blob: cd79f4d1184cec32f2555d47b62164a048269cf0 [file] [log] [blame]
// Copyright (c) 2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <string>
#include "os2.h"
#include "head.h"
// OS/2 - OS/2 and Windows Metrics
// http://www.microsoft.com/typography/otspec/os2.htm
#define TABLE_NAME "OS/2"
namespace ots {
bool ots_os2_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
Buffer table(data, length);
OpenTypeOS2 *os2 = new OpenTypeOS2;
file->os2 = os2;
if (!table.ReadU16(&os2->version) ||
!table.ReadS16(&os2->avg_char_width) ||
!table.ReadU16(&os2->weight_class) ||
!table.ReadU16(&os2->width_class) ||
!table.ReadU16(&os2->type) ||
!table.ReadS16(&os2->subscript_x_size) ||
!table.ReadS16(&os2->subscript_y_size) ||
!table.ReadS16(&os2->subscript_x_offset) ||
!table.ReadS16(&os2->subscript_y_offset) ||
!table.ReadS16(&os2->superscript_x_size) ||
!table.ReadS16(&os2->superscript_y_size) ||
!table.ReadS16(&os2->superscript_x_offset) ||
!table.ReadS16(&os2->superscript_y_offset) ||
!table.ReadS16(&os2->strikeout_size) ||
!table.ReadS16(&os2->strikeout_position) ||
!table.ReadS16(&os2->family_class)) {
return OTS_FAILURE_MSG("Error reading basic table elements");
}
if (os2->version > 5) {
return OTS_FAILURE_MSG("Unsupported table version: %u", os2->version);
}
// Follow WPF Font Selection Model's advice.
if (1 <= os2->weight_class && os2->weight_class <= 9) {
OTS_WARNING("Bad usWeightClass: %u, changing it to: %u", os2->weight_class, os2->weight_class * 100);
os2->weight_class *= 100;
}
// Ditto.
if (os2->weight_class > 999) {
OTS_WARNING("Bad usWeightClass: %u, changing it to: %d", os2->weight_class, 999);
os2->weight_class = 999;
}
if (os2->width_class < 1) {
OTS_WARNING("Bad usWidthClass: %u, changing it to: %d", os2->width_class, 1);
os2->width_class = 1;
} else if (os2->width_class > 9) {
OTS_WARNING("Bad usWidthClass: %u, changing it to: %d", os2->width_class, 9);
os2->width_class = 9;
}
// lowest 3 bits of fsType are exclusive.
if (os2->type & 0x2) {
// mask bits 2 & 3.
os2->type &= 0xfff3u;
} else if (os2->type & 0x4) {
// mask bits 1 & 3.
os2->type &= 0xfff4u;
} else if (os2->type & 0x8) {
// mask bits 1 & 2.
os2->type &= 0xfff9u;
}
// mask reserved bits. use only 0..3, 8, 9 bits.
os2->type &= 0x30f;
#define SET_TO_ZERO(a, b) \
if (os2->b < 0) { \
OTS_WARNING("Bad " a ": %d, setting it to zero", os2->b); \
os2->b = 0; \
}
SET_TO_ZERO("ySubscriptXSize", subscript_x_size);
SET_TO_ZERO("ySubscriptYSize", subscript_y_size);
SET_TO_ZERO("ySuperscriptXSize", superscript_x_size);
SET_TO_ZERO("ySuperscriptYSize", superscript_y_size);
SET_TO_ZERO("yStrikeoutSize", strikeout_size);
#undef SET_TO_ZERO
static std::string panose_strings[10] = {
"bFamilyType",
"bSerifStyle",
"bWeight",
"bProportion",
"bContrast",
"bStrokeVariation",
"bArmStyle",
"bLetterform",
"bMidline",
"bXHeight",
};
for (unsigned i = 0; i < 10; ++i) {
if (!table.ReadU8(&os2->panose[i])) {
return OTS_FAILURE_MSG("Error reading PANOSE %s", panose_strings[i].c_str());
}
}
if (!table.ReadU32(&os2->unicode_range_1) ||
!table.ReadU32(&os2->unicode_range_2) ||
!table.ReadU32(&os2->unicode_range_3) ||
!table.ReadU32(&os2->unicode_range_4) ||
!table.ReadU32(&os2->vendor_id) ||
!table.ReadU16(&os2->selection) ||
!table.ReadU16(&os2->first_char_index) ||
!table.ReadU16(&os2->last_char_index) ||
!table.ReadS16(&os2->typo_ascender) ||
!table.ReadS16(&os2->typo_descender) ||
!table.ReadS16(&os2->typo_linegap) ||
!table.ReadU16(&os2->win_ascent) ||
!table.ReadU16(&os2->win_descent)) {
return OTS_FAILURE_MSG("Error reading more basic table fields");
}
// If bit 6 is set, then bits 0 and 5 must be clear.
if (os2->selection & 0x40) {
os2->selection &= 0xffdeu;
}
// the settings of bits 0 and 1 must be reflected in the macStyle bits
// in the 'head' table.
if (!file->head) {
return OTS_FAILURE_MSG("Needed head table is missing from the font");
}
if ((os2->selection & 0x1) &&
!(file->head->mac_style & 0x2)) {
OTS_WARNING("adjusting Mac style (italic)");
file->head->mac_style |= 0x2;
}
if ((os2->selection & 0x2) &&
!(file->head->mac_style & 0x4)) {
OTS_WARNING("adjusting Mac style (underscore)");
file->head->mac_style |= 0x4;
}
// While bit 6 on implies that bits 0 and 1 of macStyle are clear,
// the reverse is not true.
if ((os2->selection & 0x40) &&
(file->head->mac_style & 0x3)) {
OTS_WARNING("adjusting Mac style (regular)");
file->head->mac_style &= 0xfffcu;
}
if ((os2->version < 4) &&
(os2->selection & 0x300)) {
// bit 8 and 9 must be unset in OS/2 table versions less than 4.
return OTS_FAILURE_MSG("Version %d incompatible with selection %d", os2->version, os2->selection);
}
// mask reserved bits. use only 0..9 bits.
os2->selection &= 0x3ff;
if (os2->first_char_index > os2->last_char_index) {
return OTS_FAILURE_MSG("first char index %d > last char index %d in os2", os2->first_char_index, os2->last_char_index);
}
if (os2->typo_linegap < 0) {
OTS_WARNING("bad linegap: %d", os2->typo_linegap);
os2->typo_linegap = 0;
}
if (os2->version < 1) {
// http://www.microsoft.com/typography/otspec/os2ver0.htm
return true;
}
if (length < offsetof(OpenTypeOS2, code_page_range_2)) {
OTS_WARNING("bad version number: %u", os2->version);
// Some fonts (e.g., kredit1.ttf and quinquef.ttf) have weird version
// numbers. Fix them.
os2->version = 0;
return true;
}
if (!table.ReadU32(&os2->code_page_range_1) ||
!table.ReadU32(&os2->code_page_range_2)) {
return OTS_FAILURE_MSG("Failed to read codepage ranges");
}
if (os2->version < 2) {
// http://www.microsoft.com/typography/otspec/os2ver1.htm
return true;
}
if (length < offsetof(OpenTypeOS2, max_context)) {
OTS_WARNING("bad version number: %u", os2->version);
// some Japanese fonts (e.g., mona.ttf) have weird version number.
// fix them.
os2->version = 1;
return true;
}
if (!table.ReadS16(&os2->x_height) ||
!table.ReadS16(&os2->cap_height) ||
!table.ReadU16(&os2->default_char) ||
!table.ReadU16(&os2->break_char) ||
!table.ReadU16(&os2->max_context)) {
return OTS_FAILURE_MSG("Failed to read version 2-specific fields");
}
if (os2->x_height < 0) {
OTS_WARNING("bad x_height: %d", os2->x_height);
os2->x_height = 0;
}
if (os2->cap_height < 0) {
OTS_WARNING("bad cap_height: %d", os2->cap_height);
os2->cap_height = 0;
}
if (os2->version < 5) {
// http://www.microsoft.com/typography/otspec/os2ver4.htm
return true;
}
if (!table.ReadU16(&os2->lower_optical_pointsize) ||
!table.ReadU16(&os2->upper_optical_pointsize)) {
return OTS_FAILURE_MSG("Failed to read version 5-specific fields");
}
if (os2->lower_optical_pointsize > 0xFFFE) {
OTS_WARNING("'usLowerOpticalPointSize' is bigger than 0xFFFE: %d", os2->lower_optical_pointsize);
os2->lower_optical_pointsize = 0xFFFE;
}
if (os2->upper_optical_pointsize < 2) {
OTS_WARNING("'usUpperOpticalPointSize' is lower than 2: %d", os2->upper_optical_pointsize);
os2->upper_optical_pointsize = 2;
}
return true;
}
bool ots_os2_should_serialise(OpenTypeFile *file) {
return file->os2 != NULL;
}
bool ots_os2_serialise(OTSStream *out, OpenTypeFile *file) {
const OpenTypeOS2 *os2 = file->os2;
if (!out->WriteU16(os2->version) ||
!out->WriteS16(os2->avg_char_width) ||
!out->WriteU16(os2->weight_class) ||
!out->WriteU16(os2->width_class) ||
!out->WriteU16(os2->type) ||
!out->WriteS16(os2->subscript_x_size) ||
!out->WriteS16(os2->subscript_y_size) ||
!out->WriteS16(os2->subscript_x_offset) ||
!out->WriteS16(os2->subscript_y_offset) ||
!out->WriteS16(os2->superscript_x_size) ||
!out->WriteS16(os2->superscript_y_size) ||
!out->WriteS16(os2->superscript_x_offset) ||
!out->WriteS16(os2->superscript_y_offset) ||
!out->WriteS16(os2->strikeout_size) ||
!out->WriteS16(os2->strikeout_position) ||
!out->WriteS16(os2->family_class)) {
return OTS_FAILURE_MSG("Failed to write basic OS2 information");
}
for (unsigned i = 0; i < 10; ++i) {
if (!out->Write(&os2->panose[i], 1)) {
return OTS_FAILURE_MSG("Failed to write os2 panose information");
}
}
if (!out->WriteU32(os2->unicode_range_1) ||
!out->WriteU32(os2->unicode_range_2) ||
!out->WriteU32(os2->unicode_range_3) ||
!out->WriteU32(os2->unicode_range_4) ||
!out->WriteU32(os2->vendor_id) ||
!out->WriteU16(os2->selection) ||
!out->WriteU16(os2->first_char_index) ||
!out->WriteU16(os2->last_char_index) ||
!out->WriteS16(os2->typo_ascender) ||
!out->WriteS16(os2->typo_descender) ||
!out->WriteS16(os2->typo_linegap) ||
!out->WriteU16(os2->win_ascent) ||
!out->WriteU16(os2->win_descent)) {
return OTS_FAILURE_MSG("Failed to write version 1-specific fields");
}
if (os2->version < 1) {
return true;
}
if (!out->WriteU32(os2->code_page_range_1) ||
!out->WriteU32(os2->code_page_range_2)) {
return OTS_FAILURE_MSG("Failed to write codepage ranges");
}
if (os2->version < 2) {
return true;
}
if (!out->WriteS16(os2->x_height) ||
!out->WriteS16(os2->cap_height) ||
!out->WriteU16(os2->default_char) ||
!out->WriteU16(os2->break_char) ||
!out->WriteU16(os2->max_context)) {
return OTS_FAILURE_MSG("Failed to write version 2-specific fields");
}
if (os2->version < 5) {
return true;
}
if (!out->WriteU16(os2->lower_optical_pointsize) ||
!out->WriteU16(os2->upper_optical_pointsize)) {
return OTS_FAILURE_MSG("Failed to write version 5-specific fields");
}
return true;
}
void ots_os2_free(OpenTypeFile *file) {
delete file->os2;
}
} // namespace ots
#undef TABLE_NAME