1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/ots/src/hdmx.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,140 @@
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 "hdmx.h"
1.9 +#include "head.h"
1.10 +#include "maxp.h"
1.11 +
1.12 +// hdmx - Horizontal Device Metrics
1.13 +// http://www.microsoft.com/typography/otspec/hdmx.htm
1.14 +
1.15 +#define TABLE_NAME "hdmx"
1.16 +
1.17 +#define DROP_THIS_TABLE \
1.18 + do { \
1.19 + delete file->hdmx; \
1.20 + file->hdmx = 0; \
1.21 + OTS_FAILURE_MSG("Table discarded"); \
1.22 + } while (0)
1.23 +
1.24 +namespace ots {
1.25 +
1.26 +bool ots_hdmx_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
1.27 + Buffer table(data, length);
1.28 + file->hdmx = new OpenTypeHDMX;
1.29 + OpenTypeHDMX * const hdmx = file->hdmx;
1.30 +
1.31 + if (!file->head || !file->maxp) {
1.32 + return OTS_FAILURE_MSG("Missing maxp or head tables in font, needed by hdmx");
1.33 + }
1.34 +
1.35 + if ((file->head->flags & 0x14) == 0) {
1.36 + // http://www.microsoft.com/typography/otspec/recom.htm
1.37 + OTS_WARNING("the table should not be present when bit 2 and 4 of the "
1.38 + "head->flags are not set");
1.39 + DROP_THIS_TABLE;
1.40 + return true;
1.41 + }
1.42 +
1.43 + int16_t num_recs;
1.44 + if (!table.ReadU16(&hdmx->version) ||
1.45 + !table.ReadS16(&num_recs) ||
1.46 + !table.ReadS32(&hdmx->size_device_record)) {
1.47 + return OTS_FAILURE_MSG("Failed to read hdmx header");
1.48 + }
1.49 + if (hdmx->version != 0) {
1.50 + OTS_WARNING("bad version: %u", hdmx->version);
1.51 + DROP_THIS_TABLE;
1.52 + return true;
1.53 + }
1.54 + if (num_recs <= 0) {
1.55 + OTS_WARNING("bad num_recs: %d", num_recs);
1.56 + DROP_THIS_TABLE;
1.57 + return true;
1.58 + }
1.59 + const int32_t actual_size_device_record = file->maxp->num_glyphs + 2;
1.60 + if (hdmx->size_device_record < actual_size_device_record) {
1.61 + OTS_WARNING("bad hdmx->size_device_record: %d", hdmx->size_device_record);
1.62 + DROP_THIS_TABLE;
1.63 + return true;
1.64 + }
1.65 +
1.66 + hdmx->pad_len = hdmx->size_device_record - actual_size_device_record;
1.67 + if (hdmx->pad_len > 3) {
1.68 + return OTS_FAILURE_MSG("Bad padding %d", hdmx->pad_len);
1.69 + }
1.70 +
1.71 + uint8_t last_pixel_size = 0;
1.72 + hdmx->records.reserve(num_recs);
1.73 + for (int i = 0; i < num_recs; ++i) {
1.74 + OpenTypeHDMXDeviceRecord rec;
1.75 +
1.76 + if (!table.ReadU8(&rec.pixel_size) ||
1.77 + !table.ReadU8(&rec.max_width)) {
1.78 + return OTS_FAILURE_MSG("Failed to read hdmx record %d", i);
1.79 + }
1.80 + if ((i != 0) &&
1.81 + (rec.pixel_size <= last_pixel_size)) {
1.82 + OTS_WARNING("records are not sorted");
1.83 + DROP_THIS_TABLE;
1.84 + return true;
1.85 + }
1.86 + last_pixel_size = rec.pixel_size;
1.87 +
1.88 + rec.widths.reserve(file->maxp->num_glyphs);
1.89 + for (unsigned j = 0; j < file->maxp->num_glyphs; ++j) {
1.90 + uint8_t width;
1.91 + if (!table.ReadU8(&width)) {
1.92 + return OTS_FAILURE_MSG("Failed to read glyph width %d in record %d", j, i);
1.93 + }
1.94 + rec.widths.push_back(width);
1.95 + }
1.96 +
1.97 + if ((hdmx->pad_len > 0) &&
1.98 + !table.Skip(hdmx->pad_len)) {
1.99 + return OTS_FAILURE_MSG("Failed to skip padding %d", hdmx->pad_len);
1.100 + }
1.101 +
1.102 + hdmx->records.push_back(rec);
1.103 + }
1.104 +
1.105 + return true;
1.106 +}
1.107 +
1.108 +bool ots_hdmx_should_serialise(OpenTypeFile *file) {
1.109 + if (!file->hdmx) return false;
1.110 + if (!file->glyf) return false; // this table is not for CFF fonts.
1.111 + return true;
1.112 +}
1.113 +
1.114 +bool ots_hdmx_serialise(OTSStream *out, OpenTypeFile *file) {
1.115 + OpenTypeHDMX * const hdmx = file->hdmx;
1.116 +
1.117 + if (!out->WriteU16(hdmx->version) ||
1.118 + !out->WriteS16(hdmx->records.size()) ||
1.119 + !out->WriteS32(hdmx->size_device_record)) {
1.120 + return OTS_FAILURE_MSG("Failed to write hdmx header");
1.121 + }
1.122 +
1.123 + for (unsigned i = 0; i < hdmx->records.size(); ++i) {
1.124 + const OpenTypeHDMXDeviceRecord& rec = hdmx->records[i];
1.125 + if (!out->Write(&rec.pixel_size, 1) ||
1.126 + !out->Write(&rec.max_width, 1) ||
1.127 + !out->Write(&rec.widths[0], rec.widths.size())) {
1.128 + return OTS_FAILURE_MSG("Failed to write hdmx record %d", i);
1.129 + }
1.130 + if ((hdmx->pad_len > 0) &&
1.131 + !out->Write((const uint8_t *)"\x00\x00\x00", hdmx->pad_len)) {
1.132 + return OTS_FAILURE_MSG("Failed to write hdmx padding of length %d", hdmx->pad_len);
1.133 + }
1.134 + }
1.135 +
1.136 + return true;
1.137 +}
1.138 +
1.139 +void ots_hdmx_free(OpenTypeFile *file) {
1.140 + delete file->hdmx;
1.141 +}
1.142 +
1.143 +} // namespace ots
