pc	Petite Capitals From Capitals
✅	c2sc	Small Capitals From Capitals
✅	dist	Distances
✅	dlig	Discretionary Ligatures
✅	dnom	Denominators
⏺️	dtls	Dotless Forms	数学符号的支持不好
✅	expt	Expert Forms
❌	falt	Final Glyph on Line Alternates deprecated
✅	fin2	Terminal Forms #2
✅	fin3	Terminal Forms #3
✅	fina	Terminal Forms
❌	flac	Flattened accent forms
✅	frac	Fractions
✅	fwid	Full Widths
✅	half	Half Forms
✅	haln	Halant Forms
✅	halt	Alternate Half Widths
✅	hist	Historical Forms
✅	hkna	Horizontal Kana Alternates
✅	hlig	Historical Ligatures
❌	hngl	Hangul deprecated
✅	hojo	Hojo Kanji Forms (JIS X 0212-1990 Kanji Forms)
✅	hwid	Half Widths
✅	init	Initial Forms
✅	isol	Isolated Forms
✅	ital	Italics
✅	jalt	Justification Alternates
✅	jp78	JIS78 Forms
✅	jp83	JIS83 Forms
✅	jp90	JIS90 Forms
✅	jp04	JIS2004 Forms
✅	kern	Kerning
❌	lfbd	Left Bounds
✅	liga	Standard Ligatures
✅	ljmo	Leading Jamo Forms
✅	lnum	Lining Figures
✅	locl	Localized Forms
❌	ltra	Left-to-right alternates
❌	ltrm	Left-to-right mirrored forms
⏺️	mark	Mark Positioning
✅	med2	Medial Forms #2
✅	medi	Medial Forms
✅	mgrk	Mathematical Greek
✅	mkmk	Mark to Mark Positioning
❌	mset	Mark Positioning via Substitution
✅	nalt	Alternate Annotation Forms
✅	nlck	NLC Kanji Forms
✅	nukt	Nukta Forms
✅	numr	Numerators
✅	onum	Oldstyle Figures
❌	opbd	Optical Bounds
✅	ordn	Ordinals
✅	ornm	Ornaments
✅	palt	Proportional Alternate Widths
✅	pcap	Petite Capitals
✅	pkna	Proportional Kana
✅	pnum	Proportional Figures
✅	pref	Pre-Base Forms
✅	pres	Pre-base Substitutions
✅	pstf	Post-base Forms
✅	psts	Post-base Substitutions
✅	pwid	Proportional Widths
✅	qwid	Quarter Widths
✅	rand	Randomize
✅	rclt	Required Contextual Alternates
✅	rkrf	Rakar Forms
✅	rlig	Required Ligatures
✅	rphf	Reph Forms
❌	rtbd	Right Bounds
✅	rtla	Right-to-left alternates
✅	rtlm	Right-to-left mirrored forms
✅	ruby	Ruby Notation Forms
❌	rvrn	Required Variation Alternates
✅	salt	Stylistic Alternates
✅	sinf	Scientific Inferiors
❌	size	Optical size deprecated
✅	smcp	Small Capitals
✅	smpl	Simplified Forms
✅	ss01 -ss20	Stylistic Set
⏺️	ssty	Math script style alternates	数学的支持度不好
❌	stch	Stretching Glyph Decomposition
✅	subs	Subscript
✅	sups	Superscript
✅	swsh	Swash
✅	titl	Titling
✅	tjmo	Trailing Jamo Forms
❌	tnam	Traditional Name Forms
✅	tnum	Tabular Figures
✅	trad	Traditional Forms
✅	twid	Third Widths
✅	unic	Unicase
❌	valt	Alternate Vertical Metrics
⏺️	vatu	Vattu Variants	vatu 貌似在浏览器上实现不了，但是其字符可以通过另外的方式获得
❌	vchw	Vertical Contextual Half-width Spacing
⏺️	vert	Vertical Writing	浏览器 unicode-range 部分形态位移
⏺️	vhal	Alternate Vertical Half Metrics	浏览器 unicode-range 部分形态位移
✅	vjmo	Vowel Jamo Forms
⏺️	vkna	Vertical Kana Alternates
✅	vkrn	Vertical Kerning
✅	vpal	Proportional Alternate Vertical Metrics
✅	vrt2	Vertical Alternates and Rotation
❌	vrtr	Vertical Alternates for Rotation
✅	zero	Slashed Zero