mirror of
https://github.com/classilla/tenfourfox.git
synced 2024-09-25 17:55:23 +00:00
94 lines
2.8 KiB
C++
94 lines
2.8 KiB
C++
// 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 "loca.h"
|
|
|
|
#include "head.h"
|
|
#include "maxp.h"
|
|
|
|
// loca - Index to Location
|
|
// http://www.microsoft.com/typography/otspec/loca.htm
|
|
|
|
namespace ots {
|
|
|
|
bool OpenTypeLOCA::Parse(const uint8_t *data, size_t length) {
|
|
Buffer table(data, length);
|
|
|
|
// We can't do anything useful in validating this data except to ensure that
|
|
// the values are monotonically increasing.
|
|
|
|
OpenTypeMAXP *maxp = static_cast<OpenTypeMAXP*>(
|
|
GetFont()->GetTypedTable(OTS_TAG_MAXP));
|
|
OpenTypeHEAD *head = static_cast<OpenTypeHEAD*>(
|
|
GetFont()->GetTypedTable(OTS_TAG_HEAD));
|
|
if (!maxp || !head) {
|
|
return Error("Required maxp or head tables are missing");
|
|
}
|
|
|
|
const unsigned num_glyphs = maxp->num_glyphs;
|
|
unsigned last_offset = 0;
|
|
this->offsets.resize(num_glyphs + 1);
|
|
// maxp->num_glyphs is uint16_t, thus the addition never overflows.
|
|
|
|
if (head->index_to_loc_format == 0) {
|
|
// Note that the <= here (and below) is correct. There is one more offset
|
|
// than the number of glyphs in order to give the length of the final
|
|
// glyph.
|
|
for (unsigned i = 0; i <= num_glyphs; ++i) {
|
|
uint16_t offset = 0;
|
|
if (!table.ReadU16(&offset)) {
|
|
return Error("Failed to read offset for glyph %d", i);
|
|
}
|
|
if (offset < last_offset) {
|
|
return Error("Out of order offset %d < %d for glyph %d", offset, last_offset, i);
|
|
}
|
|
last_offset = offset;
|
|
this->offsets[i] = offset * 2;
|
|
}
|
|
} else {
|
|
for (unsigned i = 0; i <= num_glyphs; ++i) {
|
|
uint32_t offset = 0;
|
|
if (!table.ReadU32(&offset)) {
|
|
return Error("Failed to read offset for glyph %d", i);
|
|
}
|
|
if (offset < last_offset) {
|
|
return Error("Out of order offset %d < %d for glyph %d", offset, last_offset, i);
|
|
}
|
|
last_offset = offset;
|
|
this->offsets[i] = offset;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool OpenTypeLOCA::Serialize(OTSStream *out) {
|
|
OpenTypeHEAD *head = static_cast<OpenTypeHEAD*>(
|
|
GetFont()->GetTypedTable(OTS_TAG_HEAD));
|
|
|
|
if (!head) {
|
|
return Error("Required head table is missing");
|
|
}
|
|
|
|
if (head->index_to_loc_format == 0) {
|
|
for (unsigned i = 0; i < this->offsets.size(); ++i) {
|
|
const uint16_t offset = static_cast<uint16_t>(this->offsets[i] >> 1);
|
|
if ((offset != (this->offsets[i] >> 1)) ||
|
|
!out->WriteU16(offset)) {
|
|
return Error("Failed to write glyph offset for glyph %d", i);
|
|
}
|
|
}
|
|
} else {
|
|
for (unsigned i = 0; i < this->offsets.size(); ++i) {
|
|
if (!out->WriteU32(this->offsets[i])) {
|
|
return Error("Failed to write glyph offset for glyph %d", i);
|
|
}
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
} // namespace ots
|