diff -r 000000000000 -r 6474c204b198 gfx/ots/src/gasp.cc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/ots/src/gasp.cc Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,112 @@ +// 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 "gasp.h" + +// gasp - Grid-fitting And Scan-conversion Procedure +// http://www.microsoft.com/typography/otspec/gasp.htm + +#define TABLE_NAME "gasp" + +#define DROP_THIS_TABLE \ + do { \ + delete file->gasp; \ + file->gasp = 0; \ + OTS_FAILURE_MSG("Table discarded"); \ + } while (0) + +namespace ots { + +bool ots_gasp_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { + Buffer table(data, length); + + OpenTypeGASP *gasp = new OpenTypeGASP; + file->gasp = gasp; + + uint16_t num_ranges = 0; + if (!table.ReadU16(&gasp->version) || + !table.ReadU16(&num_ranges)) { + return OTS_FAILURE_MSG("Failed to read table header"); + } + + if (gasp->version > 1) { + // Lots of Linux fonts have bad version numbers... + OTS_WARNING("bad version: %u", gasp->version); + DROP_THIS_TABLE; + return true; + } + + if (num_ranges == 0) { + OTS_WARNING("num_ranges is zero"); + DROP_THIS_TABLE; + return true; + } + + gasp->gasp_ranges.reserve(num_ranges); + for (unsigned i = 0; i < num_ranges; ++i) { + uint16_t max_ppem = 0; + uint16_t behavior = 0; + if (!table.ReadU16(&max_ppem) || + !table.ReadU16(&behavior)) { + return OTS_FAILURE_MSG("Failed to read subrange %d", i); + } + if ((i > 0) && (gasp->gasp_ranges[i - 1].first >= max_ppem)) { + // The records in the gaspRange[] array must be sorted in order of + // increasing rangeMaxPPEM value. + OTS_WARNING("ranges are not sorted"); + DROP_THIS_TABLE; + return true; + } + if ((i == num_ranges - 1u) && // never underflow. + (max_ppem != 0xffffu)) { + OTS_WARNING("The last record should be 0xFFFF as a sentinel value " + "for rangeMaxPPEM"); + DROP_THIS_TABLE; + return true; + } + + if (behavior >> 8) { + OTS_WARNING("undefined bits are used: %x", behavior); + // mask undefined bits. + behavior &= 0x000fu; + } + + if (gasp->version == 0 && (behavior >> 2) != 0) { + OTS_WARNING("changed the version number to 1"); + gasp->version = 1; + } + + gasp->gasp_ranges.push_back(std::make_pair(max_ppem, behavior)); + } + + return true; +} + +bool ots_gasp_should_serialise(OpenTypeFile *file) { + return file->gasp != NULL; +} + +bool ots_gasp_serialise(OTSStream *out, OpenTypeFile *file) { + const OpenTypeGASP *gasp = file->gasp; + + if (!out->WriteU16(gasp->version) || + !out->WriteU16(gasp->gasp_ranges.size())) { + return OTS_FAILURE_MSG("failed to write gasp header"); + } + + for (unsigned i = 0; i < gasp->gasp_ranges.size(); ++i) { + if (!out->WriteU16(gasp->gasp_ranges[i].first) || + !out->WriteU16(gasp->gasp_ranges[i].second)) { + return OTS_FAILURE_MSG("Failed to write gasp subtable %d", i); + } + } + + return true; +} + +void ots_gasp_free(OpenTypeFile *file) { + delete file->gasp; +} + +} // namespace ots