hhea.lisp

   1 ;;; Copyright (c) 2006 Zachary Beane, All Rights Reserved
   2 ;;;
   3 ;;; Redistribution and use in source and binary forms, with or without
   4 ;;; modification, are permitted provided that the following conditions
   5 ;;; are met:
   6 ;;;
   7 ;;;   * Redistributions of source code must retain the above copyright
   8 ;;;     notice, this list of conditions and the following disclaimer.
   9 ;;;
  10 ;;;   * Redistributions in binary form must reproduce the above
  11 ;;;     copyright notice, this list of conditions and the following
  12 ;;;     disclaimer in the documentation and/or other materials
  13 ;;;     provided with the distribution.
  14 ;;;
  15 ;;; THIS SOFTWARE IS PROVIDED BY THE AUTHOR 'AS IS' AND ANY EXPRESSED
  16 ;;; OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  17 ;;; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18 ;;; ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  19 ;;; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20 ;;; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  21 ;;; GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22 ;;; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23 ;;; WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  24 ;;; NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  25 ;;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26 ;;;
  27 ;;; Loading data from the "hhea" table.
  28 ;;;
  29 ;;;  http://www.microsoft.com/OpenType/OTSpec/hhea.htm
  30 ;;;  http://developer.apple.com/fonts/TTRefMan/RM06/Chap6hhea.html
  31 ;;;
  32 ;;; $Id: hhea.lisp,v 1.4 2006/02/18 23:13:43 xach Exp $
  33
  34 (in-package #:zpb-ttf)
  35
  36 (defmethod load-hhea-info ((font-loader font-loader))
  37   (seek-to-table "hhea" font-loader)
  38   (with-slots (input-stream ascender descender line-gap)
  39       font-loader
  40     (let ((version (read-fixed input-stream)))
  41       (check-version "\"hhea\" table" version #x00010000))
  42     (setf ascender (read-fword input-stream)
  43           descender (read-fword input-stream)
  44           line-gap (read-fword input-stream))))
  45
  46 (defmethod horizontal-metrics-count ((font-loader font-loader))
  47   (seek-to-table "hhea" font-loader)
  48   (with-slots (input-stream) font-loader
  49     ;; Skip to the end, since all we care about is the last item
  50     (advance-file-position input-stream 34)
  51     (read-uint16 input-stream)))