michael@0: /*
michael@0:  * Copyright © 2009,2010  Red Hat, Inc.
michael@0:  * Copyright © 2010,2011,2012  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:  * Red Hat Author(s): Behdad Esfahbod
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #define HB_SHAPER ot
michael@0: #define hb_ot_shaper_face_data_t hb_ot_layout_t
michael@0: #define hb_ot_shaper_shape_plan_data_t hb_ot_shape_plan_t
michael@0: #include "hb-shaper-impl-private.hh"
michael@0: 
michael@0: #include "hb-ot-shape-private.hh"
michael@0: #include "hb-ot-shape-complex-private.hh"
michael@0: #include "hb-ot-shape-fallback-private.hh"
michael@0: #include "hb-ot-shape-normalize-private.hh"
michael@0: 
michael@0: #include "hb-ot-layout-private.hh"
michael@0: #include "hb-set-private.hh"
michael@0: 
michael@0: 
michael@0: static hb_tag_t common_features[] = {
michael@0:   HB_TAG('c','c','m','p'),
michael@0:   HB_TAG('l','i','g','a'),
michael@0:   HB_TAG('l','o','c','l'),
michael@0:   HB_TAG('m','a','r','k'),
michael@0:   HB_TAG('m','k','m','k'),
michael@0:   HB_TAG('r','l','i','g'),
michael@0: };
michael@0: 
michael@0: 
michael@0: static hb_tag_t horizontal_features[] = {
michael@0:   HB_TAG('c','a','l','t'),
michael@0:   HB_TAG('c','l','i','g'),
michael@0:   HB_TAG('c','u','r','s'),
michael@0:   HB_TAG('k','e','r','n'),
michael@0:   HB_TAG('r','c','l','t'),
michael@0: };
michael@0: 
michael@0: static hb_tag_t vertical_features[] = {
michael@0:   HB_TAG('v','e','r','t'),
michael@0: };
michael@0: 
michael@0: 
michael@0: 
michael@0: static void
michael@0: hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
michael@0: 			      const hb_segment_properties_t  *props,
michael@0: 			      const hb_feature_t             *user_features,
michael@0: 			      unsigned int                    num_user_features)
michael@0: {
michael@0:   hb_ot_map_builder_t *map = &planner->map;
michael@0: 
michael@0:   switch (props->direction) {
michael@0:     case HB_DIRECTION_LTR:
michael@0:       map->add_global_bool_feature (HB_TAG ('l','t','r','a'));
michael@0:       map->add_global_bool_feature (HB_TAG ('l','t','r','m'));
michael@0:       break;
michael@0:     case HB_DIRECTION_RTL:
michael@0:       map->add_global_bool_feature (HB_TAG ('r','t','l','a'));
michael@0:       map->add_feature (HB_TAG ('r','t','l','m'), 1, F_NONE);
michael@0:       break;
michael@0:     case HB_DIRECTION_TTB:
michael@0:     case HB_DIRECTION_BTT:
michael@0:     case HB_DIRECTION_INVALID:
michael@0:     default:
michael@0:       break;
michael@0:   }
michael@0: 
michael@0:   map->add_feature (HB_TAG ('f','r','a','c'), 1, F_NONE);
michael@0:   map->add_feature (HB_TAG ('n','u','m','r'), 1, F_NONE);
michael@0:   map->add_feature (HB_TAG ('d','n','o','m'), 1, F_NONE);
michael@0: 
michael@0:   if (planner->shaper->collect_features)
michael@0:     planner->shaper->collect_features (planner);
michael@0: 
michael@0:   for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
michael@0:     map->add_global_bool_feature (common_features[i]);
michael@0: 
michael@0:   if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
michael@0:     for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
michael@0:       map->add_feature (horizontal_features[i], 1, F_GLOBAL |
michael@0: 			(horizontal_features[i] == HB_TAG('k','e','r','n') ?
michael@0: 			 F_HAS_FALLBACK : F_NONE));
michael@0:   else
michael@0:     for (unsigned int i = 0; i < ARRAY_LENGTH (vertical_features); i++)
michael@0:       map->add_feature (vertical_features[i], 1, F_GLOBAL |
michael@0: 			(vertical_features[i] == HB_TAG('v','k','r','n') ?
michael@0: 			 F_HAS_FALLBACK : F_NONE));
michael@0: 
michael@0:   if (planner->shaper->override_features)
michael@0:     planner->shaper->override_features (planner);
michael@0: 
michael@0:   for (unsigned int i = 0; i < num_user_features; i++) {
michael@0:     const hb_feature_t *feature = &user_features[i];
michael@0:     map->add_feature (feature->tag, feature->value,
michael@0: 		      (feature->start == 0 && feature->end == (unsigned int) -1) ?
michael@0: 		       F_GLOBAL : F_NONE);
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper face data
michael@0:  */
michael@0: 
michael@0: hb_ot_shaper_face_data_t *
michael@0: _hb_ot_shaper_face_data_create (hb_face_t *face)
michael@0: {
michael@0:   return _hb_ot_layout_create (face);
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data)
michael@0: {
michael@0:   _hb_ot_layout_destroy (data);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper font data
michael@0:  */
michael@0: 
michael@0: struct hb_ot_shaper_font_data_t {};
michael@0: 
michael@0: hb_ot_shaper_font_data_t *
michael@0: _hb_ot_shaper_font_data_create (hb_font_t *font)
michael@0: {
michael@0:   return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data)
michael@0: {
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper shape_plan data
michael@0:  */
michael@0: 
michael@0: hb_ot_shaper_shape_plan_data_t *
michael@0: _hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan,
michael@0: 				      const hb_feature_t *user_features,
michael@0: 				      unsigned int        num_user_features)
michael@0: {
michael@0:   hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t));
michael@0:   if (unlikely (!plan))
michael@0:     return NULL;
michael@0: 
michael@0:   hb_ot_shape_planner_t planner (shape_plan);
michael@0: 
michael@0:   planner.shaper = hb_ot_shape_complex_categorize (&planner);
michael@0: 
michael@0:   hb_ot_shape_collect_features (&planner, &shape_plan->props, user_features, num_user_features);
michael@0: 
michael@0:   planner.compile (*plan);
michael@0: 
michael@0:   if (plan->shaper->data_create) {
michael@0:     plan->data = plan->shaper->data_create (plan);
michael@0:     if (unlikely (!plan->data))
michael@0:       return NULL;
michael@0:   }
michael@0: 
michael@0:   return plan;
michael@0: }
michael@0: 
michael@0: void
michael@0: _hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan)
michael@0: {
michael@0:   if (plan->shaper->data_destroy)
michael@0:     plan->shaper->data_destroy (const_cast<void *> (plan->data));
michael@0: 
michael@0:   plan->finish ();
michael@0: 
michael@0:   free (plan);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * shaper
michael@0:  */
michael@0: 
michael@0: struct hb_ot_shape_context_t
michael@0: {
michael@0:   hb_ot_shape_plan_t *plan;
michael@0:   hb_font_t *font;
michael@0:   hb_face_t *face;
michael@0:   hb_buffer_t  *buffer;
michael@0:   const hb_feature_t *user_features;
michael@0:   unsigned int        num_user_features;
michael@0: 
michael@0:   /* Transient stuff */
michael@0:   hb_direction_t target_direction;
michael@0: };
michael@0: 
michael@0: 
michael@0: 
michael@0: /* Main shaper */
michael@0: 
michael@0: 
michael@0: /* Prepare */
michael@0: 
michael@0: static void
michael@0: hb_set_unicode_props (hb_buffer_t *buffer)
michael@0: {
michael@0:   unsigned int count = buffer->len;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:     _hb_glyph_info_set_unicode_props (&buffer->info[i], buffer->unicode);
michael@0: }
michael@0: 
michael@0: static void
michael@0: hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
michael@0: {
michael@0:   if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
michael@0:       _hb_glyph_info_get_general_category (&buffer->info[0]) !=
michael@0:       HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
michael@0:     return;
michael@0: 
michael@0:   if (!font->has_glyph (0x25CC))
michael@0:     return;
michael@0: 
michael@0:   hb_glyph_info_t dottedcircle;
michael@0:   dottedcircle.codepoint = 0x25CC;
michael@0:   _hb_glyph_info_set_unicode_props (&dottedcircle, buffer->unicode);
michael@0: 
michael@0:   buffer->clear_output ();
michael@0: 
michael@0:   buffer->idx = 0;
michael@0:   hb_glyph_info_t info = dottedcircle;
michael@0:   info.cluster = buffer->cur().cluster;
michael@0:   info.mask = buffer->cur().mask;
michael@0:   buffer->output_info (info);
michael@0:   while (buffer->idx < buffer->len)
michael@0:     buffer->next_glyph ();
michael@0: 
michael@0:   buffer->swap_buffers ();
michael@0: }
michael@0: 
michael@0: static void
michael@0: hb_form_clusters (hb_buffer_t *buffer)
michael@0: {
michael@0:   unsigned int count = buffer->len;
michael@0:   for (unsigned int i = 1; i < count; i++)
michael@0:     if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i])))
michael@0:       buffer->merge_clusters (i - 1, i + 1);
michael@0: }
michael@0: 
michael@0: static void
michael@0: hb_ensure_native_direction (hb_buffer_t *buffer)
michael@0: {
michael@0:   hb_direction_t direction = buffer->props.direction;
michael@0: 
michael@0:   /* TODO vertical:
michael@0:    * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
michael@0:    * Ogham fonts are supposed to be implemented BTT or not.  Need to research that
michael@0:    * first. */
michael@0:   if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) ||
michael@0:       (HB_DIRECTION_IS_VERTICAL   (direction) && direction != HB_DIRECTION_TTB))
michael@0:   {
michael@0:     hb_buffer_reverse_clusters (buffer);
michael@0:     buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: /* Substitute */
michael@0: 
michael@0: static inline void
michael@0: hb_ot_mirror_chars (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   if (HB_DIRECTION_IS_FORWARD (c->target_direction))
michael@0:     return;
michael@0: 
michael@0:   hb_buffer_t *buffer = c->buffer;
michael@0:   hb_unicode_funcs_t *unicode = buffer->unicode;
michael@0:   hb_mask_t rtlm_mask = c->plan->rtlm_mask;
michael@0: 
michael@0:   unsigned int count = buffer->len;
michael@0:   hb_glyph_info_t *info = buffer->info;
michael@0:   for (unsigned int i = 0; i < count; i++) {
michael@0:     hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
michael@0:     if (likely (codepoint == info[i].codepoint))
michael@0:       info[i].mask |= rtlm_mask;
michael@0:     else
michael@0:       info[i].codepoint = codepoint;
michael@0:   }
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_shape_setup_masks_fraction (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   if (!c->plan->has_frac)
michael@0:     return;
michael@0: 
michael@0:   hb_buffer_t *buffer = c->buffer;
michael@0: 
michael@0:   /* TODO look in pre/post context text also. */
michael@0:   unsigned int count = buffer->len;
michael@0:   hb_glyph_info_t *info = buffer->info;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:   {
michael@0:     if (info[i].codepoint == 0x2044) /* FRACTION SLASH */
michael@0:     {
michael@0:       unsigned int start = i, end = i + 1;
michael@0:       while (start &&
michael@0: 	     _hb_glyph_info_get_general_category (&info[start - 1]) ==
michael@0: 	     HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
michael@0:         start--;
michael@0:       while (end < count &&
michael@0: 	     _hb_glyph_info_get_general_category (&info[end]) ==
michael@0: 	     HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
michael@0:         end++;
michael@0: 
michael@0:       for (unsigned int j = start; j < i; j++)
michael@0:         info[j].mask |= c->plan->numr_mask | c->plan->frac_mask;
michael@0:       info[i].mask |= c->plan->frac_mask;
michael@0:       for (unsigned int j = i + 1; j < end; j++)
michael@0:         info[j].mask |= c->plan->frac_mask | c->plan->dnom_mask;
michael@0: 
michael@0:       i = end - 1;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_shape_initialize_masks (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   hb_ot_map_t *map = &c->plan->map;
michael@0:   hb_buffer_t *buffer = c->buffer;
michael@0: 
michael@0:   hb_mask_t global_mask = map->get_global_mask ();
michael@0:   buffer->reset_masks (global_mask);
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   hb_ot_map_t *map = &c->plan->map;
michael@0:   hb_buffer_t *buffer = c->buffer;
michael@0: 
michael@0:   hb_ot_shape_setup_masks_fraction (c);
michael@0: 
michael@0:   if (c->plan->shaper->setup_masks)
michael@0:     c->plan->shaper->setup_masks (c->plan, buffer, c->font);
michael@0: 
michael@0:   for (unsigned int i = 0; i < c->num_user_features; i++)
michael@0:   {
michael@0:     const hb_feature_t *feature = &c->user_features[i];
michael@0:     if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
michael@0:       unsigned int shift;
michael@0:       hb_mask_t mask = map->get_mask (feature->tag, &shift);
michael@0:       buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_map_glyphs_fast (hb_buffer_t  *buffer)
michael@0: {
michael@0:   /* Normalization process sets up glyph_index(), we just copy it. */
michael@0:   unsigned int count = buffer->len;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:     buffer->info[i].codepoint = buffer->info[i].glyph_index();
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   unsigned int count = c->buffer->len;
michael@0:   hb_glyph_info_t *info = c->buffer->info;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:     _hb_glyph_info_set_glyph_props (&info[i],
michael@0: 				    _hb_glyph_info_get_general_category (&info[i])
michael@0: 				    == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ?
michael@0: 				    HB_OT_LAYOUT_GLYPH_PROPS_MARK :
michael@0: 				    HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_substitute_default (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   hb_buffer_t *buffer = c->buffer;
michael@0: 
michael@0:   if (c->plan->shaper->preprocess_text)
michael@0:     c->plan->shaper->preprocess_text (c->plan, buffer, c->font);
michael@0: 
michael@0:   hb_ot_shape_initialize_masks (c);
michael@0: 
michael@0:   hb_ot_mirror_chars (c);
michael@0: 
michael@0:   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
michael@0: 
michael@0:   _hb_ot_shape_normalize (c->plan, buffer, c->font);
michael@0: 
michael@0:   hb_ot_shape_setup_masks (c);
michael@0: 
michael@0:   /* This is unfortunate to go here, but necessary... */
michael@0:   if (!hb_ot_layout_has_positioning (c->face))
michael@0:     _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, buffer);
michael@0: 
michael@0:   hb_ot_map_glyphs_fast (buffer);
michael@0: 
michael@0:   HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_substitute_complex (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   hb_buffer_t *buffer = c->buffer;
michael@0: 
michael@0:   hb_ot_layout_substitute_start (c->font, buffer);
michael@0: 
michael@0:   if (!hb_ot_layout_has_glyph_classes (c->face))
michael@0:     hb_synthesize_glyph_classes (c);
michael@0: 
michael@0:   c->plan->substitute (c->font, buffer);
michael@0: 
michael@0:   hb_ot_layout_substitute_finish (c->font, buffer);
michael@0: 
michael@0:   return;
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_substitute (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   hb_ot_substitute_default (c);
michael@0:   hb_ot_substitute_complex (c);
michael@0: }
michael@0: 
michael@0: /* Position */
michael@0: 
michael@0: static inline void
michael@0: zero_mark_widths_by_unicode (hb_buffer_t *buffer)
michael@0: {
michael@0:   unsigned int count = buffer->len;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:     if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
michael@0:     {
michael@0:       buffer->pos[i].x_advance = 0;
michael@0:       buffer->pos[i].y_advance = 0;
michael@0:     }
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: zero_mark_widths_by_gdef (hb_buffer_t *buffer)
michael@0: {
michael@0:   unsigned int count = buffer->len;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:     if (_hb_glyph_info_is_mark (&buffer->info[i]))
michael@0:     {
michael@0:       buffer->pos[i].x_advance = 0;
michael@0:       buffer->pos[i].y_advance = 0;
michael@0:     }
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_position_default (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   hb_direction_t direction = c->buffer->props.direction;
michael@0:   unsigned int count = c->buffer->len;
michael@0:   hb_glyph_info_t *info = c->buffer->info;
michael@0:   hb_glyph_position_t *pos = c->buffer->pos;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:   {
michael@0:     c->font->get_glyph_advance_for_direction (info[i].codepoint,
michael@0: 					      direction,
michael@0: 					      &pos[i].x_advance,
michael@0: 					      &pos[i].y_advance);
michael@0:     c->font->subtract_glyph_origin_for_direction (info[i].codepoint,
michael@0: 						  direction,
michael@0: 						  &pos[i].x_offset,
michael@0: 						  &pos[i].y_offset);
michael@0: 
michael@0:   }
michael@0: }
michael@0: 
michael@0: static inline bool
michael@0: hb_ot_position_complex (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   bool ret = false;
michael@0:   unsigned int count = c->buffer->len;
michael@0: 
michael@0:   switch (c->plan->shaper->zero_width_marks)
michael@0:   {
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
michael@0:       zero_mark_widths_by_gdef (c->buffer);
michael@0:       break;
michael@0: 
michael@0:     /* Not currently used for any shaper:
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY:
michael@0:       zero_mark_widths_by_unicode (c->buffer);
michael@0:       break;
michael@0:     */
michael@0: 
michael@0:     default:
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE:
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
michael@0:       break;
michael@0:   }
michael@0: 
michael@0:   if (hb_ot_layout_has_positioning (c->face))
michael@0:   {
michael@0:     hb_glyph_info_t *info = c->buffer->info;
michael@0:     hb_glyph_position_t *pos = c->buffer->pos;
michael@0: 
michael@0:     /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */
michael@0: 
michael@0:     for (unsigned int i = 0; i < count; i++) {
michael@0:       c->font->add_glyph_origin_for_direction (info[i].codepoint,
michael@0: 					       HB_DIRECTION_LTR,
michael@0: 					       &pos[i].x_offset,
michael@0: 					       &pos[i].y_offset);
michael@0:     }
michael@0: 
michael@0:     c->plan->position (c->font, c->buffer);
michael@0: 
michael@0:     for (unsigned int i = 0; i < count; i++) {
michael@0:       c->font->subtract_glyph_origin_for_direction (info[i].codepoint,
michael@0: 						    HB_DIRECTION_LTR,
michael@0: 						    &pos[i].x_offset,
michael@0: 						    &pos[i].y_offset);
michael@0:     }
michael@0: 
michael@0:     ret = true;
michael@0:   }
michael@0: 
michael@0:   switch (c->plan->shaper->zero_width_marks)
michael@0:   {
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE:
michael@0:       zero_mark_widths_by_unicode (c->buffer);
michael@0:       break;
michael@0: 
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
michael@0:       zero_mark_widths_by_gdef (c->buffer);
michael@0:       break;
michael@0: 
michael@0:     default:
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
michael@0:     //case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY:
michael@0:     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
michael@0:       break;
michael@0:   }
michael@0: 
michael@0:   return ret;
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: hb_ot_position (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   hb_ot_layout_position_start (c->font, c->buffer);
michael@0: 
michael@0:   hb_ot_position_default (c);
michael@0: 
michael@0:   hb_bool_t fallback = !hb_ot_position_complex (c);
michael@0: 
michael@0:   hb_ot_layout_position_finish (c->font, c->buffer);
michael@0: 
michael@0:   if (fallback && c->plan->shaper->fallback_position)
michael@0:     _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer);
michael@0: 
michael@0:   if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
michael@0:     hb_buffer_reverse (c->buffer);
michael@0: 
michael@0:   /* Visual fallback goes here. */
michael@0: 
michael@0:   if (fallback)
michael@0:     _hb_ot_shape_fallback_kern (c->plan, c->font, c->buffer);
michael@0: }
michael@0: 
michael@0: 
michael@0: /* Post-process */
michael@0: 
michael@0: static void
michael@0: hb_ot_hide_default_ignorables (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   if (c->buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES)
michael@0:     return;
michael@0: 
michael@0:   hb_codepoint_t space;
michael@0:   enum {
michael@0:     SPACE_DONT_KNOW,
michael@0:     SPACE_AVAILABLE,
michael@0:     SPACE_UNAVAILABLE
michael@0:   } space_status = SPACE_DONT_KNOW;
michael@0: 
michael@0:   unsigned int count = c->buffer->len;
michael@0:   hb_glyph_info_t *info = c->buffer->info;
michael@0:   hb_glyph_position_t *pos = c->buffer->pos;
michael@0:   unsigned int j = 0;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:   {
michael@0:     if (unlikely (!_hb_glyph_info_ligated (&info[i]) &&
michael@0: 		  _hb_glyph_info_is_default_ignorable (&info[i])))
michael@0:     {
michael@0:       if (space_status == SPACE_DONT_KNOW)
michael@0: 	space_status = c->font->get_glyph (' ', 0, &space) ? SPACE_AVAILABLE : SPACE_UNAVAILABLE;
michael@0: 
michael@0:       if (space_status == SPACE_AVAILABLE)
michael@0:       {
michael@0: 	info[i].codepoint = space;
michael@0: 	pos[i].x_advance = 0;
michael@0: 	pos[i].y_advance = 0;
michael@0:       }
michael@0:       else
michael@0: 	continue; /* Delete it. */
michael@0:     }
michael@0:     if (j != i)
michael@0:     {
michael@0:       info[j] = info[i];
michael@0:       pos[j] = pos[i];
michael@0:     }
michael@0:     j++;
michael@0:   }
michael@0:   c->buffer->len = j;
michael@0: }
michael@0: 
michael@0: 
michael@0: /* Pull it all together! */
michael@0: 
michael@0: static void
michael@0: hb_ot_shape_internal (hb_ot_shape_context_t *c)
michael@0: {
michael@0:   c->buffer->deallocate_var_all ();
michael@0: 
michael@0:   /* Save the original direction, we use it later. */
michael@0:   c->target_direction = c->buffer->props.direction;
michael@0: 
michael@0:   _hb_buffer_allocate_unicode_vars (c->buffer);
michael@0: 
michael@0:   c->buffer->clear_output ();
michael@0: 
michael@0:   hb_set_unicode_props (c->buffer);
michael@0:   hb_insert_dotted_circle (c->buffer, c->font);
michael@0:   hb_form_clusters (c->buffer);
michael@0: 
michael@0:   hb_ensure_native_direction (c->buffer);
michael@0: 
michael@0:   hb_ot_substitute (c);
michael@0:   hb_ot_position (c);
michael@0: 
michael@0:   hb_ot_hide_default_ignorables (c);
michael@0: 
michael@0:   _hb_buffer_deallocate_unicode_vars (c->buffer);
michael@0: 
michael@0:   c->buffer->props.direction = c->target_direction;
michael@0: 
michael@0:   c->buffer->deallocate_var_all ();
michael@0: }
michael@0: 
michael@0: 
michael@0: hb_bool_t
michael@0: _hb_ot_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_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features};
michael@0:   hb_ot_shape_internal (&c);
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: 
michael@0: void
michael@0: hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
michael@0: 				  hb_tag_t         table_tag,
michael@0: 				  hb_set_t        *lookup_indexes /* OUT */)
michael@0: {
michael@0:   /* XXX Does the first part always succeed? */
michael@0:   HB_SHAPER_DATA_GET (shape_plan)->collect_lookups (table_tag, lookup_indexes);
michael@0: }
michael@0: 
michael@0: 
michael@0: /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
michael@0: static void
michael@0: add_char (hb_font_t          *font,
michael@0: 	  hb_unicode_funcs_t *unicode,
michael@0: 	  hb_bool_t           mirror,
michael@0: 	  hb_codepoint_t      u,
michael@0: 	  hb_set_t           *glyphs)
michael@0: {
michael@0:   hb_codepoint_t glyph;
michael@0:   if (font->get_glyph (u, 0, &glyph))
michael@0:     glyphs->add (glyph);
michael@0:   if (mirror)
michael@0:   {
michael@0:     hb_codepoint_t m = unicode->mirroring (u);
michael@0:     if (m != u && font->get_glyph (m, 0, &glyph))
michael@0:       glyphs->add (glyph);
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: void
michael@0: hb_ot_shape_glyphs_closure (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: 			    hb_set_t           *glyphs)
michael@0: {
michael@0:   hb_ot_shape_plan_t plan;
michael@0: 
michael@0:   const char *shapers[] = {"ot", NULL};
michael@0:   hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
michael@0: 							     features, num_features, shapers);
michael@0: 
michael@0:   bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
michael@0: 
michael@0:   unsigned int count = buffer->len;
michael@0:   for (unsigned int i = 0; i < count; i++)
michael@0:     add_char (font, buffer->unicode, mirror, buffer->info[i].codepoint, glyphs);
michael@0: 
michael@0:   hb_set_t lookups;
michael@0:   lookups.init ();
michael@0:   hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, &lookups);
michael@0: 
michael@0:   /* And find transitive closure. */
michael@0:   hb_set_t copy;
michael@0:   copy.init ();
michael@0:   do {
michael@0:     copy.set (glyphs);
michael@0:     for (hb_codepoint_t lookup_index = -1; hb_set_next (&lookups, &lookup_index);)
michael@0:       hb_ot_layout_lookup_substitute_closure (font->face, lookup_index, glyphs);
michael@0:   } while (!copy.is_equal (glyphs));
michael@0: 
michael@0:   hb_shape_plan_destroy (shape_plan);
michael@0: }