1 /* 2 * Copyright © 2022 Google, Inc. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Google Author(s): Garret Rieger 25 */ 26 27 #include "graph.hh" 28 #include "../OT/Layout/Common/Coverage.hh" 29 30 #ifndef GRAPH_COVERAGE_GRAPH_HH 31 #define GRAPH_COVERAGE_GRAPH_HH 32 33 namespace graph { 34 35 struct CoverageFormat1 : public OT::Layout::Common::CoverageFormat1_3<SmallTypes> 36 { sanitizegraph::CoverageFormat137 bool sanitize (graph_t::vertex_t& vertex) const 38 { 39 int64_t vertex_len = vertex.obj.tail - vertex.obj.head; 40 constexpr unsigned min_size = OT::Layout::Common::CoverageFormat1_3<SmallTypes>::min_size; 41 if (vertex_len < min_size) return false; 42 return vertex_len >= min_size + glyphArray.get_size () - glyphArray.len.get_size (); 43 } 44 }; 45 46 struct CoverageFormat2 : public OT::Layout::Common::CoverageFormat2_4<SmallTypes> 47 { sanitizegraph::CoverageFormat248 bool sanitize (graph_t::vertex_t& vertex) const 49 { 50 int64_t vertex_len = vertex.obj.tail - vertex.obj.head; 51 constexpr unsigned min_size = OT::Layout::Common::CoverageFormat2_4<SmallTypes>::min_size; 52 if (vertex_len < min_size) return false; 53 return vertex_len >= min_size + rangeRecord.get_size () - rangeRecord.len.get_size (); 54 } 55 }; 56 57 struct Coverage : public OT::Layout::Common::Coverage 58 { clone_coveragegraph::Coverage59 static Coverage* clone_coverage (gsubgpos_graph_context_t& c, 60 unsigned coverage_id, 61 unsigned new_parent_id, 62 unsigned link_position, 63 unsigned start, unsigned end) 64 65 { 66 unsigned coverage_size = c.graph.vertices_[coverage_id].table_size (); 67 auto& coverage_v = c.graph.vertices_[coverage_id]; 68 Coverage* coverage_table = (Coverage*) coverage_v.obj.head; 69 if (!coverage_table || !coverage_table->sanitize (coverage_v)) 70 return nullptr; 71 72 auto new_coverage = 73 + hb_zip (coverage_table->iter (), hb_range ()) 74 | hb_filter ([&] (hb_pair_t<unsigned, unsigned> p) { 75 return p.second >= start && p.second < end; 76 }) 77 | hb_map_retains_sorting (hb_first) 78 ; 79 80 return add_coverage (c, new_parent_id, link_position, new_coverage, coverage_size); 81 } 82 83 template<typename It> add_coveragegraph::Coverage84 static Coverage* add_coverage (gsubgpos_graph_context_t& c, 85 unsigned parent_id, 86 unsigned link_position, 87 It glyphs, 88 unsigned max_size) 89 { 90 unsigned coverage_prime_id = c.graph.new_node (nullptr, nullptr); 91 auto& coverage_prime_vertex = c.graph.vertices_[coverage_prime_id]; 92 if (!make_coverage (c, glyphs, coverage_prime_id, max_size)) 93 return nullptr; 94 95 auto* coverage_link = c.graph.vertices_[parent_id].obj.real_links.push (); 96 coverage_link->width = SmallTypes::size; 97 coverage_link->objidx = coverage_prime_id; 98 coverage_link->position = link_position; 99 coverage_prime_vertex.parents.push (parent_id); 100 101 return (Coverage*) coverage_prime_vertex.obj.head; 102 } 103 104 template<typename It> make_coveragegraph::Coverage105 static bool make_coverage (gsubgpos_graph_context_t& c, 106 It glyphs, 107 unsigned dest_obj, 108 unsigned max_size) 109 { 110 char* buffer = (char*) hb_calloc (1, max_size); 111 hb_serialize_context_t serializer (buffer, max_size); 112 OT::Layout::Common::Coverage_serialize (&serializer, glyphs); 113 serializer.end_serialize (); 114 if (serializer.in_error ()) 115 { 116 hb_free (buffer); 117 return false; 118 } 119 120 hb_bytes_t coverage_copy = serializer.copy_bytes (); 121 c.add_buffer ((char *) coverage_copy.arrayZ); // Give ownership to the context, it will cleanup the buffer. 122 123 auto& obj = c.graph.vertices_[dest_obj].obj; 124 obj.head = (char *) coverage_copy.arrayZ; 125 obj.tail = obj.head + coverage_copy.length; 126 127 hb_free (buffer); 128 return true; 129 } 130 sanitizegraph::Coverage131 bool sanitize (graph_t::vertex_t& vertex) const 132 { 133 int64_t vertex_len = vertex.obj.tail - vertex.obj.head; 134 if (vertex_len < OT::Layout::Common::Coverage::min_size) return false; 135 switch (u.format) 136 { 137 case 1: return ((CoverageFormat1*)this)->sanitize (vertex); 138 case 2: return ((CoverageFormat2*)this)->sanitize (vertex); 139 #ifndef HB_NO_BEYOND_64K 140 // Not currently supported 141 case 3: 142 case 4: 143 #endif 144 default: return false; 145 } 146 } 147 }; 148 149 150 } 151 152 #endif // GRAPH_COVERAGE_GRAPH_HH 153