lisp/language/indian.el

   1 ;;; indian.el --- Indian languages support -*- coding: iso-2022-7bit; -*-
   2
   3 ;; Copyright (C) 1999, 2001 Free Software Foundation, Inc.
   4
   5 ;; Maintainer:  KAWABATA, Taichi <kawabata@m17n.org>
   6 ;; Keywords:    multilingual, i18n, Indian
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; This file defines in-is13194 coding system and relationship between
  28 ;; indian-glyph character-set and various CDAC fonts.
  29
  30 ;;; Code:
  31
  32 (make-coding-system
  33  'in-is13194 2 ?D
  34  "8-bit encoding for ASCII (MSB=0) and IS13194-Devanagari (MSB=1)."
  35  '(ascii indian-is13194 nil nil
  36    nil ascii-eol)
  37  `((safe-chars . ,(let ((table (make-char-table 'safe-chars nil)))
  38                     (set-char-table-range table 'indian-is13194 t)
  39                     (dotimes (i 127)
  40                       (aset table i t)
  41                       (aset table (decode-char 'ucs (+ #x900 i)) t))
  42                     table))
  43    (post-read-conversion . in-is13194-post-read-conversion)
  44    (pre-write-conversion . in-is13194-pre-write-conversion)))
  45
  46 (define-coding-system-alias 'devanagari 'in-is13194)
  47
  48 (defvar indian-font-foundry 'cdac
  49   "Font foundry for Indian characters.
  50 Currently supported foundries are `cdac' and `akruti'.")
  51
  52 (defvar indian-script-language-alist
  53   "Alist of Indian scripts vs the corresponding language list and font foundry.
  54 Each element has this form:
  55
  56   (SCRIPT LANGUAGE-LIST FONT-FOUNDRY)
  57
  58 SCRIPT is one of Indian script names.
  59
  60 LANGUAGE-LIST is a list of Indian langauge names SCRIPT is used for.
  61 The list is in the priority order.
  62
  63 FONT-FOUNDRY is a font foundry representing a group of Indian
  64 fonts.  If the value is nil, the value of `indian-font-foundry'
  65 is used."
  66   '((devanagari (hindi sanskrit) nil)
  67     (bengali (bengali assamese) nil)
  68     (gurmukhi (punjabi) nil)
  69     (gujarati (gujarati) nil)
  70     (oriya (oriya) nil)
  71     (tamil (tamil) nil)
  72     (telugu (telugu) nil)
  73     (kannada (kannada) nil)
  74     (malayalam (malayalam) nil)))
  75
  76 (defconst indian-font-char-index-table
  77   '(                                    ; for which language(s)
  78     ;; CDAC fonts
  79     (#x0000 . cdac:dv-ttsurekh)         ; hindi, etc
  80     (#x0100 . cdac:sd-ttsurekh)         ; sanskrit
  81     (#x0200 . cdac:bn-ttdurga)          ; bengali
  82     (#x0300 . cdac:tm-ttvalluvar)       ; tamil
  83     (#x0400 . cdac:tl-tthemalatha)      ; telugu
  84     (#x0500 . cdac:as-ttdurga)          ; assamese
  85     (#x0600 . cdac:or-ttsarala)         ; oriya
  86     (#x0700 . cdac:kn-ttuma)            ; kannada
  87     (#x0800 . cdac:ml-ttkarthika)       ; malayalam
  88     (#x0900 . cdac:gj-ttavantika)       ; gujarati
  89     (#x0A00 . cdac:pn-ttamar)           ; punjabi
  90
  91     ;; AKRUTI fonts
  92     (#x0B00 . akruti:dev)               ; hindi, etc
  93     (#x0C00 . akruti:bng)               ; bengali
  94     (#x0D00 . akruti:pnj)               ; punjabi
  95     (#x0E00 . akruti:guj)               ; gujarati
  96     (#x0F00 . akruti:ori)               ; oriya
  97     (#x1000 . akruti:tml)               ; tamil
  98     (#x1100 . akruti:tlg)               ; telugu
  99     (#x1200 . akruti:knd)               ; kannada
 100     (#x1300 . akruti:mal)               ; malayalam
 101     )
 102   "Aliat of indices of `indian-glyph' character vs Indian font identifiers.
 103 Each element has this form: (INDEX . FONT-IDENTIFIER)
 104
 105 INDEX is an index number of the first character in the charset
 106 `indian-glyph' assigned for glyphs in the font specified by
 107 FONT-IDENTIFIER.  Currently FONT-IDENTIFIERs are defined for CDAC
 108 and AKRUTI font groups.")
 109
 110 (defun indian-font-char (index font-identifier)
 111   "Return character of charset `indian-glyph' made from glyph index INDEX.
 112 FONT-IDENTIFIER is an identifier of an Indian font listed in the
 113 variable `indian-font-char-index-table'.  It specifies which
 114 font INDEX is for."
 115   (if (or (< index 0) (> index 255))
 116       (error "Invalid glyph index: %d" index))
 117   (let ((start (car (rassq font-identifier indian-font-char-index-table))))
 118     (if (not start)
 119         (error "Unknown font identifier: %s" font-identifier))
 120     (setq index (+ start index))
 121     (make-char 'indian-glyph (+ (/ index 96) 32) (+ (% index 96) 32))))
 122
 123 ;; Return a range of characters (cons of min and max character) of the
 124 ;; charset `indian-glyph' for displaying SCRIPT in LANGUAGE by a font
 125 ;; of FOUNDRY.
 126
 127 (defun indian-font-char-range (font-identifier)
 128   (cons (indian-font-char 0 font-identifier)
 129         (indian-font-char 255 font-identifier)))
 130
 131 (defvar indian-script-table
 132   '[
 133     devanagari
 134     sanskrit
 135     bengali
 136     tamil
 137     telugu
 138     assamese
 139     oriya
 140     kannada
 141     malayalam
 142     gujarati
 143     punjabi
 144     ]
 145   "Vector of Indian script names.")
 146
 147 (let ((len (length indian-script-table))
 148       (i 0))
 149   (while (< i len)
 150     (put (aref indian-script-table i) 'indian-glyph-code-offset (* 256 i))
 151     (setq i (1+ i))))
 152
 153 (defvar indian-default-script 'devanagari
 154   "Default script for Indian languages.
 155 Each Indian language environment sets this value
 156 to one of `indian-script-table' (which see).
 157 The default value is `devanagari'.")
 158
 159 (define-ccl-program ccl-encode-indian-glyph-font
 160   `(0
 161     ;; Shorten (r1 = (((((r1 - 32) * 96) + r2) - 32) % 256))
 162     (r1 = ((((r1 * 96) + r2) - ,(+ (* 32 96) 32)) % 256))))
 163
 164 (setq font-ccl-encoder-alist
 165       (cons (cons "-CDAC" 'ccl-encode-indian-glyph-font)
 166             font-ccl-encoder-alist))
 167
 168 (setq font-ccl-encoder-alist
 169       (cons (cons "-AKRUTI" 'ccl-encode-indian-glyph-font)
 170             font-ccl-encoder-alist))
 171
 172 (provide 'indian)
 173
 174 ;;; indian.el ends here