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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /gfx/harfbuzz/src/hb-ot-shaper-hangul.cc | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-shaper-hangul.cc')
-rw-r--r-- | gfx/harfbuzz/src/hb-ot-shaper-hangul.cc | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-shaper-hangul.cc b/gfx/harfbuzz/src/hb-ot-shaper-hangul.cc new file mode 100644 index 0000000000..c90476bc46 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-shaper-hangul.cc @@ -0,0 +1,436 @@ +/* + * Copyright © 2013 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-shaper.hh" + + +/* Hangul shaper */ + + +/* Same order as the feature array below */ +enum { + _JMO, + + LJMO, + VJMO, + TJMO, + + FIRST_HANGUL_FEATURE = LJMO, + HANGUL_FEATURE_COUNT = TJMO + 1 +}; + +static const hb_tag_t hangul_features[HANGUL_FEATURE_COUNT] = +{ + HB_TAG_NONE, + HB_TAG('l','j','m','o'), + HB_TAG('v','j','m','o'), + HB_TAG('t','j','m','o') +}; + +static void +collect_features_hangul (hb_ot_shape_planner_t *plan) +{ + hb_ot_map_builder_t *map = &plan->map; + + for (unsigned int i = FIRST_HANGUL_FEATURE; i < HANGUL_FEATURE_COUNT; i++) + map->add_feature (hangul_features[i]); +} + +static void +override_features_hangul (hb_ot_shape_planner_t *plan) +{ + /* Uniscribe does not apply 'calt' for Hangul, and certain fonts + * (Noto Sans CJK, Source Sans Han, etc) apply all of jamo lookups + * in calt, which is not desirable. */ + plan->map.disable_feature (HB_TAG('c','a','l','t')); +} + +struct hangul_shape_plan_t +{ + hb_mask_t mask_array[HANGUL_FEATURE_COUNT]; +}; + +static void * +data_create_hangul (const hb_ot_shape_plan_t *plan) +{ + hangul_shape_plan_t *hangul_plan = (hangul_shape_plan_t *) hb_calloc (1, sizeof (hangul_shape_plan_t)); + if (unlikely (!hangul_plan)) + return nullptr; + + for (unsigned int i = 0; i < HANGUL_FEATURE_COUNT; i++) + hangul_plan->mask_array[i] = plan->map.get_1_mask (hangul_features[i]); + + return hangul_plan; +} + +static void +data_destroy_hangul (void *data) +{ + hb_free (data); +} + +/* Constants for algorithmic hangul syllable [de]composition. */ +#define LBase 0x1100u +#define VBase 0x1161u +#define TBase 0x11A7u +#define LCount 19u +#define VCount 21u +#define TCount 28u +#define SBase 0xAC00u +#define NCount (VCount * TCount) +#define SCount (LCount * NCount) + +#define isCombiningL(u) (hb_in_range<hb_codepoint_t> ((u), LBase, LBase+LCount-1)) +#define isCombiningV(u) (hb_in_range<hb_codepoint_t> ((u), VBase, VBase+VCount-1)) +#define isCombiningT(u) (hb_in_range<hb_codepoint_t> ((u), TBase+1, TBase+TCount-1)) +#define isCombinedS(u) (hb_in_range<hb_codepoint_t> ((u), SBase, SBase+SCount-1)) + +#define isL(u) (hb_in_ranges<hb_codepoint_t> ((u), 0x1100u, 0x115Fu, 0xA960u, 0xA97Cu)) +#define isV(u) (hb_in_ranges<hb_codepoint_t> ((u), 0x1160u, 0x11A7u, 0xD7B0u, 0xD7C6u)) +#define isT(u) (hb_in_ranges<hb_codepoint_t> ((u), 0x11A8u, 0x11FFu, 0xD7CBu, 0xD7FBu)) + +#define isHangulTone(u) (hb_in_range<hb_codepoint_t> ((u), 0x302Eu, 0x302Fu)) + +/* buffer var allocations */ +#define hangul_shaping_feature() ot_shaper_var_u8_auxiliary() /* hangul jamo shaping feature */ + +static bool +is_zero_width_char (hb_font_t *font, + hb_codepoint_t unicode) +{ + hb_codepoint_t glyph; + return hb_font_get_glyph (font, unicode, 0, &glyph) && hb_font_get_glyph_h_advance (font, glyph) == 0; +} + +static void +preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED, + hb_buffer_t *buffer, + hb_font_t *font) +{ + HB_BUFFER_ALLOCATE_VAR (buffer, hangul_shaping_feature); + + /* Hangul syllables come in two shapes: LV, and LVT. Of those: + * + * - LV can be precomposed, or decomposed. Lets call those + * <LV> and <L,V>, + * - LVT can be fully precomposed, partially precomposed, or + * fully decomposed. Ie. <LVT>, <LV,T>, or <L,V,T>. + * + * The composition / decomposition is mechanical. However, not + * all <L,V> sequences compose, and not all <LV,T> sequences + * compose. + * + * Here are the specifics: + * + * - <L>: U+1100..115F, U+A960..A97F + * - <V>: U+1160..11A7, U+D7B0..D7C7 + * - <T>: U+11A8..11FF, U+D7CB..D7FB + * + * - Only the <L,V> sequences for some of the U+11xx ranges combine. + * - Only <LV,T> sequences for some of the Ts in U+11xx range combine. + * + * Here is what we want to accomplish in this shaper: + * + * - If the whole syllable can be precomposed, do that, + * - Otherwise, fully decompose and apply ljmo/vjmo/tjmo features. + * - If a valid syllable is followed by a Hangul tone mark, reorder the tone + * mark to precede the whole syllable - unless it is a zero-width glyph, in + * which case we leave it untouched, assuming it's designed to overstrike. + * + * That is, of the different possible syllables: + * + * <L> + * <L,V> + * <L,V,T> + * <LV> + * <LVT> + * <LV, T> + * + * - <L> needs no work. + * + * - <LV> and <LVT> can stay the way they are if the font supports them, otherwise we + * should fully decompose them if font supports. + * + * - <L,V> and <L,V,T> we should compose if the whole thing can be composed. + * + * - <LV,T> we should compose if the whole thing can be composed, otherwise we should + * decompose. + */ + + buffer->clear_output (); + unsigned int start = 0, end = 0; /* Extent of most recently seen syllable; + * valid only if start < end + */ + unsigned int count = buffer->len; + + for (buffer->idx = 0; buffer->idx < count && buffer->successful;) + { + hb_codepoint_t u = buffer->cur().codepoint; + + if (isHangulTone (u)) + { + /* + * We could cache the width of the tone marks and the existence of dotted-circle, + * but the use of the Hangul tone mark characters seems to be rare enough that + * I didn't bother for now. + */ + if (start < end && end == buffer->out_len) + { + /* Tone mark follows a valid syllable; move it in front, unless it's zero width. */ + buffer->unsafe_to_break_from_outbuffer (start, buffer->idx); + if (unlikely (!buffer->next_glyph ())) break; + if (!is_zero_width_char (font, u)) + { + buffer->merge_out_clusters (start, end + 1); + hb_glyph_info_t *info = buffer->out_info; + hb_glyph_info_t tone = info[end]; + memmove (&info[start + 1], &info[start], (end - start) * sizeof (hb_glyph_info_t)); + info[start] = tone; + } + } + else + { + /* No valid syllable as base for tone mark; try to insert dotted circle. */ + if (!(buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE) && + font->has_glyph (0x25CCu)) + { + hb_codepoint_t chars[2]; + if (!is_zero_width_char (font, u)) + { + chars[0] = u; + chars[1] = 0x25CCu; + } else + { + chars[0] = 0x25CCu; + chars[1] = u; + } + (void) buffer->replace_glyphs (1, 2, chars); + } + else + { + /* No dotted circle available in the font; just leave tone mark untouched. */ + (void) buffer->next_glyph (); + } + } + start = end = buffer->out_len; + continue; + } + + start = buffer->out_len; /* Remember current position as a potential syllable start; + * will only be used if we set end to a later position. + */ + + if (isL (u) && buffer->idx + 1 < count) + { + hb_codepoint_t l = u; + hb_codepoint_t v = buffer->cur(+1).codepoint; + if (isV (v)) + { + /* Have <L,V> or <L,V,T>. */ + hb_codepoint_t t = 0; + unsigned int tindex = 0; + if (buffer->idx + 2 < count) + { + t = buffer->cur(+2).codepoint; + if (isT (t)) + tindex = t - TBase; /* Only used if isCombiningT (t); otherwise invalid. */ + else + t = 0; /* The next character was not a trailing jamo. */ + } + buffer->unsafe_to_break (buffer->idx, buffer->idx + (t ? 3 : 2)); + + /* We've got a syllable <L,V,T?>; see if it can potentially be composed. */ + if (isCombiningL (l) && isCombiningV (v) && (t == 0 || isCombiningT (t))) + { + /* Try to compose; if this succeeds, end is set to start+1. */ + hb_codepoint_t s = SBase + (l - LBase) * NCount + (v - VBase) * TCount + tindex; + if (font->has_glyph (s)) + { + (void) buffer->replace_glyphs (t ? 3 : 2, 1, &s); + end = start + 1; + continue; + } + } + + /* We didn't compose, either because it's an Old Hangul syllable without a + * precomposed character in Unicode, or because the font didn't support the + * necessary precomposed glyph. + * Set jamo features on the individual glyphs, and advance past them. + */ + buffer->cur().hangul_shaping_feature() = LJMO; + (void) buffer->next_glyph (); + buffer->cur().hangul_shaping_feature() = VJMO; + (void) buffer->next_glyph (); + if (t) + { + buffer->cur().hangul_shaping_feature() = TJMO; + (void) buffer->next_glyph (); + end = start + 3; + } + else + end = start + 2; + if (unlikely (!buffer->successful)) + break; + if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES) + buffer->merge_out_clusters (start, end); + continue; + } + } + + else if (isCombinedS (u)) + { + /* Have <LV>, <LVT>, or <LV,T> */ + hb_codepoint_t s = u; + bool has_glyph = font->has_glyph (s); + unsigned int lindex = (s - SBase) / NCount; + unsigned int nindex = (s - SBase) % NCount; + unsigned int vindex = nindex / TCount; + unsigned int tindex = nindex % TCount; + + if (!tindex && + buffer->idx + 1 < count && + isCombiningT (buffer->cur(+1).codepoint)) + { + /* <LV,T>, try to combine. */ + unsigned int new_tindex = buffer->cur(+1).codepoint - TBase; + hb_codepoint_t new_s = s + new_tindex; + if (font->has_glyph (new_s)) + { + (void) buffer->replace_glyphs (2, 1, &new_s); + end = start + 1; + continue; + } + else + buffer->unsafe_to_break (buffer->idx, buffer->idx + 2); /* Mark unsafe between LV and T. */ + } + + /* Otherwise, decompose if font doesn't support <LV> or <LVT>, + * or if having non-combining <LV,T>. Note that we already handled + * combining <LV,T> above. */ + if (!has_glyph || + (!tindex && + buffer->idx + 1 < count && + isT (buffer->cur(+1).codepoint))) + { + hb_codepoint_t decomposed[3] = {LBase + lindex, + VBase + vindex, + TBase + tindex}; + if (font->has_glyph (decomposed[0]) && + font->has_glyph (decomposed[1]) && + (!tindex || font->has_glyph (decomposed[2]))) + { + unsigned int s_len = tindex ? 3 : 2; + (void) buffer->replace_glyphs (1, s_len, decomposed); + + /* If we decomposed an LV because of a non-combining T following, + * we want to include this T in the syllable. + */ + if (has_glyph && !tindex) + { + (void) buffer->next_glyph (); + s_len++; + } + if (unlikely (!buffer->successful)) + break; + + /* We decomposed S: apply jamo features to the individual glyphs + * that are now in buffer->out_info. + */ + hb_glyph_info_t *info = buffer->out_info; + end = start + s_len; + + unsigned int i = start; + info[i++].hangul_shaping_feature() = LJMO; + info[i++].hangul_shaping_feature() = VJMO; + if (i < end) + info[i++].hangul_shaping_feature() = TJMO; + + if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES) + buffer->merge_out_clusters (start, end); + continue; + } + else if ((!tindex && buffer->idx + 1 < count && isT (buffer->cur(+1).codepoint))) + buffer->unsafe_to_break (buffer->idx, buffer->idx + 2); /* Mark unsafe between LV and T. */ + } + + if (has_glyph) + { + /* We didn't decompose the S, so just advance past it and fall through. */ + end = start + 1; + } + } + + /* Didn't find a recognizable syllable, so we leave end <= start; + * this will prevent tone-mark reordering happening. + */ + (void) buffer->next_glyph (); + } + buffer->sync (); +} + +static void +setup_masks_hangul (const hb_ot_shape_plan_t *plan, + hb_buffer_t *buffer, + hb_font_t *font HB_UNUSED) +{ + const hangul_shape_plan_t *hangul_plan = (const hangul_shape_plan_t *) plan->data; + + if (likely (hangul_plan)) + { + unsigned int count = buffer->len; + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = 0; i < count; i++, info++) + info->mask |= hangul_plan->mask_array[info->hangul_shaping_feature()]; + } + + HB_BUFFER_DEALLOCATE_VAR (buffer, hangul_shaping_feature); +} + + +const hb_ot_shaper_t _hb_ot_shaper_hangul = +{ + collect_features_hangul, + override_features_hangul, + data_create_hangul, + data_destroy_hangul, + preprocess_text_hangul, + nullptr, /* postprocess_glyphs */ + nullptr, /* decompose */ + nullptr, /* compose */ + setup_masks_hangul, + nullptr, /* reorder_marks */ + HB_TAG_NONE, /* gpos_tag */ + HB_OT_SHAPE_NORMALIZATION_MODE_NONE, + HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, + false, /* fallback_position */ +}; + + +#endif |