The Tor Browser: comparison gfx/ots/src/metrics.cc

--1:000000000000
+:2deb1bf3c2a6
+// Copyright (c) 2011 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 "metrics.h"
+#include "head.h"
+#include "maxp.h"
+// OpenType horizontal and vertical common header format
+// http://www.microsoft.com/typography/otspec/hhea.htm
+// http://www.microsoft.com/typography/otspec/vhea.htm
+#define TABLE_NAME "metrics" // XXX: use individual table names
+namespace ots {
+bool ParseMetricsHeader(OpenTypeFile *file, Buffer *table,
+OpenTypeMetricsHeader *header) {
+if (!table->ReadS16(&header->ascent) ||
+!table->ReadS16(&header->descent) ||
+!table->ReadS16(&header->linegap) ||
+!table->ReadU16(&header->adv_width_max) ||
+!table->ReadS16(&header->min_sb1) ||
+!table->ReadS16(&header->min_sb2) ||
+!table->ReadS16(&header->max_extent) ||
+!table->ReadS16(&header->caret_slope_rise) ||
+!table->ReadS16(&header->caret_slope_run) ||
+!table->ReadS16(&header->caret_offset)) {
+return OTS_FAILURE_MSG("Failed to read metrics header");
+}
+if (header->ascent < 0) {
+OTS_WARNING("bad ascent: %d", header->ascent);
+header->ascent = 0;
+}
+if (header->linegap < 0) {
+OTS_WARNING("bad linegap: %d", header->linegap);
+header->linegap = 0;
+}
+if (!file->head) {
+return OTS_FAILURE_MSG("Missing head font table");
+}
+// if the font is non-slanted, caret_offset should be zero.
+if (!(file->head->mac_style & 2) &&
+(header->caret_offset != 0)) {
+OTS_WARNING("bad caret offset: %d", header->caret_offset);
+header->caret_offset = 0;
+}
+// skip the reserved bytes
+if (!table->Skip(8)) {
+return OTS_FAILURE_MSG("Failed to skip reserverd bytes");
+}
+int16_t data_format;
+if (!table->ReadS16(&data_format)) {
+return OTS_FAILURE_MSG("Failed to read data format");
+}
+if (data_format) {
+return OTS_FAILURE_MSG("Bad data format %d", data_format);
+}
+if (!table->ReadU16(&header->num_metrics)) {
+return OTS_FAILURE_MSG("Failed to read number of metrics");
+}
+if (!file->maxp) {
+return OTS_FAILURE_MSG("Missing maxp font table");
+}
+if (header->num_metrics > file->maxp->num_glyphs) {
+return OTS_FAILURE_MSG("Bad number of metrics %d", header->num_metrics);
+}
+return true;
+}
+bool SerialiseMetricsHeader(const ots::OpenTypeFile *file,
+OTSStream *out,
+const OpenTypeMetricsHeader *header) {
+if (!out->WriteU32(header->version) ||
+!out->WriteS16(header->ascent) ||
+!out->WriteS16(header->descent) ||
+!out->WriteS16(header->linegap) ||
+!out->WriteU16(header->adv_width_max) ||
+!out->WriteS16(header->min_sb1) ||
+!out->WriteS16(header->min_sb2) ||
+!out->WriteS16(header->max_extent) ||
+!out->WriteS16(header->caret_slope_rise) ||
+!out->WriteS16(header->caret_slope_run) ||
+!out->WriteS16(header->caret_offset) ||
+!out->WriteR64(0) ||  // reserved
+!out->WriteS16(0) ||  // metric data format
+!out->WriteU16(header->num_metrics)) {
+return OTS_FAILURE_MSG("Failed to write metrics");
+}
+return true;
+}
+bool ParseMetricsTable(const ots::OpenTypeFile *file,
+Buffer *table,
+const uint16_t num_glyphs,
+const OpenTypeMetricsHeader *header,
+OpenTypeMetricsTable *metrics) {
+// |num_metrics| is a uint16_t, so it's bounded < 65536. This limits that
+// amount of memory that we'll allocate for this to a sane amount.
+const unsigned num_metrics = header->num_metrics;
+if (num_metrics > num_glyphs) {
+return OTS_FAILURE_MSG("Bad number of metrics %d", num_metrics);
+}
+if (!num_metrics) {
+return OTS_FAILURE_MSG("No metrics!");
+}
+const unsigned num_sbs = num_glyphs - num_metrics;
+metrics->entries.reserve(num_metrics);
+for (unsigned i = 0; i < num_metrics; ++i) {
+uint16_t adv = 0;
+int16_t sb = 0;
+if (!table->ReadU16(&adv) || !table->ReadS16(&sb)) {
+return OTS_FAILURE_MSG("Failed to read metric %d", i);
+}
+// Since so many fonts don't have proper value on |adv| and |sb|,
+// we should not call ots_failure() here. For example, about 20% of fonts
+// in http://www.princexml.com/fonts/ (200+ fonts) fails these tests.
+if (adv > header->adv_width_max) {
+OTS_WARNING("bad adv: %u > %u", adv, header->adv_width_max);
+adv = header->adv_width_max;
+}
+if (sb < header->min_sb1) {
+OTS_WARNING("bad sb: %d < %d", sb, header->min_sb1);
+sb = header->min_sb1;
+}
+metrics->entries.push_back(std::make_pair(adv, sb));
+}
+metrics->sbs.reserve(num_sbs);
+for (unsigned i = 0; i < num_sbs; ++i) {
+int16_t sb;
+if (!table->ReadS16(&sb)) {
+// Some Japanese fonts (e.g., mona.ttf) fail this test.
+return OTS_FAILURE_MSG("Failed to read side bearing %d", i + num_metrics);
+}
+if (sb < header->min_sb1) {
+// The same as above. Three fonts in http://www.fontsquirrel.com/fontface
+// (e.g., Notice2Std.otf) have weird lsb values.
+OTS_WARNING("bad lsb: %d < %d", sb, header->min_sb1);
+sb = header->min_sb1;
+}
+metrics->sbs.push_back(sb);
+}
+return true;
+}
+bool SerialiseMetricsTable(const ots::OpenTypeFile *file,
+OTSStream *out,
+const OpenTypeMetricsTable *metrics) {
+for (unsigned i = 0; i < metrics->entries.size(); ++i) {
+if (!out->WriteU16(metrics->entries[i].first) ||
+!out->WriteS16(metrics->entries[i].second)) {
+return OTS_FAILURE_MSG("Failed to write metric %d", i);
+}
+}
+for (unsigned i = 0; i < metrics->sbs.size(); ++i) {
+if (!out->WriteS16(metrics->sbs[i])) {
+return OTS_FAILURE_MSG("Failed to write side bearing %ld", i + metrics->entries.size());
+}
+}
+return true;
+}
+}  // namespace ots

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comparison: gfx/ots/src/metrics.cc

gfx/ots/src/metrics.cc