xref: /aosp_15_r20/external/harfbuzz_ng/src/hb-ot-post-table-v2subset.hh (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
1 /*
2  * Copyright © 2021  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  */
25 
26 #ifndef HB_OT_POST_TABLE_V2SUBSET_HH
27 #define HB_OT_POST_TABLE_V2SUBSET_HH
28 
29 #include "hb-open-type.hh"
30 #include "hb-ot-post-table.hh"
31 
32 /*
33  * post -- PostScript
34  * https://docs.microsoft.com/en-us/typography/opentype/spec/post
35  */
36 
37 namespace OT {
38 template<typename Iterator>
serialize(hb_serialize_context_t * c,Iterator it,const void * _post) const39 HB_INTERNAL bool postV2Tail::serialize (hb_serialize_context_t *c,
40                                         Iterator it,
41                                         const void* _post) const
42 {
43   TRACE_SERIALIZE (this);
44   auto *out = c->start_embed (this);
45   if (unlikely (!c->check_success (out))) return_trace (false);
46   if (!out->glyphNameIndex.serialize (c, + it
47                                          | hb_map (hb_second)))
48       return_trace (false);
49 
50   hb_set_t copied_indices;
51   for (const auto& _ : + it )
52   {
53     unsigned glyph_id = _.first;
54     unsigned new_index = _.second;
55 
56     if (new_index < 258) continue;
57     if (copied_indices.has (new_index)) continue;
58     copied_indices.add (new_index);
59 
60     hb_bytes_t s = reinterpret_cast<const post::accelerator_t*> (_post)->find_glyph_name (glyph_id);
61     HBUINT8 *o = c->allocate_size<HBUINT8> (HBUINT8::static_size * (s.length + 1));
62     if (unlikely (!o)) return_trace (false);
63     if (!c->check_assign (o[0], s.length, HB_SERIALIZE_ERROR_INT_OVERFLOW)) return_trace (false);
64     hb_memcpy (o+1, s.arrayZ, HBUINT8::static_size * s.length);
65   }
66 
67   return_trace (true);
68 }
69 
subset(hb_subset_context_t * c) const70 HB_INTERNAL bool postV2Tail::subset (hb_subset_context_t *c) const
71 {
72   TRACE_SUBSET (this);
73 
74   const hb_map_t &reverse_glyph_map = *c->plan->reverse_glyph_map;
75   unsigned num_glyphs = c->plan->num_output_glyphs ();
76   hb_map_t old_new_index_map, old_gid_new_index_map;
77   unsigned i = 0;
78 
79   post::accelerator_t _post (c->plan->source);
80 
81   hb_hashmap_t<hb_bytes_t, uint32_t, true> glyph_name_to_new_index;
82 
83   old_new_index_map.alloc (num_glyphs);
84   old_gid_new_index_map.alloc (num_glyphs);
85   glyph_name_to_new_index.alloc (num_glyphs);
86 
87   for (auto _ : c->plan->new_to_old_gid_list)
88   {
89     hb_codepoint_t old_gid = _.second;
90     unsigned old_index = glyphNameIndex[old_gid];
91 
92     unsigned new_index;
93     const uint32_t *new_index2;
94     if (old_index <= 257)
95       new_index = old_index;
96     else if (old_new_index_map.has (old_index, &new_index2))
97       new_index = *new_index2;
98     else
99     {
100       hb_bytes_t s = _post.find_glyph_name (old_gid);
101       new_index = glyph_name_to_new_index.get (s);
102       if (new_index == (unsigned)-1)
103       {
104         int standard_glyph_index = -1;
105         for (unsigned i = 0; i < format1_names_length; i++)
106         {
107           if (s == format1_names (i))
108           {
109             standard_glyph_index = i;
110             break;
111           }
112         }
113 
114         if (standard_glyph_index == -1)
115         {
116           new_index = 258 + i;
117           i++;
118         }
119         else
120         { new_index = standard_glyph_index; }
121         glyph_name_to_new_index.set (s, new_index);
122       }
123       old_new_index_map.set (old_index, new_index);
124     }
125     old_gid_new_index_map.set (old_gid, new_index);
126   }
127 
128   if (old_gid_new_index_map.in_error())
129     return_trace (false);
130 
131   auto index_iter =
132   + hb_range (num_glyphs)
133   | hb_map_retains_sorting ([&](hb_codepoint_t new_gid)
134                             {
135                               hb_codepoint_t *old_gid;
136                               /* use 0 for retain-gid holes, which refers to the name .notdef,
137                                * as the glyphNameIndex entry for that glyph ID."*/
138                               unsigned new_index = 0;
139                               if (reverse_glyph_map.has (new_gid, &old_gid)) {
140                                 new_index = old_gid_new_index_map.get (*old_gid);
141                                 return hb_pair_t<unsigned, unsigned> (*old_gid, new_index);
142                               }
143                               return hb_pair_t<unsigned, unsigned> (new_gid, new_index);
144                             })
145   ;
146 
147   return_trace (serialize (c->serializer, index_iter, &_post));
148 }
149 
150 } /* namespace OT */
151 #endif /* HB_OT_POST_TABLE_V2SUBSET_HH */
152