third_party/ots/src/layout.h

   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 #ifndef OTS_LAYOUT_H_
   6 #define OTS_LAYOUT_H_
   7
   8 #include "ots.h"
   9
  10 // Utility functions for OpenType layout common table formats.
  11 // http://www.microsoft.com/typography/otspec/chapter2.htm
  12
  13 namespace ots {
  14
  15
  16 struct LookupSubtableParser {
  17   struct TypeParser {
  18     uint16_t type;
  19     bool (*parse)(const Font *font, const uint8_t *data,
  20                   const size_t length);
  21   };
  22   size_t num_types;
  23   uint16_t extension_type;
  24   const TypeParser *parsers;
  25
  26   bool Parse(const Font *font, const uint8_t *data,
  27              const size_t length, const uint16_t lookup_type) const;
  28 };
  29
  30 bool ParseScriptListTable(const ots::Font *font,
  31                           const uint8_t *data, const size_t length,
  32                           const uint16_t num_features);
  33
  34 bool ParseFeatureListTable(const ots::Font *font,
  35                            const uint8_t *data, const size_t length,
  36                            const uint16_t num_lookups,
  37                            uint16_t *num_features);
  38
  39 bool ParseLookupListTable(Font *font, const uint8_t *data,
  40                           const size_t length,
  41                           const LookupSubtableParser* parser,
  42                           uint16_t* num_lookups);
  43
  44 bool ParseClassDefTable(const ots::Font *font,
  45                         const uint8_t *data, size_t length,
  46                         const uint16_t num_glyphs,
  47                         const uint16_t num_classes);
  48
  49 bool ParseCoverageTable(const ots::Font *font,
  50                         const uint8_t *data, size_t length,
  51                         const uint16_t num_glyphs,
  52                         const uint16_t expected_num_glyphs = 0);
  53
  54 bool ParseDeviceTable(const ots::Font *font,
  55                       const uint8_t *data, size_t length);
  56
  57 // Parser for 'Contextual' subtable shared by GSUB/GPOS tables.
  58 bool ParseContextSubtable(const ots::Font *font,
  59                           const uint8_t *data, const size_t length,
  60                           const uint16_t num_glyphs,
  61                           const uint16_t num_lookups);
  62
  63 // Parser for 'Chaining Contextual' subtable shared by GSUB/GPOS tables.
  64 bool ParseChainingContextSubtable(const ots::Font *font,
  65                                   const uint8_t *data, const size_t length,
  66                                   const uint16_t num_glyphs,
  67                                   const uint16_t num_lookups);
  68
  69 bool ParseExtensionSubtable(const Font *font,
  70                             const uint8_t *data, const size_t length,
  71                             const LookupSubtableParser* parser);
  72
  73 }  // namespace ots
  74
  75 #endif  // OTS_LAYOUT_H_
  76