third_party/ots/src/cvt.cc

   1 // Copyright (c) 2009 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 "cvt.h"
   6
   7 // cvt - Control Value Table
   8 // http://www.microsoft.com/typography/otspec/cvt.htm
   9
  10 #define TABLE_NAME "cvt"
  11
  12 namespace ots {
  13
  14 bool ots_cvt_parse(Font *font, const uint8_t *data, size_t length) {
  15   Buffer table(data, length);
  16
  17   OpenTypeCVT *cvt = new OpenTypeCVT;
  18   font->cvt = cvt;
  19
  20   if (length >= 128 * 1024u) {
  21     return OTS_FAILURE_MSG("Length (%d) > 120K");  // almost all cvt tables are less than 4k bytes.
  22   }
  23
  24   if (length % 2 != 0) {
  25     return OTS_FAILURE_MSG("Uneven cvt length (%d)", length);
  26   }
  27
  28   if (!table.Skip(length)) {
  29     return OTS_FAILURE_MSG("Length too high");
  30   }
  31
  32   cvt->data = data;
  33   cvt->length = length;
  34   return true;
  35 }
  36
  37 bool ots_cvt_should_serialise(Font *font) {
  38   if (!font->glyf) {
  39     return false;  // this table is not for CFF fonts.
  40   }
  41   return font->cvt != NULL;
  42 }
  43
  44 bool ots_cvt_serialise(OTSStream *out, Font *font) {
  45   const OpenTypeCVT *cvt = font->cvt;
  46
  47   if (!out->Write(cvt->data, cvt->length)) {
  48     return OTS_FAILURE_MSG("Failed to write CVT table");
  49   }
  50
  51   return true;
  52 }
  53
  54 void ots_cvt_reuse(Font *font, Font *other) {
  55   font->cvt = other->cvt;
  56   font->cvt_reused = true;
  57 }
  58
  59 void ots_cvt_free(Font *font) {
  60   delete font->cvt;
  61 }
  62
  63 }  // namespace ots
  64
  65 #undef TABLE_NAME