Source code
Revision control
Copy as Markdown
Other Tools
// Copyright (c) 2009-2017 The OTS 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 "head.h"
#include <cstring>
// head - Font Header
namespace ots {
bool OpenTypeHEAD::Parse(const uint8_t *data, size_t length) {
Buffer table(data, length);
uint32_t version = 0;
if (!table.ReadU32(&version) ||
!table.ReadU32(&this->revision)) {
return Error("Failed to read table header");
}
if (version >> 16 != 1) {
return Error("Unsupported majorVersion: %d", version >> 16);
}
// Skip the checksum adjustment
if (!table.Skip(4)) {
return Error("Failed to read checksum");
}
uint32_t magic;
if (!table.ReadU32(&magic) || magic != 0x5F0F3CF5) {
return Error("Failed to read or incorrect magicNumber");
}
if (!table.ReadU16(&this->flags)) {
return Error("Failed to read flags");
}
// We allow bits 0..4, 11..13
this->flags &= 0x381f;
if (!table.ReadU16(&this->upem)) {
return Error("Failed to read unitsPerEm");
}
// upem must be in range
if (this->upem < 16 ||
this->upem > 16384) {
return Error("unitsPerEm on in the range [16, 16384]: %d", this->upem);
}
if (!table.ReadR64(&this->created) ||
!table.ReadR64(&this->modified)) {
return Error("Can't read font dates");
}
if (!table.ReadS16(&this->xmin) ||
!table.ReadS16(&this->ymin) ||
!table.ReadS16(&this->xmax) ||
!table.ReadS16(&this->ymax)) {
return Error("Failed to read font bounding box");
}
if (this->xmin > this->xmax) {
return Error("Bad x dimension in the font bounding box (%d, %d)",
this->xmin, this->xmax);
}
if (this->ymin > this->ymax) {
return Error("Bad y dimension in the font bounding box (%d, %d)",
this->ymin, this->ymax);
}
if (!table.ReadU16(&this->mac_style)) {
return Error("Failed to read macStyle");
}
// We allow bits 0..6
this->mac_style &= 0x7f;
if (!table.ReadU16(&this->min_ppem)) {
return Error("Failed to read lowestRecPPEM");
}
// We don't care about the font direction hint
if (!table.Skip(2)) {
return Error("Failed to read fontDirectionHint");
}
if (!table.ReadS16(&this->index_to_loc_format)) {
return Error("Failed to read indexToLocFormat");
}
if (this->index_to_loc_format < 0 ||
this->index_to_loc_format > 1) {
return Error("Bad indexToLocFormat %d", this->index_to_loc_format);
}
int16_t glyph_data_format;
if (!table.ReadS16(&glyph_data_format) ||
glyph_data_format) {
return Error("Failed to read or bad glyphDataFormat");
}
return true;
}
bool OpenTypeHEAD::Serialize(OTSStream *out) {
if (!out->WriteU32(0x00010000) ||
!out->WriteU32(this->revision) ||
!out->WriteU32(0) || // check sum not filled in yet
!out->WriteU32(0x5F0F3CF5) ||
!out->WriteU16(this->flags) ||
!out->WriteU16(this->upem) ||
!out->WriteR64(this->created) ||
!out->WriteR64(this->modified) ||
!out->WriteS16(this->xmin) ||
!out->WriteS16(this->ymin) ||
!out->WriteS16(this->xmax) ||
!out->WriteS16(this->ymax) ||
!out->WriteU16(this->mac_style) ||
!out->WriteU16(this->min_ppem) ||
!out->WriteS16(2) ||
!out->WriteS16(this->index_to_loc_format) ||
!out->WriteS16(0)) {
return Error("Failed to write table");
}
return true;
}
} // namespace