gfx/ots/src/os2.cc

Thu, 22 Jan 2015 13:21:57 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Thu, 22 Jan 2015 13:21:57 +0100
branch
TOR_BUG_9701
changeset 15
b8a032363ba2
permissions
-rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

michael@0 1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
michael@0 2 // Use of this source code is governed by a BSD-style license that can be
michael@0 3 // found in the LICENSE file.
michael@0 4
michael@0 5 #include "os2.h"
michael@0 6
michael@0 7 #include "head.h"
michael@0 8
michael@0 9 // OS/2 - OS/2 and Windows Metrics
michael@0 10 // http://www.microsoft.com/typography/otspec/os2.htm
michael@0 11
michael@0 12 #define TABLE_NAME "OS/2"
michael@0 13
michael@0 14 namespace ots {
michael@0 15
michael@0 16 bool ots_os2_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
michael@0 17 Buffer table(data, length);
michael@0 18
michael@0 19 OpenTypeOS2 *os2 = new OpenTypeOS2;
michael@0 20 file->os2 = os2;
michael@0 21
michael@0 22 if (!table.ReadU16(&os2->version) ||
michael@0 23 !table.ReadS16(&os2->avg_char_width) ||
michael@0 24 !table.ReadU16(&os2->weight_class) ||
michael@0 25 !table.ReadU16(&os2->width_class) ||
michael@0 26 !table.ReadU16(&os2->type) ||
michael@0 27 !table.ReadS16(&os2->subscript_x_size) ||
michael@0 28 !table.ReadS16(&os2->subscript_y_size) ||
michael@0 29 !table.ReadS16(&os2->subscript_x_offset) ||
michael@0 30 !table.ReadS16(&os2->subscript_y_offset) ||
michael@0 31 !table.ReadS16(&os2->superscript_x_size) ||
michael@0 32 !table.ReadS16(&os2->superscript_y_size) ||
michael@0 33 !table.ReadS16(&os2->superscript_x_offset) ||
michael@0 34 !table.ReadS16(&os2->superscript_y_offset) ||
michael@0 35 !table.ReadS16(&os2->strikeout_size) ||
michael@0 36 !table.ReadS16(&os2->strikeout_position) ||
michael@0 37 !table.ReadS16(&os2->family_class)) {
michael@0 38 return OTS_FAILURE_MSG("Failed toi read basic os2 elements");
michael@0 39 }
michael@0 40
michael@0 41 if (os2->version > 4) {
michael@0 42 return OTS_FAILURE_MSG("os2 version too high %d", os2->version);
michael@0 43 }
michael@0 44
michael@0 45 // Some linux fonts (e.g., Kedage-t.ttf and LucidaSansDemiOblique.ttf) have
michael@0 46 // weird weight/width classes. Overwrite them with FW_NORMAL/1/9.
michael@0 47 if (os2->weight_class < 100 ||
michael@0 48 os2->weight_class > 900 ||
michael@0 49 os2->weight_class % 100) {
michael@0 50 OTS_WARNING("bad weight: %u", os2->weight_class);
michael@0 51 os2->weight_class = 400; // FW_NORMAL
michael@0 52 }
michael@0 53 if (os2->width_class < 1) {
michael@0 54 OTS_WARNING("bad width: %u", os2->width_class);
michael@0 55 os2->width_class = 1;
michael@0 56 } else if (os2->width_class > 9) {
michael@0 57 OTS_WARNING("bad width: %u", os2->width_class);
michael@0 58 os2->width_class = 9;
michael@0 59 }
michael@0 60
michael@0 61 // lowest 3 bits of fsType are exclusive.
michael@0 62 if (os2->type & 0x2) {
michael@0 63 // mask bits 2 & 3.
michael@0 64 os2->type &= 0xfff3u;
michael@0 65 } else if (os2->type & 0x4) {
michael@0 66 // mask bits 1 & 3.
michael@0 67 os2->type &= 0xfff4u;
michael@0 68 } else if (os2->type & 0x8) {
michael@0 69 // mask bits 1 & 2.
michael@0 70 os2->type &= 0xfff9u;
michael@0 71 }
michael@0 72
michael@0 73 // mask reserved bits. use only 0..3, 8, 9 bits.
michael@0 74 os2->type &= 0x30f;
michael@0 75
michael@0 76 if (os2->subscript_x_size < 0) {
michael@0 77 OTS_WARNING("bad subscript_x_size: %d", os2->subscript_x_size);
michael@0 78 os2->subscript_x_size = 0;
michael@0 79 }
michael@0 80 if (os2->subscript_y_size < 0) {
michael@0 81 OTS_WARNING("bad subscript_y_size: %d", os2->subscript_y_size);
michael@0 82 os2->subscript_y_size = 0;
michael@0 83 }
michael@0 84 if (os2->superscript_x_size < 0) {
michael@0 85 OTS_WARNING("bad superscript_x_size: %d", os2->superscript_x_size);
michael@0 86 os2->superscript_x_size = 0;
michael@0 87 }
michael@0 88 if (os2->superscript_y_size < 0) {
michael@0 89 OTS_WARNING("bad superscript_y_size: %d", os2->superscript_y_size);
michael@0 90 os2->superscript_y_size = 0;
michael@0 91 }
michael@0 92 if (os2->strikeout_size < 0) {
michael@0 93 OTS_WARNING("bad strikeout_size: %d", os2->strikeout_size);
michael@0 94 os2->strikeout_size = 0;
michael@0 95 }
michael@0 96
michael@0 97 for (unsigned i = 0; i < 10; ++i) {
michael@0 98 if (!table.ReadU8(&os2->panose[i])) {
michael@0 99 return OTS_FAILURE_MSG("Failed to read panose in os2 table");
michael@0 100 }
michael@0 101 }
michael@0 102
michael@0 103 if (!table.ReadU32(&os2->unicode_range_1) ||
michael@0 104 !table.ReadU32(&os2->unicode_range_2) ||
michael@0 105 !table.ReadU32(&os2->unicode_range_3) ||
michael@0 106 !table.ReadU32(&os2->unicode_range_4) ||
michael@0 107 !table.ReadU32(&os2->vendor_id) ||
michael@0 108 !table.ReadU16(&os2->selection) ||
michael@0 109 !table.ReadU16(&os2->first_char_index) ||
michael@0 110 !table.ReadU16(&os2->last_char_index) ||
michael@0 111 !table.ReadS16(&os2->typo_ascender) ||
michael@0 112 !table.ReadS16(&os2->typo_descender) ||
michael@0 113 !table.ReadS16(&os2->typo_linegap) ||
michael@0 114 !table.ReadU16(&os2->win_ascent) ||
michael@0 115 !table.ReadU16(&os2->win_descent)) {
michael@0 116 return OTS_FAILURE_MSG("Failed to read more basic os2 fields");
michael@0 117 }
michael@0 118
michael@0 119 // If bit 6 is set, then bits 0 and 5 must be clear.
michael@0 120 if (os2->selection & 0x40) {
michael@0 121 os2->selection &= 0xffdeu;
michael@0 122 }
michael@0 123
michael@0 124 // the settings of bits 0 and 1 must be reflected in the macStyle bits
michael@0 125 // in the 'head' table.
michael@0 126 if (!file->head) {
michael@0 127 return OTS_FAILURE_MSG("Head table missing from font as needed by os2 table");
michael@0 128 }
michael@0 129 if ((os2->selection & 0x1) &&
michael@0 130 !(file->head->mac_style & 0x2)) {
michael@0 131 OTS_WARNING("adjusting Mac style (italic)");
michael@0 132 file->head->mac_style |= 0x2;
michael@0 133 }
michael@0 134 if ((os2->selection & 0x2) &&
michael@0 135 !(file->head->mac_style & 0x4)) {
michael@0 136 OTS_WARNING("adjusting Mac style (underscore)");
michael@0 137 file->head->mac_style |= 0x4;
michael@0 138 }
michael@0 139
michael@0 140 // While bit 6 on implies that bits 0 and 1 of macStyle are clear,
michael@0 141 // the reverse is not true.
michael@0 142 if ((os2->selection & 0x40) &&
michael@0 143 (file->head->mac_style & 0x3)) {
michael@0 144 OTS_WARNING("adjusting Mac style (regular)");
michael@0 145 file->head->mac_style &= 0xfffcu;
michael@0 146 }
michael@0 147
michael@0 148 if ((os2->version < 4) &&
michael@0 149 (os2->selection & 0x300)) {
michael@0 150 // bit 8 and 9 must be unset in OS/2 table versions less than 4.
michael@0 151 return OTS_FAILURE_MSG("OS2 version %d incompatible with selection %d", os2->version, os2->selection);
michael@0 152 }
michael@0 153
michael@0 154 // mask reserved bits. use only 0..9 bits.
michael@0 155 os2->selection &= 0x3ff;
michael@0 156
michael@0 157 if (os2->first_char_index > os2->last_char_index) {
michael@0 158 return OTS_FAILURE_MSG("first char index %d > last char index %d in os2", os2->first_char_index, os2->last_char_index);
michael@0 159 }
michael@0 160 if (os2->typo_linegap < 0) {
michael@0 161 OTS_WARNING("bad linegap: %d", os2->typo_linegap);
michael@0 162 os2->typo_linegap = 0;
michael@0 163 }
michael@0 164
michael@0 165 if (os2->version < 1) {
michael@0 166 // http://www.microsoft.com/typography/otspec/os2ver0.htm
michael@0 167 return true;
michael@0 168 }
michael@0 169
michael@0 170 if (length < offsetof(OpenTypeOS2, code_page_range_2)) {
michael@0 171 OTS_WARNING("bad version number: %u", os2->version);
michael@0 172 // Some fonts (e.g., kredit1.ttf and quinquef.ttf) have weird version
michael@0 173 // numbers. Fix them.
michael@0 174 os2->version = 0;
michael@0 175 return true;
michael@0 176 }
michael@0 177
michael@0 178 if (!table.ReadU32(&os2->code_page_range_1) ||
michael@0 179 !table.ReadU32(&os2->code_page_range_2)) {
michael@0 180 return OTS_FAILURE_MSG("Failed to read codepage ranges");
michael@0 181 }
michael@0 182
michael@0 183 if (os2->version < 2) {
michael@0 184 // http://www.microsoft.com/typography/otspec/os2ver1.htm
michael@0 185 return true;
michael@0 186 }
michael@0 187
michael@0 188 if (length < offsetof(OpenTypeOS2, max_context)) {
michael@0 189 OTS_WARNING("bad version number: %u", os2->version);
michael@0 190 // some Japanese fonts (e.g., mona.ttf) have weird version number.
michael@0 191 // fix them.
michael@0 192 os2->version = 1;
michael@0 193 return true;
michael@0 194 }
michael@0 195
michael@0 196 if (!table.ReadS16(&os2->x_height) ||
michael@0 197 !table.ReadS16(&os2->cap_height) ||
michael@0 198 !table.ReadU16(&os2->default_char) ||
michael@0 199 !table.ReadU16(&os2->break_char) ||
michael@0 200 !table.ReadU16(&os2->max_context)) {
michael@0 201 return OTS_FAILURE_MSG("Failed to read os2 version 2 information");
michael@0 202 }
michael@0 203
michael@0 204 if (os2->x_height < 0) {
michael@0 205 OTS_WARNING("bad x_height: %d", os2->x_height);
michael@0 206 os2->x_height = 0;
michael@0 207 }
michael@0 208 if (os2->cap_height < 0) {
michael@0 209 OTS_WARNING("bad cap_height: %d", os2->cap_height);
michael@0 210 os2->cap_height = 0;
michael@0 211 }
michael@0 212
michael@0 213 return true;
michael@0 214 }
michael@0 215
michael@0 216 bool ots_os2_should_serialise(OpenTypeFile *file) {
michael@0 217 return file->os2 != NULL;
michael@0 218 }
michael@0 219
michael@0 220 bool ots_os2_serialise(OTSStream *out, OpenTypeFile *file) {
michael@0 221 const OpenTypeOS2 *os2 = file->os2;
michael@0 222
michael@0 223 if (!out->WriteU16(os2->version) ||
michael@0 224 !out->WriteS16(os2->avg_char_width) ||
michael@0 225 !out->WriteU16(os2->weight_class) ||
michael@0 226 !out->WriteU16(os2->width_class) ||
michael@0 227 !out->WriteU16(os2->type) ||
michael@0 228 !out->WriteS16(os2->subscript_x_size) ||
michael@0 229 !out->WriteS16(os2->subscript_y_size) ||
michael@0 230 !out->WriteS16(os2->subscript_x_offset) ||
michael@0 231 !out->WriteS16(os2->subscript_y_offset) ||
michael@0 232 !out->WriteS16(os2->superscript_x_size) ||
michael@0 233 !out->WriteS16(os2->superscript_y_size) ||
michael@0 234 !out->WriteS16(os2->superscript_x_offset) ||
michael@0 235 !out->WriteS16(os2->superscript_y_offset) ||
michael@0 236 !out->WriteS16(os2->strikeout_size) ||
michael@0 237 !out->WriteS16(os2->strikeout_position) ||
michael@0 238 !out->WriteS16(os2->family_class)) {
michael@0 239 return OTS_FAILURE_MSG("Failed to write basic OS2 information");
michael@0 240 }
michael@0 241
michael@0 242 for (unsigned i = 0; i < 10; ++i) {
michael@0 243 if (!out->Write(&os2->panose[i], 1)) {
michael@0 244 return OTS_FAILURE_MSG("Failed to write os2 panose information");
michael@0 245 }
michael@0 246 }
michael@0 247
michael@0 248 if (!out->WriteU32(os2->unicode_range_1) ||
michael@0 249 !out->WriteU32(os2->unicode_range_2) ||
michael@0 250 !out->WriteU32(os2->unicode_range_3) ||
michael@0 251 !out->WriteU32(os2->unicode_range_4) ||
michael@0 252 !out->WriteU32(os2->vendor_id) ||
michael@0 253 !out->WriteU16(os2->selection) ||
michael@0 254 !out->WriteU16(os2->first_char_index) ||
michael@0 255 !out->WriteU16(os2->last_char_index) ||
michael@0 256 !out->WriteS16(os2->typo_ascender) ||
michael@0 257 !out->WriteS16(os2->typo_descender) ||
michael@0 258 !out->WriteS16(os2->typo_linegap) ||
michael@0 259 !out->WriteU16(os2->win_ascent) ||
michael@0 260 !out->WriteU16(os2->win_descent)) {
michael@0 261 return OTS_FAILURE_MSG("Failed to write os2 version 1 information");
michael@0 262 }
michael@0 263
michael@0 264 if (os2->version < 1) {
michael@0 265 return true;
michael@0 266 }
michael@0 267
michael@0 268 if (!out->WriteU32(os2->code_page_range_1) ||
michael@0 269 !out->WriteU32(os2->code_page_range_2)) {
michael@0 270 return OTS_FAILURE_MSG("Failed to write codepage ranges");
michael@0 271 }
michael@0 272
michael@0 273 if (os2->version < 2) {
michael@0 274 return true;
michael@0 275 }
michael@0 276
michael@0 277 if (!out->WriteS16(os2->x_height) ||
michael@0 278 !out->WriteS16(os2->cap_height) ||
michael@0 279 !out->WriteU16(os2->default_char) ||
michael@0 280 !out->WriteU16(os2->break_char) ||
michael@0 281 !out->WriteU16(os2->max_context)) {
michael@0 282 return OTS_FAILURE_MSG("Failed to write os2 version 2 information");
michael@0 283 }
michael@0 284
michael@0 285 return true;
michael@0 286 }
michael@0 287
michael@0 288 void ots_os2_free(OpenTypeFile *file) {
michael@0 289 delete file->os2;
michael@0 290 }
michael@0 291
michael@0 292 } // namespace ots

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