| /* |
| * Copyright © 2010,2012 Google, Inc. |
| * |
| * This is part of HarfBuzz, a text shaping library. |
| * |
| * Permission is hereby granted, without written agreement and without |
| * license or royalty fees, to use, copy, modify, and distribute this |
| * software and its documentation for any purpose, provided that the |
| * above copyright notice and the following two paragraphs appear in |
| * all copies of this software. |
| * |
| * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR |
| * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES |
| * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN |
| * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH |
| * DAMAGE. |
| * |
| * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, |
| * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
| * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS |
| * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO |
| * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. |
| * |
| * Google Author(s): Behdad Esfahbod |
| */ |
| |
| #include "hb.hh" |
| |
| #ifndef HB_NO_OT_SHAPE |
| |
| #include "hb-ot-shape-complex-arabic.hh" |
| #include "hb-ot-shape.hh" |
| |
| |
| /* buffer var allocations */ |
| #define arabic_shaping_action() complex_var_u8_auxiliary() /* arabic shaping action */ |
| |
| #define HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH HB_BUFFER_SCRATCH_FLAG_COMPLEX0 |
| |
| /* See: |
| * https://github.com/harfbuzz/harfbuzz/commit/6e6f82b6f3dde0fc6c3c7d991d9ec6cfff57823d#commitcomment-14248516 */ |
| #define HB_ARABIC_GENERAL_CATEGORY_IS_WORD(gen_cat) \ |
| (FLAG_UNSAFE (gen_cat) & \ |
| (FLAG (HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_PRIVATE_USE) | \ |
| /*FLAG (HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER) |*/ \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) | \ |
| /*FLAG (HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER) |*/ \ |
| /*FLAG (HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER) |*/ \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_LETTER_NUMBER) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_NUMBER) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_CURRENCY_SYMBOL) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_MATH_SYMBOL) | \ |
| FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_SYMBOL))) |
| |
| |
| /* |
| * Joining types: |
| */ |
| |
| /* |
| * Bits used in the joining tables |
| */ |
| enum hb_arabic_joining_type_t { |
| JOINING_TYPE_U = 0, |
| JOINING_TYPE_L = 1, |
| JOINING_TYPE_R = 2, |
| JOINING_TYPE_D = 3, |
| JOINING_TYPE_C = JOINING_TYPE_D, |
| JOINING_GROUP_ALAPH = 4, |
| JOINING_GROUP_DALATH_RISH = 5, |
| NUM_STATE_MACHINE_COLS = 6, |
| |
| JOINING_TYPE_T = 7, |
| JOINING_TYPE_X = 8 /* means: use general-category to choose between U or T. */ |
| }; |
| |
| #include "hb-ot-shape-complex-arabic-table.hh" |
| |
| static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat) |
| { |
| unsigned int j_type = joining_type(u); |
| if (likely (j_type != JOINING_TYPE_X)) |
| return j_type; |
| |
| return (FLAG_UNSAFE(gen_cat) & |
| (FLAG(HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | |
| FLAG(HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | |
| FLAG(HB_UNICODE_GENERAL_CATEGORY_FORMAT)) |
| ) ? JOINING_TYPE_T : JOINING_TYPE_U; |
| } |
| |
| #define FEATURE_IS_SYRIAC(tag) hb_in_range<unsigned char> ((unsigned char) (tag), '2', '3') |
| |
| static const hb_tag_t arabic_features[] = |
| { |
| HB_TAG('i','s','o','l'), |
| HB_TAG('f','i','n','a'), |
| HB_TAG('f','i','n','2'), |
| HB_TAG('f','i','n','3'), |
| HB_TAG('m','e','d','i'), |
| HB_TAG('m','e','d','2'), |
| HB_TAG('i','n','i','t'), |
| HB_TAG_NONE |
| }; |
| |
| |
| /* Same order as the feature array */ |
| enum arabic_action_t { |
| ISOL, |
| FINA, |
| FIN2, |
| FIN3, |
| MEDI, |
| MED2, |
| INIT, |
| |
| NONE, |
| |
| ARABIC_NUM_FEATURES = NONE, |
| |
| /* We abuse the same byte for other things... */ |
| STCH_FIXED, |
| STCH_REPEATING, |
| }; |
| |
| static const struct arabic_state_table_entry { |
| uint8_t prev_action; |
| uint8_t curr_action; |
| uint16_t next_state; |
| } arabic_state_table[][NUM_STATE_MACHINE_COLS] = |
| { |
| /* jt_U, jt_L, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */ |
| |
| /* State 0: prev was U, not willing to join. */ |
| { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,6}, }, |
| |
| /* State 1: prev was R or ISOL/ALAPH, not willing to join. */ |
| { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, }, |
| |
| /* State 2: prev was D/L in ISOL form, willing to join. */ |
| { {NONE,NONE,0}, {NONE,ISOL,2}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, }, |
| |
| /* State 3: prev was D in FINA form, willing to join. */ |
| { {NONE,NONE,0}, {NONE,ISOL,2}, {MEDI,FINA,1}, {MEDI,FINA,3}, {MEDI,FINA,4}, {MEDI,FINA,6}, }, |
| |
| /* State 4: prev was FINA ALAPH, not willing to join. */ |
| { {NONE,NONE,0}, {NONE,ISOL,2}, {MED2,ISOL,1}, {MED2,ISOL,2}, {MED2,FIN2,5}, {MED2,ISOL,6}, }, |
| |
| /* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */ |
| { {NONE,NONE,0}, {NONE,ISOL,2}, {ISOL,ISOL,1}, {ISOL,ISOL,2}, {ISOL,FIN2,5}, {ISOL,ISOL,6}, }, |
| |
| /* State 6: prev was DALATH/RISH, not willing to join. */ |
| { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, } |
| }; |
| |
| |
| static void |
| arabic_fallback_shape (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer); |
| |
| static void |
| record_stch (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer); |
| |
| static void |
| collect_features_arabic (hb_ot_shape_planner_t *plan) |
| { |
| hb_ot_map_builder_t *map = &plan->map; |
| |
| /* We apply features according to the Arabic spec, with pauses |
| * in between most. |
| * |
| * The pause between init/medi/... and rlig is required. See eg: |
| * https://bugzilla.mozilla.org/show_bug.cgi?id=644184 |
| * |
| * The pauses between init/medi/... themselves are not necessarily |
| * needed as only one of those features is applied to any character. |
| * The only difference it makes is when fonts have contextual |
| * substitutions. We now follow the order of the spec, which makes |
| * for better experience if that's what Uniscribe is doing. |
| * |
| * At least for Arabic, looks like Uniscribe has a pause between |
| * rlig and calt. Otherwise the IranNastaliq's ALLAH ligature won't |
| * work. However, testing shows that rlig and calt are applied |
| * together for Mongolian in Uniscribe. As such, we only add a |
| * pause for Arabic, not other scripts. |
| * |
| * A pause after calt is required to make KFGQPC Uthmanic Script HAFS |
| * work correctly. See https://github.com/harfbuzz/harfbuzz/issues/505 |
| */ |
| |
| |
| map->enable_feature (HB_TAG('s','t','c','h')); |
| map->add_gsub_pause (record_stch); |
| |
| map->enable_feature (HB_TAG('c','c','m','p')); |
| map->enable_feature (HB_TAG('l','o','c','l')); |
| |
| map->add_gsub_pause (nullptr); |
| |
| for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) |
| { |
| bool has_fallback = plan->props.script == HB_SCRIPT_ARABIC && !FEATURE_IS_SYRIAC (arabic_features[i]); |
| map->add_feature (arabic_features[i], has_fallback ? F_HAS_FALLBACK : F_NONE); |
| map->add_gsub_pause (nullptr); |
| } |
| |
| /* Normally, Unicode says a ZWNJ means "don't ligate". In Arabic script |
| * however, it says a ZWJ should also mean "don't ligate". So we run |
| * the main ligating features as MANUAL_ZWJ. */ |
| |
| map->enable_feature (HB_TAG('r','l','i','g'), F_MANUAL_ZWJ | F_HAS_FALLBACK); |
| |
| if (plan->props.script == HB_SCRIPT_ARABIC) |
| map->add_gsub_pause (arabic_fallback_shape); |
| |
| /* No pause after rclt. See 98460779bae19e4d64d29461ff154b3527bf8420. */ |
| map->enable_feature (HB_TAG('r','c','l','t'), F_MANUAL_ZWJ); |
| map->enable_feature (HB_TAG('c','a','l','t'), F_MANUAL_ZWJ); |
| map->add_gsub_pause (nullptr); |
| |
| /* The spec includes 'cswh'. Earlier versions of Windows |
| * used to enable this by default, but testing suggests |
| * that Windows 8 and later do not enable it by default, |
| * and spec now says 'Off by default'. |
| * We disabled this in ae23c24c32. |
| * Note that IranNastaliq uses this feature extensively |
| * to fixup broken glyph sequences. Oh well... |
| * Test case: U+0643,U+0640,U+0631. */ |
| //map->enable_feature (HB_TAG('c','s','w','h')); |
| map->enable_feature (HB_TAG('m','s','e','t')); |
| } |
| |
| #include "hb-ot-shape-complex-arabic-fallback.hh" |
| |
| struct arabic_shape_plan_t |
| { |
| /* The "+ 1" in the next array is to accommodate for the "NONE" command, |
| * which is not an OpenType feature, but this simplifies the code by not |
| * having to do a "if (... < NONE) ..." and just rely on the fact that |
| * mask_array[NONE] == 0. */ |
| hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1]; |
| |
| hb_atomic_ptr_t<arabic_fallback_plan_t> fallback_plan; |
| |
| unsigned int do_fallback : 1; |
| unsigned int has_stch : 1; |
| }; |
| |
| void * |
| data_create_arabic (const hb_ot_shape_plan_t *plan) |
| { |
| arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) hb_calloc (1, sizeof (arabic_shape_plan_t)); |
| if (unlikely (!arabic_plan)) |
| return nullptr; |
| |
| arabic_plan->do_fallback = plan->props.script == HB_SCRIPT_ARABIC; |
| arabic_plan->has_stch = !!plan->map.get_1_mask (HB_TAG ('s','t','c','h')); |
| for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) { |
| arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]); |
| arabic_plan->do_fallback = arabic_plan->do_fallback && |
| (FEATURE_IS_SYRIAC (arabic_features[i]) || |
| plan->map.needs_fallback (arabic_features[i])); |
| } |
| |
| return arabic_plan; |
| } |
| |
| void |
| data_destroy_arabic (void *data) |
| { |
| arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) data; |
| |
| arabic_fallback_plan_destroy (arabic_plan->fallback_plan); |
| |
| hb_free (data); |
| } |
| |
| static void |
| arabic_joining (hb_buffer_t *buffer) |
| { |
| unsigned int count = buffer->len; |
| hb_glyph_info_t *info = buffer->info; |
| unsigned int prev = UINT_MAX, state = 0; |
| |
| /* Check pre-context */ |
| for (unsigned int i = 0; i < buffer->context_len[0]; i++) |
| { |
| unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i])); |
| |
| if (unlikely (this_type == JOINING_TYPE_T)) |
| continue; |
| |
| const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; |
| state = entry->next_state; |
| break; |
| } |
| |
| for (unsigned int i = 0; i < count; i++) |
| { |
| unsigned int this_type = get_joining_type (info[i].codepoint, _hb_glyph_info_get_general_category (&info[i])); |
| |
| if (unlikely (this_type == JOINING_TYPE_T)) { |
| info[i].arabic_shaping_action() = NONE; |
| continue; |
| } |
| |
| const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; |
| |
| if (entry->prev_action != NONE && prev != UINT_MAX) |
| { |
| info[prev].arabic_shaping_action() = entry->prev_action; |
| buffer->unsafe_to_break (prev, i + 1); |
| } |
| |
| info[i].arabic_shaping_action() = entry->curr_action; |
| |
| prev = i; |
| state = entry->next_state; |
| } |
| |
| for (unsigned int i = 0; i < buffer->context_len[1]; i++) |
| { |
| unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[1][i])); |
| |
| if (unlikely (this_type == JOINING_TYPE_T)) |
| continue; |
| |
| const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; |
| if (entry->prev_action != NONE && prev != UINT_MAX) |
| info[prev].arabic_shaping_action() = entry->prev_action; |
| break; |
| } |
| } |
| |
| static void |
| mongolian_variation_selectors (hb_buffer_t *buffer) |
| { |
| /* Copy arabic_shaping_action() from base to Mongolian variation selectors. */ |
| unsigned int count = buffer->len; |
| hb_glyph_info_t *info = buffer->info; |
| for (unsigned int i = 1; i < count; i++) |
| if (unlikely (hb_in_ranges<hb_codepoint_t> (info[i].codepoint, 0x180Bu, 0x180Du, 0x180Fu, 0x180Fu))) |
| info[i].arabic_shaping_action() = info[i - 1].arabic_shaping_action(); |
| } |
| |
| void |
| setup_masks_arabic_plan (const arabic_shape_plan_t *arabic_plan, |
| hb_buffer_t *buffer, |
| hb_script_t script) |
| { |
| HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action); |
| |
| arabic_joining (buffer); |
| if (script == HB_SCRIPT_MONGOLIAN) |
| mongolian_variation_selectors (buffer); |
| |
| unsigned int count = buffer->len; |
| hb_glyph_info_t *info = buffer->info; |
| for (unsigned int i = 0; i < count; i++) |
| info[i].mask |= arabic_plan->mask_array[info[i].arabic_shaping_action()]; |
| } |
| |
| static void |
| setup_masks_arabic (const hb_ot_shape_plan_t *plan, |
| hb_buffer_t *buffer, |
| hb_font_t *font HB_UNUSED) |
| { |
| const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data; |
| setup_masks_arabic_plan (arabic_plan, buffer, plan->props.script); |
| } |
| |
| static void |
| arabic_fallback_shape (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer) |
| { |
| #ifdef HB_NO_OT_SHAPE_COMPLEX_ARABIC_FALLBACK |
| return; |
| #endif |
| |
| const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data; |
| |
| if (!arabic_plan->do_fallback) |
| return; |
| |
| retry: |
| arabic_fallback_plan_t *fallback_plan = arabic_plan->fallback_plan; |
| if (unlikely (!fallback_plan)) |
| { |
| /* This sucks. We need a font to build the fallback plan... */ |
| fallback_plan = arabic_fallback_plan_create (plan, font); |
| if (unlikely (!arabic_plan->fallback_plan.cmpexch (nullptr, fallback_plan))) |
| { |
| arabic_fallback_plan_destroy (fallback_plan); |
| goto retry; |
| } |
| } |
| |
| arabic_fallback_plan_shape (fallback_plan, font, buffer); |
| } |
| |
| /* |
| * Stretch feature: "stch". |
| * See example here: |
| * https://docs.microsoft.com/en-us/typography/script-development/syriac |
| * We implement this in a generic way, such that the Arabic subtending |
| * marks can use it as well. |
| */ |
| |
| static void |
| record_stch (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font HB_UNUSED, |
| hb_buffer_t *buffer) |
| { |
| const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data; |
| if (!arabic_plan->has_stch) |
| return; |
| |
| /* 'stch' feature was just applied. Look for anything that multiplied, |
| * and record it for stch treatment later. Note that rtlm, frac, etc |
| * are applied before stch, but we assume that they didn't result in |
| * anything multiplying into 5 pieces, so it's safe-ish... */ |
| |
| unsigned int count = buffer->len; |
| hb_glyph_info_t *info = buffer->info; |
| for (unsigned int i = 0; i < count; i++) |
| if (unlikely (_hb_glyph_info_multiplied (&info[i]))) |
| { |
| unsigned int comp = _hb_glyph_info_get_lig_comp (&info[i]); |
| info[i].arabic_shaping_action() = comp % 2 ? STCH_REPEATING : STCH_FIXED; |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH; |
| } |
| } |
| |
| static void |
| apply_stch (const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_buffer_t *buffer, |
| hb_font_t *font) |
| { |
| if (likely (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH))) |
| return; |
| |
| /* The Arabic shaper currently always processes in RTL mode, so we should |
| * stretch / position the stretched pieces to the left / preceding glyphs. */ |
| |
| /* We do a two pass implementation: |
| * First pass calculates the exact number of extra glyphs we need, |
| * We then enlarge buffer to have that much room, |
| * Second pass applies the stretch, copying things to the end of buffer. |
| */ |
| |
| int sign = font->x_scale < 0 ? -1 : +1; |
| unsigned int extra_glyphs_needed = 0; // Set during MEASURE, used during CUT |
| enum { MEASURE, CUT } /* step_t */; |
| |
| for (unsigned int step = MEASURE; step <= CUT; step = step + 1) |
| { |
| unsigned int count = buffer->len; |
| hb_glyph_info_t *info = buffer->info; |
| hb_glyph_position_t *pos = buffer->pos; |
| unsigned int new_len = count + extra_glyphs_needed; // write head during CUT |
| unsigned int j = new_len; |
| for (unsigned int i = count; i; i--) |
| { |
| if (!hb_in_range<uint8_t> (info[i - 1].arabic_shaping_action(), STCH_FIXED, STCH_REPEATING)) |
| { |
| if (step == CUT) |
| { |
| --j; |
| info[j] = info[i - 1]; |
| pos[j] = pos[i - 1]; |
| } |
| continue; |
| } |
| |
| /* Yay, justification! */ |
| |
| hb_position_t w_total = 0; // Total to be filled |
| hb_position_t w_fixed = 0; // Sum of fixed tiles |
| hb_position_t w_repeating = 0; // Sum of repeating tiles |
| int n_fixed = 0; |
| int n_repeating = 0; |
| |
| unsigned int end = i; |
| while (i && |
| hb_in_range<uint8_t> (info[i - 1].arabic_shaping_action(), STCH_FIXED, STCH_REPEATING)) |
| { |
| i--; |
| hb_position_t width = font->get_glyph_h_advance (info[i].codepoint); |
| if (info[i].arabic_shaping_action() == STCH_FIXED) |
| { |
| w_fixed += width; |
| n_fixed++; |
| } |
| else |
| { |
| w_repeating += width; |
| n_repeating++; |
| } |
| } |
| unsigned int start = i; |
| unsigned int context = i; |
| while (context && |
| !hb_in_range<uint8_t> (info[context - 1].arabic_shaping_action(), STCH_FIXED, STCH_REPEATING) && |
| (_hb_glyph_info_is_default_ignorable (&info[context - 1]) || |
| HB_ARABIC_GENERAL_CATEGORY_IS_WORD (_hb_glyph_info_get_general_category (&info[context - 1])))) |
| { |
| context--; |
| w_total += pos[context].x_advance; |
| } |
| i++; // Don't touch i again. |
| |
| DEBUG_MSG (ARABIC, nullptr, "%s stretch at (%d,%d,%d)", |
| step == MEASURE ? "measuring" : "cutting", context, start, end); |
| DEBUG_MSG (ARABIC, nullptr, "rest of word: count=%d width %d", start - context, w_total); |
| DEBUG_MSG (ARABIC, nullptr, "fixed tiles: count=%d width=%d", n_fixed, w_fixed); |
| DEBUG_MSG (ARABIC, nullptr, "repeating tiles: count=%d width=%d", n_repeating, w_repeating); |
| |
| /* Number of additional times to repeat each repeating tile. */ |
| int n_copies = 0; |
| |
| hb_position_t w_remaining = w_total - w_fixed; |
| if (sign * w_remaining > sign * w_repeating && sign * w_repeating > 0) |
| n_copies = (sign * w_remaining) / (sign * w_repeating) - 1; |
| |
| /* See if we can improve the fit by adding an extra repeat and squeezing them together a bit. */ |
| hb_position_t extra_repeat_overlap = 0; |
| hb_position_t shortfall = sign * w_remaining - sign * w_repeating * (n_copies + 1); |
| if (shortfall > 0 && n_repeating > 0) |
| { |
| ++n_copies; |
| hb_position_t excess = (n_copies + 1) * sign * w_repeating - sign * w_remaining; |
| if (excess > 0) |
| extra_repeat_overlap = excess / (n_copies * n_repeating); |
| } |
| |
| if (step == MEASURE) |
| { |
| extra_glyphs_needed += n_copies * n_repeating; |
| DEBUG_MSG (ARABIC, nullptr, "will add extra %d copies of repeating tiles", n_copies); |
| } |
| else |
| { |
| buffer->unsafe_to_break (context, end); |
| hb_position_t x_offset = 0; |
| for (unsigned int k = end; k > start; k--) |
| { |
| hb_position_t width = font->get_glyph_h_advance (info[k - 1].codepoint); |
| |
| unsigned int repeat = 1; |
| if (info[k - 1].arabic_shaping_action() == STCH_REPEATING) |
| repeat += n_copies; |
| |
| DEBUG_MSG (ARABIC, nullptr, "appending %d copies of glyph %d; j=%d", |
| repeat, info[k - 1].codepoint, j); |
| for (unsigned int n = 0; n < repeat; n++) |
| { |
| x_offset -= width; |
| if (n > 0) |
| x_offset += extra_repeat_overlap; |
| pos[k - 1].x_offset = x_offset; |
| /* Append copy. */ |
| --j; |
| info[j] = info[k - 1]; |
| pos[j] = pos[k - 1]; |
| } |
| } |
| } |
| } |
| |
| if (step == MEASURE) |
| { |
| if (unlikely (!buffer->ensure (count + extra_glyphs_needed))) |
| break; |
| } |
| else |
| { |
| assert (j == 0); |
| buffer->len = new_len; |
| } |
| } |
| } |
| |
| |
| static void |
| postprocess_glyphs_arabic (const hb_ot_shape_plan_t *plan, |
| hb_buffer_t *buffer, |
| hb_font_t *font) |
| { |
| apply_stch (plan, buffer, font); |
| |
| HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action); |
| } |
| |
| /* https://www.unicode.org/reports/tr53/ */ |
| |
| static hb_codepoint_t |
| modifier_combining_marks[] = |
| { |
| 0x0654u, /* ARABIC HAMZA ABOVE */ |
| 0x0655u, /* ARABIC HAMZA BELOW */ |
| 0x0658u, /* ARABIC MARK NOON GHUNNA */ |
| 0x06DCu, /* ARABIC SMALL HIGH SEEN */ |
| 0x06E3u, /* ARABIC SMALL LOW SEEN */ |
| 0x06E7u, /* ARABIC SMALL HIGH YEH */ |
| 0x06E8u, /* ARABIC SMALL HIGH NOON */ |
| 0x08D3u, /* ARABIC SMALL LOW WAW */ |
| 0x08F3u, /* ARABIC SMALL HIGH WAW */ |
| }; |
| |
| static inline bool |
| info_is_mcm (const hb_glyph_info_t &info) |
| { |
| hb_codepoint_t u = info.codepoint; |
| for (unsigned int i = 0; i < ARRAY_LENGTH (modifier_combining_marks); i++) |
| if (u == modifier_combining_marks[i]) |
| return true; |
| return false; |
| } |
| |
| static void |
| reorder_marks_arabic (const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_buffer_t *buffer, |
| unsigned int start, |
| unsigned int end) |
| { |
| hb_glyph_info_t *info = buffer->info; |
| |
| DEBUG_MSG (ARABIC, buffer, "Reordering marks from %d to %d", start, end); |
| |
| unsigned int i = start; |
| for (unsigned int cc = 220; cc <= 230; cc += 10) |
| { |
| DEBUG_MSG (ARABIC, buffer, "Looking for %d's starting at %d", cc, i); |
| while (i < end && info_cc(info[i]) < cc) |
| i++; |
| DEBUG_MSG (ARABIC, buffer, "Looking for %d's stopped at %d", cc, i); |
| |
| if (i == end) |
| break; |
| |
| if (info_cc(info[i]) > cc) |
| continue; |
| |
| unsigned int j = i; |
| while (j < end && info_cc(info[j]) == cc && info_is_mcm (info[j])) |
| j++; |
| |
| if (i == j) |
| continue; |
| |
| DEBUG_MSG (ARABIC, buffer, "Found %d's from %d to %d", cc, i, j); |
| |
| /* Shift it! */ |
| DEBUG_MSG (ARABIC, buffer, "Shifting %d's: %d %d", cc, i, j); |
| hb_glyph_info_t temp[HB_OT_SHAPE_COMPLEX_MAX_COMBINING_MARKS]; |
| assert (j - i <= ARRAY_LENGTH (temp)); |
| buffer->merge_clusters (start, j); |
| memmove (temp, &info[i], (j - i) * sizeof (hb_glyph_info_t)); |
| memmove (&info[start + j - i], &info[start], (i - start) * sizeof (hb_glyph_info_t)); |
| memmove (&info[start], temp, (j - i) * sizeof (hb_glyph_info_t)); |
| |
| /* Renumber CC such that the reordered sequence is still sorted. |
| * 22 and 26 are chosen because they are smaller than all Arabic categories, |
| * and are folded back to 220/230 respectively during fallback mark positioning. |
| * |
| * We do this because the CGJ-handling logic in the normalizer relies on |
| * mark sequences having an increasing order even after this reordering. |
| * https://github.com/harfbuzz/harfbuzz/issues/554 |
| * This, however, does break some obscure sequences, where the normalizer |
| * might compose a sequence that it should not. For example, in the seequence |
| * ALEF, HAMZAH, MADDAH, we should NOT try to compose ALEF+MADDAH, but with this |
| * renumbering, we will. |
| */ |
| unsigned int new_start = start + j - i; |
| unsigned int new_cc = cc == 220 ? HB_MODIFIED_COMBINING_CLASS_CCC22 : HB_MODIFIED_COMBINING_CLASS_CCC26; |
| while (start < new_start) |
| { |
| _hb_glyph_info_set_modified_combining_class (&info[start], new_cc); |
| start++; |
| } |
| |
| i = j; |
| } |
| } |
| |
| const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic = |
| { |
| collect_features_arabic, |
| nullptr, /* override_features */ |
| data_create_arabic, |
| data_destroy_arabic, |
| nullptr, /* preprocess_text */ |
| postprocess_glyphs_arabic, |
| HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT, |
| nullptr, /* decompose */ |
| nullptr, /* compose */ |
| setup_masks_arabic, |
| HB_TAG_NONE, /* gpos_tag */ |
| reorder_marks_arabic, |
| HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE, |
| true, /* fallback_position */ |
| }; |
| |
| |
| #endif |