1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/ots/src/vdmx.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,183 @@
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 "vdmx.h"
1.9 +
1.10 +// VDMX - Vertical Device Metrics
1.11 +// http://www.microsoft.com/typography/otspec/vdmx.htm
1.12 +
1.13 +#define TABLE_NAME "VDMX"
1.14 +
1.15 +#define DROP_THIS_TABLE \
1.16 + do { \
1.17 + delete file->vdmx; \
1.18 + file->vdmx = 0; \
1.19 + OTS_FAILURE_MSG("Table discarded"); \
1.20 + } while (0)
1.21 +
1.22 +namespace ots {
1.23 +
1.24 +bool ots_vdmx_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
1.25 + Buffer table(data, length);
1.26 + file->vdmx = new OpenTypeVDMX;
1.27 + OpenTypeVDMX * const vdmx = file->vdmx;
1.28 +
1.29 + if (!table.ReadU16(&vdmx->version) ||
1.30 + !table.ReadU16(&vdmx->num_recs) ||
1.31 + !table.ReadU16(&vdmx->num_ratios)) {
1.32 + return OTS_FAILURE_MSG("Failed to read table header");
1.33 + }
1.34 +
1.35 + if (vdmx->version > 1) {
1.36 + OTS_WARNING("bad version: %u", vdmx->version);
1.37 + DROP_THIS_TABLE;
1.38 + return true; // continue transcoding
1.39 + }
1.40 +
1.41 + vdmx->rat_ranges.reserve(vdmx->num_ratios);
1.42 + for (unsigned i = 0; i < vdmx->num_ratios; ++i) {
1.43 + OpenTypeVDMXRatioRecord rec;
1.44 +
1.45 + if (!table.ReadU8(&rec.charset) ||
1.46 + !table.ReadU8(&rec.x_ratio) ||
1.47 + !table.ReadU8(&rec.y_start_ratio) ||
1.48 + !table.ReadU8(&rec.y_end_ratio)) {
1.49 + return OTS_FAILURE_MSG("Failed to read ratio header %d", i);
1.50 + }
1.51 +
1.52 + if (rec.charset > 1) {
1.53 + OTS_WARNING("bad charset: %u", rec.charset);
1.54 + DROP_THIS_TABLE;
1.55 + return true;
1.56 + }
1.57 +
1.58 + if (rec.y_start_ratio > rec.y_end_ratio) {
1.59 + OTS_WARNING("bad y ratio");
1.60 + DROP_THIS_TABLE;
1.61 + return true;
1.62 + }
1.63 +
1.64 + // All values set to zero signal the default grouping to use;
1.65 + // if present, this must be the last Ratio group in the table.
1.66 + if ((i < vdmx->num_ratios - 1u) &&
1.67 + (rec.x_ratio == 0) &&
1.68 + (rec.y_start_ratio == 0) &&
1.69 + (rec.y_end_ratio == 0)) {
1.70 + // workaround for fonts which have 2 or more {0, 0, 0} terminators.
1.71 + OTS_WARNING("superfluous terminator found");
1.72 + DROP_THIS_TABLE;
1.73 + return true;
1.74 + }
1.75 +
1.76 + vdmx->rat_ranges.push_back(rec);
1.77 + }
1.78 +
1.79 + vdmx->offsets.reserve(vdmx->num_ratios);
1.80 + const size_t current_offset = table.offset();
1.81 + // current_offset is less than (2 bytes * 3) + (4 bytes * USHRT_MAX) = 256k.
1.82 + for (unsigned i = 0; i < vdmx->num_ratios; ++i) {
1.83 + uint16_t offset;
1.84 + if (!table.ReadU16(&offset)) {
1.85 + return OTS_FAILURE_MSG("Failed to read ratio offset %d", i);
1.86 + }
1.87 + if (current_offset + offset >= length) { // thus doesn't overflow.
1.88 + return OTS_FAILURE_MSG("Bad ratio offset %d for ration %d", offset, i);
1.89 + }
1.90 +
1.91 + vdmx->offsets.push_back(offset);
1.92 + }
1.93 +
1.94 + vdmx->groups.reserve(vdmx->num_recs);
1.95 + for (unsigned i = 0; i < vdmx->num_recs; ++i) {
1.96 + OpenTypeVDMXGroup group;
1.97 + if (!table.ReadU16(&group.recs) ||
1.98 + !table.ReadU8(&group.startsz) ||
1.99 + !table.ReadU8(&group.endsz)) {
1.100 + return OTS_FAILURE_MSG("Failed to read record header %d", i);
1.101 + }
1.102 + group.entries.reserve(group.recs);
1.103 + for (unsigned j = 0; j < group.recs; ++j) {
1.104 + OpenTypeVDMXVTable vt;
1.105 + if (!table.ReadU16(&vt.y_pel_height) ||
1.106 + !table.ReadS16(&vt.y_max) ||
1.107 + !table.ReadS16(&vt.y_min)) {
1.108 + return OTS_FAILURE_MSG("Failed to read reacord %d group %d", i, j);
1.109 + }
1.110 + if (vt.y_max < vt.y_min) {
1.111 + OTS_WARNING("bad y min/max");
1.112 + DROP_THIS_TABLE;
1.113 + return true;
1.114 + }
1.115 +
1.116 + // This table must appear in sorted order (sorted by yPelHeight),
1.117 + // but need not be continuous.
1.118 + if ((j != 0) && (group.entries[j - 1].y_pel_height >= vt.y_pel_height)) {
1.119 + OTS_WARNING("the table is not sorted");
1.120 + DROP_THIS_TABLE;
1.121 + return true;
1.122 + }
1.123 +
1.124 + group.entries.push_back(vt);
1.125 + }
1.126 + vdmx->groups.push_back(group);
1.127 + }
1.128 +
1.129 + return true;
1.130 +}
1.131 +
1.132 +bool ots_vdmx_should_serialise(OpenTypeFile *file) {
1.133 + if (!file->glyf) return false; // this table is not for CFF fonts.
1.134 + return file->vdmx != NULL;
1.135 +}
1.136 +
1.137 +bool ots_vdmx_serialise(OTSStream *out, OpenTypeFile *file) {
1.138 + OpenTypeVDMX * const vdmx = file->vdmx;
1.139 +
1.140 + if (!out->WriteU16(vdmx->version) ||
1.141 + !out->WriteU16(vdmx->num_recs) ||
1.142 + !out->WriteU16(vdmx->num_ratios)) {
1.143 + return OTS_FAILURE_MSG("Failed to write table header");
1.144 + }
1.145 +
1.146 + for (unsigned i = 0; i < vdmx->rat_ranges.size(); ++i) {
1.147 + const OpenTypeVDMXRatioRecord& rec = vdmx->rat_ranges[i];
1.148 + if (!out->Write(&rec.charset, 1) ||
1.149 + !out->Write(&rec.x_ratio, 1) ||
1.150 + !out->Write(&rec.y_start_ratio, 1) ||
1.151 + !out->Write(&rec.y_end_ratio, 1)) {
1.152 + return OTS_FAILURE_MSG("Failed to write ratio %d", i);
1.153 + }
1.154 + }
1.155 +
1.156 + for (unsigned i = 0; i < vdmx->offsets.size(); ++i) {
1.157 + if (!out->WriteU16(vdmx->offsets[i])) {
1.158 + return OTS_FAILURE_MSG("Failed to write ratio offset %d", i);
1.159 + }
1.160 + }
1.161 +
1.162 + for (unsigned i = 0; i < vdmx->groups.size(); ++i) {
1.163 + const OpenTypeVDMXGroup& group = vdmx->groups[i];
1.164 + if (!out->WriteU16(group.recs) ||
1.165 + !out->Write(&group.startsz, 1) ||
1.166 + !out->Write(&group.endsz, 1)) {
1.167 + return OTS_FAILURE_MSG("Failed to write group %d", i);
1.168 + }
1.169 + for (unsigned j = 0; j < group.entries.size(); ++j) {
1.170 + const OpenTypeVDMXVTable& vt = group.entries[j];
1.171 + if (!out->WriteU16(vt.y_pel_height) ||
1.172 + !out->WriteS16(vt.y_max) ||
1.173 + !out->WriteS16(vt.y_min)) {
1.174 + return OTS_FAILURE_MSG("Failed to write group %d entry %d", i, j);
1.175 + }
1.176 + }
1.177 + }
1.178 +
1.179 + return true;
1.180 +}
1.181 +
1.182 +void ots_vdmx_free(OpenTypeFile *file) {
1.183 + delete file->vdmx;
1.184 +}
1.185 +
1.186 +} // namespace ots
