1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/ots/src/gasp.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,112 @@
1.4 +// Copyright (c) 2009 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#include "gasp.h"
1.9 +
1.10 +// gasp - Grid-fitting And Scan-conversion Procedure
1.11 +// http://www.microsoft.com/typography/otspec/gasp.htm
1.12 +
1.13 +#define TABLE_NAME "gasp"
1.14 +
1.15 +#define DROP_THIS_TABLE \
1.16 + do { \
1.17 + delete file->gasp; \
1.18 + file->gasp = 0; \
1.19 + OTS_FAILURE_MSG("Table discarded"); \
1.20 + } while (0)
1.21 +
1.22 +namespace ots {
1.23 +
1.24 +bool ots_gasp_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
1.25 + Buffer table(data, length);
1.26 +
1.27 + OpenTypeGASP *gasp = new OpenTypeGASP;
1.28 + file->gasp = gasp;
1.29 +
1.30 + uint16_t num_ranges = 0;
1.31 + if (!table.ReadU16(&gasp->version) ||
1.32 + !table.ReadU16(&num_ranges)) {
1.33 + return OTS_FAILURE_MSG("Failed to read table header");
1.34 + }
1.35 +
1.36 + if (gasp->version > 1) {
1.37 + // Lots of Linux fonts have bad version numbers...
1.38 + OTS_WARNING("bad version: %u", gasp->version);
1.39 + DROP_THIS_TABLE;
1.40 + return true;
1.41 + }
1.42 +
1.43 + if (num_ranges == 0) {
1.44 + OTS_WARNING("num_ranges is zero");
1.45 + DROP_THIS_TABLE;
1.46 + return true;
1.47 + }
1.48 +
1.49 + gasp->gasp_ranges.reserve(num_ranges);
1.50 + for (unsigned i = 0; i < num_ranges; ++i) {
1.51 + uint16_t max_ppem = 0;
1.52 + uint16_t behavior = 0;
1.53 + if (!table.ReadU16(&max_ppem) ||
1.54 + !table.ReadU16(&behavior)) {
1.55 + return OTS_FAILURE_MSG("Failed to read subrange %d", i);
1.56 + }
1.57 + if ((i > 0) && (gasp->gasp_ranges[i - 1].first >= max_ppem)) {
1.58 + // The records in the gaspRange[] array must be sorted in order of
1.59 + // increasing rangeMaxPPEM value.
1.60 + OTS_WARNING("ranges are not sorted");
1.61 + DROP_THIS_TABLE;
1.62 + return true;
1.63 + }
1.64 + if ((i == num_ranges - 1u) && // never underflow.
1.65 + (max_ppem != 0xffffu)) {
1.66 + OTS_WARNING("The last record should be 0xFFFF as a sentinel value "
1.67 + "for rangeMaxPPEM");
1.68 + DROP_THIS_TABLE;
1.69 + return true;
1.70 + }
1.71 +
1.72 + if (behavior >> 8) {
1.73 + OTS_WARNING("undefined bits are used: %x", behavior);
1.74 + // mask undefined bits.
1.75 + behavior &= 0x000fu;
1.76 + }
1.77 +
1.78 + if (gasp->version == 0 && (behavior >> 2) != 0) {
1.79 + OTS_WARNING("changed the version number to 1");
1.80 + gasp->version = 1;
1.81 + }
1.82 +
1.83 + gasp->gasp_ranges.push_back(std::make_pair(max_ppem, behavior));
1.84 + }
1.85 +
1.86 + return true;
1.87 +}
1.88 +
1.89 +bool ots_gasp_should_serialise(OpenTypeFile *file) {
1.90 + return file->gasp != NULL;
1.91 +}
1.92 +
1.93 +bool ots_gasp_serialise(OTSStream *out, OpenTypeFile *file) {
1.94 + const OpenTypeGASP *gasp = file->gasp;
1.95 +
1.96 + if (!out->WriteU16(gasp->version) ||
1.97 + !out->WriteU16(gasp->gasp_ranges.size())) {
1.98 + return OTS_FAILURE_MSG("failed to write gasp header");
1.99 + }
1.100 +
1.101 + for (unsigned i = 0; i < gasp->gasp_ranges.size(); ++i) {
1.102 + if (!out->WriteU16(gasp->gasp_ranges[i].first) ||
1.103 + !out->WriteU16(gasp->gasp_ranges[i].second)) {
1.104 + return OTS_FAILURE_MSG("Failed to write gasp subtable %d", i);
1.105 + }
1.106 + }
1.107 +
1.108 + return true;
1.109 +}
1.110 +
1.111 +void ots_gasp_free(OpenTypeFile *file) {
1.112 + delete file->gasp;
1.113 +}
1.114 +
1.115 +} // namespace ots
