The Tor Browser: gfx/ots/src/gasp.cc@6474c204b198

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

     1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.

     2 // Use of this source code is governed by a BSD-style license that can be

     3 // found in the LICENSE file.

     5 #include "gasp.h"

     7 // gasp - Grid-fitting And Scan-conversion Procedure

     8 // http://www.microsoft.com/typography/otspec/gasp.htm

    10 #define TABLE_NAME "gasp"

    12 #define DROP_THIS_TABLE \

    13   do { \

    14     delete file->gasp; \

    15     file->gasp = 0; \

    16     OTS_FAILURE_MSG("Table discarded"); \

    17   } while (0)

    19 namespace ots {

    21 bool ots_gasp_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {

    22   Buffer table(data, length);

    24   OpenTypeGASP *gasp = new OpenTypeGASP;

    25   file->gasp = gasp;

    27   uint16_t num_ranges = 0;

    28   if (!table.ReadU16(&gasp->version) ||

    29       !table.ReadU16(&num_ranges)) {

    30     return OTS_FAILURE_MSG("Failed to read table header");

    31   }

    33   if (gasp->version > 1) {

    34     // Lots of Linux fonts have bad version numbers...

    35     OTS_WARNING("bad version: %u", gasp->version);

    36     DROP_THIS_TABLE;

    37     return true;

    38   }

    40   if (num_ranges == 0) {

    41     OTS_WARNING("num_ranges is zero");

    42     DROP_THIS_TABLE;

    43     return true;

    44   }

    46   gasp->gasp_ranges.reserve(num_ranges);

    47   for (unsigned i = 0; i < num_ranges; ++i) {

    48     uint16_t max_ppem = 0;

    49     uint16_t behavior = 0;

    50     if (!table.ReadU16(&max_ppem) ||

    51         !table.ReadU16(&behavior)) {

    52       return OTS_FAILURE_MSG("Failed to read subrange %d", i);

    53     }

    54     if ((i > 0) && (gasp->gasp_ranges[i - 1].first >= max_ppem)) {

    55       // The records in the gaspRange[] array must be sorted in order of

    56       // increasing rangeMaxPPEM value.

    57       OTS_WARNING("ranges are not sorted");

    58       DROP_THIS_TABLE;

    59       return true;

    60     }

    61     if ((i == num_ranges - 1u) &&  // never underflow.

    62         (max_ppem != 0xffffu)) {

    63       OTS_WARNING("The last record should be 0xFFFF as a sentinel value "

    64                   "for rangeMaxPPEM");

    65       DROP_THIS_TABLE;

    66       return true;

    67     }

    69     if (behavior >> 8) {

    70       OTS_WARNING("undefined bits are used: %x", behavior);

    71       // mask undefined bits.

    72       behavior &= 0x000fu;

    73     }

    75     if (gasp->version == 0 && (behavior >> 2) != 0) {

    76       OTS_WARNING("changed the version number to 1");

    77       gasp->version = 1;

    78     }

    80     gasp->gasp_ranges.push_back(std::make_pair(max_ppem, behavior));

    81   }

    83   return true;

    84 }

    86 bool ots_gasp_should_serialise(OpenTypeFile *file) {

    87   return file->gasp != NULL;

    88 }

    90 bool ots_gasp_serialise(OTSStream *out, OpenTypeFile *file) {

    91   const OpenTypeGASP *gasp = file->gasp;

    93   if (!out->WriteU16(gasp->version) ||

    94       !out->WriteU16(gasp->gasp_ranges.size())) {

    95     return OTS_FAILURE_MSG("failed to write gasp header");

    96   }

    98   for (unsigned i = 0; i < gasp->gasp_ranges.size(); ++i) {

    99     if (!out->WriteU16(gasp->gasp_ranges[i].first) ||

   100         !out->WriteU16(gasp->gasp_ranges[i].second)) {

   101       return OTS_FAILURE_MSG("Failed to write gasp subtable %d", i);

   102     }

   103   }

   105   return true;

   106 }

   108 void ots_gasp_free(OpenTypeFile *file) {

   109   delete file->gasp;

   110 }

   112 }  // namespace ots

The Tor Browser / file revision