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https://github.com/roytam1/palemoon27.git
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trav90
110 lines
3.0 KiB
C++
110 lines
3.0 KiB
C++
// Copyright (c) 2009 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "loca.h"
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#include "head.h"
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#include "maxp.h"
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// loca - Index to Location
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// http://www.microsoft.com/typography/otspec/loca.htm
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#define TABLE_NAME "loca"
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namespace ots {
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bool ots_loca_parse(Font *font, const uint8_t *data, size_t length) {
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Buffer table(data, length);
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// We can't do anything useful in validating this data except to ensure that
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// the values are monotonically increasing.
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OpenTypeLOCA *loca = new OpenTypeLOCA;
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font->loca = loca;
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if (!font->maxp || !font->head) {
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return OTS_FAILURE_MSG("maxp or head tables missing from font, needed by loca");
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}
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const unsigned num_glyphs = font->maxp->num_glyphs;
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unsigned last_offset = 0;
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loca->offsets.resize(num_glyphs + 1);
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// maxp->num_glyphs is uint16_t, thus the addition never overflows.
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if (font->head->index_to_loc_format == 0) {
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// Note that the <= here (and below) is correct. There is one more offset
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// than the number of glyphs in order to give the length of the final
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// glyph.
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for (unsigned i = 0; i <= num_glyphs; ++i) {
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uint16_t offset = 0;
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if (!table.ReadU16(&offset)) {
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return OTS_FAILURE_MSG("Failed to read offset for glyph %d", i);
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}
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if (offset < last_offset) {
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return OTS_FAILURE_MSG("Out of order offset %d < %d for glyph %d", offset, last_offset, i);
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}
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last_offset = offset;
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loca->offsets[i] = offset * 2;
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}
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} else {
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for (unsigned i = 0; i <= num_glyphs; ++i) {
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uint32_t offset = 0;
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if (!table.ReadU32(&offset)) {
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return OTS_FAILURE_MSG("Failed to read offset for glyph %d", i);
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}
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if (offset < last_offset) {
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return OTS_FAILURE_MSG("Out of order offset %d < %d for glyph %d", offset, last_offset, i);
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}
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last_offset = offset;
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loca->offsets[i] = offset;
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}
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}
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return true;
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}
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bool ots_loca_should_serialise(Font *font) {
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return font->loca != NULL;
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}
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bool ots_loca_serialise(OTSStream *out, Font *font) {
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const OpenTypeLOCA *loca = font->loca;
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const OpenTypeHEAD *head = font->head;
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if (!head) {
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return OTS_FAILURE_MSG("Missing head table in font needed by loca");
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}
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if (head->index_to_loc_format == 0) {
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for (unsigned i = 0; i < loca->offsets.size(); ++i) {
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const uint16_t offset = static_cast<uint16_t>(loca->offsets[i] >> 1);
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if ((offset != (loca->offsets[i] >> 1)) ||
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!out->WriteU16(offset)) {
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return OTS_FAILURE_MSG("Failed to write glyph offset for glyph %d", i);
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}
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}
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} else {
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for (unsigned i = 0; i < loca->offsets.size(); ++i) {
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if (!out->WriteU32(loca->offsets[i])) {
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return OTS_FAILURE_MSG("Failed to write glyph offset for glyph %d", i);
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}
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}
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}
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return true;
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}
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void ots_loca_reuse(Font *font, Font *other) {
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font->loca = other->loca;
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font->loca_reused = true;
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}
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void ots_loca_free(Font *font) {
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delete font->loca;
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}
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} // namespace ots
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#undef TABLE_NAME
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