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 /*

  * Copyright © 2011  Martin Hosken

  * Copyright © 2011  SIL International

  * Copyright © 2011,2012  Google, Inc.

  *

  *  This is part of HarfBuzz, a text shaping library.

  *

  * Permission is hereby granted, without written agreement and without

  * license or royalty fees, to use, copy, modify, and distribute this

  * software and its documentation for any purpose, provided that the

  * above copyright notice and the following two paragraphs appear in

  * all copies of this software.

  *

  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

  * DAMAGE.

  *

  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

  *

  * Google Author(s): Behdad Esfahbod

  */

 #define HB_SHAPER graphite2

 #define hb_graphite2_shaper_font_data_t gr_font

 #include "hb-shaper-impl-private.hh"

 #include "hb-graphite2.h"

 #include <graphite2/Segment.h>

 HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, face)

 HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, font)

 /*

  * shaper face data

  */

 typedef struct hb_graphite2_tablelist_t {

   struct hb_graphite2_tablelist_t *next;

   hb_blob_t *blob;

   unsigned int tag;

 } hb_graphite2_tablelist_t;

 struct hb_graphite2_shaper_face_data_t {

   hb_face_t *face;

   gr_face   *grface;

   hb_graphite2_tablelist_t *tlist;

 };

 static const void *hb_graphite2_get_table (const void *data, unsigned int tag, size_t *len)

 {

   hb_graphite2_shaper_face_data_t *face_data = (hb_graphite2_shaper_face_data_t *) data;

   hb_graphite2_tablelist_t *tlist = face_data->tlist;

   hb_blob_t *blob = NULL;

   for (hb_graphite2_tablelist_t *p = tlist; p; p = p->next)

     if (p->tag == tag) {

       blob = p->blob;

       break;

     }

   if (unlikely (!blob))

   {

     blob = face_data->face->reference_table (tag);

     hb_graphite2_tablelist_t *p = (hb_graphite2_tablelist_t *) calloc (1, sizeof (hb_graphite2_tablelist_t));

     if (unlikely (!p)) {

       hb_blob_destroy (blob);

       return NULL;

     }

     p->blob = blob;

     p->tag = tag;

     /* TODO Not thread-safe, but fairly harmless.

      * We can do the double-chcked pointer cmpexch thing here. */

     p->next = face_data->tlist;

     face_data->tlist = p;

   }

   unsigned int tlen;

   const char *d = hb_blob_get_data (blob, &tlen);

   *len = tlen;

   return d;

 }

 hb_graphite2_shaper_face_data_t *

 _hb_graphite2_shaper_face_data_create (hb_face_t *face)

 {

   hb_blob_t *silf_blob = face->reference_table (HB_GRAPHITE2_TAG_SILF);

   /* Umm, we just reference the table to check whether it exists.

    * Maybe add better API for this? */

   if (!hb_blob_get_length (silf_blob))

   {

     hb_blob_destroy (silf_blob);

     return NULL;

   }

   hb_blob_destroy (silf_blob);

   hb_graphite2_shaper_face_data_t *data = (hb_graphite2_shaper_face_data_t *) calloc (1, sizeof (hb_graphite2_shaper_face_data_t));

   if (unlikely (!data))

     return NULL;

   data->face = face;

   data->grface = gr_make_face (data, &hb_graphite2_get_table, gr_face_preloadAll);

   if (unlikely (!data->grface)) {

     free (data);

     return NULL;

   }

   return data;

 }

 void

 _hb_graphite2_shaper_face_data_destroy (hb_graphite2_shaper_face_data_t *data)

 {

   hb_graphite2_tablelist_t *tlist = data->tlist;

   while (tlist)

   {

     hb_graphite2_tablelist_t *old = tlist;

     hb_blob_destroy (tlist->blob);

     tlist = tlist->next;

     free (old);

   }

   gr_face_destroy (data->grface);

   free (data);

 }

 gr_face *

 hb_graphite2_face_get_gr_face (hb_face_t *face)

 {

   if (unlikely (!hb_graphite2_shaper_face_data_ensure (face))) return NULL;

   return HB_SHAPER_DATA_GET (face)->grface;

 }

 /*

  * shaper font data

  */

 static float hb_graphite2_get_advance (const void *hb_font, unsigned short gid)

 {

   return ((hb_font_t *) hb_font)->get_glyph_h_advance (gid);

 }

 hb_graphite2_shaper_font_data_t *

 _hb_graphite2_shaper_font_data_create (hb_font_t *font)

 {

   if (unlikely (!hb_graphite2_shaper_face_data_ensure (font->face))) return NULL;

   hb_face_t *face = font->face;

   hb_graphite2_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);

   return gr_make_font_with_advance_fn (font->x_scale, font, &hb_graphite2_get_advance, face_data->grface);

 }

 void

 _hb_graphite2_shaper_font_data_destroy (hb_graphite2_shaper_font_data_t *data)

 {

   gr_font_destroy (data);

 }

 gr_font *

 hb_graphite2_font_get_gr_font (hb_font_t *font)

 {

   if (unlikely (!hb_graphite2_shaper_font_data_ensure (font))) return NULL;

   return HB_SHAPER_DATA_GET (font);

 }

 /*

  * shaper shape_plan data

  */

 struct hb_graphite2_shaper_shape_plan_data_t {};

 hb_graphite2_shaper_shape_plan_data_t *

 _hb_graphite2_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,

 					     const hb_feature_t *user_features HB_UNUSED,

 					     unsigned int        num_user_features HB_UNUSED)

 {

   return (hb_graphite2_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;

 }

 void

 _hb_graphite2_shaper_shape_plan_data_destroy (hb_graphite2_shaper_shape_plan_data_t *data HB_UNUSED)

 {

 }

 /*

  * shaper

  */

 struct hb_graphite2_cluster_t {

   unsigned int base_char;

   unsigned int num_chars;

   unsigned int base_glyph;

   unsigned int num_glyphs;

 };

 hb_bool_t

 _hb_graphite2_shape (hb_shape_plan_t    *shape_plan,

 		     hb_font_t          *font,

 		     hb_buffer_t        *buffer,

 		     const hb_feature_t *features,

 		     unsigned int        num_features)

 {

   hb_face_t *face = font->face;

   gr_face *grface = HB_SHAPER_DATA_GET (face)->grface;

   gr_font *grfont = HB_SHAPER_DATA_GET (font);

   const char *lang = hb_language_to_string (hb_buffer_get_language (buffer));

   const char *lang_end = lang ? strchr (lang, '-') : NULL;

   int lang_len = lang_end ? lang_end - lang : -1;

   gr_feature_val *feats = gr_face_featureval_for_lang (grface, lang ? hb_tag_from_string (lang, lang_len) : 0);

   while (num_features--)

   {

     const gr_feature_ref *fref = gr_face_find_fref (grface, features->tag);

     if (fref)

       gr_fref_set_feature_value (fref, features->value, feats);

     features++;

   }

   gr_segment *seg = NULL;

   const gr_slot *is;

   unsigned int ci = 0, ic = 0;

   float curradvx = 0., curradvy = 0.;

   unsigned int scratch_size;

   hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);

   uint32_t *chars = (uint32_t *) scratch;

   for (unsigned int i = 0; i < buffer->len; ++i)

     chars[i] = buffer->info[i].codepoint;

   hb_tag_t script_tag[2];

   hb_ot_tags_from_script (hb_buffer_get_script (buffer), &script_tag[0], &script_tag[1]);

   seg = gr_make_seg (grfont, grface,

 		     script_tag[1] == HB_TAG_NONE ? script_tag[0] : script_tag[1],

 		     feats,

 		     gr_utf32, chars, buffer->len,

 		     2 | (hb_buffer_get_direction (buffer) == HB_DIRECTION_RTL ? 1 : 0));

   if (unlikely (!seg)) {

     if (feats) gr_featureval_destroy (feats);

     return false;

   }

   unsigned int glyph_count = gr_seg_n_slots (seg);

   if (unlikely (!glyph_count)) {

     if (feats) gr_featureval_destroy (feats);

     gr_seg_destroy (seg);

     return false;

   }

   scratch = buffer->get_scratch_buffer (&scratch_size);

   while ((DIV_CEIL (sizeof (hb_graphite2_cluster_t) * buffer->len, sizeof (*scratch)) +

 	  DIV_CEIL (sizeof (hb_codepoint_t) * glyph_count, sizeof (*scratch))) > scratch_size)

   {

     buffer->ensure (buffer->allocated * 2);

     if (unlikely (buffer->in_error)) {

       if (feats) gr_featureval_destroy (feats);

       gr_seg_destroy (seg);

       return false;

     }

     scratch = buffer->get_scratch_buffer (&scratch_size);

   }

 #define ALLOCATE_ARRAY(Type, name, len) \

   Type *name = (Type *) scratch; \

   { \

     unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \

     assert (_consumed <= scratch_size); \

     scratch += _consumed; \

     scratch_size -= _consumed; \

   }

   ALLOCATE_ARRAY (hb_graphite2_cluster_t, clusters, buffer->len);

   ALLOCATE_ARRAY (hb_codepoint_t, gids, glyph_count);

 #undef ALLOCATE_ARRAY

   memset (clusters, 0, sizeof (clusters[0]) * buffer->len);

   hb_codepoint_t *pg = gids;

   for (is = gr_seg_first_slot (seg), ic = 0; is; is = gr_slot_next_in_segment (is), ic++)

   {

     unsigned int before = gr_slot_before (is);

     unsigned int after = gr_slot_after (is);

     *pg = gr_slot_gid (is);

     pg++;

     while (clusters[ci].base_char > before && ci)

     {

       clusters[ci-1].num_chars += clusters[ci].num_chars;

       clusters[ci-1].num_glyphs += clusters[ci].num_glyphs;

       ci--;

     }

     if (gr_slot_can_insert_before (is) && clusters[ci].num_chars && before >= clusters[ci].base_char + clusters[ci].num_chars)

     {

       hb_graphite2_cluster_t *c = clusters + ci + 1;

       c->base_char = clusters[ci].base_char + clusters[ci].num_chars;

       c->num_chars = before - c->base_char;

       c->base_glyph = ic;

       c->num_glyphs = 0;

       ci++;

     }

     clusters[ci].num_glyphs++;

     if (clusters[ci].base_char + clusters[ci].num_chars < after + 1)

 	clusters[ci].num_chars = after + 1 - clusters[ci].base_char;

   }

   ci++;

   //buffer->clear_output ();

   for (unsigned int i = 0; i < ci; ++i)

   {

     for (unsigned int j = 0; j < clusters[i].num_glyphs; ++j)

     {

       hb_glyph_info_t *info = &buffer->info[clusters[i].base_glyph + j];

       info->codepoint = gids[clusters[i].base_glyph + j];

       info->cluster = gr_cinfo_base(gr_seg_cinfo(seg, clusters[i].base_char));

     }

   }

   buffer->len = glyph_count;

   //buffer->swap_buffers ();

   if (HB_DIRECTION_IS_BACKWARD(buffer->props.direction))

     curradvx = gr_seg_advance_X(seg);

   hb_glyph_position_t *pPos;

   for (pPos = hb_buffer_get_glyph_positions (buffer, NULL), is = gr_seg_first_slot (seg);

        is; pPos++, is = gr_slot_next_in_segment (is))

   {

     pPos->x_offset = gr_slot_origin_X (is) - curradvx;

     pPos->y_offset = gr_slot_origin_Y (is) - curradvy;

     pPos->x_advance = gr_slot_advance_X (is, grface, grfont);

     pPos->y_advance = gr_slot_advance_Y (is, grface, grfont);

     if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))

       curradvx -= pPos->x_advance;

     pPos->x_offset = gr_slot_origin_X (is) - curradvx;

     if (!HB_DIRECTION_IS_BACKWARD (buffer->props.direction))

       curradvx += pPos->x_advance;

     pPos->y_offset = gr_slot_origin_Y (is) - curradvy;

     curradvy += pPos->y_advance;

   }

   if (!HB_DIRECTION_IS_BACKWARD (buffer->props.direction))

     pPos[-1].x_advance += gr_seg_advance_X(seg) - curradvx;

   if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))

     hb_buffer_reverse_clusters (buffer);

   if (feats) gr_featureval_destroy (feats);

   gr_seg_destroy (seg);

   return true;

 }