;;;
;;; For Malayalam OpenType fonts to draw the reformed Malayalam script.
+;; Tested with the following fonts. All of these fonts require Halant
+;; movement for syllable-final YA, LA and VA, but not for RA.
+
+;; AnjaliOldLipi.ttf
+;; Dyuthi3.ttf
+;; Kalyani121.ttf
+;; Meera_04.ttf
+;; Rachana_04.ttf
+;; RaghuMalayalamSans2.ttf
+;; suruma2.ttf
+
(category
- ;; C: consonant (except for R, B, and P)
- ;; R: consonant RA
- ;; B: consonant (below)
- ;; P: consonant (post)
+ ;; C: ordinary consonants (except P)
+ ;; P: consonants that have a post- or below-form
;; H: HALANT
;; m: vowel sign (pre)
;; b: vowel sign (below)
;; V: independent vowel
;; N: ZWNJ (ZERO WIDTH NON-JOINER)
;; J: ZWJ (ZERO WIDTH JOINER)
- ;; X: generic
;; Z: internal use
+ ;; X: generic
(0x0D00 0x0D7F ?X) ; generic
- (0x0D00 ?Z) ; internal use
+ (0x0D00 ?Z) ; internal use
(0x0D02 0x0D03 ?A) ; SIGN ANUSVARA .. VISARGA
(0x0D05 0x0D14 ?V) ; LETTER A .. AU
(0x0D15 0x0D39 ?C) ; LETTER KA .. HA
(0x0D2F ?P) ; LETTER YA
- (0x0D30 ?R) ; LETTER RA
- (0x0D32 ?B) ; LETTER LA
+ (0x0D32 ?P) ; LETTER LA
(0x0D35 ?P) ; LETTER VA
(0x0D3E 0x0D44 ?p) ; VOWEL SIGN AA .. VOCALIC RR
(0x0D46 0x0D48 ?m) ; VOWEL SIGN E .. AI
(0x200D ?J) ; ZWJ
)
+;; Stage 0
;; Decompose two-part vowels.
(generator
(0
("." =))
*))
+;; Stage 1
;; Syllable identification and reordering.
-;; Put the mark 0x0D00 before the first pre-base consonant and after
-;; the base consonant.
+;; Put the mark Z after the base consonant.
(generator
(0
(cond
;; A syllable with a left vowel sign.
- ;;1 2 3 4
- ("([CRBP](H[CRBP])*)(m)(p?A?)"
- < | (3 =) (1 get-rh) 0x0D00 (1 move-h) (4 = *) | >)
+ ;;1 2 3 4
+ ("([CP](H[CP])*)(m)(p?A?)"
+ < | (3 =) (1 move-h) (4 = *) | >)
;; A syllable with a right vowel sign, a below vowel sign
;; and/or a vowel modifier.
- ;;1 2 3
- ("([CRBP](H[CRBP])*)(bA?|pA?|A)"
- < | (1 get-rh) 0x0D00 (1 move-h) (3 = *) | >)
+ ;;1 2 3
+ ("([CP](H[CP])*)(bA?|pA?|A)"
+ < | (1 move-h) (3 = *) | >)
- ;; Explicit Halant / forced chillu form is cut off from the preceders.
- ("(([CRBP]H)*)([CRBP]H[NJ])"
- (1 cut-off) (3 < | = * | >))
+ ;; Explicit Halant / forced chillu form is separated from the
+ ;; preceding characters.
+ ;;12 3
+ ("(([CP]H)*)([CP]H[NJ])"
+ (1 < | cut-off | >) (3 < | = * | >))
;; A syllable with no vowel signs/modifiers.
- ("([CRBP](H[CRBP])*H?)"
- < | (1 get-rh) 0x0D00 (1 move-h) | >)
+ ("[CP](H[CP])*H?"
+ < | (0 move-h) | >)
;; Starting with an independent vowel.
- ("(VA?)"
- < | (1 = *) | >)
+ ("VA?"
+ < | (0 = *) | >)
("." =))
*)
- ;; Extract RH that will be moved to the left.
- (get-rh
- (cond
- (".+HR$"
- 0x0D30 0x0D4D)))
- ;; Move the halant after the base consonant to the end.
- ;; Fill the resulting gap with 0x0D00.
- ;; Remove final RH if any.
+ ;; Move the halant that follows the base consonant to the end.
(move-h
(cond
- ;; There is a C and the syllable ends with an R. Remove final RH.
- ("([CRBPH]*C)H([RBPH]*)R$"
- (1 = *) 0x0D00 (2 = *))
+ ;; All consonants are P's.
+ ("(P)(H)([PH]*)$"
+ (1 =) 0x0D00 (3 = *) (2 =))
- ;; The syllable ends other than R. Move H.
- ("([CRBPH]*C)(H)([RBPH]+)$"
+ ;; One or more Non-P consonants.
+ ("([CPH]*C)(H)([PH]+)$"
(1 = *) 0x0D00 (3 = *) (2 =))
- ;; No C and end with R. The first consonant will be the base. Remove RH.
- ("([RBP])H([RBPH]*)R$"
- (1 =) 0x0D00 (2 = *))
-
- ;; No C and not end with R. Move H.
- ("([RBP])(H)([RBPH]+)$"
- (1 =) 0x0D00 (3 = *) (2 =))
-
- ;; Otherwise, no need to move H.
+ ;; Otherwise, final consonant is not P. No need to move H.
(".+"
= * 0x0D00)))
- ;; If there are some letters make them a separate syllable.
+ ;; If there are some letters, make them a separate syllable.
(cut-off
(cond
- (".+"
- < | = * | >)))
+ ("[CP](H[CP])*H?"
+ (0 move-h))))
)
-;; Apply GSUB features.
-;; According to Microsoft Typography
-;; <http://www.microsoft.com/typography/otfntdev/malayot/features.htm>
-;; 'chillu' are generated with the 'haln' feature. However, some
-;; fonts generate them with 'half'.
+;; Stage 2
+;; Apply 'akhn' feature.
(generator
(0
(cond
;; Ordinary syllable. We must avoid applying 'blwf' and 'pstf' to
- ;; the first consonant. Also 'haln' and 'half' must be avoided
- ;; because chillu does not appear at the beginning of a word. Thus
- ;; we apply only 'akhn' here and postpone applying other features
- ;; to the next stage.
- ;; 1 2 3 4 5
- (" (m?(RH)?Z)([CRBPH]+)(Z)([RBPHbpA]*) "
- | (1 = *) (3 otf:mlym=akhn+) (4 =) (5 otf:mlym=blwf,pstf+) |)
+ ;; the first consonant if it is a P, but 'akhn' must be applied
+ ;; always. Other GSUB features are applied in the following
+ ;; satges.
- ;; Explicit Halant.
- (" [CRBP]HN "
- = *)
+ ;; 1 2 3 4
+ (" (m)?([CPH]*)(Z)([PHbpA]*) "
+ | (1 =) (2 otf:mlym=akhn+) (3 =) (4 otf:mlym=blwf,pstf+) |)
- ;; Forced chillu form.
- (" ([CRBP]H)(J) "
- | (1 otf:mlym=haln,half+) (2 =) |)
+ ("." =))
+ *))
- ;; Sequence that was cut off from a forced form. Again we apply
- ;; only 'akhn' here.
- (" ([CRBPH]+) "
- | (1 otf:mlym=akhn+) |)
+;; Stage 3
+;; Apply 'blwf' to non-initial glyphs.
+(generator
+ (0
+ (cond
+ ;; 1 2 3
+ (" (m?[^Z])([^Z ]*)(Z[^ ]*) "
+ | (1 = *) (2 otf:mlym=blwf+) (3 = *) |)
("." =))
*))
-;; Apply postoponed GSUB features to ordinary syllables.
+;; Stage 4
+;; Apply other language forms.
(generator
(0
(cond
- ;; Ordinary syllable.
- ;; 1 2 3 4
- (" (m?(RH)?Z[^Z])([^Z]*)(Z[^ ]*) "
- | (1 = *) (3 otf:mlym=blwf,half,pstf,haln+) (4 = *) |)
+ ;; All characters should have the 'half' form glyph, and 'pstf' is
+ ;; always applied after 'half'. Thus we do not need to worry
+ ;; about applying 'pstf' to the first glyph.
+ ;; 1 2 3
+ (" (m)?([^Z ]*)(Z[^ ]*) "
+ | (1 = *) (2 otf:mlym=half,pstf+) (3 = *) |)
- ;; Explicit Halant / Forced chillu must not change to others.
- (" ([^ ]+)[NJ] "
+ ;; Explicit Halant.
+ (" ([CP]H)N "
| (1 = *) |)
- ;; Cut off sequence.
- (" ([^ ])([^ ]*) "
- | (1 =) (2 otf:mlym=blwf,half,pstf,haln+) |)
+ ;; Forced chillu form. According to Microsoft Typography
+ ;; <http://www.microsoft.com/typography/otfntdev/malayot/features.htm>
+ ;; 'chillu' glyphs are generated with the 'haln' feature. However,
+ ;; some fonts generate them with 'half'.
+ (" ([CP]HJ) "
+ | (1 otf:mlym=haln,half+) |)
("." =))
*))
+;; Stage 5
;; Second reordering. If there are glyphs before the base, move left
-;; vowel sign and RH to the left of the base.
+;; vowel sign to the left of the base.
(generator
(0
(cond
- ;; 1 2 3 4 5
- (" (m)?(RH)?Z([^Z]*)([^Z])Z([^ ]*) "
- | (3 = *) (1 =) (2 otf:mlym=pstf+) (4 =) (5 = *) |)
+ ;; 1 2 3 4
+ (" (m)?([^Z ]*)([^Z])Z([^ ]*) "
+ | (2 = *) (1 =) (3 =) (4 = *) |)
("." =))
*))
-;; Apply substitutions and GPOS features.
+;; Stage 6
+;; Apply typographical forms, 'haln' and GPOS features.
(generator
(0
(cond
(" ([^ ]+) "
- (1 otf:mlym=pres,abvs,blws,psts+abvm,blwm,dist))
+ (1 otf:mlym=pres,abvs,blws,psts,haln+abvm,blwm,dist))
("."
[ = ]))
*))
projects / m17n / m17n-db.git / commitdiff