;; GUJR-OTF.flt -- Font Layout Table for Gujarati OpenType fonts
;; Copyright (C) 2004
;;   National Institute of Advanced Industrial Science and Technology (AIST)
;;   Registration Number H15PRO112

;; This file is part of the m17n database; a sub-part of the m17n
;; library.

;; The m17n library is free software; you can redistribute it and/or
;; modify it under the terms of the GNU Lesser General Public License
;; as published by the Free Software Foundation; either version 2.1 of
;; the License, or (at your option) any later version.

;; The m17n library is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; Lesser General Public License for more details.

;; You should have received a copy of the GNU Lesser General Public
;; License along with the m17n library; if not, write to the Free
;; Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; <li> GUJR-OTF.flt
;;;
;;; For Gujarati OpenType fonts to draw the Gujarati script.
;;; Tested with padmaa-Medium-1.5.ttf <http://www.indictrans.org/>

(category
 ;; C: general consonant
 ;; R: RA
 ;; V: independent vowel
 ;; H: HALANT
 ;; m: MATRA (pre)
 ;; u: MATRA (above)
 ;; b: MATRA (below)
 ;; p: MATRA (post)
 ;; A: vowel modifier (above)
 ;; a: vowel modifier (post)
 ;; N: ZWNJ (ZERO WIDTH NON-JOINER)
 ;; J: ZWJ (ZERO WIDTH JOINER)
 ;; E: ELSE
 ;;
 (0x200C	?N)			; ZWNJ
 (0x200D	?J)			; ZWJ
 (0x0964	?E)			; DANDA
 (0x0965	?E)			; DOUBLE DANDA
 (0x0A80 0x0AFF	?E)			; ELSE
 (0x0A81	?A)			; SIGN CANDRABINDU
 (0x0A82	?A)			; SIGN ANUSVARA
 (0x0A83	?a)			; SIGN VISARGA
 (0x0A85 0x0A94	?V)			; LETTER AA .. LETTER AU
 (0x0A95 0x0AB9 ?C)			; LETTER KA .. LETTER HA
 (0x0AB0	?R)			; LETTER RA
 (0x0ABC	?n)			; SIGN NUKTA
 (0x0ABE 	?p)			; VOWEL SIGN AA (post)
 (0x0ABF	?m)			; VOWEL SIGN I (pre)
 (0x0AC0	?p)			; VOWEL SIGN II (post)
 (0x0AC1 0x0AC4	?b)			; VOWEL SIGN U, UU, R, RR (below)
 (0x0AC5 0x0AC8	?u)			; VOWEL SIGN CANDRA E, E, AI (above)
 (0x0AC9 0x0ACC	?p)			; VOWEL SIGN CANDRA O, O, AU (post)
 (0x0ACD	?H)			; SIGN VIRAMA (HALANT)
 (0x0AE0 0x0AE1	?V)			; LETTER VOCALIC RR, LL
 (0x0AE2 0x0AE3	?b)			; VOWEL SIGN VOCALIC RR, LL (below)
 (0x0AFF	?X)			; internal use
 )

;; Step 1 : Syllable identification, Reph and base consonant movements.
(generator
 (0
  (cond
   ;; A syllable ending with a vowel sign and/or a vowel modifier.
   ("(([CR]n?H)*[CR]n?)([mubp][Aa]?|[Aa])"
    < | (1 move-reph-vattu) (3 = *) | >)

   ;; Forced Halant or half form.
   ("(([CR]n?H)*[CR]n?)(H[NJ])"
    < | (1 move-reph-vattu) (3 = =) | >)

   ;; A syllable without a vowel sign nor a vowel modifier.
   ("([CR]n?H)*[CR]n?H?"
    < | move-reph-vattu | >)

   ;; A syllable starting with an independent vowel.
   ("V[Aa]?"
    < |  = * | >)

   ("." =))
  *)

 ;; Move the leading RH and the Halant on the base consonant to
 ;; appropriate positions.
 ;; 0x0AFF indicates the destination of below-, above-, post Matras.
 (move-reph-vattu
  (cond
   ;; Ending with Halnt.  Immitate a forced Halant form.
   ("(.*)(H)$"
    (1 move-reph-vattu) (2 =) 0x200C)

   ;; Both Reph and Vattu.
   ;;1   23                4  5
   ("(RH)(([CR]n?H)*[CR]n?)(H)(R)$"
    (2 = *) (5 =) (4 =) 0x0AFF (1 = =))

   ;; A special case of above.
   ("(RH)(R)$"
    (2 =) 0x0AFF (1 = =))

   ;; Reph but no Vattu.
   ("(RH)(([CR]n?H)*Cn?)$"
    (2 = *) 0x0AFF (1 = =))

   ;; No Reph but Vattu.
   ("(Cn?(H[CR]n?)*)(H)(R)$"
    (1 = *) (4 =) (3 =) 0x0AFF)

   ;; Neither Reph nor Vattu.
   (".*"
    = * 0x0AFF))))

;; Step 2 : Matra movements and OTF forms.
(generator
 (0
  (cond
   ;; 1    2        3    4   5       6
   (" (RH)?([^X ]*)X(RH)?(m)?([bup])?([Aa])? "
    |
    (4 =)
    (1 otf:gujr=~rphf,~blwf,*)
    (2 otf:gujr=~rphf,*)
    (5 =)
    (3 otf:gujr=rphf)
    (6 =)
    |)

   (" (RH)?([^X ]*)X(RH)?(HJ) "
    |
    (1 = =)
    (2 otf:gujr=~rphf)
    (3 otf:gujr=rphf)
    (4 = =)
    |)

   (" (RH)?([^X ]*)X(RH)?(H)N "
    |
    (1 otf:gujr=~rphf,~blwf,*)
    (2 otf:gujr=~rphf,*)
    (3 otf:gujr=rphf)
    (4 =)
    |)

   ("." =))
  *))

;; Step 3 : OTF substitutions and positionings.
(generator
 (0
  (cond
   (" (.*)J "
    (1 otf:gujr=~rphf,~blwf,*))
   (" ([^ ]*) "
    (1 otf:gujr=~rphf,~blwf,~half,~haln,*))
   ("."
    [ otf:gujr=+ ]))
  *))

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