1/*
2 * Copyright © 2011,2012,2013  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#include "hb-ot-shape-complex-indic-private.hh"
28
29/* buffer var allocations */
30#define myanmar_category() complex_var_u8_0() /* myanmar_category_t */
31#define myanmar_position() complex_var_u8_1() /* myanmar_position_t */
32
33
34/*
35 * Myanmar shaper.
36 */
37
38static const hb_tag_t
39basic_features[] =
40{
41  /*
42   * Basic features.
43   * These features are applied in order, one at a time, after initial_reordering.
44   */
45  HB_TAG('r','p','h','f'),
46  HB_TAG('p','r','e','f'),
47  HB_TAG('b','l','w','f'),
48  HB_TAG('p','s','t','f'),
49};
50static const hb_tag_t
51other_features[] =
52{
53  /*
54   * Other features.
55   * These features are applied all at once, after final_reordering.
56   */
57  HB_TAG('p','r','e','s'),
58  HB_TAG('a','b','v','s'),
59  HB_TAG('b','l','w','s'),
60  HB_TAG('p','s','t','s'),
61  /* Positioning features, though we don't care about the types. */
62  HB_TAG('d','i','s','t'),
63};
64
65static void
66setup_syllables (const hb_ot_shape_plan_t *plan,
67		 hb_font_t *font,
68		 hb_buffer_t *buffer);
69static void
70initial_reordering (const hb_ot_shape_plan_t *plan,
71		    hb_font_t *font,
72		    hb_buffer_t *buffer);
73static void
74final_reordering (const hb_ot_shape_plan_t *plan,
75		  hb_font_t *font,
76		  hb_buffer_t *buffer);
77
78static void
79collect_features_myanmar (hb_ot_shape_planner_t *plan)
80{
81  hb_ot_map_builder_t *map = &plan->map;
82
83  /* Do this before any lookups have been applied. */
84  map->add_gsub_pause (setup_syllables);
85
86  map->add_global_bool_feature (HB_TAG('l','o','c','l'));
87  /* The Indic specs do not require ccmp, but we apply it here since if
88   * there is a use of it, it's typically at the beginning. */
89  map->add_global_bool_feature (HB_TAG('c','c','m','p'));
90
91
92  map->add_gsub_pause (initial_reordering);
93  for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
94  {
95    map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
96    map->add_gsub_pause (NULL);
97  }
98  map->add_gsub_pause (final_reordering);
99  for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
100    map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
101}
102
103static void
104override_features_myanmar (hb_ot_shape_planner_t *plan)
105{
106  plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
107
108  /*
109   * Note:
110   *
111   * Spec says 'mark' is used, and the mmrtext.ttf font from
112   * Windows 8 has lookups for it.  But testing suggests that
113   * Windows 8 Uniscribe is NOT applying it.  It *is* applying
114   * 'mkmk' however.
115   */
116  if (hb_options ().uniscribe_bug_compatible)
117    plan->map.add_feature (HB_TAG('m','a','r','k'), 0, F_GLOBAL);
118}
119
120
121enum syllable_type_t {
122  consonant_syllable,
123  broken_cluster,
124  non_myanmar_cluster,
125};
126
127#include "hb-ot-shape-complex-myanmar-machine.hh"
128
129
130/* Note: This enum is duplicated in the -machine.rl source file.
131 * Not sure how to avoid duplication. */
132enum myanmar_category_t {
133  OT_As  = 18, /* Asat */
134  OT_D   = 19, /* Digits except zero */
135  OT_D0  = 20, /* Digit zero */
136  OT_DB  = OT_N, /* Dot below */
137  OT_GB  = OT_DOTTEDCIRCLE,
138  OT_MH  = 21, /* Various consonant medial types */
139  OT_MR  = 22, /* Various consonant medial types */
140  OT_MW  = 23, /* Various consonant medial types */
141  OT_MY  = 24, /* Various consonant medial types */
142  OT_PT  = 25, /* Pwo and other tones */
143  OT_VAbv = 26,
144  OT_VBlw = 27,
145  OT_VPre = 28,
146  OT_VPst = 29,
147  OT_VS   = 30 /* Variation selectors */
148};
149
150
151static inline bool
152is_one_of (const hb_glyph_info_t &info, unsigned int flags)
153{
154  /* If it ligated, all bets are off. */
155  if (is_a_ligature (info)) return false;
156  return !!(FLAG (info.myanmar_category()) & flags);
157}
158
159/* Note:
160 *
161 * We treat Vowels and placeholders as if they were consonants.  This is safe because Vowels
162 * cannot happen in a consonant syllable.  The plus side however is, we can call the
163 * consonant syllable logic from the vowel syllable function and get it all right! */
164#define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CM) | FLAG (OT_Ra) | FLAG (OT_V) | FLAG (OT_NBSP) | FLAG (OT_GB))
165static inline bool
166is_consonant (const hb_glyph_info_t &info)
167{
168  return is_one_of (info, CONSONANT_FLAGS);
169}
170
171
172static inline void
173set_myanmar_properties (hb_glyph_info_t &info)
174{
175  hb_codepoint_t u = info.codepoint;
176  unsigned int type = hb_indic_get_categories (u);
177  indic_category_t cat = (indic_category_t) (type & 0x7F);
178  indic_position_t pos = (indic_position_t) (type >> 8);
179
180  /* Myanmar
181   * http://www.microsoft.com/typography/OpenTypeDev/myanmar/intro.htm#analyze
182   */
183  if (unlikely (hb_in_range<hb_codepoint_t> (u, 0xFE00, 0xFE0F)))
184    cat = (indic_category_t) OT_VS;
185  else if (unlikely (u == 0x200C)) cat = (indic_category_t) OT_ZWNJ;
186  else if (unlikely (u == 0x200D)) cat = (indic_category_t) OT_ZWJ;
187
188  switch (u)
189  {
190    case 0x002D: case 0x00A0: case 0x00D7: case 0x2012:
191    case 0x2013: case 0x2014: case 0x2015: case 0x2022:
192    case 0x25CC: case 0x25FB: case 0x25FC: case 0x25FD:
193    case 0x25FE:
194      cat = (indic_category_t) OT_GB;
195      break;
196
197    case 0x1004: case 0x101B: case 0x105A:
198      cat = (indic_category_t) OT_Ra;
199      break;
200
201    case 0x1032: case 0x1036:
202      cat = (indic_category_t) OT_A;
203      break;
204
205    case 0x103A:
206      cat = (indic_category_t) OT_As;
207      break;
208
209    case 0x1041: case 0x1042: case 0x1043: case 0x1044:
210    case 0x1045: case 0x1046: case 0x1047: case 0x1048:
211    case 0x1049: case 0x1090: case 0x1091: case 0x1092:
212    case 0x1093: case 0x1094: case 0x1095: case 0x1096:
213    case 0x1097: case 0x1098: case 0x1099:
214      cat = (indic_category_t) OT_D;
215      break;
216
217    case 0x1040:
218      cat = (indic_category_t) OT_D; /* XXX The spec says D0, but Uniscribe doesn't seem to do. */
219      break;
220
221    case 0x103E: case 0x1060:
222      cat = (indic_category_t) OT_MH;
223      break;
224
225    case 0x103C:
226      cat = (indic_category_t) OT_MR;
227      break;
228
229    case 0x103D: case 0x1082:
230      cat = (indic_category_t) OT_MW;
231      break;
232
233    case 0x103B: case 0x105E: case 0x105F:
234      cat = (indic_category_t) OT_MY;
235      break;
236
237    case 0x1063: case 0x1064: case 0x1069: case 0x106A:
238    case 0x106B: case 0x106C: case 0x106D: case 0xAA7B:
239      cat = (indic_category_t) OT_PT;
240      break;
241
242    case 0x1038: case 0x1087: case 0x1088: case 0x1089:
243    case 0x108A: case 0x108B: case 0x108C: case 0x108D:
244    case 0x108F: case 0x109A: case 0x109B: case 0x109C:
245      cat = (indic_category_t) OT_SM;
246      break;
247  }
248
249  if (cat == OT_M)
250  {
251    switch ((int) pos)
252    {
253      case POS_PRE_C:	cat = (indic_category_t) OT_VPre;
254			pos = POS_PRE_M;                  break;
255      case POS_ABOVE_C:	cat = (indic_category_t) OT_VAbv; break;
256      case POS_BELOW_C:	cat = (indic_category_t) OT_VBlw; break;
257      case POS_POST_C:	cat = (indic_category_t) OT_VPst; break;
258    }
259  }
260
261  info.myanmar_category() = (myanmar_category_t) cat;
262  info.myanmar_position() = pos;
263}
264
265
266
267static void
268setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
269		   hb_buffer_t              *buffer,
270		   hb_font_t                *font HB_UNUSED)
271{
272  HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_category);
273  HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_position);
274
275  /* We cannot setup masks here.  We save information about characters
276   * and setup masks later on in a pause-callback. */
277
278  unsigned int count = buffer->len;
279  for (unsigned int i = 0; i < count; i++)
280    set_myanmar_properties (buffer->info[i]);
281}
282
283static void
284setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
285		 hb_font_t *font HB_UNUSED,
286		 hb_buffer_t *buffer)
287{
288  find_syllables (buffer);
289}
290
291static int
292compare_myanmar_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
293{
294  int a = pa->myanmar_position();
295  int b = pb->myanmar_position();
296
297  return a < b ? -1 : a == b ? 0 : +1;
298}
299
300
301/* Rules from:
302 * http://www.microsoft.com/typography/OpenTypeDev/myanmar/intro.htm */
303
304static void
305initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
306				       hb_face_t *face,
307				       hb_buffer_t *buffer,
308				       unsigned int start, unsigned int end)
309{
310  hb_glyph_info_t *info = buffer->info;
311
312  unsigned int base = end;
313  bool has_reph = false;
314
315  {
316    unsigned int limit = start;
317    if (start + 3 <= end &&
318	info[start  ].myanmar_category() == OT_Ra &&
319	info[start+1].myanmar_category() == OT_As &&
320	info[start+2].myanmar_category() == OT_H)
321    {
322      limit += 3;
323      base = start;
324      has_reph = true;
325    }
326
327    {
328      if (!has_reph)
329	base = limit;
330
331      for (unsigned int i = limit; i < end; i++)
332	if (is_consonant (info[i]))
333	{
334	  base = i;
335	  break;
336	}
337    }
338  }
339
340  /* Reorder! */
341  {
342    unsigned int i = start;
343    for (; i < start + (has_reph ? 3 : 0); i++)
344      info[i].myanmar_position() = POS_AFTER_MAIN;
345    for (; i < base; i++)
346      info[i].myanmar_position() = POS_PRE_C;
347    if (i < end)
348    {
349      info[i].myanmar_position() = POS_BASE_C;
350      i++;
351    }
352    indic_position_t pos = POS_AFTER_MAIN;
353    /* The following loop may be ugly, but it implements all of
354     * Myanmar reordering! */
355    for (; i < end; i++)
356    {
357      if (info[i].myanmar_category() == OT_MR) /* Pre-base reordering */
358      {
359	info[i].myanmar_position() = POS_PRE_C;
360	continue;
361      }
362      if (info[i].myanmar_position() < POS_BASE_C) /* Left matra */
363      {
364	continue;
365      }
366
367      if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == OT_VBlw)
368      {
369	pos = POS_BELOW_C;
370	info[i].myanmar_position() = pos;
371	continue;
372      }
373
374      if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_A)
375      {
376	info[i].myanmar_position() = POS_BEFORE_SUB;
377	continue;
378      }
379      if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_VBlw)
380      {
381	info[i].myanmar_position() = pos;
382	continue;
383      }
384      if (pos == POS_BELOW_C && info[i].myanmar_category() != OT_A)
385      {
386        pos = POS_AFTER_SUB;
387	info[i].myanmar_position() = pos;
388	continue;
389      }
390      info[i].myanmar_position() = pos;
391    }
392  }
393
394  buffer->merge_clusters (start, end);
395  /* Sit tight, rock 'n roll! */
396  hb_bubble_sort (info + start, end - start, compare_myanmar_order);
397}
398
399static void
400initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan,
401				   hb_face_t *face,
402				   hb_buffer_t *buffer,
403				   unsigned int start, unsigned int end)
404{
405  /* We already inserted dotted-circles, so just call the consonant_syllable. */
406  initial_reordering_consonant_syllable (plan, face, buffer, start, end);
407}
408
409static void
410initial_reordering_non_myanmar_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
411					hb_face_t *face HB_UNUSED,
412					hb_buffer_t *buffer HB_UNUSED,
413					unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
414{
415  /* Nothing to do right now.  If we ever switch to using the output
416   * buffer in the reordering process, we'd need to next_glyph() here. */
417}
418
419
420static void
421initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
422			     hb_face_t *face,
423			     hb_buffer_t *buffer,
424			     unsigned int start, unsigned int end)
425{
426  syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
427  switch (syllable_type) {
428  case consonant_syllable:	initial_reordering_consonant_syllable  (plan, face, buffer, start, end); return;
429  case broken_cluster:		initial_reordering_broken_cluster      (plan, face, buffer, start, end); return;
430  case non_myanmar_cluster:	initial_reordering_non_myanmar_cluster (plan, face, buffer, start, end); return;
431  }
432}
433
434static inline void
435insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
436		       hb_font_t *font,
437		       hb_buffer_t *buffer)
438{
439  /* Note: This loop is extra overhead, but should not be measurable. */
440  bool has_broken_syllables = false;
441  unsigned int count = buffer->len;
442  for (unsigned int i = 0; i < count; i++)
443    if ((buffer->info[i].syllable() & 0x0F) == broken_cluster) {
444      has_broken_syllables = true;
445      break;
446    }
447  if (likely (!has_broken_syllables))
448    return;
449
450
451  hb_codepoint_t dottedcircle_glyph;
452  if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph))
453    return;
454
455  hb_glyph_info_t dottedcircle = {0};
456  dottedcircle.codepoint = 0x25CC;
457  set_myanmar_properties (dottedcircle);
458  dottedcircle.codepoint = dottedcircle_glyph;
459
460  buffer->clear_output ();
461
462  buffer->idx = 0;
463  unsigned int last_syllable = 0;
464  while (buffer->idx < buffer->len)
465  {
466    unsigned int syllable = buffer->cur().syllable();
467    syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
468    if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
469    {
470      last_syllable = syllable;
471
472      hb_glyph_info_t info = dottedcircle;
473      info.cluster = buffer->cur().cluster;
474      info.mask = buffer->cur().mask;
475      info.syllable() = buffer->cur().syllable();
476
477      buffer->output_info (info);
478    }
479    else
480      buffer->next_glyph ();
481  }
482
483  buffer->swap_buffers ();
484}
485
486static void
487initial_reordering (const hb_ot_shape_plan_t *plan,
488		    hb_font_t *font,
489		    hb_buffer_t *buffer)
490{
491  insert_dotted_circles (plan, font, buffer);
492
493  hb_glyph_info_t *info = buffer->info;
494  unsigned int count = buffer->len;
495  if (unlikely (!count)) return;
496  unsigned int last = 0;
497  unsigned int last_syllable = info[0].syllable();
498  for (unsigned int i = 1; i < count; i++)
499    if (last_syllable != info[i].syllable()) {
500      initial_reordering_syllable (plan, font->face, buffer, last, i);
501      last = i;
502      last_syllable = info[last].syllable();
503    }
504  initial_reordering_syllable (plan, font->face, buffer, last, count);
505}
506
507static void
508final_reordering (const hb_ot_shape_plan_t *plan,
509		  hb_font_t *font HB_UNUSED,
510		  hb_buffer_t *buffer)
511{
512  hb_glyph_info_t *info = buffer->info;
513  unsigned int count = buffer->len;
514
515  /* Zero syllables now... */
516  for (unsigned int i = 0; i < count; i++)
517    info[i].syllable() = 0;
518
519  HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category);
520  HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
521}
522
523
524static hb_ot_shape_normalization_mode_t
525normalization_preference_myanmar (const hb_segment_properties_t *props HB_UNUSED)
526{
527  return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT;
528}
529
530
531const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar =
532{
533  "myanmar",
534  collect_features_myanmar,
535  override_features_myanmar,
536  NULL, /* data_create */
537  NULL, /* data_destroy */
538  NULL, /* preprocess_text */
539  normalization_preference_myanmar,
540  NULL, /* decompose */
541  NULL, /* compose */
542  setup_masks_myanmar,
543  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF,
544  false, /* fallback_position */
545};
546