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1 /*
2  * Copyright © 2015  Google, Inc.
3  * Copyright © 2019  Adobe Inc.
4  * Copyright © 2019  Ebrahim Byagowi
5  *
6  *  This is part of HarfBuzz, a text shaping library.
7  *
8  * Permission is hereby granted, without written agreement and without
9  * license or royalty fees, to use, copy, modify, and distribute this
10  * software and its documentation for any purpose, provided that the
11  * above copyright notice and the following two paragraphs appear in
12  * all copies of this software.
13  *
14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18  * DAMAGE.
19  *
20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25  *
26  * Google Author(s): Behdad Esfahbod, Garret Rieger, Roderick Sheeter
27  * Adobe Author(s): Michiharu Ariza
28  */
29 
30 #ifndef HB_OT_GLYF_TABLE_HH
31 #define HB_OT_GLYF_TABLE_HH
32 
33 #include "hb-open-type.hh"
34 #include "hb-ot-head-table.hh"
35 #include "hb-ot-hmtx-table.hh"
36 #include "hb-ot-var-gvar-table.hh"
37 #include "hb-draw.hh"
38 
39 namespace OT {
40 
41 
42 /*
43  * loca -- Index to Location
44  * https://docs.microsoft.com/en-us/typography/opentype/spec/loca
45  */
46 #define HB_OT_TAG_loca HB_TAG('l','o','c','a')
47 
48 
49 struct loca
50 {
51   friend struct glyf;
52 
53   static constexpr hb_tag_t tableTag = HB_OT_TAG_loca;
54 
sanitizeOT::loca55   bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const
56   {
57     TRACE_SANITIZE (this);
58     return_trace (true);
59   }
60 
61   protected:
62   UnsizedArrayOf<HBUINT8>
63 		dataZ;	/* Location data. */
64   public:
65   DEFINE_SIZE_MIN (0);	/* In reality, this is UNBOUNDED() type; but since we always
66 			 * check the size externally, allow Null() object of it by
67 			 * defining it _MIN instead. */
68 };
69 
70 
71 /*
72  * glyf -- TrueType Glyph Data
73  * https://docs.microsoft.com/en-us/typography/opentype/spec/glyf
74  */
75 #define HB_OT_TAG_glyf HB_TAG('g','l','y','f')
76 
77 
78 struct glyf
79 {
80   static constexpr hb_tag_t tableTag = HB_OT_TAG_glyf;
81 
sanitizeOT::glyf82   bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const
83   {
84     TRACE_SANITIZE (this);
85     /* Runtime checks as eager sanitizing each glyph is costy */
86     return_trace (true);
87   }
88 
89   template<typename Iterator,
90 	   hb_requires (hb_is_source_of (Iterator, unsigned int))>
91   static bool
_add_loca_and_headOT::glyf92   _add_loca_and_head (hb_subset_plan_t * plan, Iterator padded_offsets)
93   {
94     unsigned max_offset =
95     + padded_offsets
96     | hb_reduce (hb_add, 0)
97     ;
98     unsigned num_offsets = padded_offsets.len () + 1;
99     bool use_short_loca = max_offset < 0x1FFFF;
100     unsigned entry_size = use_short_loca ? 2 : 4;
101     char *loca_prime_data = (char *) calloc (entry_size, num_offsets);
102 
103     if (unlikely (!loca_prime_data)) return false;
104 
105     DEBUG_MSG (SUBSET, nullptr, "loca entry_size %d num_offsets %d "
106 				"max_offset %d size %d",
107 	       entry_size, num_offsets, max_offset, entry_size * num_offsets);
108 
109     if (use_short_loca)
110       _write_loca (padded_offsets, 1, hb_array ((HBUINT16 *) loca_prime_data, num_offsets));
111     else
112       _write_loca (padded_offsets, 0, hb_array ((HBUINT32 *) loca_prime_data, num_offsets));
113 
114     hb_blob_t *loca_blob = hb_blob_create (loca_prime_data,
115 					   entry_size * num_offsets,
116 					   HB_MEMORY_MODE_WRITABLE,
117 					   loca_prime_data,
118 					   free);
119 
120     bool result = plan->add_table (HB_OT_TAG_loca, loca_blob)
121 	       && _add_head_and_set_loca_version (plan, use_short_loca);
122 
123     hb_blob_destroy (loca_blob);
124     return result;
125   }
126 
127   template<typename IteratorIn, typename IteratorOut,
128 	   hb_requires (hb_is_source_of (IteratorIn, unsigned int)),
129 	   hb_requires (hb_is_sink_of (IteratorOut, unsigned))>
130   static void
_write_locaOT::glyf131   _write_loca (IteratorIn it, unsigned right_shift, IteratorOut dest)
132   {
133     unsigned int offset = 0;
134     dest << 0;
135     + it
136     | hb_map ([=, &offset] (unsigned int padded_size)
137 	      {
138 		offset += padded_size;
139 		DEBUG_MSG (SUBSET, nullptr, "loca entry offset %d", offset);
140 		return offset >> right_shift;
141 	      })
142     | hb_sink (dest)
143     ;
144   }
145 
146   /* requires source of SubsetGlyph complains the identifier isn't declared */
147   template <typename Iterator>
serializeOT::glyf148   bool serialize (hb_serialize_context_t *c,
149 		  Iterator it,
150 		  const hb_subset_plan_t *plan)
151   {
152     TRACE_SERIALIZE (this);
153     unsigned init_len = c->length ();
154     for (const auto &_ : it) _.serialize (c, plan);
155 
156     /* As a special case when all glyph in the font are empty, add a zero byte
157      * to the table, so that OTS doesn’t reject it, and to make the table work
158      * on Windows as well.
159      * See https://github.com/khaledhosny/ots/issues/52 */
160     if (init_len == c->length ())
161     {
162       HBUINT8 empty_byte;
163       empty_byte = 0;
164       c->copy (empty_byte);
165     }
166     return_trace (true);
167   }
168 
169   /* Byte region(s) per glyph to output
170      unpadded, hints removed if so requested
171      If we fail to process a glyph we produce an empty (0-length) glyph */
subsetOT::glyf172   bool subset (hb_subset_context_t *c) const
173   {
174     TRACE_SUBSET (this);
175 
176     glyf *glyf_prime = c->serializer->start_embed <glyf> ();
177     if (unlikely (!c->serializer->check_success (glyf_prime))) return_trace (false);
178 
179     hb_vector_t<SubsetGlyph> glyphs;
180     _populate_subset_glyphs (c->plan, &glyphs);
181 
182     glyf_prime->serialize (c->serializer, hb_iter (glyphs), c->plan);
183 
184     auto padded_offsets =
185     + hb_iter (glyphs)
186     | hb_map (&SubsetGlyph::padded_size)
187     ;
188 
189     if (unlikely (c->serializer->in_error ())) return_trace (false);
190     return_trace (c->serializer->check_success (_add_loca_and_head (c->plan,
191 								    padded_offsets)));
192   }
193 
194   template <typename SubsetGlyph>
195   void
_populate_subset_glyphsOT::glyf196   _populate_subset_glyphs (const hb_subset_plan_t   *plan,
197 			   hb_vector_t<SubsetGlyph> *glyphs /* OUT */) const
198   {
199     OT::glyf::accelerator_t glyf;
200     glyf.init (plan->source);
201 
202     + hb_range (plan->num_output_glyphs ())
203     | hb_map ([&] (hb_codepoint_t new_gid)
204 	      {
205 		SubsetGlyph subset_glyph = {0};
206 		subset_glyph.new_gid = new_gid;
207 
208 		/* should never fail: all old gids should be mapped */
209 		if (!plan->old_gid_for_new_gid (new_gid, &subset_glyph.old_gid))
210 		  return subset_glyph;
211 
212 		subset_glyph.source_glyph = glyf.glyph_for_gid (subset_glyph.old_gid, true);
213 		if (plan->drop_hints) subset_glyph.drop_hints_bytes ();
214 		else subset_glyph.dest_start = subset_glyph.source_glyph.get_bytes ();
215 
216 		return subset_glyph;
217 	      })
218     | hb_sink (glyphs)
219     ;
220 
221     glyf.fini ();
222   }
223 
224   static bool
_add_head_and_set_loca_versionOT::glyf225   _add_head_and_set_loca_version (hb_subset_plan_t *plan, bool use_short_loca)
226   {
227     hb_blob_t *head_blob = hb_sanitize_context_t ().reference_table<head> (plan->source);
228     hb_blob_t *head_prime_blob = hb_blob_copy_writable_or_fail (head_blob);
229     hb_blob_destroy (head_blob);
230 
231     if (unlikely (!head_prime_blob))
232       return false;
233 
234     head *head_prime = (head *) hb_blob_get_data_writable (head_prime_blob, nullptr);
235     head_prime->indexToLocFormat = use_short_loca ? 0 : 1;
236     bool success = plan->add_table (HB_OT_TAG_head, head_prime_blob);
237 
238     hb_blob_destroy (head_prime_blob);
239     return success;
240   }
241 
242   struct CompositeGlyphChain
243   {
244     protected:
245     enum composite_glyph_flag_t
246     {
247       ARG_1_AND_2_ARE_WORDS	= 0x0001,
248       ARGS_ARE_XY_VALUES	= 0x0002,
249       ROUND_XY_TO_GRID		= 0x0004,
250       WE_HAVE_A_SCALE		= 0x0008,
251       MORE_COMPONENTS		= 0x0020,
252       WE_HAVE_AN_X_AND_Y_SCALE	= 0x0040,
253       WE_HAVE_A_TWO_BY_TWO	= 0x0080,
254       WE_HAVE_INSTRUCTIONS	= 0x0100,
255       USE_MY_METRICS		= 0x0200,
256       OVERLAP_COMPOUND		= 0x0400,
257       SCALED_COMPONENT_OFFSET	= 0x0800,
258       UNSCALED_COMPONENT_OFFSET = 0x1000
259     };
260 
261     public:
get_sizeOT::glyf::CompositeGlyphChain262     unsigned int get_size () const
263     {
264       unsigned int size = min_size;
265       /* arg1 and 2 are int16 */
266       if (flags & ARG_1_AND_2_ARE_WORDS) size += 4;
267       /* arg1 and 2 are int8 */
268       else size += 2;
269 
270       /* One x 16 bit (scale) */
271       if (flags & WE_HAVE_A_SCALE) size += 2;
272       /* Two x 16 bit (xscale, yscale) */
273       else if (flags & WE_HAVE_AN_X_AND_Y_SCALE) size += 4;
274       /* Four x 16 bit (xscale, scale01, scale10, yscale) */
275       else if (flags & WE_HAVE_A_TWO_BY_TWO) size += 8;
276 
277       return size;
278     }
279 
set_glyph_indexOT::glyf::CompositeGlyphChain280     void set_glyph_index (hb_codepoint_t new_gid) { glyphIndex = new_gid; }
get_glyph_indexOT::glyf::CompositeGlyphChain281     hb_codepoint_t get_glyph_index ()       const { return glyphIndex; }
282 
drop_instructions_flagOT::glyf::CompositeGlyphChain283     void drop_instructions_flag ()  { flags = (uint16_t) flags & ~WE_HAVE_INSTRUCTIONS; }
has_instructionsOT::glyf::CompositeGlyphChain284     bool has_instructions ()  const { return   flags & WE_HAVE_INSTRUCTIONS; }
285 
has_moreOT::glyf::CompositeGlyphChain286     bool has_more ()          const { return   flags & MORE_COMPONENTS; }
is_use_my_metricsOT::glyf::CompositeGlyphChain287     bool is_use_my_metrics () const { return   flags & USE_MY_METRICS; }
is_anchoredOT::glyf::CompositeGlyphChain288     bool is_anchored ()       const { return !(flags & ARGS_ARE_XY_VALUES); }
get_anchor_pointsOT::glyf::CompositeGlyphChain289     void get_anchor_points (unsigned int &point1, unsigned int &point2) const
290     {
291       const HBUINT8 *p = &StructAfter<const HBUINT8> (glyphIndex);
292       if (flags & ARG_1_AND_2_ARE_WORDS)
293       {
294 	point1 = ((const HBUINT16 *) p)[0];
295 	point2 = ((const HBUINT16 *) p)[1];
296       }
297       else
298       {
299 	point1 = p[0];
300 	point2 = p[1];
301       }
302     }
303 
transform_pointsOT::glyf::CompositeGlyphChain304     void transform_points (contour_point_vector_t &points) const
305     {
306       float matrix[4];
307       contour_point_t trans;
308       if (get_transformation (matrix, trans))
309       {
310 	if (scaled_offsets ())
311 	{
312 	  points.translate (trans);
313 	  points.transform (matrix);
314 	}
315 	else
316 	{
317 	  points.transform (matrix);
318 	  points.translate (trans);
319 	}
320       }
321     }
322 
323     protected:
scaled_offsetsOT::glyf::CompositeGlyphChain324     bool scaled_offsets () const
325     { return (flags & (SCALED_COMPONENT_OFFSET | UNSCALED_COMPONENT_OFFSET)) == SCALED_COMPONENT_OFFSET; }
326 
get_transformationOT::glyf::CompositeGlyphChain327     bool get_transformation (float (&matrix)[4], contour_point_t &trans) const
328     {
329       matrix[0] = matrix[3] = 1.f;
330       matrix[1] = matrix[2] = 0.f;
331 
332       int tx, ty;
333       const HBINT8 *p = &StructAfter<const HBINT8> (glyphIndex);
334       if (flags & ARG_1_AND_2_ARE_WORDS)
335       {
336 	tx = *(const HBINT16 *) p;
337 	p += HBINT16::static_size;
338 	ty = *(const HBINT16 *) p;
339 	p += HBINT16::static_size;
340       }
341       else
342       {
343 	tx = *p++;
344 	ty = *p++;
345       }
346       if (is_anchored ()) tx = ty = 0;
347 
348       trans.init ((float) tx, (float) ty);
349 
350       {
351 	const F2DOT14 *points = (const F2DOT14 *) p;
352 	if (flags & WE_HAVE_A_SCALE)
353 	{
354 	  matrix[0] = matrix[3] = points[0].to_float ();
355 	  return true;
356 	}
357 	else if (flags & WE_HAVE_AN_X_AND_Y_SCALE)
358 	{
359 	  matrix[0] = points[0].to_float ();
360 	  matrix[3] = points[1].to_float ();
361 	  return true;
362 	}
363 	else if (flags & WE_HAVE_A_TWO_BY_TWO)
364 	{
365 	  matrix[0] = points[0].to_float ();
366 	  matrix[1] = points[1].to_float ();
367 	  matrix[2] = points[2].to_float ();
368 	  matrix[3] = points[3].to_float ();
369 	  return true;
370 	}
371       }
372       return tx || ty;
373     }
374 
375     protected:
376     HBUINT16	flags;
377     HBGlyphID	glyphIndex;
378     public:
379     DEFINE_SIZE_MIN (4);
380   };
381 
382   struct composite_iter_t : hb_iter_with_fallback_t<composite_iter_t, const CompositeGlyphChain &>
383   {
384     typedef const CompositeGlyphChain *__item_t__;
composite_iter_tOT::glyf::composite_iter_t385     composite_iter_t (hb_bytes_t glyph_, __item_t__ current_) :
386       glyph (glyph_), current (current_)
387     { if (!check_range (current)) current = nullptr; }
composite_iter_tOT::glyf::composite_iter_t388     composite_iter_t () : glyph (hb_bytes_t ()), current (nullptr) {}
389 
__item__OT::glyf::composite_iter_t390     const CompositeGlyphChain &__item__ () const { return *current; }
__more__OT::glyf::composite_iter_t391     bool __more__ () const { return current; }
__next__OT::glyf::composite_iter_t392     void __next__ ()
393     {
394       if (!current->has_more ()) { current = nullptr; return; }
395 
396       const CompositeGlyphChain *possible = &StructAfter<CompositeGlyphChain,
397 							 CompositeGlyphChain> (*current);
398       if (!check_range (possible)) { current = nullptr; return; }
399       current = possible;
400     }
operator !=OT::glyf::composite_iter_t401     bool operator != (const composite_iter_t& o) const
402     { return glyph != o.glyph || current != o.current; }
403 
check_rangeOT::glyf::composite_iter_t404     bool check_range (const CompositeGlyphChain *composite) const
405     {
406       return glyph.check_range (composite, CompositeGlyphChain::min_size)
407 	  && glyph.check_range (composite, composite->get_size ());
408     }
409 
410     private:
411     hb_bytes_t glyph;
412     __item_t__ current;
413   };
414 
415   enum phantom_point_index_t
416   {
417     PHANTOM_LEFT   = 0,
418     PHANTOM_RIGHT  = 1,
419     PHANTOM_TOP    = 2,
420     PHANTOM_BOTTOM = 3,
421     PHANTOM_COUNT  = 4
422   };
423 
424   struct accelerator_t;
425 
426   struct Glyph
427   {
428     enum simple_glyph_flag_t
429     {
430       FLAG_ON_CURVE  = 0x01,
431       FLAG_X_SHORT   = 0x02,
432       FLAG_Y_SHORT   = 0x04,
433       FLAG_REPEAT    = 0x08,
434       FLAG_X_SAME    = 0x10,
435       FLAG_Y_SAME    = 0x20,
436       FLAG_RESERVED1 = 0x40,
437       FLAG_RESERVED2 = 0x80
438     };
439 
440     private:
441     struct GlyphHeader
442     {
has_dataOT::glyf::Glyph::GlyphHeader443       bool has_data () const { return numberOfContours; }
444 
get_extentsOT::glyf::Glyph::GlyphHeader445       bool get_extents (hb_font_t *font, const accelerator_t &glyf_accelerator,
446 		        hb_codepoint_t gid, hb_glyph_extents_t *extents) const
447       {
448 	/* Undocumented rasterizer behavior: shift glyph to the left by (lsb - xMin), i.e., xMin = lsb */
449 	/* extents->x_bearing = hb_min (glyph_header.xMin, glyph_header.xMax); */
450 	extents->x_bearing = font->em_scale_x (glyf_accelerator.hmtx->get_side_bearing (gid));
451 	extents->y_bearing = font->em_scale_y (hb_max (yMin, yMax));
452 	extents->width     = font->em_scale_x (hb_max (xMin, xMax) - hb_min (xMin, xMax));
453 	extents->height    = font->em_scale_y (hb_min (yMin, yMax) - hb_max (yMin, yMax));
454 
455 	return true;
456       }
457 
458       HBINT16	numberOfContours;
459 			/* If the number of contours is
460 			 * greater than or equal to zero,
461 			 * this is a simple glyph; if negative,
462 			 * this is a composite glyph. */
463       FWORD	xMin;	/* Minimum x for coordinate data. */
464       FWORD	yMin;	/* Minimum y for coordinate data. */
465       FWORD	xMax;	/* Maximum x for coordinate data. */
466       FWORD	yMax;	/* Maximum y for coordinate data. */
467       public:
468       DEFINE_SIZE_STATIC (10);
469     };
470 
471     struct SimpleGlyph
472     {
473       const GlyphHeader &header;
474       hb_bytes_t bytes;
SimpleGlyphOT::glyf::Glyph::SimpleGlyph475       SimpleGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
476 	header (header_), bytes (bytes_) {}
477 
instruction_len_offsetOT::glyf::Glyph::SimpleGlyph478       unsigned int instruction_len_offset () const
479       { return GlyphHeader::static_size + 2 * header.numberOfContours; }
480 
lengthOT::glyf::Glyph::SimpleGlyph481       unsigned int length (unsigned int instruction_len) const
482       { return instruction_len_offset () + 2 + instruction_len; }
483 
instructions_lengthOT::glyf::Glyph::SimpleGlyph484       unsigned int instructions_length () const
485       {
486 	unsigned int instruction_length_offset = instruction_len_offset ();
487 	if (unlikely (instruction_length_offset + 2 > bytes.length)) return 0;
488 
489 	const HBUINT16 &instructionLength = StructAtOffset<HBUINT16> (&bytes, instruction_length_offset);
490 	/* Out of bounds of the current glyph */
491 	if (unlikely (length (instructionLength) > bytes.length)) return 0;
492 	return instructionLength;
493       }
494 
trim_paddingOT::glyf::Glyph::SimpleGlyph495       const Glyph trim_padding () const
496       {
497 	/* based on FontTools _g_l_y_f.py::trim */
498 	const char *glyph = bytes.arrayZ;
499 	const char *glyph_end = glyph + bytes.length;
500 	/* simple glyph w/contours, possibly trimmable */
501 	glyph += instruction_len_offset ();
502 
503 	if (unlikely (glyph + 2 >= glyph_end)) return Glyph ();
504 	unsigned int num_coordinates = StructAtOffset<HBUINT16> (glyph - 2, 0) + 1;
505 	unsigned int num_instructions = StructAtOffset<HBUINT16> (glyph, 0);
506 
507 	glyph += 2 + num_instructions;
508 
509 	unsigned int coord_bytes = 0;
510 	unsigned int coords_with_flags = 0;
511 	while (glyph < glyph_end)
512 	{
513 	  uint8_t flag = *glyph;
514 	  glyph++;
515 
516 	  unsigned int repeat = 1;
517 	  if (flag & FLAG_REPEAT)
518 	  {
519 	    if (unlikely (glyph >= glyph_end)) return Glyph ();
520 	    repeat = *glyph + 1;
521 	    glyph++;
522 	  }
523 
524 	  unsigned int xBytes, yBytes;
525 	  xBytes = yBytes = 0;
526 	  if (flag & FLAG_X_SHORT) xBytes = 1;
527 	  else if ((flag & FLAG_X_SAME) == 0) xBytes = 2;
528 
529 	  if (flag & FLAG_Y_SHORT) yBytes = 1;
530 	  else if ((flag & FLAG_Y_SAME) == 0) yBytes = 2;
531 
532 	  coord_bytes += (xBytes + yBytes) * repeat;
533 	  coords_with_flags += repeat;
534 	  if (coords_with_flags >= num_coordinates) break;
535 	}
536 
537 	if (unlikely (coords_with_flags != num_coordinates)) return Glyph ();
538 	return Glyph (bytes.sub_array (0, bytes.length + coord_bytes - (glyph_end - glyph)));
539       }
540 
541       /* zero instruction length */
drop_hintsOT::glyf::Glyph::SimpleGlyph542       void drop_hints ()
543       {
544 	GlyphHeader &glyph_header = const_cast<GlyphHeader &> (header);
545 	(HBUINT16 &) StructAtOffset<HBUINT16> (&glyph_header, instruction_len_offset ()) = 0;
546       }
547 
drop_hints_bytesOT::glyf::Glyph::SimpleGlyph548       void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const
549       {
550 	unsigned int instructions_len = instructions_length ();
551 	unsigned int glyph_length = length (instructions_len);
552 	dest_start = bytes.sub_array (0, glyph_length - instructions_len);
553 	dest_end = bytes.sub_array (glyph_length, bytes.length - glyph_length);
554       }
555 
read_pointsOT::glyf::Glyph::SimpleGlyph556       static bool read_points (const HBUINT8 *&p /* IN/OUT */,
557 			       contour_point_vector_t &points_ /* IN/OUT */,
558 			       const hb_bytes_t &bytes,
559 			       void (* setter) (contour_point_t &_, float v),
560 			       const simple_glyph_flag_t short_flag,
561 			       const simple_glyph_flag_t same_flag)
562       {
563 	float v = 0;
564 	for (unsigned i = 0; i < points_.length; i++)
565 	{
566 	  uint8_t flag = points_[i].flag;
567 	  if (flag & short_flag)
568 	  {
569 	    if (unlikely (!bytes.check_range (p))) return false;
570 	    if (flag & same_flag)
571 	      v += *p++;
572 	    else
573 	      v -= *p++;
574 	  }
575 	  else
576 	  {
577 	    if (!(flag & same_flag))
578 	    {
579 	      if (unlikely (!bytes.check_range ((const HBUINT16 *) p))) return false;
580 	      v += *(const HBINT16 *) p;
581 	      p += HBINT16::static_size;
582 	    }
583 	  }
584 	  setter (points_[i], v);
585 	}
586 	return true;
587       }
588 
get_contour_pointsOT::glyf::Glyph::SimpleGlyph589       bool get_contour_points (contour_point_vector_t &points_ /* OUT */,
590 			       bool phantom_only = false) const
591       {
592 	const HBUINT16 *endPtsOfContours = &StructAfter<HBUINT16> (header);
593 	int num_contours = header.numberOfContours;
594 	if (unlikely (!bytes.check_range (&endPtsOfContours[num_contours + 1]))) return false;
595 	unsigned int num_points = endPtsOfContours[num_contours - 1] + 1;
596 
597 	points_.resize (num_points);
598 	for (unsigned int i = 0; i < points_.length; i++) points_[i].init ();
599 	if (phantom_only) return true;
600 
601 	for (int i = 0; i < num_contours; i++)
602 	  points_[endPtsOfContours[i]].is_end_point = true;
603 
604 	/* Skip instructions */
605 	const HBUINT8 *p = &StructAtOffset<HBUINT8> (&endPtsOfContours[num_contours + 1],
606 						     endPtsOfContours[num_contours]);
607 
608 	/* Read flags */
609 	for (unsigned int i = 0; i < num_points; i++)
610 	{
611 	  if (unlikely (!bytes.check_range (p))) return false;
612 	  uint8_t flag = *p++;
613 	  points_[i].flag = flag;
614 	  if (flag & FLAG_REPEAT)
615 	  {
616 	    if (unlikely (!bytes.check_range (p))) return false;
617 	    unsigned int repeat_count = *p++;
618 	    while ((repeat_count-- > 0) && (++i < num_points))
619 	      points_[i].flag = flag;
620 	  }
621 	}
622 
623 	/* Read x & y coordinates */
624 	return read_points (p, points_, bytes, [] (contour_point_t &p, float v) { p.x = v; },
625 			    FLAG_X_SHORT, FLAG_X_SAME)
626 	    && read_points (p, points_, bytes, [] (contour_point_t &p, float v) { p.y = v; },
627 			    FLAG_Y_SHORT, FLAG_Y_SAME);
628       }
629     };
630 
631     struct CompositeGlyph
632     {
633       const GlyphHeader &header;
634       hb_bytes_t bytes;
CompositeGlyphOT::glyf::Glyph::CompositeGlyph635       CompositeGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
636 	header (header_), bytes (bytes_) {}
637 
get_iteratorOT::glyf::Glyph::CompositeGlyph638       composite_iter_t get_iterator () const
639       { return composite_iter_t (bytes, &StructAfter<CompositeGlyphChain, GlyphHeader> (header)); }
640 
instructions_lengthOT::glyf::Glyph::CompositeGlyph641       unsigned int instructions_length (hb_bytes_t bytes) const
642       {
643 	unsigned int start = bytes.length;
644 	unsigned int end = bytes.length;
645 	const CompositeGlyphChain *last = nullptr;
646 	for (auto &item : get_iterator ())
647 	  last = &item;
648 	if (unlikely (!last)) return 0;
649 
650 	if (last->has_instructions ())
651 	  start = (char *) last - &bytes + last->get_size ();
652 	if (unlikely (start > end)) return 0;
653 	return end - start;
654       }
655 
656       /* Trimming for composites not implemented.
657        * If removing hints it falls out of that. */
trim_paddingOT::glyf::Glyph::CompositeGlyph658       const Glyph trim_padding () const { return Glyph (bytes); }
659 
drop_hintsOT::glyf::Glyph::CompositeGlyph660       void drop_hints ()
661       {
662 	for (const auto &_ : get_iterator ())
663 	  const_cast<CompositeGlyphChain &> (_).drop_instructions_flag ();
664       }
665 
666       /* Chop instructions off the end */
drop_hints_bytesOT::glyf::Glyph::CompositeGlyph667       void drop_hints_bytes (hb_bytes_t &dest_start) const
668       { dest_start = bytes.sub_array (0, bytes.length - instructions_length (bytes)); }
669     };
670 
671     enum glyph_type_t { EMPTY, SIMPLE, COMPOSITE };
672 
673     public:
get_composite_iteratorOT::glyf::Glyph674     composite_iter_t get_composite_iterator () const
675     {
676       if (type != COMPOSITE) return composite_iter_t ();
677       return CompositeGlyph (*header, bytes).get_iterator ();
678     }
679 
trim_paddingOT::glyf::Glyph680     const Glyph trim_padding () const
681     {
682       switch (type) {
683       case COMPOSITE: return CompositeGlyph (*header, bytes).trim_padding ();
684       case SIMPLE:    return SimpleGlyph (*header, bytes).trim_padding ();
685       default:        return bytes;
686       }
687     }
688 
drop_hintsOT::glyf::Glyph689     void drop_hints ()
690     {
691       switch (type) {
692       case COMPOSITE: CompositeGlyph (*header, bytes).drop_hints (); return;
693       case SIMPLE:    SimpleGlyph (*header, bytes).drop_hints (); return;
694       default:        return;
695       }
696     }
697 
drop_hints_bytesOT::glyf::Glyph698     void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const
699     {
700       switch (type) {
701       case COMPOSITE: CompositeGlyph (*header, bytes).drop_hints_bytes (dest_start); return;
702       case SIMPLE:    SimpleGlyph (*header, bytes).drop_hints_bytes (dest_start, dest_end); return;
703       default:        return;
704       }
705     }
706 
707     /* Note: Recursively calls itself.
708      * all_points includes phantom points
709      */
get_pointsOT::glyf::Glyph710     bool get_points (hb_font_t *font, const accelerator_t &glyf_accelerator,
711 		     contour_point_vector_t &all_points /* OUT */,
712 		     bool phantom_only = false,
713 		     unsigned int depth = 0) const
714     {
715       if (unlikely (depth > HB_MAX_NESTING_LEVEL)) return false;
716       contour_point_vector_t points;
717 
718       switch (type) {
719       case COMPOSITE:
720       {
721 	/* pseudo component points for each component in composite glyph */
722 	unsigned num_points = hb_len (CompositeGlyph (*header, bytes).get_iterator ());
723 	if (unlikely (!points.resize (num_points))) return false;
724 	for (unsigned i = 0; i < points.length; i++)
725 	  points[i].init ();
726 	break;
727       }
728       case SIMPLE:
729 	if (unlikely (!SimpleGlyph (*header, bytes).get_contour_points (points, phantom_only)))
730 	  return false;
731 	break;
732       }
733 
734       /* Init phantom points */
735       if (unlikely (!points.resize (points.length + PHANTOM_COUNT))) return false;
736       hb_array_t<contour_point_t> phantoms = points.sub_array (points.length - PHANTOM_COUNT, PHANTOM_COUNT);
737       {
738 	for (unsigned i = 0; i < PHANTOM_COUNT; ++i) phantoms[i].init ();
739 	int h_delta = (int) header->xMin - glyf_accelerator.hmtx->get_side_bearing (gid);
740 	int v_orig  = (int) header->yMax + glyf_accelerator.vmtx->get_side_bearing (gid);
741 	unsigned h_adv = glyf_accelerator.hmtx->get_advance (gid);
742 	unsigned v_adv = glyf_accelerator.vmtx->get_advance (gid);
743 	phantoms[PHANTOM_LEFT].x = h_delta;
744 	phantoms[PHANTOM_RIGHT].x = h_adv + h_delta;
745 	phantoms[PHANTOM_TOP].y = v_orig;
746 	phantoms[PHANTOM_BOTTOM].y = v_orig - (int) v_adv;
747       }
748 
749 #ifndef HB_NO_VAR
750       if (unlikely (!glyf_accelerator.gvar->apply_deltas_to_points (gid, font, points.as_array ())))
751 	return false;
752 #endif
753 
754       switch (type) {
755       case SIMPLE:
756 	all_points.extend (points.as_array ());
757 	break;
758       case COMPOSITE:
759       {
760 	unsigned int comp_index = 0;
761 	for (auto &item : get_composite_iterator ())
762 	{
763 	  contour_point_vector_t comp_points;
764 	  if (unlikely (!glyf_accelerator.glyph_for_gid (item.get_glyph_index ())
765 					 .get_points (font, glyf_accelerator, comp_points,
766 			 			      phantom_only, depth + 1)
767 			|| comp_points.length < PHANTOM_COUNT))
768 	    return false;
769 
770 	  /* Copy phantom points from component if USE_MY_METRICS flag set */
771 	  if (item.is_use_my_metrics ())
772 	    for (unsigned int i = 0; i < PHANTOM_COUNT; i++)
773 	      phantoms[i] = comp_points[comp_points.length - PHANTOM_COUNT + i];
774 
775 	  /* Apply component transformation & translation */
776 	  item.transform_points (comp_points);
777 
778 	  /* Apply translation from gvar */
779 	  comp_points.translate (points[comp_index]);
780 
781 	  if (item.is_anchored ())
782 	  {
783 	    unsigned int p1, p2;
784 	    item.get_anchor_points (p1, p2);
785 	    if (likely (p1 < all_points.length && p2 < comp_points.length))
786 	    {
787 	      contour_point_t delta;
788 	      delta.init (all_points[p1].x - comp_points[p2].x,
789 			  all_points[p1].y - comp_points[p2].y);
790 
791 	      comp_points.translate (delta);
792 	    }
793 	  }
794 
795 	  all_points.extend (comp_points.sub_array (0, comp_points.length - PHANTOM_COUNT));
796 
797 	  comp_index++;
798 	}
799 
800 	all_points.extend (phantoms);
801       } break;
802       default:
803 	all_points.extend (phantoms);
804       }
805 
806       if (depth == 0) /* Apply at top level */
807       {
808 	/* Undocumented rasterizer behavior:
809 	 * Shift points horizontally by the updated left side bearing
810 	 */
811 	contour_point_t delta;
812 	delta.init (-phantoms[PHANTOM_LEFT].x, 0.f);
813 	if (delta.x) all_points.translate (delta);
814       }
815 
816       return true;
817     }
818 
get_extentsOT::glyf::Glyph819     bool get_extents (hb_font_t *font, const accelerator_t &glyf_accelerator,
820 		      hb_glyph_extents_t *extents) const
821     {
822       if (type == EMPTY) return true; /* Empty glyph; zero extents. */
823       return header->get_extents (font, glyf_accelerator, gid, extents);
824     }
825 
get_bytesOT::glyf::Glyph826     hb_bytes_t get_bytes () const { return bytes; }
827 
GlyphOT::glyf::Glyph828     Glyph (hb_bytes_t bytes_ = hb_bytes_t (),
829 	   hb_codepoint_t gid_ = (hb_codepoint_t) -1) : bytes (bytes_), gid (gid_),
830 							header (bytes.as<GlyphHeader> ())
831     {
832       int num_contours = header->numberOfContours;
833       if (unlikely (num_contours == 0)) type = EMPTY;
834       else if (num_contours > 0) type = SIMPLE;
835       else type = COMPOSITE; /* negative numbers */
836     }
837 
838     protected:
839     hb_bytes_t bytes;
840     hb_codepoint_t gid;
841     const GlyphHeader *header;
842     unsigned type;
843   };
844 
845   struct accelerator_t
846   {
initOT::glyf::accelerator_t847     void init (hb_face_t *face_)
848     {
849       short_offset = false;
850       num_glyphs = 0;
851       loca_table = nullptr;
852       glyf_table = nullptr;
853 #ifndef HB_NO_VAR
854       gvar = nullptr;
855 #endif
856       hmtx = nullptr;
857       vmtx = nullptr;
858       face = face_;
859       const OT::head &head = *face->table.head;
860       if (head.indexToLocFormat > 1 || head.glyphDataFormat > 0)
861 	/* Unknown format.  Leave num_glyphs=0, that takes care of disabling us. */
862 	return;
863       short_offset = 0 == head.indexToLocFormat;
864 
865       loca_table = hb_sanitize_context_t ().reference_table<loca> (face);
866       glyf_table = hb_sanitize_context_t ().reference_table<glyf> (face);
867 #ifndef HB_NO_VAR
868       gvar = face->table.gvar;
869 #endif
870       hmtx = face->table.hmtx;
871       vmtx = face->table.vmtx;
872 
873       num_glyphs = hb_max (1u, loca_table.get_length () / (short_offset ? 2 : 4)) - 1;
874       num_glyphs = hb_min (num_glyphs, face->get_num_glyphs ());
875     }
876 
finiOT::glyf::accelerator_t877     void fini ()
878     {
879       loca_table.destroy ();
880       glyf_table.destroy ();
881     }
882 
883     protected:
884     template<typename T>
get_pointsOT::glyf::accelerator_t885     bool get_points (hb_font_t *font, hb_codepoint_t gid, T consumer) const
886     {
887       if (gid >= num_glyphs) return false;
888 
889       /* Making this alloc free is not that easy
890 	 https://github.com/harfbuzz/harfbuzz/issues/2095
891 	 mostly because of gvar handling in VF fonts,
892 	 perhaps a separate path for non-VF fonts can be considered */
893       contour_point_vector_t all_points;
894 
895       bool phantom_only = !consumer.is_consuming_contour_points ();
896       if (unlikely (!glyph_for_gid (gid).get_points (font, *this, all_points, phantom_only)))
897 	return false;
898 
899       if (consumer.is_consuming_contour_points ())
900       {
901 	for (unsigned point_index = 0; point_index + 4 < all_points.length; ++point_index)
902 	  consumer.consume_point (all_points[point_index]);
903 	consumer.points_end ();
904       }
905 
906       /* Where to write phantoms, nullptr if not requested */
907       contour_point_t *phantoms = consumer.get_phantoms_sink ();
908       if (phantoms)
909 	for (unsigned i = 0; i < PHANTOM_COUNT; ++i)
910 	  phantoms[i] = all_points[all_points.length - PHANTOM_COUNT + i];
911 
912       return true;
913     }
914 
915 #ifndef HB_NO_VAR
916     struct points_aggregator_t
917     {
918       hb_font_t *font;
919       hb_glyph_extents_t *extents;
920       contour_point_t *phantoms;
921 
922       struct contour_bounds_t
923       {
contour_bounds_tOT::glyf::accelerator_t::points_aggregator_t::contour_bounds_t924 	contour_bounds_t () { min_x = min_y = FLT_MAX; max_x = max_y = -FLT_MAX; }
925 
addOT::glyf::accelerator_t::points_aggregator_t::contour_bounds_t926 	void add (const contour_point_t &p)
927 	{
928 	  min_x = hb_min (min_x, p.x);
929 	  min_y = hb_min (min_y, p.y);
930 	  max_x = hb_max (max_x, p.x);
931 	  max_y = hb_max (max_y, p.y);
932 	}
933 
emptyOT::glyf::accelerator_t::points_aggregator_t::contour_bounds_t934 	bool empty () const { return (min_x >= max_x) || (min_y >= max_y); }
935 
get_extentsOT::glyf::accelerator_t::points_aggregator_t::contour_bounds_t936 	void get_extents (hb_font_t *font, hb_glyph_extents_t *extents)
937 	{
938 	  if (unlikely (empty ()))
939 	  {
940 	    extents->width = 0;
941 	    extents->x_bearing = 0;
942 	    extents->height = 0;
943 	    extents->y_bearing = 0;
944 	    return;
945 	  }
946 	  extents->x_bearing = font->em_scalef_x (min_x);
947 	  extents->width = font->em_scalef_x (max_x) - extents->x_bearing;
948 	  extents->y_bearing = font->em_scalef_y (max_y);
949 	  extents->height = font->em_scalef_y (min_y) - extents->y_bearing;
950 	}
951 
952 	protected:
953 	float min_x, min_y, max_x, max_y;
954       } bounds;
955 
points_aggregator_tOT::glyf::accelerator_t::points_aggregator_t956       points_aggregator_t (hb_font_t *font_, hb_glyph_extents_t *extents_, contour_point_t *phantoms_)
957       {
958 	font = font_;
959 	extents = extents_;
960 	phantoms = phantoms_;
961 	if (extents) bounds = contour_bounds_t ();
962       }
963 
consume_pointOT::glyf::accelerator_t::points_aggregator_t964       void consume_point (const contour_point_t &point) { bounds.add (point); }
points_endOT::glyf::accelerator_t::points_aggregator_t965       void points_end () { bounds.get_extents (font, extents); }
966 
is_consuming_contour_pointsOT::glyf::accelerator_t::points_aggregator_t967       bool is_consuming_contour_points () { return extents; }
get_phantoms_sinkOT::glyf::accelerator_t::points_aggregator_t968       contour_point_t *get_phantoms_sink () { return phantoms; }
969     };
970 
971     public:
972     unsigned
get_advance_varOT::glyf::accelerator_t973     get_advance_var (hb_font_t *font, hb_codepoint_t gid, bool is_vertical) const
974     {
975       if (unlikely (gid >= num_glyphs)) return 0;
976 
977       bool success = false;
978 
979       contour_point_t phantoms[PHANTOM_COUNT];
980       if (likely (font->num_coords == gvar->get_axis_count ()))
981 	success = get_points (font, gid, points_aggregator_t (font, nullptr, phantoms));
982 
983       if (unlikely (!success))
984 	return is_vertical ? vmtx->get_advance (gid) : hmtx->get_advance (gid);
985 
986       float result = is_vertical
987 		   ? phantoms[PHANTOM_TOP].y - phantoms[PHANTOM_BOTTOM].y
988 		   : phantoms[PHANTOM_RIGHT].x - phantoms[PHANTOM_LEFT].x;
989       return hb_clamp (roundf (result), 0.f, (float) UINT_MAX / 2);
990     }
991 
get_side_bearing_varOT::glyf::accelerator_t992     int get_side_bearing_var (hb_font_t *font, hb_codepoint_t gid, bool is_vertical) const
993     {
994       if (unlikely (gid >= num_glyphs)) return 0;
995 
996       hb_glyph_extents_t extents;
997 
998       contour_point_t phantoms[PHANTOM_COUNT];
999       if (unlikely (!get_points (font, gid, points_aggregator_t (font, &extents, phantoms))))
1000 	return is_vertical ? vmtx->get_side_bearing (gid) : hmtx->get_side_bearing (gid);
1001 
1002       return is_vertical
1003 	   ? ceilf (phantoms[PHANTOM_TOP].y) - extents.y_bearing
1004 	   : floorf (phantoms[PHANTOM_LEFT].x);
1005     }
1006 #endif
1007 
1008     public:
get_extentsOT::glyf::accelerator_t1009     bool get_extents (hb_font_t *font, hb_codepoint_t gid, hb_glyph_extents_t *extents) const
1010     {
1011       if (unlikely (gid >= num_glyphs)) return false;
1012 
1013 #ifndef HB_NO_VAR
1014       if (font->num_coords && font->num_coords == gvar->get_axis_count ())
1015 	return get_points (font, gid, points_aggregator_t (font, extents, nullptr));
1016 #endif
1017       return glyph_for_gid (gid).get_extents (font, *this, extents);
1018     }
1019 
1020     const Glyph
glyph_for_gidOT::glyf::accelerator_t1021     glyph_for_gid (hb_codepoint_t gid, bool needs_padding_removal = false) const
1022     {
1023       if (unlikely (gid >= num_glyphs)) return Glyph ();
1024 
1025       unsigned int start_offset, end_offset;
1026 
1027       if (short_offset)
1028       {
1029 	const HBUINT16 *offsets = (const HBUINT16 *) loca_table->dataZ.arrayZ;
1030 	start_offset = 2 * offsets[gid];
1031 	end_offset   = 2 * offsets[gid + 1];
1032       }
1033       else
1034       {
1035 	const HBUINT32 *offsets = (const HBUINT32 *) loca_table->dataZ.arrayZ;
1036 	start_offset = offsets[gid];
1037 	end_offset   = offsets[gid + 1];
1038       }
1039 
1040       if (unlikely (start_offset > end_offset || end_offset > glyf_table.get_length ()))
1041 	return Glyph ();
1042 
1043       Glyph glyph (hb_bytes_t ((const char *) this->glyf_table + start_offset,
1044 			       end_offset - start_offset), gid);
1045       return needs_padding_removal ? glyph.trim_padding () : glyph;
1046     }
1047 
1048     void
add_gid_and_childrenOT::glyf::accelerator_t1049     add_gid_and_children (hb_codepoint_t gid, hb_set_t *gids_to_retain,
1050 			  unsigned int depth = 0) const
1051     {
1052       if (unlikely (depth++ > HB_MAX_NESTING_LEVEL)) return;
1053       /* Check if is already visited */
1054       if (gids_to_retain->has (gid)) return;
1055 
1056       gids_to_retain->add (gid);
1057 
1058       for (auto &item : glyph_for_gid (gid).get_composite_iterator ())
1059 	add_gid_and_children (item.get_glyph_index (), gids_to_retain, depth);
1060     }
1061 
1062 #ifdef HB_EXPERIMENTAL_API
1063     struct path_builder_t
1064     {
1065       hb_font_t *font;
1066       draw_helper_t *draw_helper;
1067 
1068       struct optional_point_t
1069       {
optional_point_tOT::glyf::accelerator_t::path_builder_t::optional_point_t1070 	optional_point_t () { has_data = false; }
optional_point_tOT::glyf::accelerator_t::path_builder_t::optional_point_t1071 	optional_point_t (float x_, float y_) { x = x_; y = y_; has_data = true; }
1072 
1073 	bool has_data;
1074 	float x;
1075 	float y;
1076 
lerpOT::glyf::accelerator_t::path_builder_t::optional_point_t1077 	optional_point_t lerp (optional_point_t p, float t)
1078 	{ return optional_point_t (x + t * (p.x - x), y + t * (p.y - y)); }
1079       } first_oncurve, first_offcurve, last_offcurve;
1080 
path_builder_tOT::glyf::accelerator_t::path_builder_t1081       path_builder_t (hb_font_t *font_, draw_helper_t &draw_helper_)
1082       {
1083 	font = font_;
1084 	draw_helper = &draw_helper_;
1085 	first_oncurve = first_offcurve = last_offcurve = optional_point_t ();
1086       }
1087 
1088       /* based on https://github.com/RazrFalcon/ttf-parser/blob/4f32821/src/glyf.rs#L287
1089 	 See also:
1090 	 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM01/Chap1.html
1091 	 * https://stackoverflow.com/a/20772557 */
consume_pointOT::glyf::accelerator_t::path_builder_t1092       void consume_point (const contour_point_t &point)
1093       {
1094 	/* Skip empty contours */
1095 	if (unlikely (point.is_end_point && !first_oncurve.has_data && !first_offcurve.has_data))
1096 	  return;
1097 
1098 	bool is_on_curve = point.flag & Glyph::FLAG_ON_CURVE;
1099 	optional_point_t p (point.x, point.y);
1100 	if (!first_oncurve.has_data)
1101 	{
1102 	  if (is_on_curve)
1103 	  {
1104 	    first_oncurve = p;
1105 	    draw_helper->move_to (font->em_scalef_x (p.x), font->em_scalef_y (p.y));
1106 	  }
1107 	  else
1108 	  {
1109 	    if (first_offcurve.has_data)
1110 	    {
1111 	      optional_point_t mid = first_offcurve.lerp (p, .5f);
1112 	      first_oncurve = mid;
1113 	      last_offcurve = p;
1114 	      draw_helper->move_to (font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
1115 	    }
1116 	    else
1117 	      first_offcurve = p;
1118 	  }
1119 	}
1120 	else
1121 	{
1122 	  if (last_offcurve.has_data)
1123 	  {
1124 	    if (is_on_curve)
1125 	    {
1126 	      draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1127 					 font->em_scalef_x (p.x), font->em_scalef_y (p.y));
1128 	      last_offcurve = optional_point_t ();
1129 	    }
1130 	    else
1131 	    {
1132 	      optional_point_t mid = last_offcurve.lerp (p, .5f);
1133 	      draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1134 					 font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
1135 	      last_offcurve = p;
1136 	    }
1137 	  }
1138 	  else
1139 	  {
1140 	    if (is_on_curve)
1141 	      draw_helper->line_to (font->em_scalef_x (p.x), font->em_scalef_y (p.y));
1142 	    else
1143 	      last_offcurve = p;
1144 	  }
1145 	}
1146 
1147 	if (point.is_end_point)
1148 	{
1149 	  if (first_offcurve.has_data && last_offcurve.has_data)
1150 	  {
1151 	    optional_point_t mid = last_offcurve.lerp (first_offcurve, .5f);
1152 	    draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1153 				       font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
1154 	    last_offcurve = optional_point_t ();
1155 	    /* now check the rest */
1156 	  }
1157 
1158 	  if (first_offcurve.has_data && first_oncurve.has_data)
1159 	    draw_helper->quadratic_to (font->em_scalef_x (first_offcurve.x), font->em_scalef_y (first_offcurve.y),
1160 				       font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
1161 	  else if (last_offcurve.has_data && first_oncurve.has_data)
1162 	    draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1163 				       font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
1164 	  else if (first_oncurve.has_data)
1165 	    draw_helper->line_to (font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
1166 
1167 	  /* Getting ready for the next contour */
1168 	  first_oncurve = first_offcurve = last_offcurve = optional_point_t ();
1169 	  draw_helper->end_path ();
1170 	}
1171       }
points_endOT::glyf::accelerator_t::path_builder_t1172       void points_end () {}
1173 
is_consuming_contour_pointsOT::glyf::accelerator_t::path_builder_t1174       bool is_consuming_contour_points () { return true; }
get_phantoms_sinkOT::glyf::accelerator_t::path_builder_t1175       contour_point_t *get_phantoms_sink () { return nullptr; }
1176     };
1177 
1178     bool
get_pathOT::glyf::accelerator_t1179     get_path (hb_font_t *font, hb_codepoint_t gid, draw_helper_t &draw_helper) const
1180     { return get_points (font, gid, path_builder_t (font, draw_helper)); }
1181 #endif
1182 
1183 #ifndef HB_NO_VAR
1184     const gvar_accelerator_t *gvar;
1185 #endif
1186     const hmtx_accelerator_t *hmtx;
1187     const vmtx_accelerator_t *vmtx;
1188 
1189     private:
1190     bool short_offset;
1191     unsigned int num_glyphs;
1192     hb_blob_ptr_t<loca> loca_table;
1193     hb_blob_ptr_t<glyf> glyf_table;
1194     hb_face_t *face;
1195   };
1196 
1197   struct SubsetGlyph
1198   {
1199     hb_codepoint_t new_gid;
1200     hb_codepoint_t old_gid;
1201     Glyph source_glyph;
1202     hb_bytes_t dest_start;  /* region of source_glyph to copy first */
1203     hb_bytes_t dest_end;    /* region of source_glyph to copy second */
1204 
serializeOT::glyf::SubsetGlyph1205     bool serialize (hb_serialize_context_t *c,
1206 		    const hb_subset_plan_t *plan) const
1207     {
1208       TRACE_SERIALIZE (this);
1209 
1210       hb_bytes_t dest_glyph = dest_start.copy (c);
1211       dest_glyph = hb_bytes_t (&dest_glyph, dest_glyph.length + dest_end.copy (c).length);
1212       unsigned int pad_length = padding ();
1213       DEBUG_MSG (SUBSET, nullptr, "serialize %d byte glyph, width %d pad %d", dest_glyph.length, dest_glyph.length + pad_length, pad_length);
1214 
1215       HBUINT8 pad;
1216       pad = 0;
1217       while (pad_length > 0)
1218       {
1219 	c->embed (pad);
1220 	pad_length--;
1221       }
1222 
1223       if (unlikely (!dest_glyph.length)) return_trace (true);
1224 
1225       /* update components gids */
1226       for (auto &_ : Glyph (dest_glyph).get_composite_iterator ())
1227       {
1228 	hb_codepoint_t new_gid;
1229 	if (plan->new_gid_for_old_gid (_.get_glyph_index (), &new_gid))
1230 	  const_cast<CompositeGlyphChain &> (_).set_glyph_index (new_gid);
1231       }
1232 
1233       if (plan->drop_hints) Glyph (dest_glyph).drop_hints ();
1234 
1235       return_trace (true);
1236     }
1237 
drop_hints_bytesOT::glyf::SubsetGlyph1238     void drop_hints_bytes ()
1239     { source_glyph.drop_hints_bytes (dest_start, dest_end); }
1240 
lengthOT::glyf::SubsetGlyph1241     unsigned int      length () const { return dest_start.length + dest_end.length; }
1242     /* pad to 2 to ensure 2-byte loca will be ok */
paddingOT::glyf::SubsetGlyph1243     unsigned int     padding () const { return length () % 2; }
padded_sizeOT::glyf::SubsetGlyph1244     unsigned int padded_size () const { return length () + padding (); }
1245   };
1246 
1247   protected:
1248   UnsizedArrayOf<HBUINT8>
1249 		dataZ;	/* Glyphs data. */
1250   public:
1251   DEFINE_SIZE_MIN (0);	/* In reality, this is UNBOUNDED() type; but since we always
1252 			 * check the size externally, allow Null() object of it by
1253 			 * defining it _MIN instead. */
1254 };
1255 
1256 struct glyf_accelerator_t : glyf::accelerator_t {};
1257 
1258 } /* namespace OT */
1259 
1260 
1261 #endif /* HB_OT_GLYF_TABLE_HH */
1262