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
33namespace graph {
34
35struct CoverageFormat1 : public OT::Layout::Common::CoverageFormat1_3<SmallTypes>
36{
37 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
46struct CoverageFormat2 : public OT::Layout::Common::CoverageFormat2_4<SmallTypes>
47{
48 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
57struct Coverage : public OT::Layout::Common::Coverage
58{
59 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>
84 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.add_parent (parent_id);
100
101 return (Coverage*) coverage_prime_vertex.obj.head;
102 }
103
104 template<typename It>
105 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 if (!coverage_copy.arrayZ) return false;
122 // Give ownership to the context, it will cleanup the buffer.
123 if (!c.add_buffer ((char *) coverage_copy.arrayZ))
124 {
125 hb_free ((char *) coverage_copy.arrayZ);
126 return false;
127 }
128
129 auto& obj = c.graph.vertices_[dest_obj].obj;
130 obj.head = (char *) coverage_copy.arrayZ;
131 obj.tail = obj.head + coverage_copy.length;
132
133 hb_free (buffer);
134 return true;
135 }
136
137 bool sanitize (graph_t::vertex_t& vertex) const
138 {
139 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
140 if (vertex_len < OT::Layout::Common::Coverage::min_size) return false;
141 switch (u.format)
142 {
143 case 1: return ((CoverageFormat1*)this)->sanitize (vertex);
144 case 2: return ((CoverageFormat2*)this)->sanitize (vertex);
145#ifndef HB_NO_BEYOND_64K
146 // Not currently supported
147 case 3:
148 case 4:
149#endif
150 default: return false;
151 }
152 }
153};
154
155
156}
157
158#endif // GRAPH_COVERAGE_GRAPH_HH
159