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.
19 #include <fribidi/fribidi.h>
22 #include "ass_shaper.h"
23 #include "ass_render.h"
25 #include "ass_parse.h"
34 #define NUM_FEATURES 3
39 FriBidiChar *event_text;
40 FriBidiCharType *ctypes;
41 FriBidiLevel *emblevels;
42 FriBidiStrIndex *cmap;
43 FriBidiParType base_direction;
46 hb_feature_t *features;
49 struct ass_shaper_font_data {
50 hb_font_t *fonts[ASS_FONT_MAX_FACES];
54 * \brief Print version information
56 void ass_shaper_info(ASS_Library *lib)
58 ass_msg(lib, MSGL_V, "Complex text layout enabled, using FriBidi "
59 FRIBIDI_VERSION " HarfBuzz-ng %s", hb_version_string());
63 * \brief grow arrays, if needed
64 * \param new_size requested size
66 static void check_allocations(ASS_Shaper *shaper, size_t new_size)
68 if (new_size > shaper->n_glyphs) {
69 shaper->event_text = realloc(shaper->event_text, sizeof(FriBidiChar) * new_size);
70 shaper->ctypes = realloc(shaper->ctypes, sizeof(FriBidiCharType) * new_size);
71 shaper->emblevels = realloc(shaper->emblevels, sizeof(FriBidiLevel) * new_size);
72 shaper->cmap = realloc(shaper->cmap, sizeof(FriBidiStrIndex) * new_size);
77 * \brief set up the HarfBuzz OpenType feature list with some
80 static void init_features(ASS_Shaper *shaper)
82 shaper->features = calloc(sizeof(hb_feature_t), NUM_FEATURES);
84 shaper->n_features = NUM_FEATURES;
85 shaper->features[VERT].tag = HB_TAG('v', 'e', 'r', 't');
86 shaper->features[VERT].end = INT_MAX;
87 shaper->features[VKNA].tag = HB_TAG('v', 'k', 'n', 'a');
88 shaper->features[VKNA].end = INT_MAX;
89 shaper->features[KERN].tag = HB_TAG('k', 'e', 'r', 'n');
90 shaper->features[KERN].end = INT_MAX;
94 * \brief Create a new shaper instance and preallocate data structures
95 * \param prealloc preallocation size
97 ASS_Shaper *ass_shaper_new(size_t prealloc)
99 ASS_Shaper *shaper = calloc(sizeof(*shaper), 1);
101 shaper->base_direction = FRIBIDI_PAR_ON;
102 init_features(shaper);
103 check_allocations(shaper, prealloc);
109 * \brief Free shaper and related data
111 void ass_shaper_free(ASS_Shaper *shaper)
113 free(shaper->event_text);
114 free(shaper->ctypes);
115 free(shaper->emblevels);
117 free(shaper->features);
121 void ass_shaper_font_data_free(ASS_ShaperFontData *priv)
124 for (i = 0; i < ASS_FONT_MAX_FACES; i++)
126 hb_font_destroy(priv->fonts[i]);
131 * \brief Set features depending on properties of the run
133 static void set_run_features(ASS_Shaper *shaper, GlyphInfo *info)
135 // enable vertical substitutions for @font runs
136 if (info->font->desc.vertical)
137 shaper->features[VERT].value = shaper->features[VKNA].value = 1;
139 shaper->features[VERT].value = shaper->features[VKNA].value = 0;
143 * \brief Update HarfBuzz's idea of font metrics
144 * \param hb_font HarfBuzz font
145 * \param face associated FreeType font face
147 static void update_hb_size(hb_font_t *hb_font, FT_Face face)
149 hb_font_set_scale (hb_font,
150 ((uint64_t) face->size->metrics.x_scale * (uint64_t) face->units_per_EM) >> 16,
151 ((uint64_t) face->size->metrics.y_scale * (uint64_t) face->units_per_EM) >> 16);
152 hb_font_set_ppem (hb_font, face->size->metrics.x_ppem,
153 face->size->metrics.y_ppem);
157 * \brief Retrieve HarfBuzz font from cache.
158 * Create it from FreeType font, if needed.
159 * \param info glyph cluster
160 * \return HarfBuzz font
162 static hb_font_t *get_hb_font(GlyphInfo *info)
164 ASS_Font *font = info->font;
165 hb_font_t **hb_fonts;
167 if (!font->shaper_priv)
168 font->shaper_priv = calloc(sizeof(ASS_ShaperFontData), 1);
171 hb_fonts = font->shaper_priv->fonts;
172 if (!hb_fonts[info->face_index])
173 hb_fonts[info->face_index] =
174 hb_ft_font_create(font->faces[info->face_index], NULL);
176 ass_face_set_size(font->faces[info->face_index], info->font_size);
177 update_hb_size(hb_fonts[info->face_index], font->faces[info->face_index]);
179 return hb_fonts[info->face_index];
183 * \brief Shape event text with HarfBuzz. Full OpenType shaping.
184 * \param glyphs glyph clusters
185 * \param len number of clusters
187 static void shape_harfbuzz(ASS_Shaper *shaper, GlyphInfo *glyphs, size_t len)
199 for (i = 0; i < len && run < MAX_RUNS; i++, run++) {
200 // get length and level of the current run
202 int level = glyphs[i].shape_run_id;
203 int direction = shaper->emblevels[k] % 2;
204 while (i < (len - 1) && level == glyphs[i+1].shape_run_id)
206 //printf("run %d from %d to %d with level %d\n", run, k, i, level);
207 runs[run].offset = k;
209 runs[run].buf = hb_buffer_create(i - k + 1);
210 runs[run].font = get_hb_font(glyphs + k);
211 set_run_features(shaper, glyphs + k);
212 hb_buffer_set_direction(runs[run].buf, direction ? HB_DIRECTION_RTL :
214 hb_buffer_add_utf32(runs[run].buf, shaper->event_text + k, i - k + 1,
216 hb_shape(runs[run].font, runs[run].buf, shaper->features,
219 //printf("shaped %d runs\n", run);
221 // Initialize: skip all glyphs, this is undone later as needed
222 for (i = 0; i < len; i++)
225 // Update glyph indexes, positions and advances from the shaped runs
226 for (i = 0; i < run; i++) {
227 int num_glyphs = hb_buffer_get_length(runs[i].buf);
228 hb_glyph_info_t *glyph_info = hb_buffer_get_glyph_infos(runs[i].buf, NULL);
229 hb_glyph_position_t *pos = hb_buffer_get_glyph_positions(runs[i].buf, NULL);
230 //printf("run text len %d num_glyphs %d\n", runs[i].end - runs[i].offset + 1,
233 for (j = 0; j < num_glyphs; j++) {
234 int idx = glyph_info[j].cluster + runs[i].offset;
235 GlyphInfo *info = glyphs + idx;
236 GlyphInfo *root = info;
238 printf("run %d cluster %d codepoint %d -> '%c'\n", i, idx,
239 glyph_info[j].codepoint, event_text[idx]);
240 printf("position %d %d advance %d %d\n",
241 pos[j].x_offset, pos[j].y_offset,
242 pos[j].x_advance, pos[j].y_advance);
245 // if we have more than one glyph per cluster, allocate a new one
246 // and attach to the root glyph
247 if (info->skip == 0) {
248 //printf("duplicate cluster entry, adding glyph\n");
251 info->next = malloc(sizeof(GlyphInfo));
252 memcpy(info->next, info, sizeof(GlyphInfo));
257 // set position and advance
259 info->glyph_index = glyph_info[j].codepoint;
260 info->offset.x = pos[j].x_offset * info->scale_x;
261 info->offset.y = -pos[j].y_offset * info->scale_y;
262 info->advance.x = pos[j].x_advance * info->scale_x;
263 info->advance.y = -pos[j].y_advance * info->scale_y;
265 // accumulate advance in the root glyph
266 root->cluster_advance.x += info->advance.x;
267 root->cluster_advance.y += info->advance.y;
271 // Free runs and associated data
272 for (i = 0; i < run; i++) {
273 hb_buffer_destroy(runs[i].buf);
279 * \brief Shape event text with FriBidi. Does mirroring and simple
281 * \param len number of clusters
283 static void shape_fribidi(ASS_Shaper *shaper, size_t len)
285 FriBidiJoiningType *joins = calloc(sizeof(*joins), len);
287 fribidi_get_joining_types(shaper->event_text, len, joins);
288 fribidi_join_arabic(shaper->ctypes, len, shaper->emblevels, joins);
289 fribidi_shape(FRIBIDI_FLAGS_DEFAULT | FRIBIDI_FLAGS_ARABIC,
290 shaper->emblevels, len, joins, shaper->event_text);
296 * \brief Toggle kerning for HarfBuzz shaping.
297 * NOTE: currently only works with OpenType fonts, the TrueType fallback *always*
298 * kerns. It's a bug in HarfBuzz.
300 void ass_shaper_set_kerning(ASS_Shaper *shaper, int kern)
302 shaper->features[KERN].value = !!kern;
306 * \brief Find shape runs according to the event's selected fonts
308 void ass_shaper_find_runs(ASS_Shaper *shaper, ASS_Renderer *render_priv,
309 GlyphInfo *glyphs, size_t len)
314 for (i = 0; i < len; i++) {
315 GlyphInfo *last = glyphs + i - 1;
316 GlyphInfo *info = glyphs + i;
318 if (info->symbol == 0xfffc)
320 // initialize face_index to continue with the same face, if possible
321 // XXX: can be problematic in some cases, for example if a font misses
322 // a single glyph, like space (U+0020)
324 info->face_index = last->face_index;
325 // set size and get glyph index
326 ass_font_get_index(render_priv->fontconfig_priv, info->font,
327 info->symbol, &info->face_index, &info->glyph_index);
328 // shape runs share the same font face and size
329 if (i > 0 && (last->font != info->font ||
330 last->font_size != info->font_size ||
331 last->face_index != info->face_index))
333 info->shape_run_id = shape_run;
334 //printf("glyph '%c' shape run id %d face %d\n", info->symbol, info->shape_run_id,
335 // info->face_index);
341 * \brief Set base direction (paragraph direction) of the text.
342 * \param dir base direction
344 void ass_shaper_set_base_direction(ASS_Shaper *shaper, FriBidiParType dir)
346 shaper->base_direction = dir;
350 * \brief Shape an event's text. Calculates directional runs and shapes them.
351 * \param text_info event's text
353 void ass_shaper_shape(ASS_Shaper *shaper, TextInfo *text_info)
357 GlyphInfo *glyphs = text_info->glyphs;
359 check_allocations(shaper, text_info->length);
361 // Get bidi character types and embedding levels
363 for (i = 0; i < text_info->length; i++) {
364 shaper->event_text[i] = glyphs[i].symbol;
365 // embedding levels should be calculated paragraph by paragraph
366 if (glyphs[i].symbol == '\n' || i == text_info->length - 1) {
367 //printf("paragraph from %d to %d\n", last_break, i);
368 dir = shaper->base_direction;
369 fribidi_get_bidi_types(shaper->event_text + last_break,
370 i - last_break + 1, shaper->ctypes + last_break);
371 fribidi_get_par_embedding_levels(shaper->ctypes + last_break,
372 i - last_break + 1, &dir, shaper->emblevels + last_break);
377 // add embedding levels to shape runs for final runs
378 for (i = 0; i < text_info->length; i++) {
379 glyphs[i].shape_run_id += shaper->emblevels[i];
384 for (i = 0; i < text_info->length; i++) {
385 printf("%d ", glyphs[i].shape_run_id);
390 //shape_fribidi(shaper, text_info->length);
391 shape_harfbuzz(shaper, glyphs, text_info->length);
394 for (i = 0; i < text_info->length; i++) {
395 glyphs[i].symbol = shaper->event_text[i];
396 // Skip direction override control characters
397 // NOTE: Behdad said HarfBuzz is supposed to remove these, but this hasn't
398 // been implemented yet
399 if (glyphs[i].symbol <= 0x202F && glyphs[i].symbol >= 0x202a) {
400 glyphs[i].symbol = 0;
407 * \brief clean up additional data temporarily needed for shaping and
408 * (e.g. additional glyphs allocated)
410 void ass_shaper_cleanup(ASS_Shaper *shaper, TextInfo *text_info)
414 for (i = 0; i < text_info->length; i++) {
415 GlyphInfo *info = text_info->glyphs + i;
418 GlyphInfo *next = info->next;
426 * \brief Calculate reorder map to render glyphs in visual order
428 FriBidiStrIndex *ass_shaper_reorder(ASS_Shaper *shaper, TextInfo *text_info)
432 // Initialize reorder map
433 for (i = 0; i < text_info->length; i++)
436 // Create reorder map line-by-line
437 for (i = 0; i < text_info->n_lines; i++) {
438 LineInfo *line = text_info->lines + i;
440 FriBidiParType dir = FRIBIDI_PAR_ON;
442 // FIXME: we should actually specify
443 // the correct paragraph base direction
444 level = fribidi_reorder_line(FRIBIDI_FLAGS_DEFAULT,
445 shaper->ctypes + line->offset, line->len, 0, dir,
446 shaper->emblevels + line->offset, NULL,
447 shaper->cmap + line->offset);
448 //printf("reorder line %d to level %d\n", i, level);
453 for (i = 0; i < text_info->length; i++) {
454 printf("%d ", cmap[i]);
463 * \brief Resolve a Windows font encoding number to a suitable
464 * base direction. 177 and 178 are Hebrew and Arabic respectively, and
465 * they map to RTL. 1 is autodetection and is mapped to just that.
466 * Everything else is mapped to LTR.
467 * \param enc Windows font encoding
469 FriBidiParType resolve_base_direction(int enc)
473 return FRIBIDI_PAR_ON;
476 return FRIBIDI_PAR_RTL;
478 return FRIBIDI_PAR_LTR;