1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/ots/src/post.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,182 @@
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 "post.h"
1.9 +
1.10 +#include "maxp.h"
1.11 +
1.12 +// post - PostScript
1.13 +// http://www.microsoft.com/typography/otspec/post.htm
1.14 +
1.15 +#define TABLE_NAME "post"
1.16 +
1.17 +namespace ots {
1.18 +
1.19 +bool ots_post_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
1.20 + Buffer table(data, length);
1.21 +
1.22 + OpenTypePOST *post = new OpenTypePOST;
1.23 + file->post = post;
1.24 +
1.25 + if (!table.ReadU32(&post->version) ||
1.26 + !table.ReadU32(&post->italic_angle) ||
1.27 + !table.ReadS16(&post->underline) ||
1.28 + !table.ReadS16(&post->underline_thickness) ||
1.29 + !table.ReadU32(&post->is_fixed_pitch)) {
1.30 + return OTS_FAILURE_MSG("Failed to read post header");
1.31 + }
1.32 +
1.33 + if (post->underline_thickness < 0) {
1.34 + post->underline_thickness = 1;
1.35 + }
1.36 +
1.37 + if (post->version == 0x00010000) {
1.38 + return true;
1.39 + } else if (post->version == 0x00030000) {
1.40 + return true;
1.41 + } else if (post->version != 0x00020000) {
1.42 + // 0x00025000 is deprecated. We don't accept it.
1.43 + return OTS_FAILURE_MSG("Bad post version %x", post->version);
1.44 + }
1.45 +
1.46 + // We have a version 2 table with a list of Pascal strings at the end
1.47 +
1.48 + // We don't care about the memory usage fields. We'll set all these to zero
1.49 + // when serialising
1.50 + if (!table.Skip(16)) {
1.51 + return OTS_FAILURE_MSG("Failed to skip memory usage in post table");
1.52 + }
1.53 +
1.54 + uint16_t num_glyphs = 0;
1.55 + if (!table.ReadU16(&num_glyphs)) {
1.56 + return OTS_FAILURE_MSG("Failed to read number of glyphs");
1.57 + }
1.58 +
1.59 + if (!file->maxp) {
1.60 + return OTS_FAILURE_MSG("No maxp table required by post table");
1.61 + }
1.62 +
1.63 + if (num_glyphs == 0) {
1.64 + if (file->maxp->num_glyphs > 258) {
1.65 + return OTS_FAILURE_MSG("Can't have no glyphs in the post table if there are more than 256 glyphs in the font");
1.66 + }
1.67 + OTS_WARNING("table version is 1, but no glyf names are found");
1.68 + // workaround for fonts in http://www.fontsquirrel.com/fontface
1.69 + // (e.g., yataghan.ttf).
1.70 + post->version = 0x00010000;
1.71 + return true;
1.72 + }
1.73 +
1.74 + if (num_glyphs != file->maxp->num_glyphs) {
1.75 + // Note: Fixedsys500c.ttf seems to have inconsistent num_glyphs values.
1.76 + return OTS_FAILURE_MSG("Bad number of glyphs in post table %d", num_glyphs);
1.77 + }
1.78 +
1.79 + post->glyph_name_index.resize(num_glyphs);
1.80 + for (unsigned i = 0; i < num_glyphs; ++i) {
1.81 + if (!table.ReadU16(&post->glyph_name_index[i])) {
1.82 + return OTS_FAILURE_MSG("Failed to read post information for glyph %d", i);
1.83 + }
1.84 + // Note: A strict interpretation of the specification requires name indexes
1.85 + // are less than 32768. This, however, excludes fonts like unifont.ttf
1.86 + // which cover all of unicode.
1.87 + }
1.88 +
1.89 + // Now we have an array of Pascal strings. We have to check that they are all
1.90 + // valid and read them in.
1.91 + const size_t strings_offset = table.offset();
1.92 + const uint8_t *strings = data + strings_offset;
1.93 + const uint8_t *strings_end = data + length;
1.94 +
1.95 + for (;;) {
1.96 + if (strings == strings_end) break;
1.97 + const unsigned string_length = *strings;
1.98 + if (strings + 1 + string_length > strings_end) {
1.99 + return OTS_FAILURE_MSG("Bad string length %d", string_length);
1.100 + }
1.101 + if (std::memchr(strings + 1, '\0', string_length)) {
1.102 + return OTS_FAILURE_MSG("Bad string of length %d", string_length);
1.103 + }
1.104 + post->names.push_back(
1.105 + std::string(reinterpret_cast<const char*>(strings + 1), string_length));
1.106 + strings += 1 + string_length;
1.107 + }
1.108 + const unsigned num_strings = post->names.size();
1.109 +
1.110 + // check that all the references are within bounds
1.111 + for (unsigned i = 0; i < num_glyphs; ++i) {
1.112 + unsigned offset = post->glyph_name_index[i];
1.113 + if (offset < 258) {
1.114 + continue;
1.115 + }
1.116 +
1.117 + offset -= 258;
1.118 + if (offset >= num_strings) {
1.119 + return OTS_FAILURE_MSG("Bad string index %d", offset);
1.120 + }
1.121 + }
1.122 +
1.123 + return true;
1.124 +}
1.125 +
1.126 +bool ots_post_should_serialise(OpenTypeFile *file) {
1.127 + return file->post != NULL;
1.128 +}
1.129 +
1.130 +bool ots_post_serialise(OTSStream *out, OpenTypeFile *file) {
1.131 + const OpenTypePOST *post = file->post;
1.132 +
1.133 + // OpenType with CFF glyphs must have v3 post table.
1.134 + if (file->post && file->cff && file->post->version != 0x00030000) {
1.135 + return OTS_FAILURE_MSG("Bad post version %x", post->version);
1.136 + }
1.137 +
1.138 + if (!out->WriteU32(post->version) ||
1.139 + !out->WriteU32(post->italic_angle) ||
1.140 + !out->WriteS16(post->underline) ||
1.141 + !out->WriteS16(post->underline_thickness) ||
1.142 + !out->WriteU32(post->is_fixed_pitch) ||
1.143 + !out->WriteU32(0) ||
1.144 + !out->WriteU32(0) ||
1.145 + !out->WriteU32(0) ||
1.146 + !out->WriteU32(0)) {
1.147 + return OTS_FAILURE_MSG("Failed to write post header");
1.148 + }
1.149 +
1.150 + if (post->version != 0x00020000) {
1.151 + return true; // v1.0 and v3.0 does not have glyph names.
1.152 + }
1.153 +
1.154 + if (!out->WriteU16(post->glyph_name_index.size())) {
1.155 + return OTS_FAILURE_MSG("Failed to write number of indices");
1.156 + }
1.157 +
1.158 + for (unsigned i = 0; i < post->glyph_name_index.size(); ++i) {
1.159 + if (!out->WriteU16(post->glyph_name_index[i])) {
1.160 + return OTS_FAILURE_MSG("Failed to write name index %d", i);
1.161 + }
1.162 + }
1.163 +
1.164 + // Now we just have to write out the strings in the correct order
1.165 + for (unsigned i = 0; i < post->names.size(); ++i) {
1.166 + const std::string& s = post->names[i];
1.167 + const uint8_t string_length = s.size();
1.168 + if (!out->Write(&string_length, 1)) {
1.169 + return OTS_FAILURE_MSG("Failed to write string %d", i);
1.170 + }
1.171 + // Some ttf fonts (e.g., frank.ttf on Windows Vista) have zero-length name.
1.172 + // We allow them.
1.173 + if (string_length > 0 && !out->Write(s.data(), string_length)) {
1.174 + return OTS_FAILURE_MSG("Failed to write string length for string %d", i);
1.175 + }
1.176 + }
1.177 +
1.178 + return true;
1.179 +}
1.180 +
1.181 +void ots_post_free(OpenTypeFile *file) {
1.182 + delete file->post;
1.183 +}
1.184 +
1.185 +} // namespace ots
