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