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#define HB_SHAPER graphite2
30#define hb_graphite2_shaper_font_data_t gr_font
31#include "hb-shaper-impl-private.hh"
32
33#include "hb-graphite2.h"
34
35#include <graphite2/Segment.h>
36
37
38HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, face)
39HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, font)
40
41
42/*
43 * shaper face data
44 */
45
46typedef struct hb_graphite2_tablelist_t {
47  struct hb_graphite2_tablelist_t *next;
48  hb_blob_t *blob;
49  unsigned int tag;
50} hb_graphite2_tablelist_t;
51
52struct hb_graphite2_shaper_face_data_t {
53  hb_face_t *face;
54  gr_face   *grface;
55  hb_graphite2_tablelist_t *tlist;
56};
57
58static const void *hb_graphite2_get_table (const void *data, unsigned int tag, size_t *len)
59{
60  hb_graphite2_shaper_face_data_t *face_data = (hb_graphite2_shaper_face_data_t *) data;
61  hb_graphite2_tablelist_t *tlist = face_data->tlist;
62
63  hb_blob_t *blob = NULL;
64
65  for (hb_graphite2_tablelist_t *p = tlist; p; p = p->next)
66    if (p->tag == tag) {
67      blob = p->blob;
68      break;
69    }
70
71  if (unlikely (!blob))
72  {
73    blob = face_data->face->reference_table (tag);
74
75    hb_graphite2_tablelist_t *p = (hb_graphite2_tablelist_t *) calloc (1, sizeof (hb_graphite2_tablelist_t));
76    if (unlikely (!p)) {
77      hb_blob_destroy (blob);
78      return NULL;
79    }
80    p->blob = blob;
81    p->tag = tag;
82
83    /* TODO Not thread-safe, but fairly harmless.
84     * We can do the double-chcked pointer cmpexch thing here. */
85    p->next = face_data->tlist;
86    face_data->tlist = p;
87  }
88
89  unsigned int tlen;
90  const char *d = hb_blob_get_data (blob, &tlen);
91  *len = tlen;
92  return d;
93}
94
95hb_graphite2_shaper_face_data_t *
96_hb_graphite2_shaper_face_data_create (hb_face_t *face)
97{
98  hb_blob_t *silf_blob = face->reference_table (HB_GRAPHITE2_TAG_SILF);
99  /* Umm, we just reference the table to check whether it exists.
100   * Maybe add better API for this? */
101  if (!hb_blob_get_length (silf_blob))
102  {
103    hb_blob_destroy (silf_blob);
104    return NULL;
105  }
106  hb_blob_destroy (silf_blob);
107
108  hb_graphite2_shaper_face_data_t *data = (hb_graphite2_shaper_face_data_t *) calloc (1, sizeof (hb_graphite2_shaper_face_data_t));
109  if (unlikely (!data))
110    return NULL;
111
112  data->face = face;
113  data->grface = gr_make_face (data, &hb_graphite2_get_table, gr_face_preloadAll);
114
115  if (unlikely (!data->grface)) {
116    free (data);
117    return NULL;
118  }
119
120  return data;
121}
122
123void
124_hb_graphite2_shaper_face_data_destroy (hb_graphite2_shaper_face_data_t *data)
125{
126  hb_graphite2_tablelist_t *tlist = data->tlist;
127
128  while (tlist)
129  {
130    hb_graphite2_tablelist_t *old = tlist;
131    hb_blob_destroy (tlist->blob);
132    tlist = tlist->next;
133    free (old);
134  }
135
136  gr_face_destroy (data->grface);
137
138  free (data);
139}
140
141gr_face *
142hb_graphite2_face_get_gr_face (hb_face_t *face)
143{
144  if (unlikely (!hb_graphite2_shaper_face_data_ensure (face))) return NULL;
145  return HB_SHAPER_DATA_GET (face)->grface;
146}
147
148
149/*
150 * shaper font data
151 */
152
153static float hb_graphite2_get_advance (const void *hb_font, unsigned short gid)
154{
155  return ((hb_font_t *) hb_font)->get_glyph_h_advance (gid);
156}
157
158hb_graphite2_shaper_font_data_t *
159_hb_graphite2_shaper_font_data_create (hb_font_t *font)
160{
161  if (unlikely (!hb_graphite2_shaper_face_data_ensure (font->face))) return NULL;
162
163  hb_face_t *face = font->face;
164  hb_graphite2_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
165
166  return gr_make_font_with_advance_fn (font->x_scale, font, &hb_graphite2_get_advance, face_data->grface);
167}
168
169void
170_hb_graphite2_shaper_font_data_destroy (hb_graphite2_shaper_font_data_t *data)
171{
172  gr_font_destroy (data);
173}
174
175gr_font *
176hb_graphite2_font_get_gr_font (hb_font_t *font)
177{
178  if (unlikely (!hb_graphite2_shaper_font_data_ensure (font))) return NULL;
179  return HB_SHAPER_DATA_GET (font);
180}
181
182
183/*
184 * shaper shape_plan data
185 */
186
187struct hb_graphite2_shaper_shape_plan_data_t {};
188
189hb_graphite2_shaper_shape_plan_data_t *
190_hb_graphite2_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
191					     const hb_feature_t *user_features HB_UNUSED,
192					     unsigned int        num_user_features HB_UNUSED)
193{
194  return (hb_graphite2_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
195}
196
197void
198_hb_graphite2_shaper_shape_plan_data_destroy (hb_graphite2_shaper_shape_plan_data_t *data HB_UNUSED)
199{
200}
201
202
203/*
204 * shaper
205 */
206
207struct hb_graphite2_cluster_t {
208  unsigned int base_char;
209  unsigned int num_chars;
210  unsigned int base_glyph;
211  unsigned int num_glyphs;
212  unsigned int cluster;
213};
214
215hb_bool_t
216_hb_graphite2_shape (hb_shape_plan_t    *shape_plan,
217		     hb_font_t          *font,
218		     hb_buffer_t        *buffer,
219		     const hb_feature_t *features,
220		     unsigned int        num_features)
221{
222  hb_face_t *face = font->face;
223  gr_face *grface = HB_SHAPER_DATA_GET (face)->grface;
224  gr_font *grfont = HB_SHAPER_DATA_GET (font);
225
226  const char *lang = hb_language_to_string (hb_buffer_get_language (buffer));
227  const char *lang_end = lang ? strchr (lang, '-') : NULL;
228  int lang_len = lang_end ? lang_end - lang : -1;
229  gr_feature_val *feats = gr_face_featureval_for_lang (grface, lang ? hb_tag_from_string (lang, lang_len) : 0);
230
231  while (num_features--)
232  {
233    const gr_feature_ref *fref = gr_face_find_fref (grface, features->tag);
234    if (fref)
235      gr_fref_set_feature_value (fref, features->value, feats);
236    features++;
237  }
238
239  gr_segment *seg = NULL;
240  const gr_slot *is;
241  unsigned int ci = 0, ic = 0;
242  float curradvx = 0., curradvy = 0.;
243
244  unsigned int scratch_size;
245  hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
246
247  uint32_t *chars = (uint32_t *) scratch;
248
249  for (unsigned int i = 0; i < buffer->len; ++i)
250    chars[i] = buffer->info[i].codepoint;
251
252  hb_tag_t script_tag[2];
253  hb_ot_tags_from_script (hb_buffer_get_script (buffer), &script_tag[0], &script_tag[1]);
254
255  seg = gr_make_seg (grfont, grface,
256		     script_tag[1] == HB_TAG_NONE ? script_tag[0] : script_tag[1],
257		     feats,
258		     gr_utf32, chars, buffer->len,
259		     2 | (hb_buffer_get_direction (buffer) == HB_DIRECTION_RTL ? 1 : 0));
260
261  if (unlikely (!seg)) {
262    if (feats) gr_featureval_destroy (feats);
263    return false;
264  }
265
266  unsigned int glyph_count = gr_seg_n_slots (seg);
267  if (unlikely (!glyph_count)) {
268    if (feats) gr_featureval_destroy (feats);
269    gr_seg_destroy (seg);
270    return false;
271  }
272
273  scratch = buffer->get_scratch_buffer (&scratch_size);
274  while ((DIV_CEIL (sizeof (hb_graphite2_cluster_t) * buffer->len, sizeof (*scratch)) +
275	  DIV_CEIL (sizeof (hb_codepoint_t) * glyph_count, sizeof (*scratch))) > scratch_size)
276  {
277    if (unlikely (!buffer->ensure (buffer->allocated * 2)))
278    {
279      if (feats) gr_featureval_destroy (feats);
280      gr_seg_destroy (seg);
281      return false;
282    }
283    scratch = buffer->get_scratch_buffer (&scratch_size);
284  }
285
286#define ALLOCATE_ARRAY(Type, name, len) \
287  Type *name = (Type *) scratch; \
288  { \
289    unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
290    assert (_consumed <= scratch_size); \
291    scratch += _consumed; \
292    scratch_size -= _consumed; \
293  }
294
295  ALLOCATE_ARRAY (hb_graphite2_cluster_t, clusters, buffer->len);
296  ALLOCATE_ARRAY (hb_codepoint_t, gids, glyph_count);
297
298#undef ALLOCATE_ARRAY
299
300  memset (clusters, 0, sizeof (clusters[0]) * buffer->len);
301
302  hb_codepoint_t *pg = gids;
303  clusters[0].cluster = buffer->info[0].cluster;
304  for (is = gr_seg_first_slot (seg), ic = 0; is; is = gr_slot_next_in_segment (is), ic++)
305  {
306    unsigned int before = gr_slot_before (is);
307    unsigned int after = gr_slot_after (is);
308    *pg = gr_slot_gid (is);
309    pg++;
310    while (clusters[ci].base_char > before && ci)
311    {
312      clusters[ci-1].num_chars += clusters[ci].num_chars;
313      clusters[ci-1].num_glyphs += clusters[ci].num_glyphs;
314      ci--;
315    }
316
317    if (gr_slot_can_insert_before (is) && clusters[ci].num_chars && before >= clusters[ci].base_char + clusters[ci].num_chars)
318    {
319      hb_graphite2_cluster_t *c = clusters + ci + 1;
320      c->base_char = clusters[ci].base_char + clusters[ci].num_chars;
321      c->cluster = buffer->info[c->base_char].cluster;
322      c->num_chars = before - c->base_char;
323      c->base_glyph = ic;
324      c->num_glyphs = 0;
325      ci++;
326    }
327    clusters[ci].num_glyphs++;
328
329    if (clusters[ci].base_char + clusters[ci].num_chars < after + 1)
330	clusters[ci].num_chars = after + 1 - clusters[ci].base_char;
331  }
332  ci++;
333
334  //buffer->clear_output ();
335  for (unsigned int i = 0; i < ci; ++i)
336  {
337    for (unsigned int j = 0; j < clusters[i].num_glyphs; ++j)
338    {
339      hb_glyph_info_t *info = &buffer->info[clusters[i].base_glyph + j];
340      info->codepoint = gids[clusters[i].base_glyph + j];
341      info->cluster = clusters[i].cluster;
342    }
343  }
344  buffer->len = glyph_count;
345  //buffer->swap_buffers ();
346
347  if (HB_DIRECTION_IS_BACKWARD(buffer->props.direction))
348    curradvx = gr_seg_advance_X(seg);
349
350  hb_glyph_position_t *pPos;
351  for (pPos = hb_buffer_get_glyph_positions (buffer, NULL), is = gr_seg_first_slot (seg);
352       is; pPos++, is = gr_slot_next_in_segment (is))
353  {
354    pPos->x_offset = gr_slot_origin_X (is) - curradvx;
355    pPos->y_offset = gr_slot_origin_Y (is) - curradvy;
356    pPos->x_advance = gr_slot_advance_X (is, grface, grfont);
357    pPos->y_advance = gr_slot_advance_Y (is, grface, grfont);
358    if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
359      curradvx -= pPos->x_advance;
360    pPos->x_offset = gr_slot_origin_X (is) - curradvx;
361    if (!HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
362      curradvx += pPos->x_advance;
363    pPos->y_offset = gr_slot_origin_Y (is) - curradvy;
364    curradvy += pPos->y_advance;
365  }
366  if (!HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
367    pPos[-1].x_advance += gr_seg_advance_X(seg) - curradvx;
368
369  if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
370    hb_buffer_reverse_clusters (buffer);
371
372  if (feats) gr_featureval_destroy (feats);
373  gr_seg_destroy (seg);
374
375  return true;
376}
377