diff options
Diffstat (limited to 'thirdparty/harfbuzz/src/graph/gsubgpos-graph.hh')
| -rw-r--r-- | thirdparty/harfbuzz/src/graph/gsubgpos-graph.hh | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/thirdparty/harfbuzz/src/graph/gsubgpos-graph.hh b/thirdparty/harfbuzz/src/graph/gsubgpos-graph.hh new file mode 100644 index 0000000000..a93e7d1c73 --- /dev/null +++ b/thirdparty/harfbuzz/src/graph/gsubgpos-graph.hh @@ -0,0 +1,411 @@ +/* + * Copyright © 2022 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Garret Rieger + */ + +#include "graph.hh" +#include "../hb-ot-layout-gsubgpos.hh" +#include "../OT/Layout/GSUB/ExtensionSubst.hh" +#include "gsubgpos-context.hh" +#include "pairpos-graph.hh" +#include "markbasepos-graph.hh" + +#ifndef GRAPH_GSUBGPOS_GRAPH_HH +#define GRAPH_GSUBGPOS_GRAPH_HH + +namespace graph { + +struct Lookup; + +template<typename T> +struct ExtensionFormat1 : public OT::ExtensionFormat1<T> +{ + void reset(unsigned type) + { + this->format = 1; + this->extensionLookupType = type; + this->extensionOffset = 0; + } + + bool sanitize (graph_t::vertex_t& vertex) const + { + int64_t vertex_len = vertex.obj.tail - vertex.obj.head; + return vertex_len >= OT::ExtensionFormat1<T>::static_size; + } + + unsigned get_lookup_type () const + { + return this->extensionLookupType; + } + + unsigned get_subtable_index (graph_t& graph, unsigned this_index) const + { + return graph.index_for_offset (this_index, &this->extensionOffset); + } +}; + +struct Lookup : public OT::Lookup +{ + unsigned number_of_subtables () const + { + return subTable.len; + } + + bool sanitize (graph_t::vertex_t& vertex) const + { + int64_t vertex_len = vertex.obj.tail - vertex.obj.head; + if (vertex_len < OT::Lookup::min_size) return false; + return vertex_len >= this->get_size (); + } + + bool is_extension (hb_tag_t table_tag) const + { + return lookupType == extension_type (table_tag); + } + + bool make_extension (gsubgpos_graph_context_t& c, + unsigned this_index) + { + unsigned type = lookupType; + unsigned ext_type = extension_type (c.table_tag); + if (!ext_type || is_extension (c.table_tag)) + { + // NOOP + return true; + } + + DEBUG_MSG (SUBSET_REPACK, nullptr, + "Promoting lookup type %u (obj %u) to extension.", + type, + this_index); + + for (unsigned i = 0; i < subTable.len; i++) + { + unsigned subtable_index = c.graph.index_for_offset (this_index, &subTable[i]); + if (!make_subtable_extension (c, + this_index, + subtable_index)) + return false; + } + + lookupType = ext_type; + return true; + } + + bool split_subtables_if_needed (gsubgpos_graph_context_t& c, + unsigned this_index) + { + unsigned type = lookupType; + bool is_ext = is_extension (c.table_tag); + + if (c.table_tag != HB_OT_TAG_GPOS) + return true; + + if (!is_ext && + type != OT::Layout::GPOS_impl::PosLookupSubTable::Type::Pair && + type != OT::Layout::GPOS_impl::PosLookupSubTable::Type::MarkBase) + return true; + + hb_vector_t<hb_pair_t<unsigned, hb_vector_t<unsigned>>> all_new_subtables; + for (unsigned i = 0; i < subTable.len; i++) + { + unsigned subtable_index = c.graph.index_for_offset (this_index, &subTable[i]); + if (is_ext) { + unsigned ext_subtable_index = subtable_index; + ExtensionFormat1<OT::Layout::GSUB_impl::ExtensionSubst>* extension = + (ExtensionFormat1<OT::Layout::GSUB_impl::ExtensionSubst>*) + c.graph.object (ext_subtable_index).head; + if (!extension || !extension->sanitize (c.graph.vertices_[ext_subtable_index])) + continue; + + subtable_index = extension->get_subtable_index (c.graph, ext_subtable_index); + type = extension->get_lookup_type (); + if (type != OT::Layout::GPOS_impl::PosLookupSubTable::Type::Pair + && type != OT::Layout::GPOS_impl::PosLookupSubTable::Type::MarkBase) + continue; + } + + hb_vector_t<unsigned> new_sub_tables; + switch (type) + { + case 2: + new_sub_tables = split_subtable<PairPos> (c, subtable_index); break; + case 4: + new_sub_tables = split_subtable<MarkBasePos> (c, subtable_index); break; + default: + break; + } + if (new_sub_tables.in_error ()) return false; + if (!new_sub_tables) continue; + hb_pair_t<unsigned, hb_vector_t<unsigned>>* entry = all_new_subtables.push (); + entry->first = i; + entry->second = std::move (new_sub_tables); + } + + if (all_new_subtables) { + add_sub_tables (c, this_index, type, all_new_subtables); + } + + return true; + } + + template<typename T> + hb_vector_t<unsigned> split_subtable (gsubgpos_graph_context_t& c, + unsigned objidx) + { + T* sub_table = (T*) c.graph.object (objidx).head; + if (!sub_table || !sub_table->sanitize (c.graph.vertices_[objidx])) + return hb_vector_t<unsigned> (); + + return sub_table->split_subtables (c, objidx); + } + + void add_sub_tables (gsubgpos_graph_context_t& c, + unsigned this_index, + unsigned type, + hb_vector_t<hb_pair_t<unsigned, hb_vector_t<unsigned>>>& subtable_ids) + { + bool is_ext = is_extension (c.table_tag); + auto& v = c.graph.vertices_[this_index]; + fix_existing_subtable_links (c, this_index, subtable_ids); + + unsigned new_subtable_count = 0; + for (const auto& p : subtable_ids) + new_subtable_count += p.second.length; + + size_t new_size = v.table_size () + + new_subtable_count * OT::Offset16::static_size; + char* buffer = (char*) hb_calloc (1, new_size); + c.add_buffer (buffer); + memcpy (buffer, v.obj.head, v.table_size()); + + v.obj.head = buffer; + v.obj.tail = buffer + new_size; + + Lookup* new_lookup = (Lookup*) buffer; + + unsigned shift = 0; + new_lookup->subTable.len = subTable.len + new_subtable_count; + for (const auto& p : subtable_ids) + { + unsigned offset_index = p.first + shift + 1; + shift += p.second.length; + + for (unsigned subtable_id : p.second) + { + if (is_ext) + { + unsigned ext_id = create_extension_subtable (c, subtable_id, type); + c.graph.vertices_[subtable_id].parents.push (ext_id); + subtable_id = ext_id; + } + + auto* link = v.obj.real_links.push (); + link->width = 2; + link->objidx = subtable_id; + link->position = (char*) &new_lookup->subTable[offset_index++] - + (char*) new_lookup; + c.graph.vertices_[subtable_id].parents.push (this_index); + } + } + + // Repacker sort order depends on link order, which we've messed up so resort it. + v.obj.real_links.qsort (); + + // The head location of the lookup has changed, invalidating the lookups map entry + // in the context. Update the map. + c.lookups.set (this_index, new_lookup); + } + + void fix_existing_subtable_links (gsubgpos_graph_context_t& c, + unsigned this_index, + hb_vector_t<hb_pair_t<unsigned, hb_vector_t<unsigned>>>& subtable_ids) + { + auto& v = c.graph.vertices_[this_index]; + Lookup* lookup = (Lookup*) v.obj.head; + + unsigned shift = 0; + for (const auto& p : subtable_ids) + { + unsigned insert_index = p.first + shift; + unsigned pos_offset = p.second.length * OT::Offset16::static_size; + unsigned insert_offset = (char*) &lookup->subTable[insert_index] - (char*) lookup; + shift += p.second.length; + + for (auto& l : v.obj.all_links_writer ()) + { + if (l.position > insert_offset) l.position += pos_offset; + } + } + } + + unsigned create_extension_subtable (gsubgpos_graph_context_t& c, + unsigned subtable_index, + unsigned type) + { + unsigned extension_size = OT::ExtensionFormat1<OT::Layout::GSUB_impl::ExtensionSubst>::static_size; + + unsigned ext_index = c.create_node (extension_size); + if (ext_index == (unsigned) -1) + return -1; + + auto& ext_vertex = c.graph.vertices_[ext_index]; + ExtensionFormat1<OT::Layout::GSUB_impl::ExtensionSubst>* extension = + (ExtensionFormat1<OT::Layout::GSUB_impl::ExtensionSubst>*) ext_vertex.obj.head; + extension->reset (type); + + // Make extension point at the subtable. + auto* l = ext_vertex.obj.real_links.push (); + + l->width = 4; + l->objidx = subtable_index; + l->position = 4; + + return ext_index; + } + + bool make_subtable_extension (gsubgpos_graph_context_t& c, + unsigned lookup_index, + unsigned subtable_index) + { + unsigned type = lookupType; + + unsigned ext_index = create_extension_subtable(c, subtable_index, type); + if (ext_index == (unsigned) -1) + return false; + + auto& lookup_vertex = c.graph.vertices_[lookup_index]; + for (auto& l : lookup_vertex.obj.real_links.writer ()) + { + if (l.objidx == subtable_index) + // Change lookup to point at the extension. + l.objidx = ext_index; + } + + // Make extension point at the subtable. + auto& ext_vertex = c.graph.vertices_[ext_index]; + auto& subtable_vertex = c.graph.vertices_[subtable_index]; + ext_vertex.parents.push (lookup_index); + subtable_vertex.remap_parent (lookup_index, ext_index); + + return true; + } + + private: + unsigned extension_type (hb_tag_t table_tag) const + { + switch (table_tag) + { + case HB_OT_TAG_GPOS: return 9; + case HB_OT_TAG_GSUB: return 7; + default: return 0; + } + } +}; + +template <typename T> +struct LookupList : public OT::LookupList<T> +{ + bool sanitize (const graph_t::vertex_t& vertex) const + { + int64_t vertex_len = vertex.obj.tail - vertex.obj.head; + if (vertex_len < OT::LookupList<T>::min_size) return false; + return vertex_len >= OT::LookupList<T>::item_size * this->len; + } +}; + +struct GSTAR : public OT::GSUBGPOS +{ + static GSTAR* graph_to_gstar (graph_t& graph) + { + const auto& r = graph.root (); + + GSTAR* gstar = (GSTAR*) r.obj.head; + if (!gstar || !gstar->sanitize (r)) + return nullptr; + + return gstar; + } + + const void* get_lookup_list_field_offset () const + { + switch (u.version.major) { + case 1: return u.version1.get_lookup_list_offset (); +#ifndef HB_NO_BORING_EXPANSION + case 2: return u.version2.get_lookup_list_offset (); +#endif + default: return 0; + } + } + + bool sanitize (const graph_t::vertex_t& vertex) + { + int64_t len = vertex.obj.tail - vertex.obj.head; + if (len < OT::GSUBGPOS::min_size) return false; + return len >= get_size (); + } + + void find_lookups (graph_t& graph, + hb_hashmap_t<unsigned, Lookup*>& lookups /* OUT */) + { + switch (u.version.major) { + case 1: find_lookups<SmallTypes> (graph, lookups); break; +#ifndef HB_NO_BORING_EXPANSION + case 2: find_lookups<MediumTypes> (graph, lookups); break; +#endif + } + } + + unsigned get_lookup_list_index (graph_t& graph) + { + return graph.index_for_offset (graph.root_idx (), + get_lookup_list_field_offset()); + } + + template<typename Types> + void find_lookups (graph_t& graph, + hb_hashmap_t<unsigned, Lookup*>& lookups /* OUT */) + { + unsigned lookup_list_idx = get_lookup_list_index (graph); + const LookupList<Types>* lookupList = + (const LookupList<Types>*) graph.object (lookup_list_idx).head; + if (!lookupList || !lookupList->sanitize (graph.vertices_[lookup_list_idx])) + return; + + for (unsigned i = 0; i < lookupList->len; i++) + { + unsigned lookup_idx = graph.index_for_offset (lookup_list_idx, &(lookupList->arrayZ[i])); + Lookup* lookup = (Lookup*) graph.object (lookup_idx).head; + if (!lookup || !lookup->sanitize (graph.vertices_[lookup_idx])) continue; + lookups.set (lookup_idx, lookup); + } + } +}; + + + + +} + +#endif /* GRAPH_GSUBGPOS_GRAPH_HH */ |