admin/unidata/uvs.el

   1 ;;; uvs.el --- utility for UVS (format 14) cmap subtables in OpenType fonts.
   2
   3 ;; Copyright (C) 2014  Free Software Foundation, Inc.
   4
   5 ;; Author: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software: you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;; To extract a C array definition of a UVS table for the Adobe-Japan1
  25 ;; character collection from an IVD Sequences file, execute
  26 ;;   $ emacs -batch -l uvs.el \
  27 ;;      --eval '(uvs-print-table-ivd "IVD_Sequences.txt" "Adobe-Japan1")' \
  28 ;;      > uvs.h
  29
  30 ;;; Code:
  31
  32 (defun uvs-fields-total-size (fields)
  33   (apply '+ (mapcar (lambda (field) (get field 'uvs-field-size)) fields)))
  34
  35 ;;; Fields in Format 14 header.
  36 (defconst uvs-format-14-header-fields
  37   '(format length num-var-selector-records))
  38 (put 'format 'uvs-field-size 2)
  39 (put 'length 'uvs-field-size 4)
  40 (put 'num-var-selector-records 'uvs-field-size 4)
  41 (defconst uvs-format-14-header-size
  42   (uvs-fields-total-size uvs-format-14-header-fields))
  43
  44 ;;; Fields in Variation Selector Record.
  45 (defconst uvs-variation-selector-record-fields
  46   '(var-selector default-uvs-offset non-default-uvs-offset))
  47 (put 'var-selector 'uvs-field-size 3)
  48 (put 'default-uvs-offset 'uvs-field-size 4)
  49 (put 'non-default-uvs-offset 'uvs-field-size 4)
  50 (defconst uvs-variation-selector-record-size
  51   (uvs-fields-total-size uvs-variation-selector-record-fields))
  52
  53 ;;; Fields in Non-Default UVS Table.
  54 (defconst uvs-non-default-uvs-table-header-fields '(num-uvs-mappings))
  55 (put 'num-uvs-mappings 'uvs-field-size 4)
  56 (defconst uvs-non-default-uvs-table-header-size
  57   (uvs-fields-total-size uvs-non-default-uvs-table-header-fields))
  58
  59 ;;; Fields in UVS Mapping.
  60 (defconst uvs-uvs-mapping-fields '(unicode-value glyph-id))
  61 (put 'unicode-value 'uvs-field-size 3)
  62 (put 'glyph-id 'uvs-field-size 2)
  63 (defconst uvs-uvs-mapping-size
  64   (uvs-fields-total-size uvs-uvs-mapping-fields))
  65
  66 (defun uvs-alist-from-ivd (collection-id sequence-id-to-glyph-function)
  67   "Create UVS alist from IVD Sequences and COLLECTION-ID.
  68 The IVD (Ideographic Variation Database) Sequences are obtained
  69 from the contents of the current buffer, and should be in the
  70 form of IVD_Sequences.txt specified in Unicode Technical Standard
  71 #37.  COLLECTION-ID is a string specifying the identifier of the
  72 collection to extract (e.g., \"Adobe-Japan1\").
  73 SEQUENCE-ID-TO-GLYPH-FUNC is a function to convert an identifier
  74 string of the sequence to a glyph number.  UVS alist is of the
  75 following form:
  76   ((SELECTOR1 . ((BASE11 . GLYPH11) (BASE12 . GLYPH12) ...))
  77    (SELECTOR2 . ((BASE21 . GLYPH21) (BASE22 . GLYPH22) ...)) ...),
  78 where selectors and bases are sorted in ascending order."
  79   (let (uvs-alist)
  80     (goto-char (point-min))
  81     (while (re-search-forward
  82             (concat "^[[:blank:]]*"
  83                     "\\([[:xdigit:]]+\\) \\([[:xdigit:]]+\\)"
  84                     "[[:blank:]]*;[[:blank:]]*"
  85                     "\\(?:" (regexp-quote collection-id) "\\)"
  86                     "[[:blank:]]*;[[:blank:]]*"
  87                     "\\([^\n[:blank:]]+\\)"
  88                     "[[:blank:]]*$") nil t)
  89       (let* ((base (string-to-number (match-string 1) 16))
  90              (selector (string-to-number (match-string 2) 16))
  91              (sequence-id (match-string 3))
  92              (glyph (funcall sequence-id-to-glyph-function sequence-id)))
  93         (let ((selector-bgs (assq selector uvs-alist))
  94               (base-glyph (cons base glyph)))
  95           (if selector-bgs
  96               (setcdr selector-bgs (cons base-glyph (cdr selector-bgs)))
  97             (push (cons selector (list base-glyph)) uvs-alist)))))
  98     (dolist (selector-bgs uvs-alist)
  99       (setcdr selector-bgs
 100               (sort (cdr selector-bgs)
 101                     (lambda (bg1 bg2) (< (car bg1) (car bg2))))))
 102     (sort uvs-alist (lambda (sb1 sb2) (< (car sb1) (car sb2))))))
 103
 104 (defun uvs-int-to-bytes (value size)
 105   "Convert integer VALUE to a list of SIZE bytes.
 106 The most significant byte comes first."
 107   (let (result)
 108     (dotimes (i size)
 109       (push (logand value #xff) result)
 110       (setq value (lsh value -8)))
 111     result))
 112
 113 (defun uvs-insert-fields-as-bytes (fields &rest values)
 114   "Insert VALUES for FIELDS as a sequence of bytes to the current buffer.
 115 VALUES and FIELDS are lists of integers and field symbols,
 116 respectively.  Byte length of each value is determined by the
 117 'uvs-field-size' property of the corresponding field."
 118   (while fields
 119     (let ((field (car fields))
 120           (value (car values)))
 121       (insert (apply 'unibyte-string
 122                      (uvs-int-to-bytes value (get field 'uvs-field-size))))
 123       (setq fields (cdr fields) values (cdr values)))))
 124
 125 (defun uvs-insert-alist-as-bytes (uvs-alist)
 126   "Insert UVS-ALIST as a sequence of bytes to the current buffer."
 127   (let* ((nrecords (length uvs-alist))  ; # of selectors
 128          (total-nmappings
 129           (apply '+ (mapcar
 130                      (lambda (selector-bgs) (length (cdr selector-bgs)))
 131                      uvs-alist)))
 132          (non-default-offset
 133           (+ uvs-format-14-header-size
 134              (* uvs-variation-selector-record-size nrecords))))
 135     (uvs-insert-fields-as-bytes uvs-format-14-header-fields
 136                                 14
 137                                 (+ uvs-format-14-header-size
 138                                    (* uvs-variation-selector-record-size
 139                                       nrecords)
 140                                    (* uvs-non-default-uvs-table-header-size
 141                                       nrecords)
 142                                    (* uvs-uvs-mapping-size total-nmappings))
 143                                 nrecords)
 144     (dolist (selector-bgs uvs-alist)
 145       (uvs-insert-fields-as-bytes uvs-variation-selector-record-fields
 146                                   (car selector-bgs)
 147                                   0     ; No Default UVS Tables.
 148                                   non-default-offset)
 149       (setq non-default-offset
 150             (+ non-default-offset
 151                uvs-non-default-uvs-table-header-size
 152                (* (length (cdr selector-bgs)) uvs-uvs-mapping-size))))
 153     (dolist (selector-bgs uvs-alist)
 154       (uvs-insert-fields-as-bytes uvs-non-default-uvs-table-header-fields
 155                                   (length (cdr selector-bgs)))
 156       (dolist (base-glyph (cdr selector-bgs))
 157         (uvs-insert-fields-as-bytes uvs-uvs-mapping-fields
 158                                     (car base-glyph)
 159                                     (cdr base-glyph))))))
 160
 161 (defun uvs-dump (&optional bytes-per-line separator separator-eol line-prefix)
 162   "Print the current buffer as in representation of C array contents."
 163   (or bytes-per-line (setq bytes-per-line 8))
 164   (or separator (setq separator ", "))
 165   (or separator-eol (setq separator-eol ","))
 166   (or line-prefix (setq line-prefix "    "))
 167   (goto-char (point-min))
 168   (while (> (- (point-max) (point)) bytes-per-line)
 169     (princ line-prefix)
 170     (princ (mapconcat (lambda (byte) (format "0x%02x" byte))
 171                       (string-to-unibyte
 172                        (buffer-substring (point) (+ (point) bytes-per-line)))
 173                       separator))
 174     (princ separator-eol)
 175     (terpri)
 176     (forward-char bytes-per-line))
 177   (princ line-prefix)
 178   (princ (mapconcat (lambda (byte) (format "0x%02x" byte))
 179                     (string-to-unibyte
 180                      (buffer-substring (point) (point-max)))
 181                     separator))
 182   (terpri))
 183
 184 (defun uvs-print-table-ivd (filename collection-id
 185                                      &optional sequence-id-to-glyph-func)
 186   "Print a C array definition of a UVS table for IVD Sequences.
 187 FILENAME specifies the IVD Sequences file.  COLLECTION-ID is a
 188 string specifying the identifier of the collection to
 189 extract (e.g., \"Adobe-Japan1\").  SEQUENCE-ID-TO-GLYPH-FUNC is a
 190 function to convert an identifier string of the sequence to a
 191 glyph number, and nil means to convert \"CID\\+[0-9]+\" to the
 192 corresponding number."
 193   (or sequence-id-to-glyph-func
 194       (setq sequence-id-to-glyph-func
 195             (lambda (sequence-id)
 196               (string-match "\\`CID\\+\\([[:digit:]]+\\)\\'" sequence-id)
 197               (string-to-number (match-string 1 sequence-id)))))
 198   (let ((uvs-alist
 199          (with-temp-buffer
 200            (insert-file-contents filename)
 201            (uvs-alist-from-ivd collection-id
 202                                sequence-id-to-glyph-func))))
 203     (princ "/* Automatically generated by uvs.el.  */\n")
 204     (princ
 205      (format "static const unsigned char mac_uvs_table_%s_bytes[] =\n  {\n"
 206              (replace-regexp-in-string "[^_[:alnum:]]" "_"
 207                                        (downcase collection-id))))
 208     (with-temp-buffer
 209       (set-buffer-multibyte nil)
 210       (uvs-insert-alist-as-bytes uvs-alist)
 211       (uvs-dump))
 212     (princ "  };\n")))
 213
 214 ;;; uvs.el ends here