1/*
2 * Copyright © 2017 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): Behdad Esfahbod
25 */
26
27#ifndef HB_OT_VAR_AVAR_TABLE_HH
28#define HB_OT_VAR_AVAR_TABLE_HH
29
30#include "hb-open-type.hh"
31#include "hb-ot-var-common.hh"
32
33
34/*
35 * avar -- Axis Variations
36 * https://docs.microsoft.com/en-us/typography/opentype/spec/avar
37 */
38
39#define HB_OT_TAG_avar HB_TAG('a','v','a','r')
40
41
42namespace OT {
43
44
45/* "Spec": https://github.com/be-fonts/boring-expansion-spec/issues/14 */
46struct avarV2Tail
47{
48 friend struct avar;
49
50 bool sanitize (hb_sanitize_context_t *c,
51 const void *base) const
52 {
53 TRACE_SANITIZE (this);
54 return_trace (varIdxMap.sanitize (c, base) &&
55 varStore.sanitize (c, base));
56 }
57
58 protected:
59 Offset32To<DeltaSetIndexMap> varIdxMap; /* Offset from the beginning of 'avar' table. */
60 Offset32To<VariationStore> varStore; /* Offset from the beginning of 'avar' table. */
61
62 public:
63 DEFINE_SIZE_STATIC (8);
64};
65
66
67struct AxisValueMap
68{
69 bool sanitize (hb_sanitize_context_t *c) const
70 {
71 TRACE_SANITIZE (this);
72 return_trace (c->check_struct (this));
73 }
74
75 void set_mapping (float from_coord, float to_coord)
76 {
77 coords[0].set_float (from_coord);
78 coords[1].set_float (to_coord);
79 }
80
81 bool is_outside_axis_range (const Triple& axis_range) const
82 {
83 float from_coord = coords[0].to_float ();
84 return !axis_range.contains (from_coord);
85 }
86
87 bool must_include () const
88 {
89 float from_coord = coords[0].to_float ();
90 float to_coord = coords[1].to_float ();
91 return (from_coord == -1.f && to_coord == -1.f) ||
92 (from_coord == 0.f && to_coord == 0.f) ||
93 (from_coord == 1.f && to_coord == 1.f);
94 }
95
96 void instantiate (const Triple& axis_range,
97 const Triple& unmapped_range,
98 const TripleDistances& triple_distances)
99 {
100 float from_coord = coords[0].to_float ();
101 float to_coord = coords[1].to_float ();
102
103 from_coord = renormalizeValue (from_coord, unmapped_range, triple_distances);
104 to_coord = renormalizeValue (to_coord, axis_range, triple_distances);
105
106 coords[0].set_float (from_coord);
107 coords[1].set_float (to_coord);
108 }
109
110 HB_INTERNAL static int cmp (const void *pa, const void *pb)
111 {
112 const AxisValueMap *a = (const AxisValueMap *) pa;
113 const AxisValueMap *b = (const AxisValueMap *) pb;
114
115 int a_from = a->coords[0].to_int ();
116 int b_from = b->coords[0].to_int ();
117 if (a_from != b_from)
118 return a_from - b_from;
119
120 /* this should never be reached. according to the spec, all of the axis
121 * value map records for a given axis must have different fromCoord values
122 * */
123 int a_to = a->coords[1].to_int ();
124 int b_to = b->coords[1].to_int ();
125 return a_to - b_to;
126 }
127
128 bool serialize (hb_serialize_context_t *c) const
129 {
130 TRACE_SERIALIZE (this);
131 return_trace (c->embed (this));
132 }
133
134 public:
135 F2DOT14 coords[2];
136// F2DOT14 fromCoord; /* A normalized coordinate value obtained using
137// * default normalization. */
138// F2DOT14 toCoord; /* The modified, normalized coordinate value. */
139
140 public:
141 DEFINE_SIZE_STATIC (4);
142};
143
144struct SegmentMaps : Array16Of<AxisValueMap>
145{
146 int map (int value, unsigned int from_offset = 0, unsigned int to_offset = 1) const
147 {
148#define fromCoord coords[from_offset].to_int ()
149#define toCoord coords[to_offset].to_int ()
150 /* The following special-cases are not part of OpenType, which requires
151 * that at least -1, 0, and +1 must be mapped. But we include these as
152 * part of a better error recovery scheme. */
153 if (len < 2)
154 {
155 if (!len)
156 return value;
157 else /* len == 1*/
158 return value - arrayZ[0].fromCoord + arrayZ[0].toCoord;
159 }
160
161 if (value <= arrayZ[0].fromCoord)
162 return value - arrayZ[0].fromCoord + arrayZ[0].toCoord;
163
164 unsigned int i;
165 unsigned int count = len - 1;
166 for (i = 1; i < count && value > arrayZ[i].fromCoord; i++)
167 ;
168
169 if (value >= arrayZ[i].fromCoord)
170 return value - arrayZ[i].fromCoord + arrayZ[i].toCoord;
171
172 if (unlikely (arrayZ[i-1].fromCoord == arrayZ[i].fromCoord))
173 return arrayZ[i-1].toCoord;
174
175 int denom = arrayZ[i].fromCoord - arrayZ[i-1].fromCoord;
176 return roundf (arrayZ[i-1].toCoord + ((float) (arrayZ[i].toCoord - arrayZ[i-1].toCoord) *
177 (value - arrayZ[i-1].fromCoord)) / denom);
178#undef toCoord
179#undef fromCoord
180 }
181
182 int unmap (int value) const { return map (value, 1, 0); }
183
184 Triple unmap_axis_range (const Triple& axis_range) const
185 {
186 F2DOT14 val, unmapped_val;
187
188 val.set_float (axis_range.minimum);
189 unmapped_val.set_int (unmap (val.to_int ()));
190 float unmapped_min = unmapped_val.to_float ();
191
192 val.set_float (axis_range.middle);
193 unmapped_val.set_int (unmap (val.to_int ()));
194 float unmapped_middle = unmapped_val.to_float ();
195
196 val.set_float (axis_range.maximum);
197 unmapped_val.set_int (unmap (val.to_int ()));
198 float unmapped_max = unmapped_val.to_float ();
199
200 return Triple{unmapped_min, unmapped_middle, unmapped_max};
201 }
202
203 bool subset (hb_subset_context_t *c, hb_tag_t axis_tag) const
204 {
205 TRACE_SUBSET (this);
206 /* avar mapped normalized axis range*/
207 Triple *axis_range;
208 if (!c->plan->axes_location.has (axis_tag, &axis_range))
209 return c->serializer->embed (*this);
210
211 TripleDistances *axis_triple_distances;
212 if (!c->plan->axes_triple_distances.has (axis_tag, &axis_triple_distances))
213 return_trace (false);
214
215 auto *out = c->serializer->start_embed (this);
216 if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
217
218 Triple unmapped_range = unmap_axis_range (*axis_range);
219
220 /* create a vector of retained mappings and sort */
221 hb_vector_t<AxisValueMap> value_mappings;
222 for (const auto& _ : as_array ())
223 {
224 if (_.is_outside_axis_range (unmapped_range))
225 continue;
226 AxisValueMap mapping;
227 mapping = _;
228 mapping.instantiate (*axis_range, unmapped_range, *axis_triple_distances);
229 /* (-1, -1), (0, 0), (1, 1) mappings will be added later, so avoid
230 * duplicates here */
231 if (mapping.must_include ())
232 continue;
233 value_mappings.push (std::move (mapping));
234 }
235
236 AxisValueMap m;
237 m.set_mapping (-1.f, -1.f);
238 value_mappings.push (m);
239
240 m.set_mapping (0.f, 0.f);
241 value_mappings.push (m);
242
243 m.set_mapping (1.f, 1.f);
244 value_mappings.push (m);
245
246 value_mappings.qsort ();
247
248 for (const auto& _ : value_mappings)
249 {
250 if (!_.serialize (c->serializer))
251 return_trace (false);
252 }
253 return_trace (c->serializer->check_assign (out->len, value_mappings.length, HB_SERIALIZE_ERROR_INT_OVERFLOW));
254 }
255
256 public:
257 DEFINE_SIZE_ARRAY (2, *this);
258};
259
260struct avar
261{
262 static constexpr hb_tag_t tableTag = HB_OT_TAG_avar;
263
264 bool has_data () const { return version.to_int (); }
265
266 const SegmentMaps* get_segment_maps () const
267 { return &firstAxisSegmentMaps; }
268
269 unsigned get_axis_count () const
270 { return axisCount; }
271
272 bool sanitize (hb_sanitize_context_t *c) const
273 {
274 TRACE_SANITIZE (this);
275 if (!(version.sanitize (c) &&
276 (version.major == 1
277#ifndef HB_NO_AVAR2
278 || version.major == 2
279#endif
280 ) &&
281 c->check_struct (this)))
282 return_trace (false);
283
284 const SegmentMaps *map = &firstAxisSegmentMaps;
285 unsigned int count = axisCount;
286 for (unsigned int i = 0; i < count; i++)
287 {
288 if (unlikely (!map->sanitize (c)))
289 return_trace (false);
290 map = &StructAfter<SegmentMaps> (*map);
291 }
292
293#ifndef HB_NO_AVAR2
294 if (version.major < 2)
295 return_trace (true);
296
297 const auto &v2 = * (const avarV2Tail *) map;
298 if (unlikely (!v2.sanitize (c, this)))
299 return_trace (false);
300#endif
301
302 return_trace (true);
303 }
304
305 void map_coords (int *coords, unsigned int coords_length) const
306 {
307 unsigned int count = hb_min (coords_length, axisCount);
308
309 const SegmentMaps *map = &firstAxisSegmentMaps;
310 for (unsigned int i = 0; i < count; i++)
311 {
312 coords[i] = map->map (coords[i]);
313 map = &StructAfter<SegmentMaps> (*map);
314 }
315
316#ifndef HB_NO_AVAR2
317 if (version.major < 2)
318 return;
319
320 for (; count < axisCount; count++)
321 map = &StructAfter<SegmentMaps> (*map);
322
323 const auto &v2 = * (const avarV2Tail *) map;
324
325 const auto &varidx_map = this+v2.varIdxMap;
326 const auto &var_store = this+v2.varStore;
327 auto *var_store_cache = var_store.create_cache ();
328
329 hb_vector_t<int> out;
330 out.alloc (coords_length);
331 for (unsigned i = 0; i < coords_length; i++)
332 {
333 int v = coords[i];
334 uint32_t varidx = varidx_map.map (i);
335 float delta = var_store.get_delta (varidx, coords, coords_length, var_store_cache);
336 v += roundf (delta);
337 v = hb_clamp (v, -(1<<14), +(1<<14));
338 out.push (v);
339 }
340 for (unsigned i = 0; i < coords_length; i++)
341 coords[i] = out[i];
342
343 OT::VariationStore::destroy_cache (var_store_cache);
344#endif
345 }
346
347 void unmap_coords (int *coords, unsigned int coords_length) const
348 {
349 unsigned int count = hb_min (coords_length, axisCount);
350
351 const SegmentMaps *map = &firstAxisSegmentMaps;
352 for (unsigned int i = 0; i < count; i++)
353 {
354 coords[i] = map->unmap (coords[i]);
355 map = &StructAfter<SegmentMaps> (*map);
356 }
357 }
358
359 bool subset (hb_subset_context_t *c) const
360 {
361 TRACE_SUBSET (this);
362 unsigned retained_axis_count = c->plan->axes_index_map.get_population ();
363 if (!retained_axis_count) //all axes are pinned/dropped
364 return_trace (false);
365
366 avar *out = c->serializer->allocate_min<avar> ();
367 if (unlikely (!out)) return_trace (false);
368
369 out->version.major = 1;
370 out->version.minor = 0;
371 if (!c->serializer->check_assign (out->axisCount, retained_axis_count, HB_SERIALIZE_ERROR_INT_OVERFLOW))
372 return_trace (false);
373
374 const hb_map_t& axes_index_map = c->plan->axes_index_map;
375 const SegmentMaps *map = &firstAxisSegmentMaps;
376 unsigned count = axisCount;
377 for (unsigned int i = 0; i < count; i++)
378 {
379 if (axes_index_map.has (i))
380 {
381 hb_tag_t *axis_tag;
382 if (!c->plan->axes_old_index_tag_map.has (i, &axis_tag))
383 return_trace (false);
384 if (!map->subset (c, *axis_tag))
385 return_trace (false);
386 }
387 map = &StructAfter<SegmentMaps> (*map);
388 }
389 return_trace (true);
390 }
391
392 protected:
393 FixedVersion<>version; /* Version of the avar table
394 * initially set to 0x00010000u */
395 HBUINT16 reserved; /* This field is permanently reserved. Set to 0. */
396 HBUINT16 axisCount; /* The number of variation axes in the font. This
397 * must be the same number as axisCount in the
398 * 'fvar' table. */
399 SegmentMaps firstAxisSegmentMaps;
400
401 public:
402 DEFINE_SIZE_MIN (8);
403};
404
405} /* namespace OT */
406
407
408#endif /* HB_OT_VAR_AVAR_TABLE_HH */
409