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// 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 "loca.h"
#include "head.h"
#include "maxp.h"
// loca - Index to Location
// http://www.microsoft.com/opentype/otspec/loca.htm
namespace ots {
bool ots_loca_parse(OpenTypeFile *file, 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.
OpenTypeLOCA *loca = new OpenTypeLOCA;
file->loca = loca;
if (!file->maxp || !file->head) {
return OTS_FAILURE();
}
const unsigned num_glyphs = file->maxp->num_glyphs;
unsigned last_offset = 0;
loca->offsets.resize(num_glyphs + 1);
// maxp->num_glyphs is uint16_t, thus the addition never overflows.
if (file->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 OTS_FAILURE();
}
if (offset < last_offset) {
return OTS_FAILURE();
}
last_offset = offset;
loca->offsets[i] = offset * 2;
}
} else {
for (unsigned i = 0; i <= num_glyphs; ++i) {
uint32_t offset = 0;
if (!table.ReadU32(&offset)) {
return OTS_FAILURE();
}
if (offset < last_offset) {
return OTS_FAILURE();
}
last_offset = offset;
loca->offsets[i] = offset;
}
}
return true;
}
bool ots_loca_should_serialise(OpenTypeFile *file) {
return file->loca != NULL;
}
bool ots_loca_serialise(OTSStream *out, OpenTypeFile *file) {
const OpenTypeLOCA *loca = file->loca;
const OpenTypeHEAD *head = file->head;
if (!head) {
return OTS_FAILURE();
}
if (head->index_to_loc_format == 0) {
for (unsigned i = 0; i < loca->offsets.size(); ++i) {
if (!out->WriteU16(loca->offsets[i] >> 1)) {
return OTS_FAILURE();
}
}
} else {
for (unsigned i = 0; i < loca->offsets.size(); ++i) {
if (!out->WriteU32(loca->offsets[i])) {
return OTS_FAILURE();
}
}
}
return true;
}
void ots_loca_free(OpenTypeFile *file) {
delete file->loca;
}
} // namespace ots
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