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  /* Pre-release version of Windows 8 Myanmar font had abvm,blwm
64   * features.  The released Windows 8 version of the font (as well
65   * as the released spec) used 'mark' instead.  The Windows 8
66   * shaper however didn't apply 'mark' but did apply 'mkmk'.
67   * Perhaps it applied abvm/blwm.  This was fixed in a Windows 8
68   * update, so now it applies mark/mkmk.  We are guessing that
69   * it still applies abvm/blwm too.
70   */
71  HB_TAG('a','b','v','m'),
72  HB_TAG('b','l','w','m'),
73};
74
75static void
76setup_syllables (const hb_ot_shape_plan_t *plan,
77                 hb_font_t *font,
78                 hb_buffer_t *buffer);
79static void
80initial_reordering (const hb_ot_shape_plan_t *plan,
81                    hb_font_t *font,
82                    hb_buffer_t *buffer);
83static void
84final_reordering (const hb_ot_shape_plan_t *plan,
85                  hb_font_t *font,
86                  hb_buffer_t *buffer);
87
88static void
89collect_features_myanmar (hb_ot_shape_planner_t *plan)
90{
91  hb_ot_map_builder_t *map = &plan->map;
92
93  /* Do this before any lookups have been applied. */
94  map->add_gsub_pause (setup_syllables);
95
96  map->add_global_bool_feature (HB_TAG('l','o','c','l'));
97  /* The Indic specs do not require ccmp, but we apply it here since if
98   * there is a use of it, it's typically at the beginning. */
99  map->add_global_bool_feature (HB_TAG('c','c','m','p'));
100
101
102  map->add_gsub_pause (initial_reordering);
103  for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
104  {
105    map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
106    map->add_gsub_pause (NULL);
107  }
108  map->add_gsub_pause (final_reordering);
109  for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
110    map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
111}
112
113static void
114override_features_myanmar (hb_ot_shape_planner_t *plan)
115{
116  plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
117}
118
119
120enum syllable_type_t {
121  consonant_syllable,
122  punctuation_cluster,
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_PLACEHOLDER,
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  OT_P    = 31  /* Punctuation */
149};
150
151
152static inline bool
153is_one_of (const hb_glyph_info_t &info, unsigned int flags)
154{
155  /* If it ligated, all bets are off. */
156  if (_hb_glyph_info_ligated (&info)) return false;
157  return !!(FLAG_SAFE (info.myanmar_category()) & flags);
158}
159
160static inline bool
161is_consonant (const hb_glyph_info_t &info)
162{
163  return is_one_of (info, CONSONANT_FLAGS);
164}
165
166
167static inline void
168set_myanmar_properties (hb_glyph_info_t &info)
169{
170  hb_codepoint_t u = info.codepoint;
171  unsigned int type = hb_indic_get_categories (u);
172  indic_category_t cat = (indic_category_t) (type & 0x7Fu);
173  indic_position_t pos = (indic_position_t) (type >> 8);
174
175  /* Myanmar
176   * http://www.microsoft.com/typography/OpenTypeDev/myanmar/intro.htm#analyze
177   */
178  if (unlikely (hb_in_range (u, 0xFE00u, 0xFE0Fu)))
179    cat = (indic_category_t) OT_VS;
180
181  switch (u)
182  {
183    case 0x104Eu:
184      cat = (indic_category_t) OT_C; /* The spec says C, IndicSyllableCategory doesn't have. */
185      break;
186
187    case 0x002Du: case 0x00A0u: case 0x00D7u: case 0x2012u:
188    case 0x2013u: case 0x2014u: case 0x2015u: case 0x2022u:
189    case 0x25CCu: case 0x25FBu: case 0x25FCu: case 0x25FDu:
190    case 0x25FEu:
191      cat = (indic_category_t) OT_GB;
192      break;
193
194    case 0x1004u: case 0x101Bu: case 0x105Au:
195      cat = (indic_category_t) OT_Ra;
196      break;
197
198    case 0x1032u: case 0x1036u:
199      cat = (indic_category_t) OT_A;
200      break;
201
202    case 0x1039u:
203      cat = (indic_category_t) OT_H;
204      break;
205
206    case 0x103Au:
207      cat = (indic_category_t) OT_As;
208      break;
209
210    case 0x1041u: case 0x1042u: case 0x1043u: case 0x1044u:
211    case 0x1045u: case 0x1046u: case 0x1047u: case 0x1048u:
212    case 0x1049u: case 0x1090u: case 0x1091u: case 0x1092u:
213    case 0x1093u: case 0x1094u: case 0x1095u: case 0x1096u:
214    case 0x1097u: case 0x1098u: case 0x1099u:
215      cat = (indic_category_t) OT_D;
216      break;
217
218    case 0x1040u:
219      cat = (indic_category_t) OT_D; /* XXX The spec says D0, but Uniscribe doesn't seem to do. */
220      break;
221
222    case 0x103Eu: case 0x1060u:
223      cat = (indic_category_t) OT_MH;
224      break;
225
226    case 0x103Cu:
227      cat = (indic_category_t) OT_MR;
228      break;
229
230    case 0x103Du: case 0x1082u:
231      cat = (indic_category_t) OT_MW;
232      break;
233
234    case 0x103Bu: case 0x105Eu: case 0x105Fu:
235      cat = (indic_category_t) OT_MY;
236      break;
237
238    case 0x1063u: case 0x1064u: case 0x1069u: case 0x106Au:
239    case 0x106Bu: case 0x106Cu: case 0x106Du: case 0xAA7Bu:
240      cat = (indic_category_t) OT_PT;
241      break;
242
243    case 0x1038u: case 0x1087u: case 0x1088u: case 0x1089u:
244    case 0x108Au: case 0x108Bu: case 0x108Cu: case 0x108Du:
245    case 0x108Fu: case 0x109Au: case 0x109Bu: case 0x109Cu:
246      cat = (indic_category_t) OT_SM;
247      break;
248
249    case 0x104Au: case 0x104Bu:
250      cat = (indic_category_t) OT_P;
251      break;
252
253    case 0xAA74u: case 0xAA75u: case 0xAA76u:
254      /* https://github.com/roozbehp/unicode-data/issues/3 */
255      cat = (indic_category_t) OT_C;
256      break;
257  }
258
259  if (cat == OT_M)
260  {
261    switch ((int) pos)
262    {
263      case POS_PRE_C:   cat = (indic_category_t) OT_VPre;
264                        pos = POS_PRE_M;                  break;
265      case POS_ABOVE_C: cat = (indic_category_t) OT_VAbv; break;
266      case POS_BELOW_C: cat = (indic_category_t) OT_VBlw; break;
267      case POS_POST_C:  cat = (indic_category_t) OT_VPst; break;
268    }
269  }
270
271  info.myanmar_category() = (myanmar_category_t) cat;
272  info.myanmar_position() = pos;
273}
274
275
276
277static void
278setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
279                   hb_buffer_t              *buffer,
280                   hb_font_t                *font HB_UNUSED)
281{
282  HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_category);
283  HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_position);
284
285  /* We cannot setup masks here.  We save information about characters
286   * and setup masks later on in a pause-callback. */
287
288  unsigned int count = buffer->len;
289  hb_glyph_info_t *info = buffer->info;
290  for (unsigned int i = 0; i < count; i++)
291    set_myanmar_properties (info[i]);
292}
293
294static void
295setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
296                 hb_font_t *font HB_UNUSED,
297                 hb_buffer_t *buffer)
298{
299  find_syllables (buffer);
300}
301
302static int
303compare_myanmar_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
304{
305  int a = pa->myanmar_position();
306  int b = pb->myanmar_position();
307
308  return a < b ? -1 : a == b ? 0 : +1;
309}
310
311
312/* Rules from:
313 * http://www.microsoft.com/typography/OpenTypeDev/myanmar/intro.htm */
314
315static void
316initial_reordering_consonant_syllable (hb_buffer_t *buffer,
317                                       unsigned int start, unsigned int end)
318{
319  hb_glyph_info_t *info = buffer->info;
320
321  unsigned int base = end;
322  bool has_reph = false;
323
324  {
325    unsigned int limit = start;
326    if (start + 3 <= end &&
327        info[start  ].myanmar_category() == OT_Ra &&
328        info[start+1].myanmar_category() == OT_As &&
329        info[start+2].myanmar_category() == OT_H)
330    {
331      limit += 3;
332      base = start;
333      has_reph = true;
334    }
335
336    {
337      if (!has_reph)
338        base = limit;
339
340      for (unsigned int i = limit; i < end; i++)
341        if (is_consonant (info[i]))
342        {
343          base = i;
344          break;
345        }
346    }
347  }
348
349  /* Reorder! */
350  {
351    unsigned int i = start;
352    for (; i < start + (has_reph ? 3 : 0); i++)
353      info[i].myanmar_position() = POS_AFTER_MAIN;
354    for (; i < base; i++)
355      info[i].myanmar_position() = POS_PRE_C;
356    if (i < end)
357    {
358      info[i].myanmar_position() = POS_BASE_C;
359      i++;
360    }
361    indic_position_t pos = POS_AFTER_MAIN;
362    /* The following loop may be ugly, but it implements all of
363     * Myanmar reordering! */
364    for (; i < end; i++)
365    {
366      if (info[i].myanmar_category() == OT_MR) /* Pre-base reordering */
367      {
368        info[i].myanmar_position() = POS_PRE_C;
369        continue;
370      }
371      if (info[i].myanmar_position() < POS_BASE_C) /* Left matra */
372      {
373        continue;
374      }
375
376      if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == OT_VBlw)
377      {
378        pos = POS_BELOW_C;
379        info[i].myanmar_position() = pos;
380        continue;
381      }
382
383      if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_A)
384      {
385        info[i].myanmar_position() = POS_BEFORE_SUB;
386        continue;
387      }
388      if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_VBlw)
389      {
390        info[i].myanmar_position() = pos;
391        continue;
392      }
393      if (pos == POS_BELOW_C && info[i].myanmar_category() != OT_A)
394      {
395        pos = POS_AFTER_SUB;
396        info[i].myanmar_position() = pos;
397        continue;
398      }
399      info[i].myanmar_position() = pos;
400    }
401  }
402
403  /* Sit tight, rock 'n roll! */
404  buffer->sort (start, end, compare_myanmar_order);
405}
406
407static void
408initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
409                             hb_face_t *face,
410                             hb_buffer_t *buffer,
411                             unsigned int start, unsigned int end)
412{
413  syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
414  switch (syllable_type) {
415
416    case broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */
417    case consonant_syllable:
418      initial_reordering_consonant_syllable  (buffer, start, end);
419      break;
420
421    case punctuation_cluster:
422    case non_myanmar_cluster:
423      break;
424  }
425}
426
427static inline void
428insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
429                       hb_font_t *font,
430                       hb_buffer_t *buffer)
431{
432  /* Note: This loop is extra overhead, but should not be measurable. */
433  bool has_broken_syllables = false;
434  unsigned int count = buffer->len;
435  hb_glyph_info_t *info = buffer->info;
436  for (unsigned int i = 0; i < count; i++)
437    if ((info[i].syllable() & 0x0F) == broken_cluster)
438    {
439      has_broken_syllables = true;
440      break;
441    }
442  if (likely (!has_broken_syllables))
443    return;
444
445
446  hb_codepoint_t dottedcircle_glyph;
447  if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
448    return;
449
450  hb_glyph_info_t dottedcircle = {0};
451  dottedcircle.codepoint = 0x25CCu;
452  set_myanmar_properties (dottedcircle);
453  dottedcircle.codepoint = dottedcircle_glyph;
454
455  buffer->clear_output ();
456
457  buffer->idx = 0;
458  unsigned int last_syllable = 0;
459  while (buffer->idx < buffer->len && !buffer->in_error)
460  {
461    unsigned int syllable = buffer->cur().syllable();
462    syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
463    if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
464    {
465      last_syllable = syllable;
466
467      hb_glyph_info_t ginfo = dottedcircle;
468      ginfo.cluster = buffer->cur().cluster;
469      ginfo.mask = buffer->cur().mask;
470      ginfo.syllable() = buffer->cur().syllable();
471
472      buffer->output_info (ginfo);
473    }
474    else
475      buffer->next_glyph ();
476  }
477
478  buffer->swap_buffers ();
479}
480
481static void
482initial_reordering (const hb_ot_shape_plan_t *plan,
483                    hb_font_t *font,
484                    hb_buffer_t *buffer)
485{
486  insert_dotted_circles (plan, font, buffer);
487
488  foreach_syllable (buffer, start, end)
489    initial_reordering_syllable (plan, font->face, buffer, start, end);
490}
491
492static void
493final_reordering (const hb_ot_shape_plan_t *plan,
494                  hb_font_t *font HB_UNUSED,
495                  hb_buffer_t *buffer)
496{
497  hb_glyph_info_t *info = buffer->info;
498  unsigned int count = buffer->len;
499
500  /* Zero syllables now... */
501  for (unsigned int i = 0; i < count; i++)
502    info[i].syllable() = 0;
503
504  HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category);
505  HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
506}
507
508
509/* Uniscribe seems to have a shaper for 'mymr' that is like the
510 * generic shaper, except that it zeros mark advances GDEF_LATE. */
511const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar_old =
512{
513  "default",
514  NULL, /* collect_features */
515  NULL, /* override_features */
516  NULL, /* data_create */
517  NULL, /* data_destroy */
518  NULL, /* preprocess_text */
519  NULL, /* postprocess_glyphs */
520  HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT,
521  NULL, /* decompose */
522  NULL, /* compose */
523  NULL, /* setup_masks */
524  NULL, /* disable_otl */
525  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
526  true, /* fallback_position */
527};
528
529const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar =
530{
531  "myanmar",
532  collect_features_myanmar,
533  override_features_myanmar,
534  NULL, /* data_create */
535  NULL, /* data_destroy */
536  NULL, /* preprocess_text */
537  NULL, /* postprocess_glyphs */
538  HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
539  NULL, /* decompose */
540  NULL, /* compose */
541  setup_masks_myanmar,
542  NULL, /* disable_otl */
543  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
544  false, /* fallback_position */
545};
546