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 *) 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 *) calloc (1, sizeof (hb_graphite2_face_data_t));
127 if (unlikely (!data))
128 return nullptr;
129
130 data->face = face;
131 data->grface = gr_make_face (data, &hb_graphite2_get_table, gr_face_preloadAll);
132
133 if (unlikely (!data->grface)) {
134 free (data);
135 return nullptr;
136 }
137
138 return data;
139}
140
141void
142_hb_graphite2_shaper_face_data_destroy (hb_graphite2_face_data_t *data)
143{
144 hb_graphite2_tablelist_t *tlist = data->tlist;
145
146 while (tlist)
147 {
148 hb_graphite2_tablelist_t *old = tlist;
149 hb_blob_destroy (tlist->blob);
150 tlist = tlist->next;
151 free (old);
152 }
153
154 gr_face_destroy (data->grface);
155
156 free (data);
157}
158
159/**
160 * hb_graphite2_face_get_gr_face:
161 * @face: @hb_face_t to query
162 *
163 * Fetches the Graphite2 gr_face corresponding to the specified
164 * #hb_face_t face object.
165 *
166 * Return value: the gr_face found
167 *
168 * Since: 0.9.10
169 */
170gr_face *
171hb_graphite2_face_get_gr_face (hb_face_t *face)
172{
173 const hb_graphite2_face_data_t *data = face->data.graphite2;
174 return data ? data->grface : nullptr;
175}
176
177
178/*
179 * shaper font data
180 */
181
182struct hb_graphite2_font_data_t {};
183
184hb_graphite2_font_data_t *
185_hb_graphite2_shaper_font_data_create (hb_font_t *font HB_UNUSED)
186{
187 return (hb_graphite2_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
188}
189
190void
191_hb_graphite2_shaper_font_data_destroy (hb_graphite2_font_data_t *data HB_UNUSED)
192{
193}
194
195#ifndef HB_DISABLE_DEPRECATED
196/**
197 * hb_graphite2_font_get_gr_font:
198 *
199 * Since: 0.9.10
200 * Deprecated: 1.4.2
201 */
202gr_font *
203hb_graphite2_font_get_gr_font (hb_font_t *font HB_UNUSED)
204{
205 return nullptr;
206}
207#endif
208
209
210/*
211 * shaper
212 */
213
214struct hb_graphite2_cluster_t {
215 unsigned int base_char;
216 unsigned int num_chars;
217 unsigned int base_glyph;
218 unsigned int num_glyphs;
219 unsigned int cluster;
220 unsigned int advance;
221};
222
223hb_bool_t
224_hb_graphite2_shape (hb_shape_plan_t *shape_plan HB_UNUSED,
225 hb_font_t *font,
226 hb_buffer_t *buffer,
227 const hb_feature_t *features,
228 unsigned int num_features)
229{
230 hb_face_t *face = font->face;
231 gr_face *grface = face->data.graphite2->grface;
232
233 const char *lang = hb_language_to_string (hb_buffer_get_language (buffer));
234 const char *lang_end = lang ? strchr (lang, '-') : nullptr;
235 int lang_len = lang_end ? lang_end - lang : -1;
236 gr_feature_val *feats = gr_face_featureval_for_lang (grface, lang ? hb_tag_from_string (lang, lang_len) : 0);
237
238 for (unsigned int i = 0; i < num_features; i++)
239 {
240 const gr_feature_ref *fref = gr_face_find_fref (grface, features[i].tag);
241 if (fref)
242 gr_fref_set_feature_value (fref, features[i].value, feats);
243 }
244
245 gr_segment *seg = nullptr;
246 const gr_slot *is;
247 unsigned int ci = 0, ic = 0;
248 unsigned int curradvx = 0, curradvy = 0;
249
250 unsigned int scratch_size;
251 hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
252
253 uint32_t *chars = (uint32_t *) scratch;
254
255 for (unsigned int i = 0; i < buffer->len; ++i)
256 chars[i] = buffer->info[i].codepoint;
257
258 /* TODO ensure_native_direction. */
259
260 hb_tag_t script_tag[HB_OT_MAX_TAGS_PER_SCRIPT];
261 unsigned int count = HB_OT_MAX_TAGS_PER_SCRIPT;
262 hb_ot_tags_from_script_and_language (hb_buffer_get_script (buffer),
263 HB_LANGUAGE_INVALID,
264 &count,
265 script_tag,
266 nullptr, nullptr);
267
268 seg = gr_make_seg (nullptr, grface,
269 count ? script_tag[count - 1] : HB_OT_TAG_DEFAULT_SCRIPT,
270 feats,
271 gr_utf32, chars, buffer->len,
272 2 | (hb_buffer_get_direction (buffer) == HB_DIRECTION_RTL ? 1 : 0));
273
274 if (unlikely (!seg)) {
275 if (feats) gr_featureval_destroy (feats);
276 return false;
277 }
278
279 unsigned int glyph_count = gr_seg_n_slots (seg);
280 if (unlikely (!glyph_count)) {
281 if (feats) gr_featureval_destroy (feats);
282 gr_seg_destroy (seg);
283 buffer->len = 0;
284 return true;
285 }
286
287 buffer->ensure (glyph_count);
288 scratch = buffer->get_scratch_buffer (&scratch_size);
289 while ((DIV_CEIL (sizeof (hb_graphite2_cluster_t) * buffer->len, sizeof (*scratch)) +
290 DIV_CEIL (sizeof (hb_codepoint_t) * glyph_count, sizeof (*scratch))) > scratch_size)
291 {
292 if (unlikely (!buffer->ensure (buffer->allocated * 2)))
293 {
294 if (feats) gr_featureval_destroy (feats);
295 gr_seg_destroy (seg);
296 return false;
297 }
298 scratch = buffer->get_scratch_buffer (&scratch_size);
299 }
300
301#define ALLOCATE_ARRAY(Type, name, len) \
302 Type *name = (Type *) scratch; \
303 do { \
304 unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
305 assert (_consumed <= scratch_size); \
306 scratch += _consumed; \
307 scratch_size -= _consumed; \
308 } while (0)
309
310 ALLOCATE_ARRAY (hb_graphite2_cluster_t, clusters, buffer->len);
311 ALLOCATE_ARRAY (hb_codepoint_t, gids, glyph_count);
312
313#undef ALLOCATE_ARRAY
314
315 memset (clusters, 0, sizeof (clusters[0]) * buffer->len);
316
317 hb_codepoint_t *pg = gids;
318 clusters[0].cluster = buffer->info[0].cluster;
319 unsigned int upem = hb_face_get_upem (face);
320 float xscale = (float) font->x_scale / upem;
321 float yscale = (float) font->y_scale / upem;
322 yscale *= yscale / xscale;
323 unsigned int curradv = 0;
324 if (HB_DIRECTION_IS_BACKWARD(buffer->props.direction))
325 {
326 curradv = gr_slot_origin_X(gr_seg_first_slot(seg)) * xscale;
327 clusters[0].advance = gr_seg_advance_X(seg) * xscale - curradv;
328 }
329 else
330 clusters[0].advance = 0;
331 for (is = gr_seg_first_slot (seg), ic = 0; is; is = gr_slot_next_in_segment (is), ic++)
332 {
333 unsigned int before = gr_slot_before (is);
334 unsigned int after = gr_slot_after (is);
335 *pg = gr_slot_gid (is);
336 pg++;
337 while (clusters[ci].base_char > before && ci)
338 {
339 clusters[ci-1].num_chars += clusters[ci].num_chars;
340 clusters[ci-1].num_glyphs += clusters[ci].num_glyphs;
341 clusters[ci-1].advance += clusters[ci].advance;
342 ci--;
343 }
344
345 if (gr_slot_can_insert_before (is) && clusters[ci].num_chars && before >= clusters[ci].base_char + clusters[ci].num_chars)
346 {
347 hb_graphite2_cluster_t *c = clusters + ci + 1;
348 c->base_char = clusters[ci].base_char + clusters[ci].num_chars;
349 c->cluster = buffer->info[c->base_char].cluster;
350 c->num_chars = before - c->base_char;
351 c->base_glyph = ic;
352 c->num_glyphs = 0;
353 if (HB_DIRECTION_IS_BACKWARD(buffer->props.direction))
354 {
355 c->advance = curradv - gr_slot_origin_X(is) * xscale;
356 curradv -= c->advance;
357 }
358 else
359 {
360 c->advance = 0;
361 clusters[ci].advance += gr_slot_origin_X(is) * xscale - curradv;
362 curradv += clusters[ci].advance;
363 }
364 ci++;
365 }
366 clusters[ci].num_glyphs++;
367
368 if (clusters[ci].base_char + clusters[ci].num_chars < after + 1)
369 clusters[ci].num_chars = after + 1 - clusters[ci].base_char;
370 }
371
372 if (HB_DIRECTION_IS_BACKWARD(buffer->props.direction))
373 clusters[ci].advance += curradv;
374 else
375 clusters[ci].advance += gr_seg_advance_X(seg) * xscale - curradv;
376 ci++;
377
378 for (unsigned int i = 0; i < ci; ++i)
379 {
380 for (unsigned int j = 0; j < clusters[i].num_glyphs; ++j)
381 {
382 hb_glyph_info_t *info = &buffer->info[clusters[i].base_glyph + j];
383 info->codepoint = gids[clusters[i].base_glyph + j];
384 info->cluster = clusters[i].cluster;
385 info->var1.i32 = clusters[i].advance; // all glyphs in the cluster get the same advance
386 }
387 }
388 buffer->len = glyph_count;
389
390 /* Positioning. */
391 unsigned int currclus = UINT_MAX;
392 const hb_glyph_info_t *info = buffer->info;
393 hb_glyph_position_t *pPos = hb_buffer_get_glyph_positions (buffer, nullptr);
394 if (!HB_DIRECTION_IS_BACKWARD(buffer->props.direction))
395 {
396 curradvx = 0;
397 for (is = gr_seg_first_slot (seg); is; pPos++, ++info, is = gr_slot_next_in_segment (is))
398 {
399 pPos->x_offset = gr_slot_origin_X (is) * xscale - curradvx;
400 pPos->y_offset = gr_slot_origin_Y (is) * yscale - curradvy;
401 if (info->cluster != currclus) {
402 pPos->x_advance = info->var1.i32;
403 curradvx += pPos->x_advance;
404 currclus = info->cluster;
405 } else
406 pPos->x_advance = 0.;
407
408 pPos->y_advance = gr_slot_advance_Y (is, grface, nullptr) * yscale;
409 curradvy += pPos->y_advance;
410 }
411 }
412 else
413 {
414 curradvx = gr_seg_advance_X(seg) * xscale;
415 for (is = gr_seg_first_slot (seg); is; pPos++, info++, is = gr_slot_next_in_segment (is))
416 {
417 if (info->cluster != currclus)
418 {
419 pPos->x_advance = info->var1.i32;
420 curradvx -= pPos->x_advance;
421 currclus = info->cluster;
422 } else
423 pPos->x_advance = 0.;
424
425 pPos->y_advance = gr_slot_advance_Y (is, grface, nullptr) * yscale;
426 curradvy -= pPos->y_advance;
427 pPos->x_offset = gr_slot_origin_X (is) * xscale - info->var1.i32 - curradvx + pPos->x_advance;
428 pPos->y_offset = gr_slot_origin_Y (is) * yscale - curradvy;
429 }
430 hb_buffer_reverse_clusters (buffer);
431 }
432
433 if (feats) gr_featureval_destroy (feats);
434 gr_seg_destroy (seg);
435
436 buffer->unsafe_to_break_all ();
437
438 return true;
439}
440
441
442#endif
443