| // Copyright (c) 2011-2017 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 "gdef.h" |
| |
| #include <limits> |
| #include <vector> |
| |
| #include "gpos.h" |
| #include "gsub.h" |
| #include "layout.h" |
| #include "maxp.h" |
| #include "variations.h" |
| |
| // GDEF - The Glyph Definition Table |
| // http://www.microsoft.com/typography/otspec/gdef.htm |
| |
| namespace { |
| |
| // The maximum class value in the glyph class definision table. |
| const uint16_t kMaxGlyphClassDefValue = 4; |
| // The maximum format number of caret value tables. |
| const uint16_t kMaxCaretValueFormat = 3; |
| |
| } // namespace |
| |
| namespace ots { |
| |
| bool OpenTypeGDEF::ParseAttachListTable(const uint8_t *data, size_t length) { |
| ots::Buffer subtable(data, length); |
| |
| uint16_t offset_coverage = 0; |
| uint16_t glyph_count = 0; |
| if (!subtable.ReadU16(&offset_coverage) || |
| !subtable.ReadU16(&glyph_count)) { |
| return Error("Failed to read gdef header"); |
| } |
| const unsigned attach_points_end = |
| 2 * static_cast<unsigned>(glyph_count) + 4; |
| if (attach_points_end > std::numeric_limits<uint16_t>::max()) { |
| return Error("Bad glyph count in gdef"); |
| } |
| if (offset_coverage == 0 || offset_coverage >= length || |
| offset_coverage < attach_points_end) { |
| return Error("Bad coverage offset %d", offset_coverage); |
| } |
| if (glyph_count > this->m_num_glyphs) { |
| return Error("Bad glyph count %u", glyph_count); |
| } |
| |
| std::vector<uint16_t> attach_points; |
| attach_points.resize(glyph_count); |
| for (unsigned i = 0; i < glyph_count; ++i) { |
| if (!subtable.ReadU16(&attach_points[i])) { |
| return Error("Can't read attachment point %d", i); |
| } |
| if (attach_points[i] >= length || |
| attach_points[i] < attach_points_end) { |
| return Error("Bad attachment point %d of %d", i, attach_points[i]); |
| } |
| } |
| |
| // Parse coverage table |
| if (!ots::ParseCoverageTable(GetFont(), data + offset_coverage, |
| length - offset_coverage, this->m_num_glyphs)) { |
| return Error("Bad coverage table"); |
| } |
| |
| // Parse attach point table |
| for (unsigned i = 0; i < attach_points.size(); ++i) { |
| subtable.set_offset(attach_points[i]); |
| uint16_t point_count = 0; |
| if (!subtable.ReadU16(&point_count)) { |
| return Error("Can't read point count %d", i); |
| } |
| if (point_count == 0) { |
| return Error("zero point count %d", i); |
| } |
| uint16_t last_point_index = 0; |
| uint16_t point_index = 0; |
| for (unsigned j = 0; j < point_count; ++j) { |
| if (!subtable.ReadU16(&point_index)) { |
| return Error("Can't read point index %d in point %d", j, i); |
| } |
| // Contour point indices are in increasing numerical order |
| if (last_point_index != 0 && last_point_index >= point_index) { |
| return Error("bad contour indices: %u >= %u", |
| last_point_index, point_index); |
| } |
| last_point_index = point_index; |
| } |
| } |
| return true; |
| } |
| |
| bool OpenTypeGDEF::ParseLigCaretListTable(const uint8_t *data, size_t length) { |
| ots::Buffer subtable(data, length); |
| uint16_t offset_coverage = 0; |
| uint16_t lig_glyph_count = 0; |
| if (!subtable.ReadU16(&offset_coverage) || |
| !subtable.ReadU16(&lig_glyph_count)) { |
| return Error("Can't read caret structure"); |
| } |
| const unsigned lig_glyphs_end = |
| 2 * static_cast<unsigned>(lig_glyph_count) + 4; |
| if (lig_glyphs_end > std::numeric_limits<uint16_t>::max()) { |
| return Error("Bad caret structure"); |
| } |
| if (offset_coverage == 0 || offset_coverage >= length || |
| offset_coverage < lig_glyphs_end) { |
| return Error("Bad caret coverate offset %d", offset_coverage); |
| } |
| if (lig_glyph_count > this->m_num_glyphs) { |
| return Error("bad ligature glyph count: %u", lig_glyph_count); |
| } |
| |
| std::vector<uint16_t> lig_glyphs; |
| lig_glyphs.resize(lig_glyph_count); |
| for (unsigned i = 0; i < lig_glyph_count; ++i) { |
| if (!subtable.ReadU16(&lig_glyphs[i])) { |
| return Error("Can't read ligature glyph location %d", i); |
| } |
| if (lig_glyphs[i] >= length || lig_glyphs[i] < lig_glyphs_end) { |
| return Error("Bad ligature glyph location %d in glyph %d", lig_glyphs[i], i); |
| } |
| } |
| |
| // Parse coverage table |
| if (!ots::ParseCoverageTable(GetFont(), data + offset_coverage, |
| length - offset_coverage, this->m_num_glyphs)) { |
| return Error("Can't parse caret coverage table"); |
| } |
| |
| // Parse ligature glyph table |
| for (unsigned i = 0; i < lig_glyphs.size(); ++i) { |
| subtable.set_offset(lig_glyphs[i]); |
| uint16_t caret_count = 0; |
| if (!subtable.ReadU16(&caret_count)) { |
| return Error("Can't read caret count for glyph %d", i); |
| } |
| if (caret_count == 0) { |
| return Error("bad caret value count: %u", caret_count); |
| } |
| |
| std::vector<uint16_t> caret_value_offsets; |
| caret_value_offsets.resize(caret_count); |
| unsigned caret_value_offsets_end = 2 * static_cast<unsigned>(caret_count) + 2; |
| for (unsigned j = 0; j < caret_count; ++j) { |
| if (!subtable.ReadU16(&caret_value_offsets[j])) { |
| return Error("Can't read caret offset %d for glyph %d", j, i); |
| } |
| if (caret_value_offsets[j] >= length || caret_value_offsets[j] < caret_value_offsets_end) { |
| return Error("Bad caret offset %d for caret %d glyph %d", caret_value_offsets[j], j, i); |
| } |
| } |
| |
| // Parse caret values table |
| for (unsigned j = 0; j < caret_count; ++j) { |
| subtable.set_offset(lig_glyphs[i] + caret_value_offsets[j]); |
| uint16_t caret_format = 0; |
| if (!subtable.ReadU16(&caret_format)) { |
| return Error("Can't read caret values table %d in glyph %d", j, i); |
| } |
| if (caret_format == 0 || caret_format > kMaxCaretValueFormat) { |
| return Error("bad caret value format: %u", caret_format); |
| } |
| // CaretValueFormats contain a 2-byte field which could be |
| // arbitrary value. |
| if (!subtable.Skip(2)) { |
| return Error("Bad caret value table structure %d in glyph %d", j, i); |
| } |
| if (caret_format == 3) { |
| uint16_t offset_device = 0; |
| if (!subtable.ReadU16(&offset_device)) { |
| return Error("Can't read device offset for caret value %d " |
| "in glyph %d", j, i); |
| } |
| uint16_t absolute_offset = lig_glyphs[i] + caret_value_offsets[j] |
| + offset_device; |
| if (offset_device == 0 || absolute_offset >= length) { |
| return Error("Bad device offset for caret value %d in glyph %d: %d", |
| j, i, offset_device); |
| } |
| if (!ots::ParseDeviceTable(GetFont(), data + absolute_offset, |
| length - absolute_offset)) { |
| return Error("Bad device table for caret value %d in glyph %d", |
| j, i, offset_device); |
| } |
| } |
| } |
| } |
| return true; |
| } |
| |
| bool OpenTypeGDEF::ParseMarkGlyphSetsDefTable(const uint8_t *data, size_t length) { |
| ots::Buffer subtable(data, length); |
| uint16_t format = 0; |
| uint16_t mark_set_count = 0; |
| if (!subtable.ReadU16(&format) || |
| !subtable.ReadU16(&mark_set_count)) { |
| return Error("Can' read mark glyph table structure"); |
| } |
| if (format != 1) { |
| return Error("bad mark glyph set table format: %u", format); |
| } |
| |
| const unsigned mark_sets_end = 2 * static_cast<unsigned>(mark_set_count) + 4; |
| if (mark_sets_end > std::numeric_limits<uint16_t>::max()) { |
| return Error("Bad mark_set %d", mark_sets_end); |
| } |
| for (unsigned i = 0; i < mark_set_count; ++i) { |
| uint32_t offset_coverage = 0; |
| if (!subtable.ReadU32(&offset_coverage)) { |
| return Error("Can't read covrage location for mark set %d", i); |
| } |
| if (offset_coverage >= length || |
| offset_coverage < mark_sets_end) { |
| return Error("Bad coverage location %d for mark set %d", offset_coverage, i); |
| } |
| if (!ots::ParseCoverageTable(GetFont(), data + offset_coverage, |
| length - offset_coverage, this->m_num_glyphs)) { |
| return Error("Failed to parse coverage table for mark set %d", i); |
| } |
| } |
| this->num_mark_glyph_sets = mark_set_count; |
| return true; |
| } |
| |
| bool OpenTypeGDEF::Parse(const uint8_t *data, size_t length) { |
| OpenTypeMAXP *maxp = static_cast<OpenTypeMAXP*>( |
| GetFont()->GetTypedTable(OTS_TAG_MAXP)); |
| |
| // Grab the number of glyphs in the font from the maxp table to check |
| // GlyphIDs in GDEF table. |
| if (!maxp) { |
| return Error("No maxp table in font, needed by GDEF"); |
| } |
| this->m_num_glyphs = maxp->num_glyphs; |
| |
| Buffer table(data, length); |
| |
| uint16_t version_major = 0, version_minor = 0; |
| if (!table.ReadU16(&version_major) || |
| !table.ReadU16(&version_minor)) { |
| return Error("Incomplete table"); |
| } |
| if (version_major != 1 || version_minor == 1) { // there is no v1.1 |
| return Error("Bad version"); |
| } |
| |
| uint16_t offset_glyph_class_def = 0; |
| uint16_t offset_attach_list = 0; |
| uint16_t offset_lig_caret_list = 0; |
| uint16_t offset_mark_attach_class_def = 0; |
| if (!table.ReadU16(&offset_glyph_class_def) || |
| !table.ReadU16(&offset_attach_list) || |
| !table.ReadU16(&offset_lig_caret_list) || |
| !table.ReadU16(&offset_mark_attach_class_def)) { |
| return Error("Incomplete table"); |
| } |
| uint16_t offset_mark_glyph_sets_def = 0; |
| if (version_minor >= 2) { |
| if (!table.ReadU16(&offset_mark_glyph_sets_def)) { |
| return Error("Incomplete table"); |
| } |
| } |
| uint32_t item_var_store_offset = 0; |
| if (version_minor >= 3) { |
| if (!table.ReadU32(&item_var_store_offset)) { |
| return Error("Incomplete table"); |
| } |
| } |
| |
| unsigned gdef_header_end = 4 + 4 * 2; |
| if (version_minor >= 2) |
| gdef_header_end += 2; |
| if (version_minor >= 3) |
| gdef_header_end += 4; |
| |
| // Parse subtables |
| if (offset_glyph_class_def) { |
| if (offset_glyph_class_def >= length || |
| offset_glyph_class_def < gdef_header_end) { |
| return Error("Invalid offset to glyph classes"); |
| } |
| if (!ots::ParseClassDefTable(GetFont(), data + offset_glyph_class_def, |
| length - offset_glyph_class_def, |
| this->m_num_glyphs, kMaxGlyphClassDefValue)) { |
| return Error("Invalid glyph classes"); |
| } |
| } |
| |
| if (offset_attach_list) { |
| if (offset_attach_list >= length || |
| offset_attach_list < gdef_header_end) { |
| return Error("Invalid offset to attachment list"); |
| } |
| if (!ParseAttachListTable(data + offset_attach_list, |
| length - offset_attach_list)) { |
| return Error("Invalid attachment list"); |
| } |
| } |
| |
| if (offset_lig_caret_list) { |
| if (offset_lig_caret_list >= length || |
| offset_lig_caret_list < gdef_header_end) { |
| return Error("Invalid offset to ligature caret list"); |
| } |
| if (!ParseLigCaretListTable(data + offset_lig_caret_list, |
| length - offset_lig_caret_list)) { |
| return Error("Invalid ligature caret list"); |
| } |
| } |
| |
| if (offset_mark_attach_class_def) { |
| if (offset_mark_attach_class_def >= length || |
| offset_mark_attach_class_def < gdef_header_end) { |
| return Error("Invalid offset to mark attachment list"); |
| } |
| if (!ots::ParseClassDefTable(GetFont(), |
| data + offset_mark_attach_class_def, |
| length - offset_mark_attach_class_def, |
| this->m_num_glyphs, kMaxClassDefValue)) { |
| return Error("Invalid mark attachment list"); |
| } |
| } |
| |
| if (offset_mark_glyph_sets_def) { |
| if (offset_mark_glyph_sets_def >= length || |
| offset_mark_glyph_sets_def < gdef_header_end) { |
| return Error("invalid offset to mark glyph sets"); |
| } |
| if (!ParseMarkGlyphSetsDefTable(data + offset_mark_glyph_sets_def, |
| length - offset_mark_glyph_sets_def)) { |
| return Error("Invalid mark glyph sets"); |
| } |
| } |
| |
| if (item_var_store_offset) { |
| if (item_var_store_offset >= length || |
| item_var_store_offset < gdef_header_end) { |
| return Error("invalid offset to item variation store"); |
| } |
| if (!ParseItemVariationStore(GetFont(), data + item_var_store_offset, |
| length - item_var_store_offset)) { |
| return Error("Invalid item variation store"); |
| } |
| } |
| |
| this->m_data = data; |
| this->m_length = length; |
| return true; |
| } |
| |
| bool OpenTypeGDEF::Serialize(OTSStream *out) { |
| if (!out->Write(this->m_data, this->m_length)) { |
| return Error("Failed to write table"); |
| } |
| |
| return true; |
| } |
| |
| } // namespace ots |