third_party/ots/src/vhea.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "vhea.h"
   6
   7 #include "gsub.h"
   8 #include "head.h"
   9 #include "maxp.h"
  10
  11 // vhea - Vertical Header Table
  12 // http://www.microsoft.com/typography/otspec/vhea.htm
  13
  14 #define TABLE_NAME "vhea"
  15
  16 namespace ots {
  17
  18 bool ots_vhea_parse(Font *font, const uint8_t *data, size_t length) {
  19   Buffer table(data, length);
  20   OpenTypeVHEA *vhea = new OpenTypeVHEA;
  21   font->vhea = vhea;
  22
  23   if (!table.ReadU32(&vhea->header.version)) {
  24     return OTS_FAILURE_MSG("Failed to read version");
  25   }
  26   if (vhea->header.version != 0x00010000 &&
  27       vhea->header.version != 0x00011000) {
  28     return OTS_FAILURE_MSG("Bad vhea version %x", vhea->header.version);
  29   }
  30
  31   if (!ParseMetricsHeader(font, &table, &vhea->header)) {
  32     return OTS_FAILURE_MSG("Failed to parse metrics in vhea");
  33   }
  34
  35   return true;
  36 }
  37
  38 bool ots_vhea_should_serialise(Font *font) {
  39   // vhea should'nt serialise when vmtx doesn't exist.
  40   // Firefox developer pointed out that vhea/vmtx should serialise iff GSUB is
  41   // preserved. See http://crbug.com/77386
  42   return font->vhea != NULL && font->vmtx != NULL &&
  43       ots_gsub_should_serialise(font);
  44 }
  45
  46 bool ots_vhea_serialise(OTSStream *out, Font *font) {
  47   if (!SerialiseMetricsHeader(font, out, &font->vhea->header)) {
  48     return OTS_FAILURE_MSG("Failed to write vhea metrics");
  49   }
  50   return true;
  51 }
  52
  53 void ots_vhea_reuse(Font *font, Font *other) {
  54   font->vhea = other->vhea;
  55   font->vhea_reused = true;
  56 }
  57
  58 void ots_vhea_free(Font *font) {
  59   delete font->vhea;
  60 }
  61
  62 }  // namespace ots
  63
  64 #undef TABLE_NAME