michael@0: /*
michael@0:  * Copyright © 2011  Martin Hosken
michael@0:  * Copyright © 2011  SIL International
michael@0:  * Copyright © 2011,2012  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #define HB_SHAPER graphite2
michael@0: #define hb_graphite2_shaper_font_data_t gr_font
michael@0: #include "hb-shaper-impl-private.hh"
michael@0: 
michael@0: #include "hb-graphite2.h"
michael@0: 
michael@0: #include <graphite2/Segment.h>
michael@0: 
michael@0: 
michael@0: HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, face)
michael@0: HB_SHAPER_DATA_ENSURE_DECLARE(graphite2, font)
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper face data
michael@0:  */
michael@0: 
michael@0: typedef struct hb_graphite2_tablelist_t {
michael@0:   struct hb_graphite2_tablelist_t *next;
michael@0:   hb_blob_t *blob;
michael@0:   unsigned int tag;
michael@0: } hb_graphite2_tablelist_t;
michael@0: 
michael@0: struct hb_graphite2_shaper_face_data_t {
michael@0:   hb_face_t *face;
michael@0:   gr_face   *grface;
michael@0:   hb_graphite2_tablelist_t *tlist;
michael@0: };
michael@0: 
michael@0: static const void *hb_graphite2_get_table (const void *data, unsigned int tag, size_t *len)
michael@0: {
michael@0:   hb_graphite2_shaper_face_data_t *face_data = (hb_graphite2_shaper_face_data_t *) data;
michael@0:   hb_graphite2_tablelist_t *tlist = face_data->tlist;
michael@0: 
michael@0:   hb_blob_t *blob = NULL;
michael@0: 
michael@0:   for (hb_graphite2_tablelist_t *p = tlist; p; p = p->next)
michael@0:     if (p->tag == tag) {
michael@0:       blob = p->blob;
michael@0:       break;
michael@0:     }
michael@0: 
michael@0:   if (unlikely (!blob))
michael@0:   {
michael@0:     blob = face_data->face->reference_table (tag);
michael@0: 
michael@0:     hb_graphite2_tablelist_t *p = (hb_graphite2_tablelist_t *) calloc (1, sizeof (hb_graphite2_tablelist_t));
michael@0:     if (unlikely (!p)) {
michael@0:       hb_blob_destroy (blob);
michael@0:       return NULL;
michael@0:     }
michael@0:     p->blob = blob;
michael@0:     p->tag = tag;
michael@0: 
michael@0:     /* TODO Not thread-safe, but fairly harmless.
michael@0:      * We can do the double-chcked pointer cmpexch thing here. */
michael@0:     p->next = face_data->tlist;
michael@0:     face_data->tlist = p;
michael@0:   }
michael@0: 
michael@0:   unsigned int tlen;
michael@0:   const char *d = hb_blob_get_data (blob, &tlen);
michael@0:   *len = tlen;
michael@0:   return d;
michael@0: }
michael@0: 
michael@0: hb_graphite2_shaper_face_data_t *
michael@0: _hb_graphite2_shaper_face_data_create (hb_face_t *face)
michael@0: {
michael@0:   hb_blob_t *silf_blob = face->reference_table (HB_GRAPHITE2_TAG_SILF);
michael@0:   /* Umm, we just reference the table to check whether it exists.
michael@0:    * Maybe add better API for this? */
michael@0:   if (!hb_blob_get_length (silf_blob))
michael@0:   {
michael@0:     hb_blob_destroy (silf_blob);
michael@0:     return NULL;
michael@0:   }
michael@0:   hb_blob_destroy (silf_blob);
michael@0: 
michael@0:   hb_graphite2_shaper_face_data_t *data = (hb_graphite2_shaper_face_data_t *) calloc (1, sizeof (hb_graphite2_shaper_face_data_t));
michael@0:   if (unlikely (!data))
michael@0:     return NULL;
michael@0: 
michael@0:   data->face = face;
michael@0:   data->grface = gr_make_face (data, &hb_graphite2_get_table, gr_face_preloadAll);
michael@0: 
michael@0:   if (unlikely (!data->grface)) {
michael@0:     free (data);
michael@0:     return NULL;
michael@0:   }
michael@0: 
michael@0:   return data;
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_graphite2_shaper_face_data_destroy (hb_graphite2_shaper_face_data_t *data)
michael@0: {
michael@0:   hb_graphite2_tablelist_t *tlist = data->tlist;
michael@0: 
michael@0:   while (tlist)
michael@0:   {
michael@0:     hb_graphite2_tablelist_t *old = tlist;
michael@0:     hb_blob_destroy (tlist->blob);
michael@0:     tlist = tlist->next;
michael@0:     free (old);
michael@0:   }
michael@0: 
michael@0:   gr_face_destroy (data->grface);
michael@0: 
michael@0:   free (data);
michael@0: }
michael@0: 
michael@0: gr_face *
michael@0: hb_graphite2_face_get_gr_face (hb_face_t *face)
michael@0: {
michael@0:   if (unlikely (!hb_graphite2_shaper_face_data_ensure (face))) return NULL;
michael@0:   return HB_SHAPER_DATA_GET (face)->grface;
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper font data
michael@0:  */
michael@0: 
michael@0: static float hb_graphite2_get_advance (const void *hb_font, unsigned short gid)
michael@0: {
michael@0:   return ((hb_font_t *) hb_font)->get_glyph_h_advance (gid);
michael@0: }
michael@0: 
michael@0: hb_graphite2_shaper_font_data_t *
michael@0: _hb_graphite2_shaper_font_data_create (hb_font_t *font)
michael@0: {
michael@0:   if (unlikely (!hb_graphite2_shaper_face_data_ensure (font->face))) return NULL;
michael@0: 
michael@0:   hb_face_t *face = font->face;
michael@0:   hb_graphite2_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
michael@0: 
michael@0:   return gr_make_font_with_advance_fn (font->x_scale, font, &hb_graphite2_get_advance, face_data->grface);
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_graphite2_shaper_font_data_destroy (hb_graphite2_shaper_font_data_t *data)
michael@0: {
michael@0:   gr_font_destroy (data);
michael@0: }
michael@0: 
michael@0: gr_font *
michael@0: hb_graphite2_font_get_gr_font (hb_font_t *font)
michael@0: {
michael@0:   if (unlikely (!hb_graphite2_shaper_font_data_ensure (font))) return NULL;
michael@0:   return HB_SHAPER_DATA_GET (font);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper shape_plan data
michael@0:  */
michael@0: 
michael@0: struct hb_graphite2_shaper_shape_plan_data_t {};
michael@0: 
michael@0: hb_graphite2_shaper_shape_plan_data_t *
michael@0: _hb_graphite2_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
michael@0: 					     const hb_feature_t *user_features HB_UNUSED,
michael@0: 					     unsigned int        num_user_features HB_UNUSED)
michael@0: {
michael@0:   return (hb_graphite2_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_graphite2_shaper_shape_plan_data_destroy (hb_graphite2_shaper_shape_plan_data_t *data HB_UNUSED)
michael@0: {
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper
michael@0:  */
michael@0: 
michael@0: struct hb_graphite2_cluster_t {
michael@0:   unsigned int base_char;
michael@0:   unsigned int num_chars;
michael@0:   unsigned int base_glyph;
michael@0:   unsigned int num_glyphs;
michael@0: };
michael@0: 
michael@0: hb_bool_t
michael@0: _hb_graphite2_shape (hb_shape_plan_t    *shape_plan,
michael@0: 		     hb_font_t          *font,
michael@0: 		     hb_buffer_t        *buffer,
michael@0: 		     const hb_feature_t *features,
michael@0: 		     unsigned int        num_features)
michael@0: {
michael@0:   hb_face_t *face = font->face;
michael@0:   gr_face *grface = HB_SHAPER_DATA_GET (face)->grface;
michael@0:   gr_font *grfont = HB_SHAPER_DATA_GET (font);
michael@0: 
michael@0:   const char *lang = hb_language_to_string (hb_buffer_get_language (buffer));
michael@0:   const char *lang_end = lang ? strchr (lang, '-') : NULL;
michael@0:   int lang_len = lang_end ? lang_end - lang : -1;
michael@0:   gr_feature_val *feats = gr_face_featureval_for_lang (grface, lang ? hb_tag_from_string (lang, lang_len) : 0);
michael@0: 
michael@0:   while (num_features--)
michael@0:   {
michael@0:     const gr_feature_ref *fref = gr_face_find_fref (grface, features->tag);
michael@0:     if (fref)
michael@0:       gr_fref_set_feature_value (fref, features->value, feats);
michael@0:     features++;
michael@0:   }
michael@0: 
michael@0:   gr_segment *seg = NULL;
michael@0:   const gr_slot *is;
michael@0:   unsigned int ci = 0, ic = 0;
michael@0:   float curradvx = 0., curradvy = 0.;
michael@0: 
michael@0:   unsigned int scratch_size;
michael@0:   hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
michael@0: 
michael@0:   uint32_t *chars = (uint32_t *) scratch;
michael@0: 
michael@0:   for (unsigned int i = 0; i < buffer->len; ++i)
michael@0:     chars[i] = buffer->info[i].codepoint;
michael@0: 
michael@0:   hb_tag_t script_tag[2];
michael@0:   hb_ot_tags_from_script (hb_buffer_get_script (buffer), &script_tag[0], &script_tag[1]);
michael@0: 
michael@0:   seg = gr_make_seg (grfont, grface,
michael@0: 		     script_tag[1] == HB_TAG_NONE ? script_tag[0] : script_tag[1],
michael@0: 		     feats,
michael@0: 		     gr_utf32, chars, buffer->len,
michael@0: 		     2 | (hb_buffer_get_direction (buffer) == HB_DIRECTION_RTL ? 1 : 0));
michael@0: 
michael@0:   if (unlikely (!seg)) {
michael@0:     if (feats) gr_featureval_destroy (feats);
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   unsigned int glyph_count = gr_seg_n_slots (seg);
michael@0:   if (unlikely (!glyph_count)) {
michael@0:     if (feats) gr_featureval_destroy (feats);
michael@0:     gr_seg_destroy (seg);
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   scratch = buffer->get_scratch_buffer (&scratch_size);
michael@0:   while ((DIV_CEIL (sizeof (hb_graphite2_cluster_t) * buffer->len, sizeof (*scratch)) +
michael@0: 	  DIV_CEIL (sizeof (hb_codepoint_t) * glyph_count, sizeof (*scratch))) > scratch_size)
michael@0:   {
michael@0:     buffer->ensure (buffer->allocated * 2);
michael@0:     if (unlikely (buffer->in_error)) {
michael@0:       if (feats) gr_featureval_destroy (feats);
michael@0:       gr_seg_destroy (seg);
michael@0:       return false;
michael@0:     }
michael@0:     scratch = buffer->get_scratch_buffer (&scratch_size);
michael@0:   }
michael@0: 
michael@0: #define ALLOCATE_ARRAY(Type, name, len) \
michael@0:   Type *name = (Type *) scratch; \
michael@0:   { \
michael@0:     unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
michael@0:     assert (_consumed <= scratch_size); \
michael@0:     scratch += _consumed; \
michael@0:     scratch_size -= _consumed; \
michael@0:   }
michael@0: 
michael@0:   ALLOCATE_ARRAY (hb_graphite2_cluster_t, clusters, buffer->len);
michael@0:   ALLOCATE_ARRAY (hb_codepoint_t, gids, glyph_count);
michael@0: 
michael@0: #undef ALLOCATE_ARRAY
michael@0: 
michael@0:   memset (clusters, 0, sizeof (clusters[0]) * buffer->len);
michael@0: 
michael@0:   hb_codepoint_t *pg = gids;
michael@0:   for (is = gr_seg_first_slot (seg), ic = 0; is; is = gr_slot_next_in_segment (is), ic++)
michael@0:   {
michael@0:     unsigned int before = gr_slot_before (is);
michael@0:     unsigned int after = gr_slot_after (is);
michael@0:     *pg = gr_slot_gid (is);
michael@0:     pg++;
michael@0:     while (clusters[ci].base_char > before && ci)
michael@0:     {
michael@0:       clusters[ci-1].num_chars += clusters[ci].num_chars;
michael@0:       clusters[ci-1].num_glyphs += clusters[ci].num_glyphs;
michael@0:       ci--;
michael@0:     }
michael@0: 
michael@0:     if (gr_slot_can_insert_before (is) && clusters[ci].num_chars && before >= clusters[ci].base_char + clusters[ci].num_chars)
michael@0:     {
michael@0:       hb_graphite2_cluster_t *c = clusters + ci + 1;
michael@0:       c->base_char = clusters[ci].base_char + clusters[ci].num_chars;
michael@0:       c->num_chars = before - c->base_char;
michael@0:       c->base_glyph = ic;
michael@0:       c->num_glyphs = 0;
michael@0:       ci++;
michael@0:     }
michael@0:     clusters[ci].num_glyphs++;
michael@0: 
michael@0:     if (clusters[ci].base_char + clusters[ci].num_chars < after + 1)
michael@0: 	clusters[ci].num_chars = after + 1 - clusters[ci].base_char;
michael@0:   }
michael@0:   ci++;
michael@0: 
michael@0:   //buffer->clear_output ();
michael@0:   for (unsigned int i = 0; i < ci; ++i)
michael@0:   {
michael@0:     for (unsigned int j = 0; j < clusters[i].num_glyphs; ++j)
michael@0:     {
michael@0:       hb_glyph_info_t *info = &buffer->info[clusters[i].base_glyph + j];
michael@0:       info->codepoint = gids[clusters[i].base_glyph + j];
michael@0:       info->cluster = gr_cinfo_base(gr_seg_cinfo(seg, clusters[i].base_char));
michael@0:     }
michael@0:   }
michael@0:   buffer->len = glyph_count;
michael@0:   //buffer->swap_buffers ();
michael@0: 
michael@0:   if (HB_DIRECTION_IS_BACKWARD(buffer->props.direction))
michael@0:     curradvx = gr_seg_advance_X(seg);
michael@0: 
michael@0:   hb_glyph_position_t *pPos;
michael@0:   for (pPos = hb_buffer_get_glyph_positions (buffer, NULL), is = gr_seg_first_slot (seg);
michael@0:        is; pPos++, is = gr_slot_next_in_segment (is))
michael@0:   {
michael@0:     pPos->x_offset = gr_slot_origin_X (is) - curradvx;
michael@0:     pPos->y_offset = gr_slot_origin_Y (is) - curradvy;
michael@0:     pPos->x_advance = gr_slot_advance_X (is, grface, grfont);
michael@0:     pPos->y_advance = gr_slot_advance_Y (is, grface, grfont);
michael@0:     if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
michael@0:       curradvx -= pPos->x_advance;
michael@0:     pPos->x_offset = gr_slot_origin_X (is) - curradvx;
michael@0:     if (!HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
michael@0:       curradvx += pPos->x_advance;
michael@0:     pPos->y_offset = gr_slot_origin_Y (is) - curradvy;
michael@0:     curradvy += pPos->y_advance;
michael@0:   }
michael@0:   if (!HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
michael@0:     pPos[-1].x_advance += gr_seg_advance_X(seg) - curradvx;
michael@0: 
michael@0:   if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
michael@0:     hb_buffer_reverse_clusters (buffer);
michael@0: 
michael@0:   if (feats) gr_featureval_destroy (feats);
michael@0:   gr_seg_destroy (seg);
michael@0: 
michael@0:   return true;
michael@0: }