2 * Copyright © 2010,2012 Google, Inc.
4 * This is part of HarfBuzz, a text shaping library.
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.
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
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.
24 * Google Author(s): Behdad Esfahbod
29 #ifndef HB_NO_OT_SHAPE
31 #include "hb-ot-shape-complex-arabic.hh"
32 #include "hb-ot-shape.hh"
35 /* buffer var allocations */
36 #define arabic_shaping_action() complex_var_u8_auxiliary() /* arabic shaping action */
38 #define HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH HB_BUFFER_SCRATCH_FLAG_COMPLEX0
41 * https://github.com/harfbuzz/harfbuzz/commit/6e6f82b6f3dde0fc6c3c7d991d9ec6cfff57823d#commitcomment-14248516 */
42 #define HB_ARABIC_GENERAL_CATEGORY_IS_WORD(gen_cat) \
43 (FLAG_UNSAFE (gen_cat) & \
44 (FLAG (HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED) | \
45 FLAG (HB_UNICODE_GENERAL_CATEGORY_PRIVATE_USE) | \
46 /*FLAG (HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER) |*/ \
47 FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER) | \
48 FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) | \
49 /*FLAG (HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER) |*/ \
50 /*FLAG (HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER) |*/ \
51 FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | \
52 FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | \
53 FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | \
54 FLAG (HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER) | \
55 FLAG (HB_UNICODE_GENERAL_CATEGORY_LETTER_NUMBER) | \
56 FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_NUMBER) | \
57 FLAG (HB_UNICODE_GENERAL_CATEGORY_CURRENCY_SYMBOL) | \
58 FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL) | \
59 FLAG (HB_UNICODE_GENERAL_CATEGORY_MATH_SYMBOL) | \
60 FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_SYMBOL)))
68 * Bits used in the joining tables
70 enum hb_arabic_joining_type_t
{
75 JOINING_TYPE_C
= JOINING_TYPE_D
,
76 JOINING_GROUP_ALAPH
= 4,
77 JOINING_GROUP_DALATH_RISH
= 5,
78 NUM_STATE_MACHINE_COLS
= 6,
81 JOINING_TYPE_X
= 8 /* means: use general-category to choose between U or T. */
84 #include "hb-ot-shape-complex-arabic-table.hh"
86 static unsigned int get_joining_type (hb_codepoint_t u
, hb_unicode_general_category_t gen_cat
)
88 unsigned int j_type
= joining_type(u
);
89 if (likely (j_type
!= JOINING_TYPE_X
))
92 return (FLAG_UNSAFE(gen_cat
) &
93 (FLAG(HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK
) |
94 FLAG(HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK
) |
95 FLAG(HB_UNICODE_GENERAL_CATEGORY_FORMAT
))
96 ) ? JOINING_TYPE_T
: JOINING_TYPE_U
;
99 #define FEATURE_IS_SYRIAC(tag) hb_in_range<unsigned char> ((unsigned char) (tag), '2', '3')
101 static const hb_tag_t arabic_features
[] =
103 HB_TAG('i','s','o','l'),
104 HB_TAG('f','i','n','a'),
105 HB_TAG('f','i','n','2'),
106 HB_TAG('f','i','n','3'),
107 HB_TAG('m','e','d','i'),
108 HB_TAG('m','e','d','2'),
109 HB_TAG('i','n','i','t'),
114 /* Same order as the feature array */
115 enum arabic_action_t
{
126 ARABIC_NUM_FEATURES
= NONE
,
128 /* We abuse the same byte for other things... */
133 static const struct arabic_state_table_entry
{
137 } arabic_state_table
[][NUM_STATE_MACHINE_COLS
] =
139 /* jt_U, jt_L, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */
141 /* State 0: prev was U, not willing to join. */
142 { {NONE
,NONE
,0}, {NONE
,ISOL
,2}, {NONE
,ISOL
,1}, {NONE
,ISOL
,2}, {NONE
,ISOL
,1}, {NONE
,ISOL
,6}, },
144 /* State 1: prev was R or ISOL/ALAPH, not willing to join. */
145 { {NONE
,NONE
,0}, {NONE
,ISOL
,2}, {NONE
,ISOL
,1}, {NONE
,ISOL
,2}, {NONE
,FIN2
,5}, {NONE
,ISOL
,6}, },
147 /* State 2: prev was D/L in ISOL form, willing to join. */
148 { {NONE
,NONE
,0}, {NONE
,ISOL
,2}, {INIT
,FINA
,1}, {INIT
,FINA
,3}, {INIT
,FINA
,4}, {INIT
,FINA
,6}, },
150 /* State 3: prev was D in FINA form, willing to join. */
151 { {NONE
,NONE
,0}, {NONE
,ISOL
,2}, {MEDI
,FINA
,1}, {MEDI
,FINA
,3}, {MEDI
,FINA
,4}, {MEDI
,FINA
,6}, },
153 /* State 4: prev was FINA ALAPH, not willing to join. */
154 { {NONE
,NONE
,0}, {NONE
,ISOL
,2}, {MED2
,ISOL
,1}, {MED2
,ISOL
,2}, {MED2
,FIN2
,5}, {MED2
,ISOL
,6}, },
156 /* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */
157 { {NONE
,NONE
,0}, {NONE
,ISOL
,2}, {ISOL
,ISOL
,1}, {ISOL
,ISOL
,2}, {ISOL
,FIN2
,5}, {ISOL
,ISOL
,6}, },
159 /* State 6: prev was DALATH/RISH, not willing to join. */
160 { {NONE
,NONE
,0}, {NONE
,ISOL
,2}, {NONE
,ISOL
,1}, {NONE
,ISOL
,2}, {NONE
,FIN3
,5}, {NONE
,ISOL
,6}, }
165 arabic_fallback_shape (const hb_ot_shape_plan_t
*plan
,
167 hb_buffer_t
*buffer
);
170 record_stch (const hb_ot_shape_plan_t
*plan
,
172 hb_buffer_t
*buffer
);
175 collect_features_arabic (hb_ot_shape_planner_t
*plan
)
177 hb_ot_map_builder_t
*map
= &plan
->map
;
179 /* We apply features according to the Arabic spec, with pauses
182 * The pause between init/medi/... and rlig is required. See eg:
183 * https://bugzilla.mozilla.org/show_bug.cgi?id=644184
185 * The pauses between init/medi/... themselves are not necessarily
186 * needed as only one of those features is applied to any character.
187 * The only difference it makes is when fonts have contextual
188 * substitutions. We now follow the order of the spec, which makes
189 * for better experience if that's what Uniscribe is doing.
191 * At least for Arabic, looks like Uniscribe has a pause between
192 * rlig and calt. Otherwise the IranNastaliq's ALLAH ligature won't
193 * work. However, testing shows that rlig and calt are applied
194 * together for Mongolian in Uniscribe. As such, we only add a
195 * pause for Arabic, not other scripts.
197 * A pause after calt is required to make KFGQPC Uthmanic Script HAFS
198 * work correctly. See https://github.com/harfbuzz/harfbuzz/issues/505
202 map
->enable_feature (HB_TAG('s','t','c','h'));
203 map
->add_gsub_pause (record_stch
);
205 map
->enable_feature (HB_TAG('c','c','m','p'));
206 map
->enable_feature (HB_TAG('l','o','c','l'));
208 map
->add_gsub_pause (nullptr);
210 for (unsigned int i
= 0; i
< ARABIC_NUM_FEATURES
; i
++)
212 bool has_fallback
= plan
->props
.script
== HB_SCRIPT_ARABIC
&& !FEATURE_IS_SYRIAC (arabic_features
[i
]);
213 map
->add_feature (arabic_features
[i
], has_fallback
? F_HAS_FALLBACK
: F_NONE
);
214 map
->add_gsub_pause (nullptr);
217 /* Normally, Unicode says a ZWNJ means "don't ligate". In Arabic script
218 * however, it says a ZWJ should also mean "don't ligate". So we run
219 * the main ligating features as MANUAL_ZWJ. */
221 map
->enable_feature (HB_TAG('r','l','i','g'), F_MANUAL_ZWJ
| F_HAS_FALLBACK
);
223 if (plan
->props
.script
== HB_SCRIPT_ARABIC
)
224 map
->add_gsub_pause (arabic_fallback_shape
);
226 /* No pause after rclt. See 98460779bae19e4d64d29461ff154b3527bf8420. */
227 map
->enable_feature (HB_TAG('r','c','l','t'), F_MANUAL_ZWJ
);
228 map
->enable_feature (HB_TAG('c','a','l','t'), F_MANUAL_ZWJ
);
229 map
->add_gsub_pause (nullptr);
231 /* The spec includes 'cswh'. Earlier versions of Windows
232 * used to enable this by default, but testing suggests
233 * that Windows 8 and later do not enable it by default,
234 * and spec now says 'Off by default'.
235 * We disabled this in ae23c24c32.
236 * Note that IranNastaliq uses this feature extensively
237 * to fixup broken glyph sequences. Oh well...
238 * Test case: U+0643,U+0640,U+0631. */
239 //map->enable_feature (HB_TAG('c','s','w','h'));
240 map
->enable_feature (HB_TAG('m','s','e','t'));
243 #include "hb-ot-shape-complex-arabic-fallback.hh"
245 struct arabic_shape_plan_t
247 /* The "+ 1" in the next array is to accommodate for the "NONE" command,
248 * which is not an OpenType feature, but this simplifies the code by not
249 * having to do a "if (... < NONE) ..." and just rely on the fact that
250 * mask_array[NONE] == 0. */
251 hb_mask_t mask_array
[ARABIC_NUM_FEATURES
+ 1];
253 hb_atomic_ptr_t
<arabic_fallback_plan_t
> fallback_plan
;
255 unsigned int do_fallback
: 1;
256 unsigned int has_stch
: 1;
260 data_create_arabic (const hb_ot_shape_plan_t
*plan
)
262 arabic_shape_plan_t
*arabic_plan
= (arabic_shape_plan_t
*) hb_calloc (1, sizeof (arabic_shape_plan_t
));
263 if (unlikely (!arabic_plan
))
266 arabic_plan
->do_fallback
= plan
->props
.script
== HB_SCRIPT_ARABIC
;
267 arabic_plan
->has_stch
= !!plan
->map
.get_1_mask (HB_TAG ('s','t','c','h'));
268 for (unsigned int i
= 0; i
< ARABIC_NUM_FEATURES
; i
++) {
269 arabic_plan
->mask_array
[i
] = plan
->map
.get_1_mask (arabic_features
[i
]);
270 arabic_plan
->do_fallback
= arabic_plan
->do_fallback
&&
271 (FEATURE_IS_SYRIAC (arabic_features
[i
]) ||
272 plan
->map
.needs_fallback (arabic_features
[i
]));
279 data_destroy_arabic (void *data
)
281 arabic_shape_plan_t
*arabic_plan
= (arabic_shape_plan_t
*) data
;
283 arabic_fallback_plan_destroy (arabic_plan
->fallback_plan
);
289 arabic_joining (hb_buffer_t
*buffer
)
291 unsigned int count
= buffer
->len
;
292 hb_glyph_info_t
*info
= buffer
->info
;
293 unsigned int prev
= UINT_MAX
, state
= 0;
295 /* Check pre-context */
296 for (unsigned int i
= 0; i
< buffer
->context_len
[0]; i
++)
298 unsigned int this_type
= get_joining_type (buffer
->context
[0][i
], buffer
->unicode
->general_category (buffer
->context
[0][i
]));
300 if (unlikely (this_type
== JOINING_TYPE_T
))
303 const arabic_state_table_entry
*entry
= &arabic_state_table
[state
][this_type
];
304 state
= entry
->next_state
;
308 for (unsigned int i
= 0; i
< count
; i
++)
310 unsigned int this_type
= get_joining_type (info
[i
].codepoint
, _hb_glyph_info_get_general_category (&info
[i
]));
312 if (unlikely (this_type
== JOINING_TYPE_T
)) {
313 info
[i
].arabic_shaping_action() = NONE
;
317 const arabic_state_table_entry
*entry
= &arabic_state_table
[state
][this_type
];
319 if (entry
->prev_action
!= NONE
&& prev
!= UINT_MAX
)
321 info
[prev
].arabic_shaping_action() = entry
->prev_action
;
322 buffer
->unsafe_to_break (prev
, i
+ 1);
326 if (prev
== UINT_MAX
)
328 if (this_type
>= JOINING_TYPE_R
)
329 buffer
->unsafe_to_concat_from_outbuffer (0, i
+ 1);
333 if (this_type
>= JOINING_TYPE_R
||
334 (2 <= state
&& state
<= 5) /* States that have a possible prev_action. */)
335 buffer
->unsafe_to_concat (prev
, i
+ 1);
339 info
[i
].arabic_shaping_action() = entry
->curr_action
;
342 state
= entry
->next_state
;
345 for (unsigned int i
= 0; i
< buffer
->context_len
[1]; i
++)
347 unsigned int this_type
= get_joining_type (buffer
->context
[1][i
], buffer
->unicode
->general_category (buffer
->context
[1][i
]));
349 if (unlikely (this_type
== JOINING_TYPE_T
))
352 const arabic_state_table_entry
*entry
= &arabic_state_table
[state
][this_type
];
353 if (entry
->prev_action
!= NONE
&& prev
!= UINT_MAX
)
355 info
[prev
].arabic_shaping_action() = entry
->prev_action
;
356 buffer
->unsafe_to_break (prev
, buffer
->len
);
358 else if (2 <= state
&& state
<= 5) /* States that have a possible prev_action. */
360 buffer
->unsafe_to_concat (prev
, buffer
->len
);
367 mongolian_variation_selectors (hb_buffer_t
*buffer
)
369 /* Copy arabic_shaping_action() from base to Mongolian variation selectors. */
370 unsigned int count
= buffer
->len
;
371 hb_glyph_info_t
*info
= buffer
->info
;
372 for (unsigned int i
= 1; i
< count
; i
++)
373 if (unlikely (hb_in_ranges
<hb_codepoint_t
> (info
[i
].codepoint
, 0x180Bu
, 0x180Du
, 0x180Fu
, 0x180Fu
)))
374 info
[i
].arabic_shaping_action() = info
[i
- 1].arabic_shaping_action();
378 setup_masks_arabic_plan (const arabic_shape_plan_t
*arabic_plan
,
382 HB_BUFFER_ALLOCATE_VAR (buffer
, arabic_shaping_action
);
384 arabic_joining (buffer
);
385 if (script
== HB_SCRIPT_MONGOLIAN
)
386 mongolian_variation_selectors (buffer
);
388 unsigned int count
= buffer
->len
;
389 hb_glyph_info_t
*info
= buffer
->info
;
390 for (unsigned int i
= 0; i
< count
; i
++)
391 info
[i
].mask
|= arabic_plan
->mask_array
[info
[i
].arabic_shaping_action()];
395 setup_masks_arabic (const hb_ot_shape_plan_t
*plan
,
397 hb_font_t
*font HB_UNUSED
)
399 const arabic_shape_plan_t
*arabic_plan
= (const arabic_shape_plan_t
*) plan
->data
;
400 setup_masks_arabic_plan (arabic_plan
, buffer
, plan
->props
.script
);
404 arabic_fallback_shape (const hb_ot_shape_plan_t
*plan
,
408 #ifdef HB_NO_OT_SHAPE_COMPLEX_ARABIC_FALLBACK
412 const arabic_shape_plan_t
*arabic_plan
= (const arabic_shape_plan_t
*) plan
->data
;
414 if (!arabic_plan
->do_fallback
)
418 arabic_fallback_plan_t
*fallback_plan
= arabic_plan
->fallback_plan
;
419 if (unlikely (!fallback_plan
))
421 /* This sucks. We need a font to build the fallback plan... */
422 fallback_plan
= arabic_fallback_plan_create (plan
, font
);
423 if (unlikely (!arabic_plan
->fallback_plan
.cmpexch (nullptr, fallback_plan
)))
425 arabic_fallback_plan_destroy (fallback_plan
);
430 arabic_fallback_plan_shape (fallback_plan
, font
, buffer
);
434 * Stretch feature: "stch".
436 * https://docs.microsoft.com/en-us/typography/script-development/syriac
437 * We implement this in a generic way, such that the Arabic subtending
438 * marks can use it as well.
442 record_stch (const hb_ot_shape_plan_t
*plan
,
443 hb_font_t
*font HB_UNUSED
,
446 const arabic_shape_plan_t
*arabic_plan
= (const arabic_shape_plan_t
*) plan
->data
;
447 if (!arabic_plan
->has_stch
)
450 /* 'stch' feature was just applied. Look for anything that multiplied,
451 * and record it for stch treatment later. Note that rtlm, frac, etc
452 * are applied before stch, but we assume that they didn't result in
453 * anything multiplying into 5 pieces, so it's safe-ish... */
455 unsigned int count
= buffer
->len
;
456 hb_glyph_info_t
*info
= buffer
->info
;
457 for (unsigned int i
= 0; i
< count
; i
++)
458 if (unlikely (_hb_glyph_info_multiplied (&info
[i
])))
460 unsigned int comp
= _hb_glyph_info_get_lig_comp (&info
[i
]);
461 info
[i
].arabic_shaping_action() = comp
% 2 ? STCH_REPEATING
: STCH_FIXED
;
462 buffer
->scratch_flags
|= HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH
;
467 apply_stch (const hb_ot_shape_plan_t
*plan HB_UNUSED
,
471 if (likely (!(buffer
->scratch_flags
& HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH
)))
474 /* The Arabic shaper currently always processes in RTL mode, so we should
475 * stretch / position the stretched pieces to the left / preceding glyphs. */
477 /* We do a two pass implementation:
478 * First pass calculates the exact number of extra glyphs we need,
479 * We then enlarge buffer to have that much room,
480 * Second pass applies the stretch, copying things to the end of buffer.
483 int sign
= font
->x_scale
< 0 ? -1 : +1;
484 unsigned int extra_glyphs_needed
= 0; // Set during MEASURE, used during CUT
485 enum { MEASURE
, CUT
} /* step_t */;
487 for (unsigned int step
= MEASURE
; step
<= CUT
; step
= step
+ 1)
489 unsigned int count
= buffer
->len
;
490 hb_glyph_info_t
*info
= buffer
->info
;
491 hb_glyph_position_t
*pos
= buffer
->pos
;
492 unsigned int new_len
= count
+ extra_glyphs_needed
; // write head during CUT
493 unsigned int j
= new_len
;
494 for (unsigned int i
= count
; i
; i
--)
496 if (!hb_in_range
<uint8_t> (info
[i
- 1].arabic_shaping_action(), STCH_FIXED
, STCH_REPEATING
))
501 info
[j
] = info
[i
- 1];
507 /* Yay, justification! */
509 hb_position_t w_total
= 0; // Total to be filled
510 hb_position_t w_fixed
= 0; // Sum of fixed tiles
511 hb_position_t w_repeating
= 0; // Sum of repeating tiles
515 unsigned int end
= i
;
517 hb_in_range
<uint8_t> (info
[i
- 1].arabic_shaping_action(), STCH_FIXED
, STCH_REPEATING
))
520 hb_position_t width
= font
->get_glyph_h_advance (info
[i
].codepoint
);
521 if (info
[i
].arabic_shaping_action() == STCH_FIXED
)
528 w_repeating
+= width
;
532 unsigned int start
= i
;
533 unsigned int context
= i
;
535 !hb_in_range
<uint8_t> (info
[context
- 1].arabic_shaping_action(), STCH_FIXED
, STCH_REPEATING
) &&
536 (_hb_glyph_info_is_default_ignorable (&info
[context
- 1]) ||
537 HB_ARABIC_GENERAL_CATEGORY_IS_WORD (_hb_glyph_info_get_general_category (&info
[context
- 1]))))
540 w_total
+= pos
[context
].x_advance
;
542 i
++; // Don't touch i again.
544 DEBUG_MSG (ARABIC
, nullptr, "%s stretch at (%d,%d,%d)",
545 step
== MEASURE
? "measuring" : "cutting", context
, start
, end
);
546 DEBUG_MSG (ARABIC
, nullptr, "rest of word: count=%d width %d", start
- context
, w_total
);
547 DEBUG_MSG (ARABIC
, nullptr, "fixed tiles: count=%d width=%d", n_fixed
, w_fixed
);
548 DEBUG_MSG (ARABIC
, nullptr, "repeating tiles: count=%d width=%d", n_repeating
, w_repeating
);
550 /* Number of additional times to repeat each repeating tile. */
553 hb_position_t w_remaining
= w_total
- w_fixed
;
554 if (sign
* w_remaining
> sign
* w_repeating
&& sign
* w_repeating
> 0)
555 n_copies
= (sign
* w_remaining
) / (sign
* w_repeating
) - 1;
557 /* See if we can improve the fit by adding an extra repeat and squeezing them together a bit. */
558 hb_position_t extra_repeat_overlap
= 0;
559 hb_position_t shortfall
= sign
* w_remaining
- sign
* w_repeating
* (n_copies
+ 1);
560 if (shortfall
> 0 && n_repeating
> 0)
563 hb_position_t excess
= (n_copies
+ 1) * sign
* w_repeating
- sign
* w_remaining
;
565 extra_repeat_overlap
= excess
/ (n_copies
* n_repeating
);
570 extra_glyphs_needed
+= n_copies
* n_repeating
;
571 DEBUG_MSG (ARABIC
, nullptr, "will add extra %d copies of repeating tiles", n_copies
);
575 buffer
->unsafe_to_break (context
, end
);
576 hb_position_t x_offset
= 0;
577 for (unsigned int k
= end
; k
> start
; k
--)
579 hb_position_t width
= font
->get_glyph_h_advance (info
[k
- 1].codepoint
);
581 unsigned int repeat
= 1;
582 if (info
[k
- 1].arabic_shaping_action() == STCH_REPEATING
)
585 DEBUG_MSG (ARABIC
, nullptr, "appending %d copies of glyph %d; j=%d",
586 repeat
, info
[k
- 1].codepoint
, j
);
587 for (unsigned int n
= 0; n
< repeat
; n
++)
591 x_offset
+= extra_repeat_overlap
;
592 pos
[k
- 1].x_offset
= x_offset
;
595 info
[j
] = info
[k
- 1];
604 if (unlikely (!buffer
->ensure (count
+ extra_glyphs_needed
)))
610 buffer
->len
= new_len
;
617 postprocess_glyphs_arabic (const hb_ot_shape_plan_t
*plan
,
621 apply_stch (plan
, buffer
, font
);
623 HB_BUFFER_DEALLOCATE_VAR (buffer
, arabic_shaping_action
);
626 /* https://www.unicode.org/reports/tr53/ */
628 static hb_codepoint_t
629 modifier_combining_marks
[] =
631 0x0654u
, /* ARABIC HAMZA ABOVE */
632 0x0655u
, /* ARABIC HAMZA BELOW */
633 0x0658u
, /* ARABIC MARK NOON GHUNNA */
634 0x06DCu
, /* ARABIC SMALL HIGH SEEN */
635 0x06E3u
, /* ARABIC SMALL LOW SEEN */
636 0x06E7u
, /* ARABIC SMALL HIGH YEH */
637 0x06E8u
, /* ARABIC SMALL HIGH NOON */
638 0x08CAu
, /* ARABIC SMALL HIGH FARSI YEH */
639 0x08CBu
, /* ARABIC SMALL HIGH YEH BARREE WITH TWO DOTS BELOW */
640 0x08CDu
, /* ARABIC SMALL HIGH ZAH */
641 0x08CEu
, /* ARABIC LARGE ROUND DOT ABOVE */
642 0x08CFu
, /* ARABIC LARGE ROUND DOT BELOW */
643 0x08D3u
, /* ARABIC SMALL LOW WAW */
644 0x08F3u
, /* ARABIC SMALL HIGH WAW */
648 info_is_mcm (const hb_glyph_info_t
&info
)
650 hb_codepoint_t u
= info
.codepoint
;
651 for (unsigned int i
= 0; i
< ARRAY_LENGTH (modifier_combining_marks
); i
++)
652 if (u
== modifier_combining_marks
[i
])
658 reorder_marks_arabic (const hb_ot_shape_plan_t
*plan HB_UNUSED
,
663 hb_glyph_info_t
*info
= buffer
->info
;
665 DEBUG_MSG (ARABIC
, buffer
, "Reordering marks from %d to %d", start
, end
);
667 unsigned int i
= start
;
668 for (unsigned int cc
= 220; cc
<= 230; cc
+= 10)
670 DEBUG_MSG (ARABIC
, buffer
, "Looking for %d's starting at %d", cc
, i
);
671 while (i
< end
&& info_cc(info
[i
]) < cc
)
673 DEBUG_MSG (ARABIC
, buffer
, "Looking for %d's stopped at %d", cc
, i
);
678 if (info_cc(info
[i
]) > cc
)
682 while (j
< end
&& info_cc(info
[j
]) == cc
&& info_is_mcm (info
[j
]))
688 DEBUG_MSG (ARABIC
, buffer
, "Found %d's from %d to %d", cc
, i
, j
);
691 DEBUG_MSG (ARABIC
, buffer
, "Shifting %d's: %d %d", cc
, i
, j
);
692 hb_glyph_info_t temp
[HB_OT_SHAPE_COMPLEX_MAX_COMBINING_MARKS
];
693 assert (j
- i
<= ARRAY_LENGTH (temp
));
694 buffer
->merge_clusters (start
, j
);
695 memmove (temp
, &info
[i
], (j
- i
) * sizeof (hb_glyph_info_t
));
696 memmove (&info
[start
+ j
- i
], &info
[start
], (i
- start
) * sizeof (hb_glyph_info_t
));
697 memmove (&info
[start
], temp
, (j
- i
) * sizeof (hb_glyph_info_t
));
699 /* Renumber CC such that the reordered sequence is still sorted.
700 * 22 and 26 are chosen because they are smaller than all Arabic categories,
701 * and are folded back to 220/230 respectively during fallback mark positioning.
703 * We do this because the CGJ-handling logic in the normalizer relies on
704 * mark sequences having an increasing order even after this reordering.
705 * https://github.com/harfbuzz/harfbuzz/issues/554
706 * This, however, does break some obscure sequences, where the normalizer
707 * might compose a sequence that it should not. For example, in the seequence
708 * ALEF, HAMZAH, MADDAH, we should NOT try to compose ALEF+MADDAH, but with this
709 * renumbering, we will.
711 unsigned int new_start
= start
+ j
- i
;
712 unsigned int new_cc
= cc
== 220 ? HB_MODIFIED_COMBINING_CLASS_CCC22
: HB_MODIFIED_COMBINING_CLASS_CCC26
;
713 while (start
< new_start
)
715 _hb_glyph_info_set_modified_combining_class (&info
[start
], new_cc
);
723 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic
=
725 collect_features_arabic
,
726 nullptr, /* override_features */
729 nullptr, /* preprocess_text */
730 postprocess_glyphs_arabic
,
731 HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT
,
732 nullptr, /* decompose */
733 nullptr, /* compose */
735 HB_TAG_NONE
, /* gpos_tag */
736 reorder_marks_arabic
,
737 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE
,
738 true, /* fallback_position */