;; DEVA-OTF.flt -- Font Layout Table for Devanagari OpenType font
;; Copyright (C) 2003, 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., 59 Temple Place, Suite 330, Boston, MA
;; 02111-1307, USA.

;;; <li> DEVA-OTF.flt
;;;
;;; For Devanagari OpenType fonts to draw the Devanagari script.

(category
 ;; C: consonant (except for R)
 ;; R: consonant RA
 ;; n: NUKTA
 ;; H: HALANT
 ;; m: MATRA (pre)
 ;; u: MATRA (above)
 ;; b: MATRA (below)
 ;; p: MATRA (post)
 ;; A: vowel modifier (above)
 ;; a: vowel modifier (post)
 ;; S: stress sign (above)
 ;; s: stress sign (below)
 ;; V: independent vowel
 ;; N: ZWNJ (ZERO WIDTH NON-JOINER)
 ;; J: ZWJ (ZERO WIDTH JOINER)
 ;; E: ELSE
 ;;
 (#x0900 #x097F	?E)			; ELSE
 (#x0901	?A)			; SIGN CANDRABINDU (above)
 (#x0902	?A)			; SIGN ANUSVARA (above)
 (#x0903	?a)			; SIGN VISARGA (post)
 (#x0905 #x0914	?V)			; LETTER A .. LETTER AU
 (#x0915 #x0939 ?C)			; LETTER KA .. LETTER HA
 (#x0930	?R)			; LETTER RA
 (#x093C	?n)			; SIGN NUKTA
 (#x093D	?E)			; SIGN AVAGRAHA
 (#x093E #x094C	?p)			; VOWEL SIGN (post)
 (#x093F	?m)			; VOWEL SIGN I (pre)
 (#x0941 #x0944	?b)			; VOWEL SIGN (below)
 (#x0945 #x0948	?u)			; VOWEL SIGN (above)
 (#x094D	?H)			; SIGN VIRAMA (HALANT)
 (#x0950	?E)			; OM
 (#x0951 #x0954	?S)		    ; STRESS SIGN or TONE MARK (above)
 (#x0952	?s)		    ; STRESS SIGN or TONE MARK (below)
 (#x0958 #x095E	?C)			; LETTER QA .. LETTER YYA
 (#x0960	?V)			; LETTER VOCALIC RR
 (#x0961	?V)			; LETTER VOCALIC LL
 (#x0962 #x0963	?b)			; VOWEL SIGN (below)
 (#x0964 #x0970	?E)			; DANDA .. ABBREVIATION SIGN
 (#x200C	?N)			; ZWNJ
 (#x200D	?J)			; ZWJ
 (#x097D	?x)		; internally used tag to indicate Reph
 (#x097E	?y)		; internally used tag to indicate Mpost
 (#x097F	?z)		; internally used tag to indicate Cbase
 )

;; The first stage is to extract a syllable and re-order characters in
;; it.
(generator
 (0
  (cond
   ;; If [CR]H is followed by ZWNJ/ZWJ, move ZWNJ/ZWJ to the head so
   ;; that the later stages find it quickly.
   ("([CR]n?H)([NJ])"
    < | (2 =) (1 = *) | > )

   ;; A syllable starting with RH (Reph) and ending with a vowel
   ;; and/or a vowel modifier.
   ("(RH)(([CR]n?H)*[CR]n?)([mubp][Aa]?[Ss]?|[Aa][Ss]?|[Ss])"
    < | (1 #x097D = =) (2 move-base-Halant) (4 reorder-post-base) | >)

   ;; A syllable starting with RH (Reph) and ending without a vowel
   ;; nor a vowel modifier.
   ("(RH)(([CR]n?H)*[CR]n?)(H)?"
    < | (1 #x097D = =) (2 move-base-Halant) (4 =) | >)

   ;; A syllable starting with the other consonant and ending with a
   ;; vowel and/or a vowel modifier.
   ("(([CR]n?H)*[CR]n?)([mubp][Aa]?[Ss]?|[Aa][Ss]?|[Ss])"
    < | (1 move-base-Halant) (3 reorder-post-base) | >)

   ;; A syllable starting with the other consonant and ending without
   ;; a vowel nor a vowel modifier.
   ("(([CR]n?H)*[CR]n?)(H)?"
    < | (1 move-base-Halant) (3 =) | >)

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

   ("." =))
  *)

 ;; Move Halant on a base consonant to the tail.
 (move-base-Halant
  (cond
   ("(([CR]n?H)*[CR]n?)(H)(R)"
    (1 = *)
    (4 =)
    (3 =))
   (".*"
    = *)))

 ;; Re-order post modifiers.
 (reorder-post-base
  ;; 12   3   4   5    67   8     9   10
  ("((m)|(u)|(b)|(p))?((A)|(a))?((S)|(s))?$"
   (2 =) (4 =) (10 =) (3 =) (5 =)
   #x097E
   (7 =) (9 =) (8))))

;; The second stage is to reorder Reph and Mpre.
(generator
 (0
  (cond
   (" [NJ]([^ ]*) "
    = *)
   (" (x(..))([CRnH]*) "
    | (3 = *) (2 otf:deva=rphf) |)
   (" (x(..))([CRnH]*)(m?)([^y]*)y([^ ]*) "
    | (4 =) (3 = *) (5 = *) (2 otf:deva=rphf) (6 = *) |)
   (" ([CRnH][CRnH]*) "
    = *)
   (" ([CRnH][CRnH]*)(m?)([^y]*)y([^ ]*) "
    | (2 =) (1 = *) (3 = *) (4 = *) |)
   ("." =))
  *))

;; The third stage is to drive OTF tables.  For the moment, we use
;; the default LangSys, and try all GSUB/GPOS features except for the
;; sequence followed by ZWNJ in which case try "nukt" and "haln"
;; features only.
(generator
 (0
  (cond
   (" N([^ ]*) "
    (1 otf:deva=nukt,haln))

   (" J([^ ]*) "
    (1 otf:deva))

   (" ([^ ]*)(CH) "
    (1 otf:deva=~rphf,*) (2 otf:deva=haln))

   (" ([^ ]*) "
    (1 otf:deva=~rphf,*))

   ("."
    \[ otf:deva=+ \] ))
  *))

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