1#ifndef OT_GLYF_GLYF_HH
2#define OT_GLYF_GLYF_HH
3
4
5#include "../../hb-open-type.hh"
6#include "../../hb-ot-head-table.hh"
7#include "../../hb-ot-hmtx-table.hh"
8#include "../../hb-ot-var-gvar-table.hh"
9#include "../../hb-draw.hh"
10#include "../../hb-paint.hh"
11
12#include "glyf-helpers.hh"
13#include "Glyph.hh"
14#include "SubsetGlyph.hh"
15#include "loca.hh"
16#include "path-builder.hh"
17
18
19namespace OT {
20
21
22/*
23 * glyf -- TrueType Glyph Data
24 * https://docs.microsoft.com/en-us/typography/opentype/spec/glyf
25 */
26#define HB_OT_TAG_glyf HB_TAG('g','l','y','f')
27
28struct glyf
29{
30 friend struct glyf_accelerator_t;
31
32 static constexpr hb_tag_t tableTag = HB_OT_TAG_glyf;
33
34 static bool has_valid_glyf_format(const hb_face_t* face)
35 {
36 const OT::head &head = *face->table.head;
37 return head.indexToLocFormat <= 1 && head.glyphDataFormat <= 1;
38 }
39
40 bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const
41 {
42 TRACE_SANITIZE (this);
43 /* Runtime checks as eager sanitizing each glyph is costy */
44 return_trace (true);
45 }
46
47 /* requires source of SubsetGlyph complains the identifier isn't declared */
48 template <typename Iterator>
49 bool serialize (hb_serialize_context_t *c,
50 Iterator it,
51 bool use_short_loca,
52 const hb_subset_plan_t *plan)
53 {
54 TRACE_SERIALIZE (this);
55
56 unsigned init_len = c->length ();
57 for (auto &_ : it)
58 if (unlikely (!_.serialize (c, use_short_loca, plan)))
59 return false;
60
61 /* As a special case when all glyph in the font are empty, add a zero byte
62 * to the table, so that OTS doesn’t reject it, and to make the table work
63 * on Windows as well.
64 * See https://github.com/khaledhosny/ots/issues/52 */
65 if (init_len == c->length ())
66 {
67 HBUINT8 empty_byte;
68 empty_byte = 0;
69 c->copy (empty_byte);
70 }
71 return_trace (true);
72 }
73
74 /* Byte region(s) per glyph to output
75 unpadded, hints removed if so requested
76 If we fail to process a glyph we produce an empty (0-length) glyph */
77 bool subset (hb_subset_context_t *c) const
78 {
79 TRACE_SUBSET (this);
80
81 if (!has_valid_glyf_format (c->plan->source)) {
82 // glyf format is unknown don't attempt to subset it.
83 DEBUG_MSG (SUBSET, nullptr,
84 "unkown glyf format, dropping from subset.");
85 return_trace (false);
86 }
87
88 hb_font_t *font = nullptr;
89 if (c->plan->normalized_coords)
90 {
91 font = _create_font_for_instancing (c->plan);
92 if (unlikely (!font))
93 return_trace (false);
94 }
95
96 hb_vector_t<unsigned> padded_offsets;
97 if (unlikely (!padded_offsets.alloc (c->plan->new_to_old_gid_list.length, true)))
98 return_trace (false);
99
100 hb_vector_t<glyf_impl::SubsetGlyph> glyphs;
101 if (!_populate_subset_glyphs (c->plan, font, glyphs))
102 {
103 hb_font_destroy (font);
104 return_trace (false);
105 }
106
107 if (font)
108 hb_font_destroy (font);
109
110 unsigned max_offset = 0;
111 for (auto &g : glyphs)
112 {
113 unsigned size = g.padded_size ();
114 padded_offsets.push (size);
115 max_offset += size;
116 }
117
118 bool use_short_loca = false;
119 if (likely (!c->plan->force_long_loca))
120 use_short_loca = max_offset < 0x1FFFF;
121
122 if (!use_short_loca)
123 {
124 padded_offsets.resize (0);
125 for (auto &g : glyphs)
126 padded_offsets.push (g.length ());
127 }
128
129 auto *glyf_prime = c->serializer->start_embed <glyf> ();
130 bool result = glyf_prime->serialize (c->serializer, hb_iter (glyphs), use_short_loca, c->plan);
131 if (c->plan->normalized_coords && !c->plan->pinned_at_default)
132 _free_compiled_subset_glyphs (glyphs);
133
134 if (unlikely (!c->serializer->check_success (glyf_impl::_add_loca_and_head (c,
135 padded_offsets.iter (),
136 use_short_loca))))
137 return_trace (false);
138
139 return result;
140 }
141
142 bool
143 _populate_subset_glyphs (const hb_subset_plan_t *plan,
144 hb_font_t *font,
145 hb_vector_t<glyf_impl::SubsetGlyph>& glyphs /* OUT */) const;
146
147 hb_font_t *
148 _create_font_for_instancing (const hb_subset_plan_t *plan) const;
149
150 void _free_compiled_subset_glyphs (hb_vector_t<glyf_impl::SubsetGlyph> &glyphs) const
151 {
152 for (auto &g : glyphs)
153 g.free_compiled_bytes ();
154 }
155
156 protected:
157 UnsizedArrayOf<HBUINT8>
158 dataZ; /* Glyphs data. */
159 public:
160 DEFINE_SIZE_MIN (0); /* In reality, this is UNBOUNDED() type; but since we always
161 * check the size externally, allow Null() object of it by
162 * defining it _MIN instead. */
163};
164
165struct glyf_accelerator_t
166{
167 glyf_accelerator_t (hb_face_t *face)
168 {
169 short_offset = false;
170 num_glyphs = 0;
171 loca_table = nullptr;
172 glyf_table = nullptr;
173#ifndef HB_NO_VAR
174 gvar = nullptr;
175#endif
176 hmtx = nullptr;
177#ifndef HB_NO_VERTICAL
178 vmtx = nullptr;
179#endif
180 const OT::head &head = *face->table.head;
181 if (!glyf::has_valid_glyf_format (face))
182 /* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */
183 return;
184 short_offset = 0 == head.indexToLocFormat;
185
186 loca_table = face->table.loca.get_blob (); // Needs no destruct!
187 glyf_table = hb_sanitize_context_t ().reference_table<glyf> (face);
188#ifndef HB_NO_VAR
189 gvar = face->table.gvar;
190#endif
191 hmtx = face->table.hmtx;
192#ifndef HB_NO_VERTICAL
193 vmtx = face->table.vmtx;
194#endif
195
196 num_glyphs = hb_max (1u, loca_table.get_length () / (short_offset ? 2 : 4)) - 1;
197 num_glyphs = hb_min (num_glyphs, face->get_num_glyphs ());
198 }
199 ~glyf_accelerator_t ()
200 {
201 glyf_table.destroy ();
202 }
203
204 bool has_data () const { return num_glyphs; }
205
206 protected:
207 template<typename T>
208 bool get_points (hb_font_t *font, hb_codepoint_t gid, T consumer) const
209 {
210 if (gid >= num_glyphs) return false;
211
212 /* Making this allocfree is not that easy
213 https://github.com/harfbuzz/harfbuzz/issues/2095
214 mostly because of gvar handling in VF fonts,
215 perhaps a separate path for non-VF fonts can be considered */
216 contour_point_vector_t all_points;
217
218 bool phantom_only = !consumer.is_consuming_contour_points ();
219 if (unlikely (!glyph_for_gid (gid).get_points (font, *this, all_points, nullptr, nullptr, nullptr, true, true, phantom_only)))
220 return false;
221
222 unsigned count = all_points.length;
223 assert (count >= glyf_impl::PHANTOM_COUNT);
224 count -= glyf_impl::PHANTOM_COUNT;
225
226 if (consumer.is_consuming_contour_points ())
227 {
228 for (auto &point : all_points.as_array ().sub_array (0, count))
229 consumer.consume_point (point);
230 consumer.points_end ();
231 }
232
233 /* Where to write phantoms, nullptr if not requested */
234 contour_point_t *phantoms = consumer.get_phantoms_sink ();
235 if (phantoms)
236 for (unsigned i = 0; i < glyf_impl::PHANTOM_COUNT; ++i)
237 phantoms[i] = all_points.arrayZ[count + i];
238
239 return true;
240 }
241
242 public:
243
244#ifndef HB_NO_VAR
245 struct points_aggregator_t
246 {
247 hb_font_t *font;
248 hb_glyph_extents_t *extents;
249 contour_point_t *phantoms;
250 bool scaled;
251
252 struct contour_bounds_t
253 {
254 contour_bounds_t () { min_x = min_y = FLT_MAX; max_x = max_y = -FLT_MAX; }
255
256 void add (const contour_point_t &p)
257 {
258 min_x = hb_min (min_x, p.x);
259 min_y = hb_min (min_y, p.y);
260 max_x = hb_max (max_x, p.x);
261 max_y = hb_max (max_y, p.y);
262 }
263
264 bool empty () const { return (min_x >= max_x) || (min_y >= max_y); }
265
266 void get_extents (hb_font_t *font, hb_glyph_extents_t *extents, bool scaled)
267 {
268 if (unlikely (empty ()))
269 {
270 extents->width = 0;
271 extents->x_bearing = 0;
272 extents->height = 0;
273 extents->y_bearing = 0;
274 return;
275 }
276 {
277 extents->x_bearing = roundf (min_x);
278 extents->width = roundf (max_x - extents->x_bearing);
279 extents->y_bearing = roundf (max_y);
280 extents->height = roundf (min_y - extents->y_bearing);
281
282 if (scaled)
283 font->scale_glyph_extents (extents);
284 }
285 }
286
287 protected:
288 float min_x, min_y, max_x, max_y;
289 } bounds;
290
291 points_aggregator_t (hb_font_t *font_, hb_glyph_extents_t *extents_, contour_point_t *phantoms_, bool scaled_)
292 {
293 font = font_;
294 extents = extents_;
295 phantoms = phantoms_;
296 scaled = scaled_;
297 if (extents) bounds = contour_bounds_t ();
298 }
299
300 HB_ALWAYS_INLINE
301 void consume_point (const contour_point_t &point) { bounds.add (point); }
302 void points_end () { bounds.get_extents (font, extents, scaled); }
303
304 bool is_consuming_contour_points () { return extents; }
305 contour_point_t *get_phantoms_sink () { return phantoms; }
306 };
307
308 unsigned
309 get_advance_with_var_unscaled (hb_font_t *font, hb_codepoint_t gid, bool is_vertical) const
310 {
311 if (unlikely (gid >= num_glyphs)) return 0;
312
313 bool success = false;
314
315 contour_point_t phantoms[glyf_impl::PHANTOM_COUNT];
316 if (font->num_coords)
317 success = get_points (font, gid, points_aggregator_t (font, nullptr, phantoms, false));
318
319 if (unlikely (!success))
320 return
321#ifndef HB_NO_VERTICAL
322 is_vertical ? vmtx->get_advance_without_var_unscaled (gid) :
323#endif
324 hmtx->get_advance_without_var_unscaled (gid);
325
326 float result = is_vertical
327 ? phantoms[glyf_impl::PHANTOM_TOP].y - phantoms[glyf_impl::PHANTOM_BOTTOM].y
328 : phantoms[glyf_impl::PHANTOM_RIGHT].x - phantoms[glyf_impl::PHANTOM_LEFT].x;
329 return hb_clamp (roundf (result), 0.f, (float) UINT_MAX / 2);
330 }
331
332 bool get_leading_bearing_with_var_unscaled (hb_font_t *font, hb_codepoint_t gid, bool is_vertical, int *lsb) const
333 {
334 if (unlikely (gid >= num_glyphs)) return false;
335
336 hb_glyph_extents_t extents;
337
338 contour_point_t phantoms[glyf_impl::PHANTOM_COUNT];
339 if (unlikely (!get_points (font, gid, points_aggregator_t (font, &extents, phantoms, false))))
340 return false;
341
342 *lsb = is_vertical
343 ? roundf (phantoms[glyf_impl::PHANTOM_TOP].y) - extents.y_bearing
344 : roundf (phantoms[glyf_impl::PHANTOM_LEFT].x);
345 return true;
346 }
347#endif
348
349 bool get_leading_bearing_without_var_unscaled (hb_codepoint_t gid, bool is_vertical, int *lsb) const
350 {
351 if (unlikely (gid >= num_glyphs)) return false;
352 if (is_vertical) return false; // TODO Humm, what to do here?
353
354 *lsb = glyph_for_gid (gid).get_header ()->xMin;
355 return true;
356 }
357
358 public:
359 bool get_extents (hb_font_t *font, hb_codepoint_t gid, hb_glyph_extents_t *extents) const
360 {
361 if (unlikely (gid >= num_glyphs)) return false;
362
363#ifndef HB_NO_VAR
364 if (font->num_coords)
365 return get_points (font, gid, points_aggregator_t (font, extents, nullptr, true));
366#endif
367 return glyph_for_gid (gid).get_extents_without_var_scaled (font, *this, extents);
368 }
369
370 bool paint_glyph (hb_font_t *font, hb_codepoint_t gid, hb_paint_funcs_t *funcs, void *data, hb_color_t foreground) const
371 {
372 funcs->push_clip_glyph (data, gid, font);
373 funcs->color (data, true, foreground);
374 funcs->pop_clip (data);
375
376 return true;
377 }
378
379 const glyf_impl::Glyph
380 glyph_for_gid (hb_codepoint_t gid, bool needs_padding_removal = false) const
381 {
382 if (unlikely (gid >= num_glyphs)) return glyf_impl::Glyph ();
383
384 unsigned int start_offset, end_offset;
385
386 if (short_offset)
387 {
388 const HBUINT16 *offsets = (const HBUINT16 *) loca_table->dataZ.arrayZ;
389 start_offset = 2 * offsets[gid];
390 end_offset = 2 * offsets[gid + 1];
391 }
392 else
393 {
394 const HBUINT32 *offsets = (const HBUINT32 *) loca_table->dataZ.arrayZ;
395 start_offset = offsets[gid];
396 end_offset = offsets[gid + 1];
397 }
398
399 if (unlikely (start_offset > end_offset || end_offset > glyf_table.get_length ()))
400 return glyf_impl::Glyph ();
401
402 glyf_impl::Glyph glyph (hb_bytes_t ((const char *) this->glyf_table + start_offset,
403 end_offset - start_offset), gid);
404 return needs_padding_removal ? glyf_impl::Glyph (glyph.trim_padding (), gid) : glyph;
405 }
406
407 bool
408 get_path (hb_font_t *font, hb_codepoint_t gid, hb_draw_session_t &draw_session) const
409 { return get_points (font, gid, glyf_impl::path_builder_t (font, draw_session)); }
410
411#ifndef HB_NO_VAR
412 const gvar_accelerator_t *gvar;
413#endif
414 const hmtx_accelerator_t *hmtx;
415#ifndef HB_NO_VERTICAL
416 const vmtx_accelerator_t *vmtx;
417#endif
418
419 private:
420 bool short_offset;
421 unsigned int num_glyphs;
422 hb_blob_ptr_t<loca> loca_table;
423 hb_blob_ptr_t<glyf> glyf_table;
424};
425
426
427inline bool
428glyf::_populate_subset_glyphs (const hb_subset_plan_t *plan,
429 hb_font_t *font,
430 hb_vector_t<glyf_impl::SubsetGlyph>& glyphs /* OUT */) const
431{
432 OT::glyf_accelerator_t glyf (plan->source);
433 if (!glyphs.alloc (plan->new_to_old_gid_list.length, true)) return false;
434
435 for (const auto &pair : plan->new_to_old_gid_list)
436 {
437 hb_codepoint_t new_gid = pair.first;
438 hb_codepoint_t old_gid = pair.second;
439 glyf_impl::SubsetGlyph *p = glyphs.push ();
440 glyf_impl::SubsetGlyph& subset_glyph = *p;
441 subset_glyph.old_gid = old_gid;
442
443 if (unlikely (old_gid == 0 && new_gid == 0 &&
444 !(plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE)) &&
445 !plan->normalized_coords)
446 subset_glyph.source_glyph = glyf_impl::Glyph ();
447 else
448 {
449 /* If plan has an accelerator, the preprocessing step already trimmed glyphs.
450 * Don't trim them again! */
451 subset_glyph.source_glyph = glyf.glyph_for_gid (subset_glyph.old_gid, !plan->accelerator);
452 }
453
454 if (plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
455 subset_glyph.drop_hints_bytes ();
456 else
457 subset_glyph.dest_start = subset_glyph.source_glyph.get_bytes ();
458
459 if (font)
460 {
461 if (unlikely (!subset_glyph.compile_bytes_with_deltas (plan, font, glyf)))
462 {
463 // when pinned at default, only bounds are updated, thus no need to free
464 if (!plan->pinned_at_default)
465 _free_compiled_subset_glyphs (glyphs);
466 return false;
467 }
468 }
469 }
470 return true;
471}
472
473inline hb_font_t *
474glyf::_create_font_for_instancing (const hb_subset_plan_t *plan) const
475{
476 hb_font_t *font = hb_font_create (plan->source);
477 if (unlikely (font == hb_font_get_empty ())) return nullptr;
478
479 hb_vector_t<hb_variation_t> vars;
480 if (unlikely (!vars.alloc (plan->user_axes_location.get_population (), true)))
481 {
482 hb_font_destroy (font);
483 return nullptr;
484 }
485
486 for (auto _ : plan->user_axes_location)
487 {
488 hb_variation_t var;
489 var.tag = _.first;
490 var.value = _.second.middle;
491 vars.push (var);
492 }
493
494#ifndef HB_NO_VAR
495 hb_font_set_variations (font, vars.arrayZ, plan->user_axes_location.get_population ());
496#endif
497 return font;
498}
499
500
501} /* namespace OT */
502
503
504#endif /* OT_GLYF_GLYF_HH */
505