xref: /aosp_15_r20/external/harfbuzz_ng/src/hb-ot-var-cvar-table.hh (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
1 /*
2  * Copyright © 2023  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_VAR_CVAR_TABLE_HH
27 #define HB_OT_VAR_CVAR_TABLE_HH
28 
29 #include "hb-ot-var-common.hh"
30 #include "hb-ot-var-fvar-table.hh"
31 
32 
33 namespace OT {
34 /*
35  * cvar -- control value table (CVT) Variations
36  * https://docs.microsoft.com/en-us/typography/opentype/spec/cvar
37  */
38 #define HB_OT_TAG_cvar HB_TAG('c','v','a','r')
39 
40 struct cvar
41 {
42   static constexpr hb_tag_t tableTag = HB_OT_TAG_cvar;
43 
sanitizeOT::cvar44   bool sanitize (hb_sanitize_context_t *c) const
45   {
46     TRACE_SANITIZE (this);
47     return_trace (c->check_struct (this) &&
48 		  hb_barrier () &&
49 		  likely (version.major == 1) &&
50 		  tupleVariationData.sanitize (c));
51   }
52 
get_tuple_var_dataOT::cvar53   const TupleVariationData* get_tuple_var_data (void) const
54   { return &tupleVariationData; }
55 
decompile_tuple_variationsOT::cvar56   bool decompile_tuple_variations (unsigned axis_count,
57                                    unsigned point_count,
58                                    hb_blob_t *blob,
59                                    bool is_gvar,
60                                    const hb_map_t *axes_old_index_tag_map,
61                                    TupleVariationData::tuple_variations_t& tuple_variations /* OUT */) const
62   {
63     hb_vector_t<unsigned> shared_indices;
64     TupleVariationData::tuple_iterator_t iterator;
65     hb_bytes_t var_data_bytes = blob->as_bytes ().sub_array (4);
66     if (!TupleVariationData::get_tuple_iterator (var_data_bytes, axis_count, this,
67                                                  shared_indices, &iterator))
68       return false;
69 
70     return tupleVariationData.decompile_tuple_variations (point_count, is_gvar, iterator,
71                                                           axes_old_index_tag_map,
72                                                           shared_indices,
73                                                           hb_array<const F2DOT14> (),
74                                                           tuple_variations);
75   }
76 
calculate_cvt_deltasOT::cvar77   static bool calculate_cvt_deltas (unsigned axis_count,
78                                     hb_array_t<int> coords,
79                                     unsigned num_cvt_item,
80                                     const TupleVariationData *tuple_var_data,
81                                     const void *base,
82                                     hb_vector_t<float>& cvt_deltas /* OUT */)
83   {
84     if (!coords) return true;
85     hb_vector_t<unsigned> shared_indices;
86     TupleVariationData::tuple_iterator_t iterator;
87     unsigned var_data_length = tuple_var_data->get_size (axis_count);
88     hb_bytes_t var_data_bytes = hb_bytes_t (reinterpret_cast<const char*> (tuple_var_data), var_data_length);
89     if (!TupleVariationData::get_tuple_iterator (var_data_bytes, axis_count, base,
90                                                  shared_indices, &iterator))
91       return true; /* isn't applied at all */
92 
93     hb_array_t<const F2DOT14> shared_tuples = hb_array<F2DOT14> ();
94     hb_vector_t<unsigned> private_indices;
95     hb_vector_t<int> unpacked_deltas;
96 
97     do
98     {
99       float scalar = iterator.current_tuple->calculate_scalar (coords, axis_count, shared_tuples);
100       if (scalar == 0.f) continue;
101       const HBUINT8 *p = iterator.get_serialized_data ();
102       unsigned int length = iterator.current_tuple->get_data_size ();
103       if (unlikely (!iterator.var_data_bytes.check_range (p, length)))
104         return false;
105 
106       const HBUINT8 *end = p + length;
107 
108       bool has_private_points = iterator.current_tuple->has_private_points ();
109       if (has_private_points &&
110           !TupleVariationData::decompile_points (p, private_indices, end))
111         return false;
112       const hb_vector_t<unsigned int> &indices = has_private_points ? private_indices : shared_indices;
113 
114       bool apply_to_all = (indices.length == 0);
115       unsigned num_deltas = apply_to_all ? num_cvt_item : indices.length;
116       if (unlikely (!unpacked_deltas.resize (num_deltas, false))) return false;
117       if (unlikely (!TupleVariationData::decompile_deltas (p, unpacked_deltas, end))) return false;
118 
119       for (unsigned int i = 0; i < num_deltas; i++)
120       {
121         unsigned int idx = apply_to_all ? i : indices[i];
122         if (unlikely (idx >= num_cvt_item)) continue;
123         if (scalar != 1.0f) cvt_deltas[idx] += unpacked_deltas[i] * scalar ;
124         else cvt_deltas[idx] += unpacked_deltas[i];
125       }
126     } while (iterator.move_to_next ());
127 
128     return true;
129   }
130 
serializeOT::cvar131   bool serialize (hb_serialize_context_t *c,
132                   TupleVariationData::tuple_variations_t& tuple_variations) const
133   {
134     TRACE_SERIALIZE (this);
135     if (!tuple_variations) return_trace (false);
136     if (unlikely (!c->embed (version))) return_trace (false);
137 
138     return_trace (tupleVariationData.serialize (c, false, tuple_variations));
139   }
140 
subsetOT::cvar141   bool subset (hb_subset_context_t *c) const
142   {
143     TRACE_SUBSET (this);
144     if (c->plan->all_axes_pinned)
145       return_trace (false);
146 
147     OT::TupleVariationData::tuple_variations_t tuple_variations;
148     unsigned axis_count = c->plan->axes_old_index_tag_map.get_population ();
149 
150     const hb_tag_t cvt = HB_TAG('c','v','t',' ');
151     hb_blob_t *cvt_blob = hb_face_reference_table (c->plan->source, cvt);
152     unsigned point_count = hb_blob_get_length (cvt_blob) / FWORD::static_size;
153     hb_blob_destroy (cvt_blob);
154 
155     if (!decompile_tuple_variations (axis_count, point_count,
156                                      c->source_blob, false,
157                                      &(c->plan->axes_old_index_tag_map),
158                                      tuple_variations))
159       return_trace (false);
160 
161     if (!tuple_variations.instantiate (c->plan->axes_location, c->plan->axes_triple_distances))
162       return_trace (false);
163 
164     if (!tuple_variations.compile_bytes (c->plan->axes_index_map, c->plan->axes_old_index_tag_map,
165                                          false /* do not use shared points */))
166       return_trace (false);
167 
168     return_trace (serialize (c->serializer, tuple_variations));
169   }
170 
add_cvt_and_apply_deltasOT::cvar171   static bool add_cvt_and_apply_deltas (hb_subset_plan_t *plan,
172                                         const TupleVariationData *tuple_var_data,
173                                         const void *base)
174   {
175     const hb_tag_t cvt = HB_TAG('c','v','t',' ');
176     hb_blob_t *cvt_blob = hb_face_reference_table (plan->source, cvt);
177     hb_blob_t *cvt_prime_blob = hb_blob_copy_writable_or_fail (cvt_blob);
178     hb_blob_destroy (cvt_blob);
179 
180     if (unlikely (!cvt_prime_blob))
181       return false;
182 
183     unsigned cvt_blob_length = hb_blob_get_length (cvt_prime_blob);
184     unsigned num_cvt_item = cvt_blob_length / FWORD::static_size;
185 
186     hb_vector_t<float> cvt_deltas;
187     if (unlikely (!cvt_deltas.resize (num_cvt_item)))
188     {
189       hb_blob_destroy (cvt_prime_blob);
190       return false;
191     }
192 
193     if (!calculate_cvt_deltas (plan->normalized_coords.length, plan->normalized_coords.as_array (),
194                                num_cvt_item, tuple_var_data, base, cvt_deltas))
195     {
196       hb_blob_destroy (cvt_prime_blob);
197       return false;
198     }
199 
200     FWORD *cvt_prime = (FWORD *) hb_blob_get_data_writable (cvt_prime_blob, nullptr);
201     for (unsigned i = 0; i < num_cvt_item; i++)
202       cvt_prime[i] += (int) roundf (cvt_deltas[i]);
203 
204     bool success = plan->add_table (cvt, cvt_prime_blob);
205     hb_blob_destroy (cvt_prime_blob);
206     return success;
207   }
208 
209   protected:
210   FixedVersion<>version;		/* Version of the CVT variation table
211 					 * initially set to 0x00010000u */
212   TupleVariationData tupleVariationData; /* TupleVariationDate for cvar table */
213   public:
214   DEFINE_SIZE_MIN (8);
215 };
216 
217 } /* namespace OT */
218 
219 
220 #endif /* HB_OT_VAR_CVAR_TABLE_HH */
221