code.delx.au - gnu-emacs/blob - 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 <batta@beige.ocn.ne.jp>
   6 ;; Keywords:    multilingual, 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-charsets ascii indian-is13194)
  38    (post-read-conversion . in-is13194-post-read-conversion)
  39    (pre-write-conversion . in-is13194-pre-write-conversion)))
  40
  41 (defvar indian-script-table
  42   '[
  43     devanagari
  44     sanskrit
  45     bengali
  46     tamil
  47     telugu
  48     assamese
  49     oriya
  50     kannada
  51     malayalam
  52     gujarati
  53     punjabi
  54     ]
  55   "Vector of Indian script names.")
  56
  57 (let ((len (length indian-script-table))
  58       (i 0))
  59   (while (< i len)
  60     (put (aref indian-script-table i) 'indian-glyph-code-offset (* 256 i))
  61     (setq i (1+ i))))
  62
  63 (defvar indian-default-script 'devanagari
  64   "Default script for Indian languages.
  65 Each Indian language environment sets this value
  66 to one of `indian-script-table' (which see).
  67 The default value is `devanagari'.")
  68
  69 (defun indian-glyph-char (index &optional script)
  70   "Return character of charset `indian-glyph' made from glyph index INDEX.
  71 The variable `indian-default-script' specifies the script of the glyph.
  72 Optional argument SCRIPT, if non-nil, overrides `indian-default-script'.
  73 See also the function `indian-char-glyph'."
  74   (or script
  75       (setq script indian-default-script))
  76   (let ((offset (get script 'indian-glyph-code-offset)))
  77     (or (integerp offset)
  78         (error "Invalid script name: %s" script))
  79     (or (and (>= index 0) (< index 256))
  80         (error "Invalid glyph index: %d" index))
  81     (setq index (+ offset index))
  82     (make-char 'indian-glyph (+ (/ index 96) 32) (+ (% index 96) 32))))
  83
  84 (defvar indian-glyph-max-char
  85   (indian-glyph-char
  86    255 (aref indian-script-table (1- (length indian-script-table))))
  87   "The maximum valid code of characters in the charset `indian-glyph'")
  88
  89 (defun indian-char-glyph (char)
  90   "Return information about the glphy code for CHAR of `indian-glyph' charset.
  91 The value is (INDEX . SCRIPT), where INDEX is the glyph index
  92 in the font that Indian script name SCRIPT specifies.
  93 See also the function `indian-glyph-char'."
  94   (let ((split (split-char char))
  95         code)
  96     (or (eq (car split) 'indian-glyph)
  97         (error "Charset of `%c' is not indian-glyph" char))
  98     (or (<= char indian-glyph-max-char)
  99         (error "Invalid indian-glyph char: %d" char))
 100     (setq code (+ (* (- (nth 1 split) 32) 96) (nth 2 split) -32))
 101     (cons (% code 256) (aref indian-script-table (/ code 256)))))
 102
 103 (define-ccl-program ccl-encode-indian-glyph-font
 104   `(0
 105     ;; Shorten (r1 = (((((r1 - 32) * 96) + r2) - 32) % 256))
 106     (r1 = ((((r1 * 96) + r2) - ,(+ (* 32 96) 32)) % 256))))
 107
 108 (setq font-ccl-encoder-alist
 109       (cons (cons "-CDAC" 'ccl-encode-indian-glyph-font)
 110             font-ccl-encoder-alist))
 111
 112 (setq font-ccl-encoder-alist
 113       (cons '("ISO10646.*-1" . ccl-encode-unicode-font)
 114             font-ccl-encoder-alist))
 115
 116 (provide 'indian)
 117
 118 ;;; indian.el ends here