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 "os2.h"
6
7#include "head.h"
8
9// OS/2 - OS/2 and Windows Metrics
10// http://www.microsoft.com/opentype/otspec/os2.htm
11
12namespace ots {
13
14bool ots_os2_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
15  Buffer table(data, length);
16
17  OpenTypeOS2 *os2 = new OpenTypeOS2;
18  file->os2 = os2;
19
20  if (!table.ReadU16(&os2->version) ||
21      !table.ReadS16(&os2->avg_char_width) ||
22      !table.ReadU16(&os2->weight_class) ||
23      !table.ReadU16(&os2->width_class) ||
24      !table.ReadU16(&os2->type) ||
25      !table.ReadS16(&os2->subscript_x_size) ||
26      !table.ReadS16(&os2->subscript_y_size) ||
27      !table.ReadS16(&os2->subscript_x_offset) ||
28      !table.ReadS16(&os2->subscript_y_offset) ||
29      !table.ReadS16(&os2->superscript_x_size) ||
30      !table.ReadS16(&os2->superscript_y_size) ||
31      !table.ReadS16(&os2->superscript_x_offset) ||
32      !table.ReadS16(&os2->superscript_y_offset) ||
33      !table.ReadS16(&os2->strikeout_size) ||
34      !table.ReadS16(&os2->strikeout_position) ||
35      !table.ReadS16(&os2->family_class)) {
36    return OTS_FAILURE();
37  }
38
39  if (os2->version > 4) {
40    return OTS_FAILURE();
41  }
42
43  // Some linux fonts (e.g., Kedage-t.ttf and LucidaSansDemiOblique.ttf) have
44  // weird weight/width classes. Overwrite them with FW_NORMAL/1/9.
45  if (os2->weight_class < 100 ||
46      os2->weight_class > 900 ||
47      os2->weight_class % 100) {
48    OTS_WARNING("bad weight: %u", os2->weight_class);
49    os2->weight_class = 400;  // FW_NORMAL
50  }
51  if (os2->width_class < 1) {
52    OTS_WARNING("bad width: %u", os2->width_class);
53    os2->width_class = 1;
54  } else if (os2->width_class > 9) {
55    OTS_WARNING("bad width: %u", os2->width_class);
56    os2->width_class = 9;
57  }
58
59  // lowest 3 bits of fsType are exclusive.
60  if (os2->type & 0x2) {
61    // mask bits 2 & 3.
62    os2->type &= 0xfff3u;
63  } else if (os2->type & 0x4) {
64    // mask bits 1 & 3.
65    os2->type &= 0xfff4u;
66  } else if (os2->type & 0x8) {
67    // mask bits 1 & 2.
68    os2->type &= 0xfff9u;
69  }
70
71  // mask reserved bits. use only 0..3, 8, 9 bits.
72  os2->type &= 0x30f;
73
74  if (os2->subscript_x_size < 0) {
75    OTS_WARNING("bad subscript_x_size: %d", os2->subscript_x_size);
76    os2->subscript_x_size = 0;
77  }
78  if (os2->subscript_y_size < 0) {
79    OTS_WARNING("bad subscript_y_size: %d", os2->subscript_y_size);
80    os2->subscript_y_size = 0;
81  }
82  if (os2->superscript_x_size < 0) {
83    OTS_WARNING("bad superscript_x_size: %d", os2->superscript_x_size);
84    os2->superscript_x_size = 0;
85  }
86  if (os2->superscript_y_size < 0) {
87    OTS_WARNING("bad superscript_y_size: %d", os2->superscript_y_size);
88    os2->superscript_y_size = 0;
89  }
90  if (os2->strikeout_size < 0) {
91    OTS_WARNING("bad strikeout_size: %d", os2->strikeout_size);
92    os2->strikeout_size = 0;
93  }
94
95  for (unsigned i = 0; i < 10; ++i) {
96    if (!table.ReadU8(&os2->panose[i])) {
97      return OTS_FAILURE();
98    }
99  }
100
101  if (!table.ReadU32(&os2->unicode_range_1) ||
102      !table.ReadU32(&os2->unicode_range_2) ||
103      !table.ReadU32(&os2->unicode_range_3) ||
104      !table.ReadU32(&os2->unicode_range_4) ||
105      !table.ReadU32(&os2->vendor_id) ||
106      !table.ReadU16(&os2->selection) ||
107      !table.ReadU16(&os2->first_char_index) ||
108      !table.ReadU16(&os2->last_char_index) ||
109      !table.ReadS16(&os2->typo_ascender) ||
110      !table.ReadS16(&os2->typo_descender) ||
111      !table.ReadS16(&os2->typo_linegap) ||
112      !table.ReadU16(&os2->win_ascent) ||
113      !table.ReadU16(&os2->win_descent)) {
114    return OTS_FAILURE();
115  }
116
117  // If bit 6 is set, then bits 0 and 5 must be clear.
118  if (os2->selection & 0x40) {
119    os2->selection &= 0xffdeu;
120  }
121
122  // the settings of bits 0 and 1 must be reflected in the macStyle bits
123  // in the 'head' table.
124  if (!file->head) {
125    return OTS_FAILURE();
126  }
127  if ((os2->selection & 0x1) &&
128      !(file->head->mac_style & 0x2)) {
129    OTS_WARNING("adjusting Mac style (italic)");
130    file->head->mac_style |= 0x2;
131  }
132  if ((os2->selection & 0x2) &&
133      !(file->head->mac_style & 0x4)) {
134    OTS_WARNING("adjusting Mac style (underscore)");
135    file->head->mac_style |= 0x4;
136  }
137
138  // While bit 6 on implies that bits 0 and 1 of macStyle are clear,
139  // the reverse is not true.
140  if ((os2->selection & 0x40) &&
141      (file->head->mac_style & 0x3)) {
142    OTS_WARNING("adjusting Mac style (regular)");
143    file->head->mac_style &= 0xfffcu;
144  }
145
146  if ((os2->version < 4) &&
147      (os2->selection & 0x300)) {
148    // bit 8 and 9 must be unset in OS/2 table versions less than 4.
149    return OTS_FAILURE();
150  }
151
152  // mask reserved bits. use only 0..9 bits.
153  os2->selection &= 0x3ff;
154
155  if (os2->first_char_index > os2->last_char_index) {
156    return OTS_FAILURE();
157  }
158  if (os2->typo_linegap < 0) {
159    OTS_WARNING("bad linegap: %d", os2->typo_linegap);
160    os2->typo_linegap = 0;
161  }
162
163  if (os2->version < 1) {
164    // http://www.microsoft.com/typography/otspec/os2ver0.htm
165    return true;
166  }
167
168  if (length < offsetof(OpenTypeOS2, code_page_range_2)) {
169    OTS_WARNING("bad version number: %u", os2->version);
170    // Some fonts (e.g., kredit1.ttf and quinquef.ttf) have weird version
171    // numbers. Fix them.
172    os2->version = 0;
173    return true;
174  }
175
176  if (!table.ReadU32(&os2->code_page_range_1) ||
177      !table.ReadU32(&os2->code_page_range_2)) {
178    return OTS_FAILURE();
179  }
180
181  if (os2->version < 2) {
182    // http://www.microsoft.com/typography/otspec/os2ver1.htm
183    return true;
184  }
185
186  if (length < offsetof(OpenTypeOS2, max_context)) {
187    OTS_WARNING("bad version number: %u", os2->version);
188    // some Japanese fonts (e.g., mona.ttf) have weird version number.
189    // fix them.
190    os2->version = 1;
191    return true;
192  }
193
194  if (!table.ReadS16(&os2->x_height) ||
195      !table.ReadS16(&os2->cap_height) ||
196      !table.ReadU16(&os2->default_char) ||
197      !table.ReadU16(&os2->break_char) ||
198      !table.ReadU16(&os2->max_context)) {
199    return OTS_FAILURE();
200  }
201
202  if (os2->x_height < 0) {
203    OTS_WARNING("bad x_height: %d", os2->x_height);
204    os2->x_height = 0;
205  }
206  if (os2->cap_height < 0) {
207    OTS_WARNING("bad cap_height: %d", os2->cap_height);
208    os2->cap_height = 0;
209  }
210
211  return true;
212}
213
214bool ots_os2_should_serialise(OpenTypeFile *file) {
215  return file->os2 != NULL;
216}
217
218bool ots_os2_serialise(OTSStream *out, OpenTypeFile *file) {
219  const OpenTypeOS2 *os2 = file->os2;
220
221  if (!out->WriteU16(os2->version) ||
222      !out->WriteS16(os2->avg_char_width) ||
223      !out->WriteU16(os2->weight_class) ||
224      !out->WriteU16(os2->width_class) ||
225      !out->WriteU16(os2->type) ||
226      !out->WriteS16(os2->subscript_x_size) ||
227      !out->WriteS16(os2->subscript_y_size) ||
228      !out->WriteS16(os2->subscript_x_offset) ||
229      !out->WriteS16(os2->subscript_y_offset) ||
230      !out->WriteS16(os2->superscript_x_size) ||
231      !out->WriteS16(os2->superscript_y_size) ||
232      !out->WriteS16(os2->superscript_x_offset) ||
233      !out->WriteS16(os2->superscript_y_offset) ||
234      !out->WriteS16(os2->strikeout_size) ||
235      !out->WriteS16(os2->strikeout_position) ||
236      !out->WriteS16(os2->family_class)) {
237    return OTS_FAILURE();
238  }
239
240  for (unsigned i = 0; i < 10; ++i) {
241    if (!out->Write(&os2->panose[i], 1)) {
242      return OTS_FAILURE();
243    }
244  }
245
246  if (!out->WriteU32(os2->unicode_range_1) ||
247      !out->WriteU32(os2->unicode_range_2) ||
248      !out->WriteU32(os2->unicode_range_3) ||
249      !out->WriteU32(os2->unicode_range_4) ||
250      !out->WriteU32(os2->vendor_id) ||
251      !out->WriteU16(os2->selection) ||
252      !out->WriteU16(os2->first_char_index) ||
253      !out->WriteU16(os2->last_char_index) ||
254      !out->WriteS16(os2->typo_ascender) ||
255      !out->WriteS16(os2->typo_descender) ||
256      !out->WriteS16(os2->typo_linegap) ||
257      !out->WriteU16(os2->win_ascent) ||
258      !out->WriteU16(os2->win_descent)) {
259    return OTS_FAILURE();
260  }
261
262  if (os2->version < 1) {
263    return true;
264  }
265
266  if (!out->WriteU32(os2->code_page_range_1) ||
267      !out->WriteU32(os2->code_page_range_2)) {
268    return OTS_FAILURE();
269  }
270
271  if (os2->version < 2) {
272    return true;
273  }
274
275  if (!out->WriteS16(os2->x_height) ||
276      !out->WriteS16(os2->cap_height) ||
277      !out->WriteU16(os2->default_char) ||
278      !out->WriteU16(os2->break_char) ||
279      !out->WriteU16(os2->max_context)) {
280    return OTS_FAILURE();
281  }
282
283  return true;
284}
285
286void ots_os2_free(OpenTypeFile *file) {
287  delete file->os2;
288}
289
290}  // namespace ots
291