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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /gfx/ots/src/gasp.cc | |
parent | Initial commit. (diff) | |
download | firefox-upstream/124.0.1.tar.xz firefox-upstream/124.0.1.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | gfx/ots/src/gasp.cc | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/gfx/ots/src/gasp.cc b/gfx/ots/src/gasp.cc new file mode 100644 index 0000000000..2a03c831ff --- /dev/null +++ b/gfx/ots/src/gasp.cc @@ -0,0 +1,84 @@ +// Copyright (c) 2009-2017 The OTS 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 + +namespace ots { + +bool OpenTypeGASP::Parse(const uint8_t *data, size_t length) { + Buffer table(data, length); + + uint16_t num_ranges = 0; + if (!table.ReadU16(&this->version) || + !table.ReadU16(&num_ranges)) { + return Error("Failed to read table header"); + } + + if (this->version > 1) { + // Lots of Linux fonts have bad version numbers... + return Drop("Unsupported version: %u", this->version); + } + + if (num_ranges == 0) { + return Drop("numRanges is zero"); + } + + this->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 Error("Failed to read GASPRANGE %d", i); + } + if ((i > 0) && (this->gasp_ranges[i - 1].first >= max_ppem)) { + // The records in the gaspRange[] array must be sorted in order of + // increasing rangeMaxPPEM value. + return Drop("Ranges are not sorted"); + } + if ((i == num_ranges - 1u) && // never underflow. + (max_ppem != 0xffffu)) { + return Drop("The last record should be 0xFFFF as a sentinel value " + "for rangeMaxPPEM"); + } + + if (behavior >> 8) { + Warning("Undefined bits are used: %x", behavior); + // mask undefined bits. + behavior &= 0x000fu; + } + + if (this->version == 0 && (behavior >> 2) != 0) { + Warning("Changed the version number to 1"); + this->version = 1; + } + + this->gasp_ranges.push_back(std::make_pair(max_ppem, behavior)); + } + + return true; +} + +bool OpenTypeGASP::Serialize(OTSStream *out) { + const uint16_t num_ranges = static_cast<uint16_t>(this->gasp_ranges.size()); + if (num_ranges != this->gasp_ranges.size() || + !out->WriteU16(this->version) || + !out->WriteU16(num_ranges)) { + return Error("Failed to write table header"); + } + + for (uint16_t i = 0; i < num_ranges; ++i) { + if (!out->WriteU16(this->gasp_ranges[i].first) || + !out->WriteU16(this->gasp_ranges[i].second)) { + return Error("Failed to write GASPRANGE %d", i); + } + } + + return true; +} + +} // namespace ots |