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