1/*
2 * Copyright 2011 Google Inc. All Rights Reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "sfntly/tools/subsetter/glyph_table_subsetter.h"
18
19#include "sfntly/table/truetype/glyph_table.h"
20#include "sfntly/table/truetype/loca_table.h"
21#include "sfntly/tag.h"
22#include "sfntly/tools/subsetter/subsetter.h"
23#include "sfntly/port/exception_type.h"
24
25namespace sfntly {
26
27const int32_t kGlyphTableSubsetterTags[2] = {Tag::glyf, Tag::loca};
28
29GlyphTableSubsetter::GlyphTableSubsetter()
30    : TableSubsetterImpl(kGlyphTableSubsetterTags, 2) {
31}
32
33GlyphTableSubsetter::~GlyphTableSubsetter() {}
34
35bool GlyphTableSubsetter::Subset(Subsetter* subsetter,
36                                 Font* font,
37                                 Font::Builder* font_builder) {
38  assert(font);
39  assert(subsetter);
40  assert(font_builder);
41
42  IntegerList* permutation_table = subsetter->GlyphPermutationTable();
43  if (!permutation_table || permutation_table->empty())
44    return false;
45
46  GlyphTablePtr glyph_table = down_cast<GlyphTable*>(font->GetTable(Tag::glyf));
47  LocaTablePtr loca_table = down_cast<LocaTable*>(font->GetTable(Tag::loca));
48  if (glyph_table == NULL || loca_table == NULL) {
49#if !defined (SFNTLY_NO_EXCEPTION)
50    throw RuntimeException("Font to subset is not valid.");
51#endif
52    return false;
53  }
54
55  GlyphTableBuilderPtr glyph_table_builder =
56      down_cast<GlyphTable::Builder*>
57      (font_builder->NewTableBuilder(Tag::glyf));
58  LocaTableBuilderPtr loca_table_builder =
59      down_cast<LocaTable::Builder*>
60      (font_builder->NewTableBuilder(Tag::loca));
61  if (glyph_table_builder == NULL || loca_table_builder == NULL) {
62#if !defined (SFNTLY_NO_EXCEPTION)
63    throw RuntimeException("Builder for subset is not valid.");
64#endif
65    return false;
66  }
67  GlyphTable::GlyphBuilderList* glyph_builders =
68      glyph_table_builder->GlyphBuilders();
69  for (IntegerList::iterator old_glyph_id = permutation_table->begin(),
70                             old_glyph_id_end = permutation_table->end();
71                             old_glyph_id != old_glyph_id_end; ++old_glyph_id) {
72    int old_offset = loca_table->GlyphOffset(*old_glyph_id);
73    int old_length = loca_table->GlyphLength(*old_glyph_id);
74    GlyphPtr glyph;
75    glyph.Attach(glyph_table->GetGlyph(old_offset, old_length));
76    ReadableFontDataPtr data = glyph->ReadFontData();
77    WritableFontDataPtr copy_data;
78    copy_data.Attach(WritableFontData::CreateWritableFontData(data->Length()));
79    data->CopyTo(copy_data);
80    GlyphBuilderPtr glyph_builder;
81    glyph_builder.Attach(glyph_table_builder->GlyphBuilder(copy_data));
82    glyph_builders->push_back(glyph_builder);
83  }
84  IntegerList loca_list;
85  glyph_table_builder->GenerateLocaList(&loca_list);
86  loca_table_builder->SetLocaList(&loca_list);
87  return true;
88}
89
90}  // namespace sfntly
91