Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 1 | // Copyright 2013 Google Inc. All Rights Reserved. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | // |
| 15 | // Font management utilities |
| 16 | |
| 17 | #include "./font.h" |
| 18 | |
| 19 | #include <algorithm> |
| 20 | |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 21 | #include "./buffer.h" |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 22 | #include "./port.h" |
| 23 | #include "./store_bytes.h" |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 24 | #include "./table_tags.h" |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 25 | |
| 26 | namespace woff2 { |
| 27 | |
| 28 | Font::Table* Font::FindTable(uint32_t tag) { |
| 29 | std::map<uint32_t, Font::Table>::iterator it = tables.find(tag); |
| 30 | return it == tables.end() ? 0 : &it->second; |
| 31 | } |
| 32 | |
| 33 | const Font::Table* Font::FindTable(uint32_t tag) const { |
| 34 | std::map<uint32_t, Font::Table>::const_iterator it = tables.find(tag); |
| 35 | return it == tables.end() ? 0 : &it->second; |
| 36 | } |
| 37 | |
| 38 | bool ReadFont(const uint8_t* data, size_t len, Font* font) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 39 | Buffer file(data, len); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 40 | |
| 41 | // We don't care about the search_range, entry_selector and range_shift |
| 42 | // fields, they will always be computed upon writing the font. |
| 43 | if (!file.ReadU32(&font->flavor) || |
| 44 | !file.ReadU16(&font->num_tables) || |
| 45 | !file.Skip(6)) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 46 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 47 | } |
| 48 | |
| 49 | std::map<uint32_t, uint32_t> intervals; |
| 50 | for (uint16_t i = 0; i < font->num_tables; ++i) { |
| 51 | Font::Table table; |
| 52 | if (!file.ReadU32(&table.tag) || |
| 53 | !file.ReadU32(&table.checksum) || |
| 54 | !file.ReadU32(&table.offset) || |
| 55 | !file.ReadU32(&table.length)) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 56 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 57 | } |
| 58 | if ((table.offset & 3) != 0 || |
| 59 | table.length > len || |
| 60 | len - table.length < table.offset) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 61 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 62 | } |
| 63 | intervals[table.offset] = table.length; |
| 64 | table.data = data + table.offset; |
| 65 | if (font->tables.find(table.tag) != font->tables.end()) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 66 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 67 | } |
| 68 | font->tables[table.tag] = table; |
| 69 | } |
| 70 | |
| 71 | // Check that tables are non-overlapping. |
| 72 | uint32_t last_offset = 12UL + 16UL * font->num_tables; |
| 73 | for (const auto& i : intervals) { |
| 74 | if (i.first < last_offset || i.first + i.second < i.first) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 75 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 76 | } |
| 77 | last_offset = i.first + i.second; |
| 78 | } |
| 79 | return true; |
| 80 | } |
| 81 | |
| 82 | size_t FontFileSize(const Font& font) { |
| 83 | size_t max_offset = 12ULL + 16ULL * font.num_tables; |
| 84 | for (const auto& i : font.tables) { |
| 85 | const Font::Table& table = i.second; |
| 86 | size_t padding_size = (4 - (table.length & 3)) & 3; |
| 87 | size_t end_offset = (padding_size + table.offset) + table.length; |
| 88 | max_offset = std::max(max_offset, end_offset); |
| 89 | } |
| 90 | return max_offset; |
| 91 | } |
| 92 | |
| 93 | bool WriteFont(const Font& font, uint8_t* dst, size_t dst_size) { |
| 94 | if (dst_size < 12ULL + 16ULL * font.num_tables) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 95 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 96 | } |
| 97 | size_t offset = 0; |
| 98 | StoreU32(font.flavor, &offset, dst); |
| 99 | Store16(font.num_tables, &offset, dst); |
| 100 | uint16_t max_pow2 = font.num_tables ? Log2Floor(font.num_tables) : 0; |
| 101 | uint16_t search_range = max_pow2 ? 1 << (max_pow2 + 4) : 0; |
| 102 | uint16_t range_shift = (font.num_tables << 4) - search_range; |
| 103 | Store16(search_range, &offset, dst); |
| 104 | Store16(max_pow2, &offset, dst); |
| 105 | Store16(range_shift, &offset, dst); |
| 106 | for (const auto& i : font.tables) { |
| 107 | const Font::Table& table = i.second; |
| 108 | StoreU32(table.tag, &offset, dst); |
| 109 | StoreU32(table.checksum, &offset, dst); |
| 110 | StoreU32(table.offset, &offset, dst); |
| 111 | StoreU32(table.length, &offset, dst); |
| 112 | if (table.offset + table.length < table.offset || |
| 113 | dst_size < table.offset + table.length) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 114 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 115 | } |
| 116 | memcpy(dst + table.offset, table.data, table.length); |
| 117 | size_t padding_size = (4 - (table.length & 3)) & 3; |
| 118 | if (table.offset + table.length + padding_size < padding_size || |
| 119 | dst_size < table.offset + table.length + padding_size) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 120 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 121 | } |
| 122 | memset(dst + table.offset + table.length, 0, padding_size); |
| 123 | } |
| 124 | return true; |
| 125 | } |
| 126 | |
| 127 | int NumGlyphs(const Font& font) { |
| 128 | const Font::Table* head_table = font.FindTable(kHeadTableTag); |
| 129 | const Font::Table* loca_table = font.FindTable(kLocaTableTag); |
| 130 | if (head_table == NULL || loca_table == NULL || head_table->length < 52) { |
| 131 | return 0; |
| 132 | } |
| 133 | int index_fmt = head_table->data[51]; |
| 134 | return (loca_table->length / (index_fmt == 0 ? 2 : 4)) - 1; |
| 135 | } |
| 136 | |
| 137 | bool GetGlyphData(const Font& font, int glyph_index, |
| 138 | const uint8_t** glyph_data, size_t* glyph_size) { |
| 139 | if (glyph_index < 0) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 140 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 141 | } |
| 142 | const Font::Table* head_table = font.FindTable(kHeadTableTag); |
| 143 | const Font::Table* loca_table = font.FindTable(kLocaTableTag); |
| 144 | const Font::Table* glyf_table = font.FindTable(kGlyfTableTag); |
| 145 | if (head_table == NULL || loca_table == NULL || glyf_table == NULL || |
| 146 | head_table->length < 52) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 147 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 148 | } |
| 149 | int index_fmt = head_table->data[51]; |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 150 | Buffer loca_buf(loca_table->data, loca_table->length); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 151 | if (index_fmt == 0) { |
| 152 | uint16_t offset1, offset2; |
| 153 | if (!loca_buf.Skip(2 * glyph_index) || |
| 154 | !loca_buf.ReadU16(&offset1) || |
| 155 | !loca_buf.ReadU16(&offset2) || |
| 156 | offset2 < offset1 || |
| 157 | 2 * offset2 > glyf_table->length) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 158 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 159 | } |
| 160 | *glyph_data = glyf_table->data + 2 * offset1; |
| 161 | *glyph_size = 2 * (offset2 - offset1); |
| 162 | } else { |
| 163 | uint32_t offset1, offset2; |
| 164 | if (!loca_buf.Skip(4 * glyph_index) || |
| 165 | !loca_buf.ReadU32(&offset1) || |
| 166 | !loca_buf.ReadU32(&offset2) || |
| 167 | offset2 < offset1 || |
| 168 | offset2 > glyf_table->length) { |
Kenichi Ishibashi | 142d888 | 2014-05-30 09:06:32 +0900 | [diff] [blame] | 169 | return FONT_COMPRESSION_FAILURE(); |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 170 | } |
| 171 | *glyph_data = glyf_table->data + offset1; |
| 172 | *glyph_size = offset2 - offset1; |
| 173 | } |
| 174 | return true; |
| 175 | } |
| 176 | |
Roderick Sheeter | 2ec0cb8 | 2014-05-07 11:01:07 -0700 | [diff] [blame] | 177 | bool RemoveDigitalSignature(Font* font) { |
| 178 | std::map<uint32_t, Font::Table>::iterator it = |
| 179 | font->tables.find(kDsigTableTag); |
| 180 | if (it != font->tables.end()) { |
| 181 | font->tables.erase(it); |
| 182 | font->num_tables = font->tables.size(); |
| 183 | } |
| 184 | return true; |
| 185 | } |
| 186 | |
Roderick Sheeter | 437bbad | 2013-11-19 14:32:56 -0800 | [diff] [blame] | 187 | } // namespace woff2 |