The Tor Browser: gfx/ots/src/metrics.cc@6474c204b198 (annotated)

gfx/ots/src/metrics.cc@6474c204b198 (annotated)

gfx/ots/src/metrics.cc

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // 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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gfx/ots/src/metrics.cc@6474c204b198 (annotated)

gfx/ots/src/metrics.cc