diff options
Diffstat (limited to 'src/3rdparty/harfbuzz-ng/src/hb-ot-shape-complex-arabic.cc')
| -rw-r--r-- | src/3rdparty/harfbuzz-ng/src/hb-ot-shape-complex-arabic.cc | 249 |
1 files changed, 242 insertions, 7 deletions
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-complex-arabic.cc b/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-complex-arabic.cc index cde02e0a56..56ec5cd65c 100644 --- a/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-complex-arabic.cc +++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-shape-complex-arabic.cc @@ -28,9 +28,38 @@ #include "hb-ot-shape-private.hh" +#ifndef HB_DEBUG_ARABIC +#define HB_DEBUG_ARABIC (HB_DEBUG+0) +#endif + + /* buffer var allocations */ #define arabic_shaping_action() complex_var_u8_0() /* arabic shaping action */ +#define HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH HB_BUFFER_SCRATCH_FLAG_COMPLEX0 + +/* See: + * https://github.com/behdad/harfbuzz/commit/6e6f82b6f3dde0fc6c3c7d991d9ec6cfff57823d#commitcomment-14248516 */ +#define HB_ARABIC_GENERAL_CATEGORY_IS_WORD(gen_cat) \ + (FLAG_SAFE (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: @@ -84,7 +113,7 @@ static const hb_tag_t arabic_features[] = /* Same order as the feature array */ -enum { +enum arabic_action_t { ISOL, FINA, FIN2, @@ -95,7 +124,11 @@ enum { NONE, - ARABIC_NUM_FEATURES = NONE + ARABIC_NUM_FEATURES = NONE, + + /* We abuse the same byte for other things... */ + STCH_FIXED, + STCH_REPEATING, }; static const struct arabic_state_table_entry { @@ -140,6 +173,11 @@ arabic_fallback_shape (const hb_ot_shape_plan_t *plan, 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; @@ -165,6 +203,9 @@ collect_features_arabic (hb_ot_shape_planner_t *plan) map->add_gsub_pause (nuke_joiners); + map->add_global_bool_feature (HB_TAG('s','t','c','h')); + map->add_gsub_pause (record_stch); + map->add_global_bool_feature (HB_TAG('c','c','m','p')); map->add_global_bool_feature (HB_TAG('l','o','c','l')); @@ -182,7 +223,6 @@ collect_features_arabic (hb_ot_shape_planner_t *plan) map->add_gsub_pause (arabic_fallback_shape); map->add_global_bool_feature (HB_TAG('c','a','l','t')); - map->add_gsub_pause (NULL); /* The spec includes 'cswh'. Earlier versions of Windows * used to enable this by default, but testing suggests @@ -192,6 +232,7 @@ collect_features_arabic (hb_ot_shape_planner_t *plan) * Note that IranNastaliq uses this feature extensively * to fixup broken glyph sequences. Oh well... * Test case: U+0643,U+0640,U+0631. */ + //map->add_gsub_pause (NULL); //map->add_global_bool_feature (HB_TAG('c','s','w','h')); map->add_global_bool_feature (HB_TAG('m','s','e','t')); } @@ -208,8 +249,10 @@ struct arabic_shape_plan_t * mask_array[NONE] == 0. */ hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1]; - bool do_fallback; arabic_fallback_plan_t *fallback_plan; + + unsigned int do_fallback : 1; + unsigned int has_stch : 1; }; void * @@ -220,6 +263,7 @@ data_create_arabic (const hb_ot_shape_plan_t *plan) return NULL; 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 && @@ -320,8 +364,6 @@ setup_masks_arabic_plan (const arabic_shape_plan_t *arabic_plan, 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()]; - - HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action); } static void @@ -371,6 +413,197 @@ retry: arabic_fallback_plan_shape (fallback_plan, font, buffer); } +/* + * Stretch feature: "stch". + * See example here: + * https://www.microsoft.com/typography/OpenTypeDev/syriac/intro.htm + * 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_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_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 + typedef enum { MEASURE, CUT } step_t; + + for (step_t step = MEASURE; step <= CUT; step = (step_t) (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<unsigned> (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<unsigned> (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<unsigned> (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, NULL, "%s stretch at (%d,%d,%d)", + step == MEASURE ? "measuring" : "cutting", context, start, end); + DEBUG_MSG (ARABIC, NULL, "rest of word: count=%d width %d", start - context, w_total); + DEBUG_MSG (ARABIC, NULL, "fixed tiles: count=%d width=%d", n_fixed, w_fixed); + DEBUG_MSG (ARABIC, NULL, "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_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, NULL, "will add extra %d copies of repeating tiles", n_copies); + } + else + { + 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, NULL, "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); +} const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic = { @@ -379,11 +612,13 @@ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic = NULL, /* override_features */ data_create_arabic, data_destroy_arabic, - NULL, /* preprocess_text_arabic */ + NULL, /* preprocess_text */ + postprocess_glyphs_arabic, HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT, NULL, /* decompose */ NULL, /* compose */ setup_masks_arabic, + NULL, /* disable_otl */ HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE, true, /* fallback_position */ }; |