2 * Copyright (C) 2011 Grigori Goronzy <greg@chown.ath.cx>
4 * This file is part of libass.
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 #include "ass_shaper.h"
22 #include "ass_render.h"
24 #include "ass_parse.h"
25 #include "ass_cache.h"
29 #ifdef CONFIG_HARFBUZZ
38 #define NUM_FEATURES 5
42 ASS_ShapingLevel shaping_level;
46 FriBidiChar *event_text;
47 FriBidiCharType *ctypes;
48 FriBidiLevel *emblevels;
49 FriBidiStrIndex *cmap;
50 FriBidiParType base_direction;
52 #ifdef CONFIG_HARFBUZZ
55 hb_feature_t *features;
56 hb_language_t language;
58 // Glyph metrics cache, to speed up shaping
63 #ifdef CONFIG_HARFBUZZ
64 struct ass_shaper_metrics_data {
66 GlyphMetricsHashKey hash_key;
70 struct ass_shaper_font_data {
71 hb_font_t *fonts[ASS_FONT_MAX_FACES];
72 hb_font_funcs_t *font_funcs[ASS_FONT_MAX_FACES];
73 struct ass_shaper_metrics_data *metrics_data[ASS_FONT_MAX_FACES];
78 * \brief Print version information
80 void ass_shaper_info(ASS_Library *lib)
82 ass_msg(lib, MSGL_V, "Shaper: FriBidi "
83 FRIBIDI_VERSION " (SIMPLE)"
84 #ifdef CONFIG_HARFBUZZ
85 " HarfBuzz-ng %s (COMPLEX)", hb_version_string()
91 * \brief grow arrays, if needed
92 * \param new_size requested size
94 static bool check_allocations(ASS_Shaper *shaper, size_t new_size)
96 if (new_size > shaper->n_glyphs) {
97 if (!ASS_REALLOC_ARRAY(shaper->event_text, new_size) ||
98 !ASS_REALLOC_ARRAY(shaper->ctypes, new_size) ||
99 !ASS_REALLOC_ARRAY(shaper->emblevels, new_size) ||
100 !ASS_REALLOC_ARRAY(shaper->cmap, new_size))
107 * \brief Free shaper and related data
109 void ass_shaper_free(ASS_Shaper *shaper)
111 #ifdef CONFIG_HARFBUZZ
112 ass_cache_done(shaper->metrics_cache);
113 free(shaper->features);
115 free(shaper->event_text);
116 free(shaper->ctypes);
117 free(shaper->emblevels);
122 void ass_shaper_font_data_free(ASS_ShaperFontData *priv)
124 #ifdef CONFIG_HARFBUZZ
126 for (i = 0; i < ASS_FONT_MAX_FACES; i++)
127 if (priv->fonts[i]) {
128 free(priv->metrics_data[i]);
129 hb_font_destroy(priv->fonts[i]);
130 hb_font_funcs_destroy(priv->font_funcs[i]);
136 #ifdef CONFIG_HARFBUZZ
138 * \brief set up the HarfBuzz OpenType feature list with some
141 static bool init_features(ASS_Shaper *shaper)
143 shaper->features = calloc(sizeof(hb_feature_t), NUM_FEATURES);
144 if (!shaper->features)
147 shaper->n_features = NUM_FEATURES;
148 shaper->features[VERT].tag = HB_TAG('v', 'e', 'r', 't');
149 shaper->features[VERT].end = UINT_MAX;
150 shaper->features[VKNA].tag = HB_TAG('v', 'k', 'n', 'a');
151 shaper->features[VKNA].end = UINT_MAX;
152 shaper->features[KERN].tag = HB_TAG('k', 'e', 'r', 'n');
153 shaper->features[KERN].end = UINT_MAX;
154 shaper->features[LIGA].tag = HB_TAG('l', 'i', 'g', 'a');
155 shaper->features[LIGA].end = UINT_MAX;
156 shaper->features[CLIG].tag = HB_TAG('c', 'l', 'i', 'g');
157 shaper->features[CLIG].end = UINT_MAX;
163 * \brief Set features depending on properties of the run
165 static void set_run_features(ASS_Shaper *shaper, GlyphInfo *info)
167 // enable vertical substitutions for @font runs
168 if (info->font->desc.vertical)
169 shaper->features[VERT].value = shaper->features[VKNA].value = 1;
171 shaper->features[VERT].value = shaper->features[VKNA].value = 0;
173 // disable ligatures if horizontal spacing is non-standard
175 shaper->features[LIGA].value = shaper->features[CLIG].value = 0;
177 shaper->features[LIGA].value = shaper->features[CLIG].value = 1;
181 * \brief Update HarfBuzz's idea of font metrics
182 * \param hb_font HarfBuzz font
183 * \param face associated FreeType font face
185 static void update_hb_size(hb_font_t *hb_font, FT_Face face)
187 hb_font_set_scale (hb_font,
188 ((uint64_t) face->size->metrics.x_scale * (uint64_t) face->units_per_EM) >> 16,
189 ((uint64_t) face->size->metrics.y_scale * (uint64_t) face->units_per_EM) >> 16);
190 hb_font_set_ppem (hb_font, face->size->metrics.x_ppem,
191 face->size->metrics.y_ppem);
196 * Cached glyph metrics getters follow
198 * These functions replace HarfBuzz' standard FreeType font functions
199 * and provide cached access to essential glyph metrics. This usually
200 * speeds up shaping a lot. It also allows us to use custom load flags.
204 GlyphMetricsHashValue *
205 get_cached_metrics(struct ass_shaper_metrics_data *metrics, FT_Face face,
206 hb_codepoint_t unicode, hb_codepoint_t glyph)
208 GlyphMetricsHashValue *val;
210 metrics->hash_key.glyph_index = glyph;
211 val = ass_cache_get(metrics->metrics_cache, &metrics->hash_key);
214 int load_flags = FT_LOAD_DEFAULT | FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH
215 | FT_LOAD_IGNORE_TRANSFORM;
216 GlyphMetricsHashValue new_val;
218 if (FT_Load_Glyph(face, glyph, load_flags))
221 memcpy(&new_val.metrics, &face->glyph->metrics, sizeof(FT_Glyph_Metrics));
223 // if @font rendering is enabled and the glyph should be rotated,
224 // make cached_h_advance pick up the right advance later
225 if (metrics->vertical && unicode >= VERTICAL_LOWER_BOUND)
226 new_val.metrics.horiAdvance = new_val.metrics.vertAdvance;
228 val = ass_cache_put(metrics->metrics_cache, &metrics->hash_key, &new_val);
235 get_glyph(hb_font_t *font, void *font_data, hb_codepoint_t unicode,
236 hb_codepoint_t variation, hb_codepoint_t *glyph, void *user_data)
238 FT_Face face = font_data;
239 struct ass_shaper_metrics_data *metrics_priv = user_data;
242 *glyph = FT_Face_GetCharVariantIndex(face, ass_font_index_magic(face, unicode), variation);
244 *glyph = FT_Get_Char_Index(face, ass_font_index_magic(face, unicode));
246 // rotate glyph advances for @fonts while we still know the Unicode codepoints
248 get_cached_metrics(metrics_priv, face, unicode, *glyph);
254 cached_h_advance(hb_font_t *font, void *font_data, hb_codepoint_t glyph,
257 FT_Face face = font_data;
258 struct ass_shaper_metrics_data *metrics_priv = user_data;
259 GlyphMetricsHashValue *metrics = get_cached_metrics(metrics_priv, face, 0, glyph);
264 return metrics->metrics.horiAdvance;
268 cached_v_advance(hb_font_t *font, void *font_data, hb_codepoint_t glyph,
271 FT_Face face = font_data;
272 struct ass_shaper_metrics_data *metrics_priv = user_data;
273 GlyphMetricsHashValue *metrics = get_cached_metrics(metrics_priv, face, 0, glyph);
278 return metrics->metrics.vertAdvance;
283 cached_h_origin(hb_font_t *font, void *font_data, hb_codepoint_t glyph,
284 hb_position_t *x, hb_position_t *y, void *user_data)
290 cached_v_origin(hb_font_t *font, void *font_data, hb_codepoint_t glyph,
291 hb_position_t *x, hb_position_t *y, void *user_data)
293 FT_Face face = font_data;
294 struct ass_shaper_metrics_data *metrics_priv = user_data;
295 GlyphMetricsHashValue *metrics = get_cached_metrics(metrics_priv, face, 0, glyph);
300 *x = metrics->metrics.horiBearingX - metrics->metrics.vertBearingX;
301 *y = metrics->metrics.horiBearingY - (-metrics->metrics.vertBearingY);
307 get_h_kerning(hb_font_t *font, void *font_data, hb_codepoint_t first,
308 hb_codepoint_t second, void *user_data)
310 FT_Face face = font_data;
313 if (FT_Get_Kerning (face, first, second, FT_KERNING_DEFAULT, &kern))
320 get_v_kerning(hb_font_t *font, void *font_data, hb_codepoint_t first,
321 hb_codepoint_t second, void *user_data)
327 cached_extents(hb_font_t *font, void *font_data, hb_codepoint_t glyph,
328 hb_glyph_extents_t *extents, void *user_data)
330 FT_Face face = font_data;
331 struct ass_shaper_metrics_data *metrics_priv = user_data;
332 GlyphMetricsHashValue *metrics = get_cached_metrics(metrics_priv, face, 0, glyph);
337 extents->x_bearing = metrics->metrics.horiBearingX;
338 extents->y_bearing = metrics->metrics.horiBearingY;
339 extents->width = metrics->metrics.width;
340 extents->height = -metrics->metrics.height;
346 get_contour_point(hb_font_t *font, void *font_data, hb_codepoint_t glyph,
347 unsigned int point_index, hb_position_t *x,
348 hb_position_t *y, void *user_data)
350 FT_Face face = font_data;
351 int load_flags = FT_LOAD_DEFAULT | FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH
352 | FT_LOAD_IGNORE_TRANSFORM;
354 if (FT_Load_Glyph(face, glyph, load_flags))
357 if (point_index >= (unsigned)face->glyph->outline.n_points)
360 *x = face->glyph->outline.points[point_index].x;
361 *y = face->glyph->outline.points[point_index].y;
367 * \brief Retrieve HarfBuzz font from cache.
368 * Create it from FreeType font, if needed.
369 * \param info glyph cluster
370 * \return HarfBuzz font
372 static hb_font_t *get_hb_font(ASS_Shaper *shaper, GlyphInfo *info)
374 ASS_Font *font = info->font;
375 hb_font_t **hb_fonts;
377 if (!font->shaper_priv)
378 font->shaper_priv = calloc(sizeof(ASS_ShaperFontData), 1);
381 hb_fonts = font->shaper_priv->fonts;
382 if (!hb_fonts[info->face_index]) {
383 hb_fonts[info->face_index] =
384 hb_ft_font_create(font->faces[info->face_index], NULL);
386 // set up cached metrics access
387 font->shaper_priv->metrics_data[info->face_index] =
388 calloc(sizeof(struct ass_shaper_metrics_data), 1);
389 struct ass_shaper_metrics_data *metrics =
390 font->shaper_priv->metrics_data[info->face_index];
391 metrics->metrics_cache = shaper->metrics_cache;
392 metrics->vertical = info->font->desc.vertical;
394 hb_font_funcs_t *funcs = hb_font_funcs_create();
395 font->shaper_priv->font_funcs[info->face_index] = funcs;
396 hb_font_funcs_set_glyph_func(funcs, get_glyph,
398 hb_font_funcs_set_glyph_h_advance_func(funcs, cached_h_advance,
400 hb_font_funcs_set_glyph_v_advance_func(funcs, cached_v_advance,
402 hb_font_funcs_set_glyph_h_origin_func(funcs, cached_h_origin,
404 hb_font_funcs_set_glyph_v_origin_func(funcs, cached_v_origin,
406 hb_font_funcs_set_glyph_h_kerning_func(funcs, get_h_kerning,
408 hb_font_funcs_set_glyph_v_kerning_func(funcs, get_v_kerning,
410 hb_font_funcs_set_glyph_extents_func(funcs, cached_extents,
412 hb_font_funcs_set_glyph_contour_point_func(funcs, get_contour_point,
414 hb_font_set_funcs(hb_fonts[info->face_index], funcs,
415 font->faces[info->face_index], NULL);
418 ass_face_set_size(font->faces[info->face_index], info->font_size);
419 update_hb_size(hb_fonts[info->face_index], font->faces[info->face_index]);
421 // update hash key for cached metrics
422 struct ass_shaper_metrics_data *metrics =
423 font->shaper_priv->metrics_data[info->face_index];
424 metrics->hash_key.font = info->font;
425 metrics->hash_key.face_index = info->face_index;
426 metrics->hash_key.size = info->font_size;
427 metrics->hash_key.scale_x = double_to_d6(info->scale_x);
428 metrics->hash_key.scale_y = double_to_d6(info->scale_y);
430 return hb_fonts[info->face_index];
434 * \brief Map script to default language.
436 * This maps a script to a language, if a script has a representative
437 * language it is typically used with. Otherwise, the invalid language
440 * The mapping is similar to Pango's pango-language.c.
442 * \param script script tag
443 * \return language tag
445 static hb_language_t script_to_language(hb_script_t script)
449 case HB_SCRIPT_ARABIC: return hb_language_from_string("ar", -1); break;
450 case HB_SCRIPT_ARMENIAN: return hb_language_from_string("hy", -1); break;
451 case HB_SCRIPT_BENGALI: return hb_language_from_string("bn", -1); break;
452 case HB_SCRIPT_CANADIAN_ABORIGINAL: return hb_language_from_string("iu", -1); break;
453 case HB_SCRIPT_CHEROKEE: return hb_language_from_string("chr", -1); break;
454 case HB_SCRIPT_COPTIC: return hb_language_from_string("cop", -1); break;
455 case HB_SCRIPT_CYRILLIC: return hb_language_from_string("ru", -1); break;
456 case HB_SCRIPT_DEVANAGARI: return hb_language_from_string("hi", -1); break;
457 case HB_SCRIPT_GEORGIAN: return hb_language_from_string("ka", -1); break;
458 case HB_SCRIPT_GREEK: return hb_language_from_string("el", -1); break;
459 case HB_SCRIPT_GUJARATI: return hb_language_from_string("gu", -1); break;
460 case HB_SCRIPT_GURMUKHI: return hb_language_from_string("pa", -1); break;
461 case HB_SCRIPT_HANGUL: return hb_language_from_string("ko", -1); break;
462 case HB_SCRIPT_HEBREW: return hb_language_from_string("he", -1); break;
463 case HB_SCRIPT_HIRAGANA: return hb_language_from_string("ja", -1); break;
464 case HB_SCRIPT_KANNADA: return hb_language_from_string("kn", -1); break;
465 case HB_SCRIPT_KATAKANA: return hb_language_from_string("ja", -1); break;
466 case HB_SCRIPT_LAO: return hb_language_from_string("lo", -1); break;
467 case HB_SCRIPT_LATIN: return hb_language_from_string("en", -1); break;
468 case HB_SCRIPT_MALAYALAM: return hb_language_from_string("ml", -1); break;
469 case HB_SCRIPT_MONGOLIAN: return hb_language_from_string("mn", -1); break;
470 case HB_SCRIPT_ORIYA: return hb_language_from_string("or", -1); break;
471 case HB_SCRIPT_SYRIAC: return hb_language_from_string("syr", -1); break;
472 case HB_SCRIPT_TAMIL: return hb_language_from_string("ta", -1); break;
473 case HB_SCRIPT_TELUGU: return hb_language_from_string("te", -1); break;
474 case HB_SCRIPT_THAI: return hb_language_from_string("th", -1); break;
477 case HB_SCRIPT_TIBETAN: return hb_language_from_string("bo", -1); break;
480 case HB_SCRIPT_ETHIOPIC: return hb_language_from_string("am", -1); break;
481 case HB_SCRIPT_KHMER: return hb_language_from_string("km", -1); break;
482 case HB_SCRIPT_MYANMAR: return hb_language_from_string("my", -1); break;
483 case HB_SCRIPT_SINHALA: return hb_language_from_string("si", -1); break;
484 case HB_SCRIPT_THAANA: return hb_language_from_string("dv", -1); break;
487 case HB_SCRIPT_BUHID: return hb_language_from_string("bku", -1); break;
488 case HB_SCRIPT_HANUNOO: return hb_language_from_string("hnn", -1); break;
489 case HB_SCRIPT_TAGALOG: return hb_language_from_string("tl", -1); break;
490 case HB_SCRIPT_TAGBANWA: return hb_language_from_string("tbw", -1); break;
493 case HB_SCRIPT_UGARITIC: return hb_language_from_string("uga", -1); break;
496 case HB_SCRIPT_BUGINESE: return hb_language_from_string("bug", -1); break;
497 case HB_SCRIPT_OLD_PERSIAN: return hb_language_from_string("peo", -1); break;
498 case HB_SCRIPT_SYLOTI_NAGRI: return hb_language_from_string("syl", -1); break;
501 case HB_SCRIPT_NKO: return hb_language_from_string("nko", -1); break;
503 // no representative language exists
504 default: return HB_LANGUAGE_INVALID; break;
509 * \brief Determine language to be used for shaping a run.
511 * \param shaper shaper instance
512 * \param script script tag associated with run
513 * \return language tag
516 hb_shaper_get_run_language(ASS_Shaper *shaper, hb_script_t script)
520 // override set, use it
521 if (shaper->language != HB_LANGUAGE_INVALID)
522 return shaper->language;
524 // get default language for given script
525 lang = script_to_language(script);
527 // no dice, use system default
528 if (lang == HB_LANGUAGE_INVALID)
529 lang = hb_language_get_default();
535 * \brief Feed a run of shaped characters into the GlyphInfo array.
537 * \param glyphs GlyphInfo array
538 * \param buf buffer of shaped run
539 * \param offset offset into GlyphInfo array
542 shape_harfbuzz_process_run(GlyphInfo *glyphs, hb_buffer_t *buf, int offset)
545 int num_glyphs = hb_buffer_get_length(buf);
546 hb_glyph_info_t *glyph_info = hb_buffer_get_glyph_infos(buf, NULL);
547 hb_glyph_position_t *pos = hb_buffer_get_glyph_positions(buf, NULL);
549 for (j = 0; j < num_glyphs; j++) {
550 unsigned idx = glyph_info[j].cluster + offset;
551 GlyphInfo *info = glyphs + idx;
552 GlyphInfo *root = info;
554 // if we have more than one glyph per cluster, allocate a new one
555 // and attach to the root glyph
556 if (info->skip == 0) {
559 info->next = malloc(sizeof(GlyphInfo));
561 memcpy(info->next, info, sizeof(GlyphInfo));
567 // set position and advance
569 info->glyph_index = glyph_info[j].codepoint;
570 info->offset.x = pos[j].x_offset * info->scale_x;
571 info->offset.y = -pos[j].y_offset * info->scale_y;
572 info->advance.x = pos[j].x_advance * info->scale_x;
573 info->advance.y = -pos[j].y_advance * info->scale_y;
575 // accumulate advance in the root glyph
576 root->cluster_advance.x += info->advance.x;
577 root->cluster_advance.y += info->advance.y;
582 * \brief Shape event text with HarfBuzz. Full OpenType shaping.
583 * \param glyphs glyph clusters
584 * \param len number of clusters
586 static void shape_harfbuzz(ASS_Shaper *shaper, GlyphInfo *glyphs, size_t len)
589 hb_buffer_t *buf = hb_buffer_create();
590 hb_segment_properties_t props = HB_SEGMENT_PROPERTIES_DEFAULT;
592 // Initialize: skip all glyphs, this is undone later as needed
593 for (i = 0; i < len; i++)
596 for (i = 0; i < len; i++) {
598 hb_font_t *font = get_hb_font(shaper, glyphs + offset);
599 int level = glyphs[offset].shape_run_id;
600 int direction = shaper->emblevels[offset] % 2;
602 // advance in text until end of run
603 while (i < (len - 1) && level == glyphs[i+1].shape_run_id)
606 hb_buffer_pre_allocate(buf, i - offset + 1);
607 hb_buffer_add_utf32(buf, shaper->event_text + offset, i - offset + 1,
610 props.direction = direction ? HB_DIRECTION_RTL : HB_DIRECTION_LTR;
611 props.script = glyphs[offset].script;
612 props.language = hb_shaper_get_run_language(shaper, props.script);
613 hb_buffer_set_segment_properties(buf, &props);
615 set_run_features(shaper, glyphs + offset);
616 hb_shape(font, buf, shaper->features, shaper->n_features);
618 shape_harfbuzz_process_run(glyphs, buf, offset);
619 hb_buffer_reset(buf);
622 hb_buffer_destroy(buf);
626 * \brief Determine script property of all characters. Characters of script
627 * common and inherited get their script from their context.
630 void ass_shaper_determine_script(ASS_Shaper *shaper, GlyphInfo *glyphs,
634 int backwards_scan = 0;
635 hb_unicode_funcs_t *ufuncs = hb_unicode_funcs_get_default();
636 hb_script_t last_script = HB_SCRIPT_UNKNOWN;
638 // determine script (forward scan)
639 for (i = 0; i < len; i++) {
640 GlyphInfo *info = glyphs + i;
641 info->script = hb_unicode_script(ufuncs, info->symbol);
643 // common/inherit codepoints inherit script from context
644 if (info->script == HB_SCRIPT_COMMON ||
645 info->script == HB_SCRIPT_INHERITED) {
646 // unknown is not a valid context
647 if (last_script != HB_SCRIPT_UNKNOWN)
648 info->script = last_script;
650 // do a backwards scan to check if next codepoint
651 // contains a valid script for context
654 last_script = info->script;
658 // determine script (backwards scan, if needed)
659 last_script = HB_SCRIPT_UNKNOWN;
660 for (i = len - 1; i >= 0 && backwards_scan; i--) {
661 GlyphInfo *info = glyphs + i;
663 // common/inherit codepoints inherit script from context
664 if (info->script == HB_SCRIPT_COMMON ||
665 info->script == HB_SCRIPT_INHERITED) {
666 // unknown script is not a valid context
667 if (last_script != HB_SCRIPT_UNKNOWN)
668 info->script = last_script;
670 last_script = info->script;
677 * \brief Shape event text with FriBidi. Does mirroring and simple
679 * \param len number of clusters
681 static void shape_fribidi(ASS_Shaper *shaper, GlyphInfo *glyphs, size_t len)
684 FriBidiJoiningType *joins = calloc(sizeof(*joins), len);
686 // shape on codepoint level
687 fribidi_get_joining_types(shaper->event_text, len, joins);
688 fribidi_join_arabic(shaper->ctypes, len, shaper->emblevels, joins);
689 fribidi_shape(FRIBIDI_FLAGS_DEFAULT | FRIBIDI_FLAGS_ARABIC,
690 shaper->emblevels, len, joins, shaper->event_text);
693 for (i = 0; i < len; i++) {
694 GlyphInfo *info = glyphs + i;
695 FT_Face face = info->font->faces[info->face_index];
696 info->symbol = shaper->event_text[i];
697 info->glyph_index = FT_Get_Char_Index(face, ass_font_index_magic(face, shaper->event_text[i]));
704 * \brief Toggle kerning for HarfBuzz shaping.
705 * NOTE: currently only works with OpenType fonts, the TrueType fallback *always*
706 * kerns. It's a bug in HarfBuzz.
708 void ass_shaper_set_kerning(ASS_Shaper *shaper, int kern)
710 #ifdef CONFIG_HARFBUZZ
711 shaper->features[KERN].value = !!kern;
716 * \brief Find shape runs according to the event's selected fonts
718 void ass_shaper_find_runs(ASS_Shaper *shaper, ASS_Renderer *render_priv,
719 GlyphInfo *glyphs, size_t len)
724 #ifdef CONFIG_HARFBUZZ
725 ass_shaper_determine_script(shaper, glyphs, len);
728 // find appropriate fonts for the shape runs
729 for (i = 0; i < len; i++) {
730 GlyphInfo *last = glyphs + i - 1;
731 GlyphInfo *info = glyphs + i;
733 if (info->symbol == 0xfffc)
735 // set size and get glyph index
736 ass_font_get_index(render_priv->fontconfig_priv, info->font,
737 info->symbol, &info->face_index, &info->glyph_index);
738 // shape runs break on: xbord, ybord, xshad, yshad,
739 // all four colors, all four alphas, be, blur, fn, fs,
740 // fscx, fscy, fsp, bold, italic, underline, strikeout,
741 // frx, fry, frz, fax, fay, karaoke start, karaoke type,
742 // and on every line break
743 if (i > 0 && (last->font != info->font ||
744 last->face_index != info->face_index ||
745 last->script != info->script ||
746 last->font_size != info->font_size ||
747 last->c[0] != info->c[0] ||
748 last->c[1] != info->c[1] ||
749 last->c[2] != info->c[2] ||
750 last->c[3] != info->c[3] ||
751 last->be != info->be ||
752 last->blur != info->blur ||
753 last->shadow_x != info->shadow_x ||
754 last->shadow_y != info->shadow_y ||
755 last->frx != info->frx ||
756 last->fry != info->fry ||
757 last->frz != info->frz ||
758 last->fax != info->fax ||
759 last->fay != info->fay ||
760 last->scale_x != info->scale_x ||
761 last->scale_y != info->scale_y ||
762 last->border_style != info->border_style ||
763 last->border_x != info->border_x ||
764 last->border_y != info->border_y ||
765 last->hspacing != info->hspacing ||
766 last->italic != info->italic ||
767 last->bold != info->bold ||
768 last->flags != info->flags))
770 info->shape_run_id = shape_run;
775 * \brief Set base direction (paragraph direction) of the text.
776 * \param dir base direction
778 void ass_shaper_set_base_direction(ASS_Shaper *shaper, FriBidiParType dir)
780 shaper->base_direction = dir;
784 * \brief Set language hint. Some languages have specific character variants,
785 * like Serbian Cyrillic.
786 * \param lang ISO 639-1 two-letter language code
788 void ass_shaper_set_language(ASS_Shaper *shaper, const char *code)
790 #ifdef CONFIG_HARFBUZZ
794 lang = hb_language_from_string(code, -1);
796 lang = HB_LANGUAGE_INVALID;
798 shaper->language = lang;
803 * Set shaping level. Essentially switches between FriBidi and HarfBuzz.
805 void ass_shaper_set_level(ASS_Shaper *shaper, ASS_ShapingLevel level)
807 shaper->shaping_level = level;
811 * \brief Remove all zero-width invisible characters from the text.
812 * \param text_info text
814 static void ass_shaper_skip_characters(TextInfo *text_info)
817 GlyphInfo *glyphs = text_info->glyphs;
819 for (i = 0; i < text_info->length; i++) {
820 // Skip direction override control characters
821 if ((glyphs[i].symbol <= 0x202e && glyphs[i].symbol >= 0x202a)
822 || (glyphs[i].symbol <= 0x200f && glyphs[i].symbol >= 0x200b)
823 || (glyphs[i].symbol <= 0x2063 && glyphs[i].symbol >= 0x2060)
824 || glyphs[i].symbol == 0xfeff
825 || glyphs[i].symbol == 0x00ad
826 || glyphs[i].symbol == 0x034f) {
827 glyphs[i].symbol = 0;
834 * \brief Shape an event's text. Calculates directional runs and shapes them.
835 * \param text_info event's text
836 * \return success, when 0
838 int ass_shaper_shape(ASS_Shaper *shaper, TextInfo *text_info)
840 int i, ret, last_break;
842 GlyphInfo *glyphs = text_info->glyphs;
844 if (!check_allocations(shaper, text_info->length))
847 // Get bidi character types and embedding levels
849 for (i = 0; i < text_info->length; i++) {
850 shaper->event_text[i] = glyphs[i].symbol;
851 // embedding levels should be calculated paragraph by paragraph
852 if (glyphs[i].symbol == '\n' || i == text_info->length - 1) {
853 dir = shaper->base_direction;
854 fribidi_get_bidi_types(shaper->event_text + last_break,
855 i - last_break + 1, shaper->ctypes + last_break);
856 ret = fribidi_get_par_embedding_levels(shaper->ctypes + last_break,
857 i - last_break + 1, &dir, shaper->emblevels + last_break);
864 // add embedding levels to shape runs for final runs
865 for (i = 0; i < text_info->length; i++) {
866 glyphs[i].shape_run_id += shaper->emblevels[i];
869 #ifdef CONFIG_HARFBUZZ
870 switch (shaper->shaping_level) {
871 case ASS_SHAPING_SIMPLE:
872 shape_fribidi(shaper, glyphs, text_info->length);
873 ass_shaper_skip_characters(text_info);
875 case ASS_SHAPING_COMPLEX:
876 shape_harfbuzz(shaper, glyphs, text_info->length);
880 shape_fribidi(shaper, glyphs, text_info->length);
881 ass_shaper_skip_characters(text_info);
888 * \brief Create a new shaper instance and preallocate data structures
889 * \param prealloc preallocation size
891 ASS_Shaper *ass_shaper_new(size_t prealloc)
893 ASS_Shaper *shaper = calloc(sizeof(*shaper), 1);
897 shaper->base_direction = FRIBIDI_PAR_ON;
898 if (!check_allocations(shaper, prealloc))
901 #ifdef CONFIG_HARFBUZZ
902 if (!init_features(shaper))
904 shaper->metrics_cache = ass_glyph_metrics_cache_create();
905 if (!shaper->metrics_cache)
912 ass_shaper_free(shaper);
918 * \brief clean up additional data temporarily needed for shaping and
919 * (e.g. additional glyphs allocated)
921 void ass_shaper_cleanup(ASS_Shaper *shaper, TextInfo *text_info)
925 for (i = 0; i < text_info->length; i++) {
926 GlyphInfo *info = text_info->glyphs + i;
929 GlyphInfo *next = info->next;
937 * \brief Calculate reorder map to render glyphs in visual order
938 * \param shaper shaper instance
939 * \param text_info text to be reordered
940 * \return map of reordered characters, or NULL
942 FriBidiStrIndex *ass_shaper_reorder(ASS_Shaper *shaper, TextInfo *text_info)
946 // Initialize reorder map
947 for (i = 0; i < text_info->length; i++)
950 // Create reorder map line-by-line
951 for (i = 0; i < text_info->n_lines; i++) {
952 LineInfo *line = text_info->lines + i;
953 FriBidiParType dir = FRIBIDI_PAR_ON;
955 ret = fribidi_reorder_line(0,
956 shaper->ctypes + line->offset, line->len, 0, dir,
957 shaper->emblevels + line->offset, NULL,
958 shaper->cmap + line->offset);
967 * \brief Resolve a Windows font charset number to a suitable
968 * base direction. 177 and 178 are Hebrew and Arabic respectively, and
969 * they map to RTL. Everything else maps to LTR for compatibility
970 * reasons. The special value -1, which is not a legal Windows font charset
971 * number, can be used for autodetection.
972 * \param enc Windows font encoding
974 FriBidiParType resolve_base_direction(int enc)
978 return FRIBIDI_PAR_ON;
981 return FRIBIDI_PAR_RTL;
983 return FRIBIDI_PAR_LTR;