1/*
2 * Copyright © 2011 Martin Hosken
3 * Copyright © 2011 SIL International
4 * Copyright © 2011,2012 Google, Inc.
5 *
6 * This is part of HarfBuzz, a text shaping library.
7 *
8 * Permission is hereby granted, without written agreement and without
9 * license or royalty fees, to use, copy, modify, and distribute this
10 * software and its documentation for any purpose, provided that the
11 * above copyright notice and the following two paragraphs appear in
12 * all copies of this software.
13 *
14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * DAMAGE.
19 *
20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 *
26 * Google Author(s): Behdad Esfahbod
27 */
28
29#include "hb.hh"
30
31#ifdef HAVE_GRAPHITE2
32
33#include "hb-shaper-impl.hh"
34
35#include "hb-graphite2.h"
36
37#include <graphite2/Segment.h>
38
39#include "hb-ot-layout.h"
40
41
42/**
43 * SECTION:hb-graphite2
44 * @title: hb-graphite2
45 * @short_description: Graphite2 integration
46 * @include: hb-graphite2.h
47 *
48 * Functions for using HarfBuzz with fonts that include Graphite features.
49 *
50 * For Graphite features to work, you must be sure that HarfBuzz was compiled
51 * with the `graphite2` shaping engine enabled. Currently, the default is to
52 * not enable `graphite2` shaping.
53 **/
54
55
56/*
57 * shaper face data
58 */
59
60typedef struct hb_graphite2_tablelist_t
61{
62 struct hb_graphite2_tablelist_t *next;
63 hb_blob_t *blob;
64 unsigned int tag;
65} hb_graphite2_tablelist_t;
66
67struct hb_graphite2_face_data_t
68{
69 hb_face_t *face;
70 gr_face *grface;
71 hb_atomic_ptr_t<hb_graphite2_tablelist_t> tlist;
72};
73
74static const void *hb_graphite2_get_table (const void *data, unsigned int tag, size_t *len)
75{
76 hb_graphite2_face_data_t *face_data = (hb_graphite2_face_data_t *) data;
77 hb_graphite2_tablelist_t *tlist = face_data->tlist;
78
79 hb_blob_t *blob = nullptr;
80
81 for (hb_graphite2_tablelist_t *p = tlist; p; p = p->next)
82 if (p->tag == tag) {
83 blob = p->blob;
84 break;
85 }
86
87 if (unlikely (!blob))
88 {
89 blob = face_data->face->reference_table (tag);
90
91 hb_graphite2_tablelist_t *p = (hb_graphite2_tablelist_t *) hb_calloc (1, sizeof (hb_graphite2_tablelist_t));
92 if (unlikely (!p)) {
93 hb_blob_destroy (blob);
94 return nullptr;
95 }
96 p->blob = blob;
97 p->tag = tag;
98
99retry:
100 hb_graphite2_tablelist_t *tlist = face_data->tlist;
101 p->next = tlist;
102
103 if (unlikely (!face_data->tlist.cmpexch (tlist, p)))
104 goto retry;
105 }
106
107 unsigned int tlen;
108 const char *d = hb_blob_get_data (blob, &tlen);
109 *len = tlen;
110 return d;
111}
112
113hb_graphite2_face_data_t *
114_hb_graphite2_shaper_face_data_create (hb_face_t *face)
115{
116 hb_blob_t *silf_blob = face->reference_table (HB_GRAPHITE2_TAG_SILF);
117 /* Umm, we just reference the table to check whether it exists.
118 * Maybe add better API for this? */
119 if (!hb_blob_get_length (silf_blob))
120 {
121 hb_blob_destroy (silf_blob);
122 return nullptr;
123 }
124 hb_blob_destroy (silf_blob);
125
126 hb_graphite2_face_data_t *data = (hb_graphite2_face_data_t *) hb_calloc (1, sizeof (hb_graphite2_face_data_t));
127 if (unlikely (!data))
128 return nullptr;
129
130 data->face = face;
131 const gr_face_ops ops = {sizeof(gr_face_ops), &hb_graphite2_get_table, NULL};
132 data->grface = gr_make_face_with_ops (data, &ops, gr_face_preloadAll);
133
134 if (unlikely (!data->grface)) {
135 hb_free (data);
136 return nullptr;
137 }
138
139 return data;
140}
141
142void
143_hb_graphite2_shaper_face_data_destroy (hb_graphite2_face_data_t *data)
144{
145 hb_graphite2_tablelist_t *tlist = data->tlist;
146
147 while (tlist)
148 {
149 hb_graphite2_tablelist_t *old = tlist;
150 hb_blob_destroy (tlist->blob);
151 tlist = tlist->next;
152 hb_free (old);
153 }
154
155 gr_face_destroy (data->grface);
156
157 hb_free (data);
158}
159
160/**
161 * hb_graphite2_face_get_gr_face: (skip)
162 * @face: @hb_face_t to query
163 *
164 * Fetches the Graphite2 gr_face corresponding to the specified
165 * #hb_face_t face object.
166 *
167 * Return value: the gr_face found
168 *
169 * Since: 0.9.10
170 */
171gr_face *
172hb_graphite2_face_get_gr_face (hb_face_t *face)
173{
174 const hb_graphite2_face_data_t *data = face->data.graphite2;
175 return data ? data->grface : nullptr;
176}
177
178
179/*
180 * shaper font data
181 */
182
183struct hb_graphite2_font_data_t {};
184
185hb_graphite2_font_data_t *
186_hb_graphite2_shaper_font_data_create (hb_font_t *font HB_UNUSED)
187{
188 return (hb_graphite2_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
189}
190
191void
192_hb_graphite2_shaper_font_data_destroy (hb_graphite2_font_data_t *data HB_UNUSED)
193{
194}
195
196#ifndef HB_DISABLE_DEPRECATED
197/**
198 * hb_graphite2_font_get_gr_font: (skip)
199 * @font: An #hb_font_t
200 *
201 * Always returns `NULL`. Use hb_graphite2_face_get_gr_face() instead.
202 *
203 * Return value: (nullable): Graphite2 font associated with @font.
204 *
205 * Since: 0.9.10
206 * Deprecated: 1.4.2
207 */
208gr_font *
209hb_graphite2_font_get_gr_font (hb_font_t *font HB_UNUSED)
210{
211 return nullptr;
212}
213#endif
214
215
216/*
217 * shaper
218 */
219
220struct hb_graphite2_cluster_t {
221 unsigned int base_char;
222 unsigned int num_chars;
223 unsigned int base_glyph;
224 unsigned int num_glyphs;
225 unsigned int cluster;
226 int advance;
227};
228
229hb_bool_t
230_hb_graphite2_shape (hb_shape_plan_t *shape_plan HB_UNUSED,
231 hb_font_t *font,
232 hb_buffer_t *buffer,
233 const hb_feature_t *features,
234 unsigned int num_features)
235{
236 hb_face_t *face = font->face;
237 gr_face *grface = face->data.graphite2->grface;
238
239 const char *lang = hb_language_to_string (hb_buffer_get_language (buffer));
240 const char *lang_end = lang ? strchr (lang, '-') : nullptr;
241 int lang_len = lang_end ? lang_end - lang : -1;
242 gr_feature_val *feats = gr_face_featureval_for_lang (grface, lang ? hb_tag_from_string (lang, lang_len) : 0);
243
244 for (unsigned int i = 0; i < num_features; i++)
245 {
246 const gr_feature_ref *fref = gr_face_find_fref (grface, features[i].tag);
247 if (fref)
248 gr_fref_set_feature_value (fref, features[i].value, feats);
249 }
250
251 hb_direction_t direction = buffer->props.direction;
252 hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
253 /* TODO vertical:
254 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
255 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
256 * first. */
257 if ((HB_DIRECTION_IS_HORIZONTAL (direction) &&
258 direction != horiz_dir && horiz_dir != HB_DIRECTION_INVALID) ||
259 (HB_DIRECTION_IS_VERTICAL (direction) &&
260 direction != HB_DIRECTION_TTB))
261 {
262 hb_buffer_reverse_clusters (buffer);
263 direction = HB_DIRECTION_REVERSE (direction);
264 }
265
266 gr_segment *seg = nullptr;
267 const gr_slot *is;
268 unsigned int ci = 0, ic = 0;
269 unsigned int curradvx = 0, curradvy = 0;
270
271 unsigned int scratch_size;
272 hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
273
274 uint32_t *chars = (uint32_t *) scratch;
275
276 for (unsigned int i = 0; i < buffer->len; ++i)
277 chars[i] = buffer->info[i].codepoint;
278
279 seg = gr_make_seg (nullptr, grface,
280 HB_TAG_NONE, // https://github.com/harfbuzz/harfbuzz/issues/3439#issuecomment-1442650148
281 feats,
282 gr_utf32, chars, buffer->len,
283 2 | (direction == HB_DIRECTION_RTL ? 1 : 0));
284
285 if (unlikely (!seg)) {
286 if (feats) gr_featureval_destroy (feats);
287 return false;
288 }
289
290 unsigned int glyph_count = gr_seg_n_slots (seg);
291 if (unlikely (!glyph_count)) {
292 if (feats) gr_featureval_destroy (feats);
293 gr_seg_destroy (seg);
294 buffer->len = 0;
295 return true;
296 }
297
298 (void) buffer->ensure (glyph_count);
299 scratch = buffer->get_scratch_buffer (&scratch_size);
300 while ((DIV_CEIL (sizeof (hb_graphite2_cluster_t) * buffer->len, sizeof (*scratch)) +
301 DIV_CEIL (sizeof (hb_codepoint_t) * glyph_count, sizeof (*scratch))) > scratch_size)
302 {
303 if (unlikely (!buffer->ensure (buffer->allocated * 2)))
304 {
305 if (feats) gr_featureval_destroy (feats);
306 gr_seg_destroy (seg);
307 return false;
308 }
309 scratch = buffer->get_scratch_buffer (&scratch_size);
310 }
311
312#define ALLOCATE_ARRAY(Type, name, len) \
313 Type *name = (Type *) scratch; \
314 do { \
315 unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
316 assert (_consumed <= scratch_size); \
317 scratch += _consumed; \
318 scratch_size -= _consumed; \
319 } while (0)
320
321 ALLOCATE_ARRAY (hb_graphite2_cluster_t, clusters, buffer->len);
322 ALLOCATE_ARRAY (hb_codepoint_t, gids, glyph_count);
323
324#undef ALLOCATE_ARRAY
325
326 hb_memset (clusters, 0, sizeof (clusters[0]) * buffer->len);
327
328 hb_codepoint_t *pg = gids;
329 clusters[0].cluster = buffer->info[0].cluster;
330 unsigned int upem = hb_face_get_upem (face);
331 float xscale = (float) font->x_scale / upem;
332 float yscale = (float) font->y_scale / upem;
333 yscale *= yscale / xscale;
334 unsigned int curradv = 0;
335 if (HB_DIRECTION_IS_BACKWARD (direction))
336 {
337 curradv = gr_slot_origin_X(gr_seg_first_slot(seg)) * xscale;
338 clusters[0].advance = gr_seg_advance_X(seg) * xscale - curradv;
339 }
340 else
341 clusters[0].advance = 0;
342 for (is = gr_seg_first_slot (seg), ic = 0; is; is = gr_slot_next_in_segment (is), ic++)
343 {
344 unsigned int before = gr_slot_before (is);
345 unsigned int after = gr_slot_after (is);
346 *pg = gr_slot_gid (is);
347 pg++;
348 while (clusters[ci].base_char > before && ci)
349 {
350 clusters[ci-1].num_chars += clusters[ci].num_chars;
351 clusters[ci-1].num_glyphs += clusters[ci].num_glyphs;
352 clusters[ci-1].advance += clusters[ci].advance;
353 ci--;
354 }
355
356 if (gr_slot_can_insert_before (is) && clusters[ci].num_chars && before >= clusters[ci].base_char + clusters[ci].num_chars)
357 {
358 hb_graphite2_cluster_t *c = clusters + ci + 1;
359 c->base_char = clusters[ci].base_char + clusters[ci].num_chars;
360 c->cluster = buffer->info[c->base_char].cluster;
361 c->num_chars = before - c->base_char;
362 c->base_glyph = ic;
363 c->num_glyphs = 0;
364 if (HB_DIRECTION_IS_BACKWARD (direction))
365 {
366 c->advance = curradv - gr_slot_origin_X(is) * xscale;
367 curradv -= c->advance;
368 }
369 else
370 {
371 auto origin_X = gr_slot_origin_X (is) * xscale;
372 c->advance = 0;
373 clusters[ci].advance += origin_X - curradv;
374 curradv = origin_X;
375 }
376 ci++;
377 }
378 clusters[ci].num_glyphs++;
379
380 if (clusters[ci].base_char + clusters[ci].num_chars < after + 1)
381 clusters[ci].num_chars = after + 1 - clusters[ci].base_char;
382 }
383
384 if (HB_DIRECTION_IS_BACKWARD (direction))
385 clusters[ci].advance += curradv;
386 else
387 clusters[ci].advance += gr_seg_advance_X(seg) * xscale - curradv;
388 ci++;
389
390 for (unsigned int i = 0; i < ci; ++i)
391 {
392 for (unsigned int j = 0; j < clusters[i].num_glyphs; ++j)
393 {
394 hb_glyph_info_t *info = &buffer->info[clusters[i].base_glyph + j];
395 info->codepoint = gids[clusters[i].base_glyph + j];
396 info->cluster = clusters[i].cluster;
397 info->var1.i32 = clusters[i].advance; // all glyphs in the cluster get the same advance
398 }
399 }
400 buffer->len = glyph_count;
401
402 /* Positioning. */
403 unsigned int currclus = UINT_MAX;
404 const hb_glyph_info_t *info = buffer->info;
405 hb_glyph_position_t *pPos = hb_buffer_get_glyph_positions (buffer, nullptr);
406 if (!HB_DIRECTION_IS_BACKWARD (direction))
407 {
408 curradvx = 0;
409 for (is = gr_seg_first_slot (seg); is; pPos++, ++info, is = gr_slot_next_in_segment (is))
410 {
411 pPos->x_offset = gr_slot_origin_X (is) * xscale - curradvx;
412 pPos->y_offset = gr_slot_origin_Y (is) * yscale - curradvy;
413 if (info->cluster != currclus) {
414 pPos->x_advance = info->var1.i32;
415 curradvx += pPos->x_advance;
416 currclus = info->cluster;
417 } else
418 pPos->x_advance = 0.;
419
420 pPos->y_advance = gr_slot_advance_Y (is, grface, nullptr) * yscale;
421 curradvy += pPos->y_advance;
422 }
423 }
424 else
425 {
426 curradvx = gr_seg_advance_X(seg) * xscale;
427 for (is = gr_seg_first_slot (seg); is; pPos++, info++, is = gr_slot_next_in_segment (is))
428 {
429 if (info->cluster != currclus)
430 {
431 pPos->x_advance = info->var1.i32;
432 curradvx -= pPos->x_advance;
433 currclus = info->cluster;
434 } else
435 pPos->x_advance = 0.;
436
437 pPos->y_advance = gr_slot_advance_Y (is, grface, nullptr) * yscale;
438 curradvy -= pPos->y_advance;
439 pPos->x_offset = gr_slot_origin_X (is) * xscale - info->var1.i32 - curradvx + pPos->x_advance;
440 pPos->y_offset = gr_slot_origin_Y (is) * yscale - curradvy;
441 }
442 hb_buffer_reverse_clusters (buffer);
443 }
444
445 if (feats) gr_featureval_destroy (feats);
446 gr_seg_destroy (seg);
447
448 buffer->clear_glyph_flags ();
449 buffer->unsafe_to_break ();
450
451 return true;
452}
453
454
455#endif
456