Line data Source code
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 <string>
6 :
7 : #include "os2.h"
8 : #include "head.h"
9 :
10 : // OS/2 - OS/2 and Windows Metrics
11 : // http://www.microsoft.com/typography/otspec/os2.htm
12 :
13 : #define TABLE_NAME "OS/2"
14 :
15 : namespace ots {
16 :
17 0 : bool ots_os2_parse(Font *font, const uint8_t *data, size_t length) {
18 0 : Buffer table(data, length);
19 :
20 0 : OpenTypeOS2 *os2 = new OpenTypeOS2;
21 0 : font->os2 = os2;
22 :
23 0 : if (!table.ReadU16(&os2->version) ||
24 0 : !table.ReadS16(&os2->avg_char_width) ||
25 0 : !table.ReadU16(&os2->weight_class) ||
26 0 : !table.ReadU16(&os2->width_class) ||
27 0 : !table.ReadU16(&os2->type) ||
28 0 : !table.ReadS16(&os2->subscript_x_size) ||
29 0 : !table.ReadS16(&os2->subscript_y_size) ||
30 0 : !table.ReadS16(&os2->subscript_x_offset) ||
31 0 : !table.ReadS16(&os2->subscript_y_offset) ||
32 0 : !table.ReadS16(&os2->superscript_x_size) ||
33 0 : !table.ReadS16(&os2->superscript_y_size) ||
34 0 : !table.ReadS16(&os2->superscript_x_offset) ||
35 0 : !table.ReadS16(&os2->superscript_y_offset) ||
36 0 : !table.ReadS16(&os2->strikeout_size) ||
37 0 : !table.ReadS16(&os2->strikeout_position) ||
38 0 : !table.ReadS16(&os2->family_class)) {
39 0 : return OTS_FAILURE_MSG("Error reading basic table elements");
40 : }
41 :
42 0 : if (os2->version > 5) {
43 0 : return OTS_FAILURE_MSG("Unsupported table version: %u", os2->version);
44 : }
45 :
46 : // Follow WPF Font Selection Model's advice.
47 0 : if (1 <= os2->weight_class && os2->weight_class <= 9) {
48 0 : OTS_WARNING("Bad usWeightClass: %u, changing it to: %u", os2->weight_class, os2->weight_class * 100);
49 0 : os2->weight_class *= 100;
50 : }
51 : // Ditto.
52 0 : if (os2->weight_class > 999) {
53 0 : OTS_WARNING("Bad usWeightClass: %u, changing it to: %d", os2->weight_class, 999);
54 0 : os2->weight_class = 999;
55 : }
56 :
57 0 : if (os2->width_class < 1) {
58 0 : OTS_WARNING("Bad usWidthClass: %u, changing it to: %d", os2->width_class, 1);
59 0 : os2->width_class = 1;
60 0 : } else if (os2->width_class > 9) {
61 0 : OTS_WARNING("Bad usWidthClass: %u, changing it to: %d", os2->width_class, 9);
62 0 : os2->width_class = 9;
63 : }
64 :
65 : // lowest 3 bits of fsType are exclusive.
66 0 : if (os2->type & 0x2) {
67 : // mask bits 2 & 3.
68 0 : os2->type &= 0xfff3u;
69 0 : } else if (os2->type & 0x4) {
70 : // mask bits 1 & 3.
71 0 : os2->type &= 0xfff4u;
72 0 : } else if (os2->type & 0x8) {
73 : // mask bits 1 & 2.
74 0 : os2->type &= 0xfff9u;
75 : }
76 :
77 : // mask reserved bits. use only 0..3, 8, 9 bits.
78 0 : os2->type &= 0x30f;
79 :
80 : #define SET_TO_ZERO(a, b) \
81 : if (os2->b < 0) { \
82 : OTS_WARNING("Bad " a ": %d, setting it to zero", os2->b); \
83 : os2->b = 0; \
84 : }
85 :
86 0 : SET_TO_ZERO("ySubscriptXSize", subscript_x_size);
87 0 : SET_TO_ZERO("ySubscriptYSize", subscript_y_size);
88 0 : SET_TO_ZERO("ySuperscriptXSize", superscript_x_size);
89 0 : SET_TO_ZERO("ySuperscriptYSize", superscript_y_size);
90 0 : SET_TO_ZERO("yStrikeoutSize", strikeout_size);
91 : #undef SET_TO_ZERO
92 :
93 : static std::string panose_strings[10] = {
94 : "bFamilyType",
95 : "bSerifStyle",
96 : "bWeight",
97 : "bProportion",
98 : "bContrast",
99 : "bStrokeVariation",
100 : "bArmStyle",
101 : "bLetterform",
102 : "bMidline",
103 : "bXHeight",
104 0 : };
105 0 : for (unsigned i = 0; i < 10; ++i) {
106 0 : if (!table.ReadU8(&os2->panose[i])) {
107 0 : return OTS_FAILURE_MSG("Error reading PANOSE %s", panose_strings[i].c_str());
108 : }
109 : }
110 :
111 0 : if (!table.ReadU32(&os2->unicode_range_1) ||
112 0 : !table.ReadU32(&os2->unicode_range_2) ||
113 0 : !table.ReadU32(&os2->unicode_range_3) ||
114 0 : !table.ReadU32(&os2->unicode_range_4) ||
115 0 : !table.ReadU32(&os2->vendor_id) ||
116 0 : !table.ReadU16(&os2->selection) ||
117 0 : !table.ReadU16(&os2->first_char_index) ||
118 0 : !table.ReadU16(&os2->last_char_index) ||
119 0 : !table.ReadS16(&os2->typo_ascender) ||
120 0 : !table.ReadS16(&os2->typo_descender) ||
121 0 : !table.ReadS16(&os2->typo_linegap) ||
122 0 : !table.ReadU16(&os2->win_ascent) ||
123 0 : !table.ReadU16(&os2->win_descent)) {
124 0 : return OTS_FAILURE_MSG("Error reading more basic table fields");
125 : }
126 :
127 : // If bit 6 is set, then bits 0 and 5 must be clear.
128 0 : if (os2->selection & 0x40) {
129 0 : os2->selection &= 0xffdeu;
130 : }
131 :
132 : // the settings of bits 0 and 1 must be reflected in the macStyle bits
133 : // in the 'head' table.
134 0 : if (!font->head) {
135 0 : return OTS_FAILURE_MSG("Needed head table is missing from the font");
136 : }
137 0 : if ((os2->selection & 0x1) &&
138 0 : !(font->head->mac_style & 0x2)) {
139 0 : OTS_WARNING("adjusting Mac style (italic)");
140 0 : font->head->mac_style |= 0x2;
141 : }
142 0 : if ((os2->selection & 0x2) &&
143 0 : !(font->head->mac_style & 0x4)) {
144 0 : OTS_WARNING("adjusting Mac style (underscore)");
145 0 : font->head->mac_style |= 0x4;
146 : }
147 :
148 : // While bit 6 on implies that bits 0 and 1 of macStyle are clear,
149 : // the reverse is not true.
150 0 : if ((os2->selection & 0x40) &&
151 0 : (font->head->mac_style & 0x3)) {
152 0 : OTS_WARNING("adjusting Mac style (regular)");
153 0 : font->head->mac_style &= 0xfffcu;
154 : }
155 :
156 0 : if ((os2->version < 4) &&
157 0 : (os2->selection & 0x300)) {
158 : // bit 8 and 9 must be unset in OS/2 table versions less than 4.
159 0 : return OTS_FAILURE_MSG("Version %d incompatible with selection %d", os2->version, os2->selection);
160 : }
161 :
162 : // mask reserved bits. use only 0..9 bits.
163 0 : os2->selection &= 0x3ff;
164 :
165 0 : if (os2->first_char_index > os2->last_char_index) {
166 0 : return OTS_FAILURE_MSG("first char index %d > last char index %d in os2", os2->first_char_index, os2->last_char_index);
167 : }
168 0 : if (os2->typo_linegap < 0) {
169 0 : OTS_WARNING("bad linegap: %d", os2->typo_linegap);
170 0 : os2->typo_linegap = 0;
171 : }
172 :
173 0 : if (os2->version < 1) {
174 : // http://www.microsoft.com/typography/otspec/os2ver0.htm
175 0 : return true;
176 : }
177 :
178 0 : if (length < offsetof(OpenTypeOS2, code_page_range_2)) {
179 0 : OTS_WARNING("bad version number: %u", os2->version);
180 : // Some fonts (e.g., kredit1.ttf and quinquef.ttf) have weird version
181 : // numbers. Fix them.
182 0 : os2->version = 0;
183 0 : return true;
184 : }
185 :
186 0 : if (!table.ReadU32(&os2->code_page_range_1) ||
187 0 : !table.ReadU32(&os2->code_page_range_2)) {
188 0 : return OTS_FAILURE_MSG("Failed to read codepage ranges");
189 : }
190 :
191 0 : if (os2->version < 2) {
192 : // http://www.microsoft.com/typography/otspec/os2ver1.htm
193 0 : return true;
194 : }
195 :
196 0 : if (length < offsetof(OpenTypeOS2, max_context)) {
197 0 : OTS_WARNING("bad version number: %u", os2->version);
198 : // some Japanese fonts (e.g., mona.ttf) have weird version number.
199 : // fix them.
200 0 : os2->version = 1;
201 0 : return true;
202 : }
203 :
204 0 : if (!table.ReadS16(&os2->x_height) ||
205 0 : !table.ReadS16(&os2->cap_height) ||
206 0 : !table.ReadU16(&os2->default_char) ||
207 0 : !table.ReadU16(&os2->break_char) ||
208 0 : !table.ReadU16(&os2->max_context)) {
209 0 : return OTS_FAILURE_MSG("Failed to read version 2-specific fields");
210 : }
211 :
212 0 : if (os2->x_height < 0) {
213 0 : OTS_WARNING("bad x_height: %d", os2->x_height);
214 0 : os2->x_height = 0;
215 : }
216 0 : if (os2->cap_height < 0) {
217 0 : OTS_WARNING("bad cap_height: %d", os2->cap_height);
218 0 : os2->cap_height = 0;
219 : }
220 :
221 0 : if (os2->version < 5) {
222 : // http://www.microsoft.com/typography/otspec/os2ver4.htm
223 0 : return true;
224 : }
225 :
226 0 : if (!table.ReadU16(&os2->lower_optical_pointsize) ||
227 0 : !table.ReadU16(&os2->upper_optical_pointsize)) {
228 0 : return OTS_FAILURE_MSG("Failed to read version 5-specific fields");
229 : }
230 :
231 0 : if (os2->lower_optical_pointsize > 0xFFFE) {
232 0 : OTS_WARNING("'usLowerOpticalPointSize' is bigger than 0xFFFE: %d", os2->lower_optical_pointsize);
233 0 : os2->lower_optical_pointsize = 0xFFFE;
234 : }
235 :
236 0 : if (os2->upper_optical_pointsize < 2) {
237 0 : OTS_WARNING("'usUpperOpticalPointSize' is lower than 2: %d", os2->upper_optical_pointsize);
238 0 : os2->upper_optical_pointsize = 2;
239 : }
240 :
241 0 : return true;
242 : }
243 :
244 0 : bool ots_os2_should_serialise(Font *font) {
245 0 : return font->os2 != NULL;
246 : }
247 :
248 0 : bool ots_os2_serialise(OTSStream *out, Font *font) {
249 0 : const OpenTypeOS2 *os2 = font->os2;
250 :
251 0 : if (!out->WriteU16(os2->version) ||
252 0 : !out->WriteS16(os2->avg_char_width) ||
253 0 : !out->WriteU16(os2->weight_class) ||
254 0 : !out->WriteU16(os2->width_class) ||
255 0 : !out->WriteU16(os2->type) ||
256 0 : !out->WriteS16(os2->subscript_x_size) ||
257 0 : !out->WriteS16(os2->subscript_y_size) ||
258 0 : !out->WriteS16(os2->subscript_x_offset) ||
259 0 : !out->WriteS16(os2->subscript_y_offset) ||
260 0 : !out->WriteS16(os2->superscript_x_size) ||
261 0 : !out->WriteS16(os2->superscript_y_size) ||
262 0 : !out->WriteS16(os2->superscript_x_offset) ||
263 0 : !out->WriteS16(os2->superscript_y_offset) ||
264 0 : !out->WriteS16(os2->strikeout_size) ||
265 0 : !out->WriteS16(os2->strikeout_position) ||
266 0 : !out->WriteS16(os2->family_class)) {
267 0 : return OTS_FAILURE_MSG("Failed to write basic OS2 information");
268 : }
269 :
270 0 : for (unsigned i = 0; i < 10; ++i) {
271 0 : if (!out->Write(&os2->panose[i], 1)) {
272 0 : return OTS_FAILURE_MSG("Failed to write os2 panose information");
273 : }
274 : }
275 :
276 0 : if (!out->WriteU32(os2->unicode_range_1) ||
277 0 : !out->WriteU32(os2->unicode_range_2) ||
278 0 : !out->WriteU32(os2->unicode_range_3) ||
279 0 : !out->WriteU32(os2->unicode_range_4) ||
280 0 : !out->WriteU32(os2->vendor_id) ||
281 0 : !out->WriteU16(os2->selection) ||
282 0 : !out->WriteU16(os2->first_char_index) ||
283 0 : !out->WriteU16(os2->last_char_index) ||
284 0 : !out->WriteS16(os2->typo_ascender) ||
285 0 : !out->WriteS16(os2->typo_descender) ||
286 0 : !out->WriteS16(os2->typo_linegap) ||
287 0 : !out->WriteU16(os2->win_ascent) ||
288 0 : !out->WriteU16(os2->win_descent)) {
289 0 : return OTS_FAILURE_MSG("Failed to write version 1-specific fields");
290 : }
291 :
292 0 : if (os2->version < 1) {
293 0 : return true;
294 : }
295 :
296 0 : if (!out->WriteU32(os2->code_page_range_1) ||
297 0 : !out->WriteU32(os2->code_page_range_2)) {
298 0 : return OTS_FAILURE_MSG("Failed to write codepage ranges");
299 : }
300 :
301 0 : if (os2->version < 2) {
302 0 : return true;
303 : }
304 :
305 0 : if (!out->WriteS16(os2->x_height) ||
306 0 : !out->WriteS16(os2->cap_height) ||
307 0 : !out->WriteU16(os2->default_char) ||
308 0 : !out->WriteU16(os2->break_char) ||
309 0 : !out->WriteU16(os2->max_context)) {
310 0 : return OTS_FAILURE_MSG("Failed to write version 2-specific fields");
311 : }
312 :
313 0 : if (os2->version < 5) {
314 0 : return true;
315 : }
316 :
317 0 : if (!out->WriteU16(os2->lower_optical_pointsize) ||
318 0 : !out->WriteU16(os2->upper_optical_pointsize)) {
319 0 : return OTS_FAILURE_MSG("Failed to write version 5-specific fields");
320 : }
321 :
322 0 : return true;
323 : }
324 :
325 0 : void ots_os2_reuse(Font *font, Font *other) {
326 0 : font->os2 = other->os2;
327 0 : font->os2_reused = true;
328 0 : }
329 :
330 0 : void ots_os2_free(Font *font) {
331 0 : delete font->os2;
332 0 : }
333 :
334 : } // namespace ots
335 :
336 : #undef TABLE_NAME
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