;;; <li> TELU-OTF.flt
;;;
-;;; For Telugu OpenType fonts to draw Telugu.
-;;; Designed for Pothana2000.ttf <http://www.kavya-nandanam.com/>
+;;; For Telugu OpenType fonts to draw the Telugu script.
(font layouter telu-otf nil
- (font (nil nil unicode-bmp :otf=telu=haln)))
+ (font (nil nil unicode-bmp :otf=telu=blwf)))
(category
- ;; C: general consonant
+ ;; C: consonant
;; H: HALANT
- ;; u: MATRA (above)
- ;; b: MATRA (below)
- ;; p: MATRA (post)
- ;; t: MATRA (two-part)
+ ;; u: vowel sign (above)
+ ;; p: vowel sign (post)
+ ;; b: ai length mark (below)
;; a: vowel modifier (post)
;; V: independent vowel
;; N: ZWNJ (ZERO WIDTH NON-JOINER)
;; J: ZWJ (ZERO WIDTH JOINER)
- ;; E: ELSE
- ;;
+ ;; X: generic
+ (0x0C00 0x0C7F ?E) ; generic
+ (0x0C01 0x0C03 ?a) ; SIGN CANDRABINDU .. VISARGA
+ (0x0C05 0x0C14 ?V) ; LETTER A .. AU
+ (0x0C15 0x0C39 ?C) ; LETTER KA .. HA
+ (0x0C3E 0x0C40 ?u) ; VOWEL SIGN AA .. II
+ (0x0C41 0x0C44 ?p) ; VOWEL SIGN U .. VOCALIC RR
+ (0x0C46 0x0C47 ?u) ; VOWEL SIGN E .. EE
+ (0x0C4A 0x0C4C ?u) ; VOWEL SIGN O .. AU
+ (0x0C4D ?H) ; SIGN VIRAMA
+ (0x0C55 ?u) ; LENGTH MARK
+ (0x0C56 ?b) ; AI LENGTH MARK
+ (0x0C60 0x0C61 ?V) ; LETTER VOCALIC RR .. VOCALIC LL
+ (0x0964 0x0965 ?X) ; DANDA .. DOUBLE DANDA
(0x200C ?N) ; ZWNJ
(0x200D ?J) ; ZWJ
- (0x0964 ?E) ; DANDA
- (0x0965 ?E) ; DOUBLE DANDA
- (0x0C00 0x0C7F ?E) ; ELSE
- (0x0C01 0x0C03 ?a) ; post signs
- (0x0C05 0x0C14 ?V) ; LETTER A .. LETTER AU
- (0x0C15 0x0C39 ?C) ; LETTER KA .. LETTER HA
- (0x0C3E 0x0C40 ?u) ; VOWEL SIGN AA, I, II (above)
- (0x0C41 0x0C44 ?p) ; VOWEL SIGN U, UU, R, RR (post)
- (0x0C46 0x0C47 ?u) ; VOWEL SIGN E, EE (above)
- (0x0C48 ?t) ; VOWEL SIGN AI (two-part)
- (0x0C4A 0x0C4C ?u) ; VOWEL SIGN O, OO, AU (above)
- (0x0C4D ?H) ; SIGN VIRAMA (HALANT)
- (0x0C55 ?u) ; LENGTH MARK (above)
- (0x0C56 ?b) ; AI LENGTH MARK (below)
- (0x0C60 0x0C61 ?V) ; LETTER VOCALIC RR, LL
- (0x0C7E ?Y) ; internal use
- (0x0C7F ?X) ; internal use
)
-;; Step 1 : Syllable identification and Halant movement.
+;; Decompose two-part vowels.
(generator
(0
(cond
- ;; A syllable containing a two-part vowel sign.
- ("(C(HC)*)(t)(a)?"
- < | (1 move-base-Halant) (3 0x0C46 0x0C56) (4 =) | >)
-
- ;; A syllable ending with vowel signs and/or a vowel modifier.
- ("(C(HC)*)([ubp]+a?|a)"
- < | (1 move-base-Halant) (3 = *) | >)
-
- ;; Forced Halant form
- ("(CH)N"
- < | (1 move-base-Halant) | >)
+ ((0x0C48)
+ 0x0C46 0x0C56)
+ ("." =))
+ *))
- ;; A syllable without a vowel sign nor a vowel modifier.
- ("C(HC)*H?"
- < | move-base-Halant | >)
+;; Syllable identification and reordering. The base consonant is
+;; always the first one, because all Telugu consonants have a below
+;; form.
+(generator
+ (0
+ (cond
+ ;; A syllable with a vowel sign.
+ ;;1 23 4 5
+ ("(C)((HC)*)(ub?|p)(a)?"
+ < | (1 =) (2 move-h) (4 = *) (5 =) | >)
+
+ ;; A syllable with a vowel modifier.
+ ;;1 23 4
+ ("(C)((HC)*)(a)"
+ < | (1 =) (2 move-h) (4 =) | >)
+
+ ;; No vowel signs, no vowel modifiers. If the syllable ends with a
+ ;; Halant, cancel the Halant movement.
+ ;;1 23 4
+ ("(C)((HC)*)(HN?)?"
+ < | (1 =) (4 0x0C4D) (2 move-h) | >)
;; A syllable starting with an independent vowel.
("Va?"
- < | = * | > )
+ < | = * | >)
("." =))
*)
- ;; Move Halant on the base consonant to the tail if the syllable ends
- ;; with a consonant.
- ;; A leading 0x0C7F means Halant movement.
- ;; A leading 0x0C7E means a syllable ending with a Halant.
- (move-base-Halant
+ (move-h
(cond
- (".*H$"
- 0x0C7E = *)
- ("(.)(H)(.*)"
- 0x0C7F (1 =) (3 = *) (2 =))
- (".*"
- = *))))
-
-;; Step 2 : Move Matra if applicable.
-;; The base consonant in a Halant-ending syllable is changed into Halant form.
-(generator
- (0
- (cond
- ;; 1 2 3 4 5 6
- (" X(.)([CH]*)(u)?(b)?(p)?(a)? "
- | (1 =) (3 =) (4 =) (5 =) (2 = *) (6 =) |)
- (" Y(..)([^ ]*) "
- | (1 otf:telu=haln) (2 = *) |)
- ("." =))
- *))
+ ("(H)(.+)"
+ (2 = *) (1 =)))))
-;; Step 3 : Drive OTF tables.
+;; Apply OTF features. In case of Telugu, 'akhn' is applied after
+;; reordering.
(generator
(0
(cond
- (" ([^ ]*) "
- (1 otf:telu))
+ ;; A syllable that ends with a Halant.
+ (" (CH)([^ ]*) "
+ (1 otf:telu=haln+) (2 otf:telu=akhn,blwf,abvs,blws,psts+abvm,blwm,dist))
+
+ ;; Ordinary syllables.
+ (" ([^ ]+) "
+ (1 otf:telu=akhn,blwf,abvs,blws,psts+absm,blwm,dist))
+
("."
- [ otf:telu=+ ]))
+ [ = ]))
*))
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