third_party/harfbuzz-ng/src/hb-graphite2.cc

   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
  38 HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, face)
  39 HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, font)
  40
  41
  42 /*
  43  * shaper face data
  44  */
  45
  46 typedef 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
  52 struct hb_graphite2_shaper_face_data_t {
  53   hb_face_t *face;
  54   gr_face   *grface;
  55   hb_graphite2_tablelist_t *tlist;
  56 };
  57
  58 static 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
  95 hb_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
 123 void
 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
 141 gr_face *
 142 hb_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
 153 static 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
 158 hb_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
 169 void
 170 _hb_graphite2_shaper_font_data_destroy (hb_graphite2_shaper_font_data_t *data)
 171 {
 172   gr_font_destroy (data);
 173 }
 174
 175 gr_font *
 176 hb_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
 187 struct hb_graphite2_shaper_shape_plan_data_t {};
 188
 189 hb_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
 197 void
 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
 207 struct 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
 215 hb_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 }