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 #include "hb-ot-tag.h"
  38
  39
  40 HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, face)
  41 HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, font)
  42
  43
  44 /*
  45  * shaper face data
  46  */
  47
  48 typedef 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
  54 struct hb_graphite2_shaper_face_data_t {
  55   hb_face_t *face;
  56   gr_face   *grface;
  57   hb_graphite2_tablelist_t *tlist;
  58 };
  59
  60 static 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
  97 hb_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
 125 void
 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
 143 gr_face *
 144 hb_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
 155 static 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
 160 hb_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
 171 void
 172 _hb_graphite2_shaper_font_data_destroy (hb_graphite2_shaper_font_data_t *data)
 173 {
 174   gr_font_destroy (data);
 175 }
 176
 177 gr_font *
 178 hb_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
 189 struct hb_graphite2_shaper_shape_plan_data_t {};
 190
 191 hb_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
 199 void
 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
 209 struct 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
 216 hb_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 }