;; TAML-OTF.flt -- Font Layout Table for Tamil OpenType fonts
;; Copyright (C) 2004, 2006
;;   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> TAML-OTF.flt
;;;
;;; For Tamil OpenType fonts to draw Tamil.
;;; Fonts are available from <http://sourceforge.net/projects/tamillinux/>.

(category
 ;; C: general consonant
 ;; 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
 (0x0B80 0x0BFF	?E)			; ELSE
 (0x0B85 0x0B94	?V)			; LETTER AA .. LETTER AU
 (0x0B95 0x0BB9 ?C)			; LETTER KA .. LETTER HA
 (0x0BBE 	?p)			; VOWEL SIGN AA (post)
 (0x0BBF	?p)			; VOWEL SIGN I (post)
 (0x0BC0	?u)			; VOWEL SIGN II (above)
 (0x0BC1 	?b)			; VOWEL SIGN U (below)
 (0x0BC2	?b)			; VOWEL SIGN UU (below)
 (0x0BC6 0x0BC8	?m)			; VOWEL SIGN E, EE, AI (pre)
 (0x0BCA 0x0BCC	?t)			; VOWEL SIGN O, OO, AU (two-part)
 (0x0BCD	?H)			; VIRAMA
 (0x0BD7	?p)			; AU LENGTH MARK (post)
 )

;; Step 1 : Syllable identification.
(generator
 (0
  (cond
   ;; Special ligature SRI
   ((0x0BB8 0x0BCD 0x0BB0 0x0BC0)
    otf:taml=akhn)

   ;; A syllable ending with a two-part vowel sign.
   ("((CH)*C)(t)"
    < | (1 otf:taml=akhn) (3 two-part) | >)

   ;; A syllable ending with a vowel sign.
   ("((CH)*C)([mubp])"
    < | (1 otf:taml=akhn) (3 =) | >)

   ;; No vowel sign.
   ("(CH)*CH?"
    < | otf:taml=akhn | >)

   ;; A variation of AU.
   ((0x0B92 0x0BD7)
    0x0B94)

   ("." =))
  *)

 (two-part
  (cond
   ((0x0BCA)
    0x0BC6 0x0BBE)
   ((0x0BCB)
    0x0BC7 0x0BBE)
   ((0x0BCC)
    0x0BC6 0x0BD7))))

;; Step 2 : Matra movements.
(generator
 (0
  (cond
   (" ([^ mubp]*)([^ mubp])(m)?([ubp])? "
    | (1 = *) (3 =) (2 =) (4 =) |)
   ("." =))
  *))

;; Step 3 : OTF substitutions and positionings.
(generator
 (0
  (cond
   (" ([^ ]*) "
    (1 otf:taml))
   ("."
    [ otf:taml=+ ]))
  *))

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