harfbuzz-ng roll

third_party/harfbuzz-ng/src/hb-ot-shape.cc

 /*
  * Copyright © 2009,2010  Red Hat, Inc.
- * Copyright © 2010,2011  Google, Inc.
+ * Copyright © 2010,2011,2012  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.
  *
  * Red Hat Author(s): Behdad Esfahbod
  * Google Author(s): Behdad Esfahbod
  */
 
+#define HB_SHAPER ot
+#define hb_ot_shaper_face_data_t hb_ot_layout_t
+#define hb_ot_shaper_shape_plan_data_t hb_ot_shape_plan_t
+#include "hb-shaper-impl-private.hh"
+
 #include "hb-ot-shape-private.hh"
+#include "hb-ot-shape-complex-private.hh"
+#include "hb-ot-shape-fallback-private.hh"
 #include "hb-ot-shape-normalize-private.hh"
 
-#include "hb-font-private.hh"
+#include "hb-ot-layout-private.hh"
 #include "hb-set-private.hh"
 
 
-
-hb_tag_t common_features[] = {
+static hb_tag_t common_features[] = {
   HB_TAG('c','c','m','p'),
   HB_TAG('l','i','g','a'),
   HB_TAG('l','o','c','l'),
   HB_TAG('m','a','r','k'),
   HB_TAG('m','k','m','k'),
   HB_TAG('r','l','i','g'),
 };
 
 
-hb_tag_t horizontal_features[] = {
+static hb_tag_t horizontal_features[] = {
   HB_TAG('c','a','l','t'),
   HB_TAG('c','l','i','g'),
   HB_TAG('c','u','r','s'),
   HB_TAG('k','e','r','n'),
+  HB_TAG('r','c','l','t'),
 };
 
 /* Note:
  * Technically speaking, vrt2 and vert are mutually exclusive.
  * According to the spec, valt and vpal are also mutually exclusive.
  * But we apply them all for now.
  */
-hb_tag_t vertical_features[] = {
+static hb_tag_t vertical_features[] = {
   HB_TAG('v','a','l','t'),
   HB_TAG('v','e','r','t'),
   HB_TAG('v','k','r','n'),
   HB_TAG('v','p','a','l'),
   HB_TAG('v','r','t','2'),
 };
 
 
 
-struct hb_ot_shape_planner_t
-{
-  hb_ot_map_builder_t map;
-  hb_ot_complex_shaper_t shaper;
-
-  hb_ot_shape_planner_t (void) : map () {}
-  ~hb_ot_shape_planner_t (void) { map.finish (); }
-
-  inline void compile (hb_face_t *face,
-                       const hb_segment_properties_t *props,
-                       struct hb_ot_shape_plan_t &plan)
-  {
-    plan.shaper = shaper;
-    map.compile (face, props, plan.map);
-  }
-
-  private:
-  NO_COPY (hb_ot_shape_planner_t);
-};
-
 static void
 hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
                               const hb_segment_properties_t  *props,
                               const hb_feature_t             *user_features,
                               unsigned int                    num_user_features)
 {
+  hb_ot_map_builder_t *map = &planner->map;
+
   switch (props->direction) {
     case HB_DIRECTION_LTR:
-      planner->map.add_bool_feature (HB_TAG ('l','t','r','a'));
-      planner->map.add_bool_feature (HB_TAG ('l','t','r','m'));
+      map->add_bool_feature (HB_TAG ('l','t','r','a'));
+      map->add_bool_feature (HB_TAG ('l','t','r','m'));
       break;
     case HB_DIRECTION_RTL:
-      planner->map.add_bool_feature (HB_TAG ('r','t','l','a'));
-      planner->map.add_bool_feature (HB_TAG ('r','t','l','m'), false);
+      map->add_bool_feature (HB_TAG ('r','t','l','a'));
+      map->add_bool_feature (HB_TAG ('r','t','l','m'), false);
       break;
     case HB_DIRECTION_TTB:
     case HB_DIRECTION_BTT:
     case HB_DIRECTION_INVALID:
     default:
       break;
   }
 
 #define ADD_FEATURES(array) \
   HB_STMT_START { \
     for (unsigned int i = 0; i < ARRAY_LENGTH (array); i++) \
-      planner->map.add_bool_feature (array[i]); \
+      map->add_bool_feature (array[i]); \
   } HB_STMT_END
 
-  hb_ot_shape_complex_collect_features (planner->shaper, &planner->map, props);
+  if (planner->shaper->collect_features)
+    planner->shaper->collect_features (planner);
 
   ADD_FEATURES (common_features);
 
   if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
     ADD_FEATURES (horizontal_features);
   else
     ADD_FEATURES (vertical_features);
 
+  if (planner->shaper->override_features)
+    planner->shaper->override_features (planner);
+
 #undef ADD_FEATURES
 
   for (unsigned int i = 0; i < num_user_features; i++) {
     const hb_feature_t *feature = &user_features[i];
-    planner->map.add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
+    map->add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
   }
 }
 
 
+/*
+ * shaper face data
+ */
+
+hb_ot_shaper_face_data_t *
+_hb_ot_shaper_face_data_create (hb_face_t *face)
+{
+  return _hb_ot_layout_create (face);
+}
+
+void
+_hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data)
+{
+  _hb_ot_layout_destroy (data);
+}
+
+
+/*
+ * shaper font data
+ */
+
+struct hb_ot_shaper_font_data_t {};
+
+hb_ot_shaper_font_data_t *
+_hb_ot_shaper_font_data_create (hb_font_t *font)
+{
+  return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
+}
+
+void
+_hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data)
+{
+}
+
+
+/*
+ * shaper shape_plan data
+ */
+
+hb_ot_shaper_shape_plan_data_t *
+_hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan,
+                                      const hb_feature_t *user_features,
+                                      unsigned int        num_user_features)
+{
+  hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t));
+  if (unlikely (!plan))
+    return NULL;
+
+  hb_ot_shape_planner_t planner (shape_plan);
+
+  planner.shaper = hb_ot_shape_complex_categorize (&shape_plan->props);
+
+  hb_ot_shape_collect_features (&planner, &shape_plan->props, user_features, num_user_features);
+
+  planner.compile (*plan);
+
+  if (plan->shaper->data_create) {
+    plan->data = plan->shaper->data_create (plan);
+    if (unlikely (!plan->data))
+      return NULL;
+  }
+
+  return plan;
+}
+
+void
+_hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan)
+{
+  if (plan->shaper->data_destroy)
+    plan->shaper->data_destroy (const_cast<void *> (plan->data));
+
+  plan->finish ();
+
+  free (plan);
+}
+
+
+/*
+ * shaper
+ */
+
 struct hb_ot_shape_context_t
 {
-  /* Input to hb_ot_shape_execute() */
   hb_ot_shape_plan_t *plan;
   hb_font_t *font;
   hb_face_t *face;
   hb_buffer_t  *buffer;
   const hb_feature_t *user_features;
   unsigned int        num_user_features;
 
   /* Transient stuff */
   hb_direction_t target_direction;
-  hb_bool_t applied_position_complex;
 };
 
-static void
-hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
-{
-  hb_mask_t global_mask = c->plan->map.get_global_mask ();
-  c->buffer->reset_masks (global_mask);
-
-  hb_ot_shape_complex_setup_masks (c->plan->shaper, &c->plan->map, c->buffer, c->font);
-
-  for (unsigned int i = 0; i < c->num_user_features; i++)
-  {
-    const hb_feature_t *feature = &c->user_features[i];
-    if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
-      unsigned int shift;
-      hb_mask_t mask = c->plan->map.get_mask (feature->tag, &shift);
-      c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
-    }
-  }
-}
 
 
 /* Main shaper */
 
+
 /* Prepare */
 
 static void
 hb_set_unicode_props (hb_buffer_t *buffer)
 {
   unsigned int count = buffer->len;
   for (unsigned int i = 0; i < count; i++)
     _hb_glyph_info_set_unicode_props (&buffer->info[i], buffer->unicode);
 }
 
 static void
+hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
+{
+  /* TODO One day, when we keep _before_ text for the buffer, take
+   * that into consideration.  For now, insert dotted-circle if the
+   * very first character is a non-spacing mark. */
+  if (_hb_glyph_info_get_general_category (&buffer->info[0]) !=
+      HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
+    return;
+
+  hb_codepoint_t dottedcircle_glyph;
+  if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph))
+    return;
+
+  hb_glyph_info_t dottedcircle;
+  dottedcircle.codepoint = 0x25CC;
+  _hb_glyph_info_set_unicode_props (&dottedcircle, buffer->unicode);
+
+  buffer->clear_output ();
+
+  buffer->idx = 0;
+  hb_glyph_info_t info = dottedcircle;
+  info.cluster = buffer->cur().cluster;
+  info.mask = buffer->cur().mask;
+  buffer->output_info (info);
+  while (buffer->idx < buffer->len)
+    buffer->next_glyph ();
+
+  buffer->swap_buffers ();
+}
+
+static void
 hb_form_clusters (hb_buffer_t *buffer)
 {
   unsigned int count = buffer->len;
   for (unsigned int i = 1; i < count; i++)
-    if (FLAG (_hb_glyph_info_get_general_category (&buffer->info[i])) &
-        (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) |
-         FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) |
-         FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
-      buffer->info[i].cluster = buffer->info[i - 1].cluster; /* XXX do the min() here */
+    if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i])))
+      buffer->merge_clusters (i - 1, i + 1);
 }
 
 static void
 hb_ensure_native_direction (hb_buffer_t *buffer)
 {
   hb_direction_t direction = buffer->props.direction;
 
   /* TODO vertical:
    * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
    * Ogham fonts are supposed to be implemented BTT or not.  Need to research that
    * first. */
   if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) ||
       (HB_DIRECTION_IS_VERTICAL   (direction) && direction != HB_DIRECTION_TTB))
   {
     hb_buffer_reverse_clusters (buffer);
     buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
   }
 }
 
 
 /* Substitute */
 
-static void
-hb_mirror_chars (hb_ot_shape_context_t *c)
+static inline void
+hb_ot_mirror_chars (hb_ot_shape_context_t *c)
 {
-  hb_unicode_funcs_t *unicode = c->buffer->unicode;
-
   if (HB_DIRECTION_IS_FORWARD (c->target_direction))
     return;
 
+  hb_unicode_funcs_t *unicode = c->buffer->unicode;
   hb_mask_t rtlm_mask = c->plan->map.get_1_mask (HB_TAG ('r','t','l','m'));
 
   unsigned int count = c->buffer->len;
   for (unsigned int i = 0; i < count; i++) {
-    hb_codepoint_t codepoint = hb_unicode_mirroring (unicode, c->buffer->info[i].codepoint);
+    hb_codepoint_t codepoint = unicode->mirroring (c->buffer->info[i].codepoint);
     if (likely (codepoint == c->buffer->info[i].codepoint))
-      c->buffer->info[i].mask |= rtlm_mask; /* XXX this should be moved to before setting user-feature masks */
+      c->buffer->info[i].mask |= rtlm_mask;
     else
       c->buffer->info[i].codepoint = codepoint;
   }
 }
 
-static void
-hb_map_glyphs (hb_font_t    *font,
-               hb_buffer_t  *buffer)
+static inline void
+hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
 {
-  hb_codepoint_t glyph;
+  hb_ot_map_t *map = &c->plan->map;
 
-  if (unlikely (!buffer->len))
-    return;
+  hb_mask_t global_mask = map->get_global_mask ();
+  c->buffer->reset_masks (global_mask);
 
-  buffer->clear_output ();
+  if (c->plan->shaper->setup_masks)
+    c->plan->shaper->setup_masks (c->plan, c->buffer, c->font);
 
-  unsigned int count = buffer->len - 1;
-  for (buffer->idx = 0; buffer->idx < count;) {
-    if (unlikely (_hb_unicode_is_variation_selector (buffer->cur(+1).codepoint))) {
-      hb_font_get_glyph (font, buffer->cur().codepoint, buffer->cur(+1).codepoint, &glyph);
-      buffer->replace_glyphs (2, 1, &glyph);
-    } else {
-      hb_font_get_glyph (font, buffer->cur().codepoint, 0, &glyph);
-      buffer->replace_glyph (glyph);
+  for (unsigned int i = 0; i < c->num_user_features; i++)
+  {
+    const hb_feature_t *feature = &c->user_features[i];
+    if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
+      unsigned int shift;
+      hb_mask_t mask = map->get_mask (feature->tag, &shift);
+      c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
     }
   }
-  if (likely (buffer->idx < buffer->len)) {
-    hb_font_get_glyph (font, buffer->cur().codepoint, 0, &glyph);
-    buffer->replace_glyph (glyph);
-  }
-  buffer->swap_buffers ();
 }
 
-static void
-hb_substitute_default (hb_ot_shape_context_t *c)
+static inline void
+hb_ot_map_glyphs_fast (hb_buffer_t  *buffer)
 {
-  hb_ot_layout_substitute_start (c->buffer);
-
-  hb_mirror_chars (c);
-
-  hb_map_glyphs (c->font, c->buffer);
+  /* Normalization process sets up glyph_index(), we just copy it. */
+  unsigned int count = buffer->len;
+  for (unsigned int i = 0; i < count; i++)
+    buffer->info[i].codepoint = buffer->info[i].glyph_index();
 }
 
-static void
+static inline void
+hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
+{
+  unsigned int count = c->buffer->len;
+  for (unsigned int i = 0; i < count; i++)
+    c->buffer->info[i].glyph_props() = _hb_glyph_info_get_general_category (&c->buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ?
+                                       HB_OT_LAYOUT_GLYPH_CLASS_MARK :
+                                       HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
+}
+
+static inline void
+hb_ot_substitute_default (hb_ot_shape_context_t *c)
+{
+  if (c->plan->shaper->preprocess_text)
+    c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
+
+  hb_ot_mirror_chars (c);
+
+  HB_BUFFER_ALLOCATE_VAR (c->buffer, glyph_index);
+
+  _hb_ot_shape_normalize (c->font, c->buffer,
+                          c->plan->shaper->normalization_preference ?
+                          c->plan->shaper->normalization_preference (c->plan) :
+                          HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT);
+
+  hb_ot_shape_setup_masks (c);
+
+  /* This is unfortunate to go here, but necessary... */
+  if (!hb_ot_layout_has_positioning (c->face))
+    _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, c->buffer);
+
+  hb_ot_map_glyphs_fast (c->buffer);
+
+  HB_BUFFER_DEALLOCATE_VAR (c->buffer, glyph_index);
+}
+
+static inline void
 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
 {
-  if (hb_ot_layout_has_substitution (c->face)) {
-    c->plan->map.substitute (c->face, c->buffer);
-  }
+  hb_ot_layout_substitute_start (c->font, c->buffer);
 
-  hb_ot_layout_substitute_finish (c->buffer);
+  if (!hb_ot_layout_has_glyph_classes (c->face))
+    hb_synthesize_glyph_classes (c);
+
+  c->plan->substitute (c->font, c->buffer);
+
+  hb_ot_layout_substitute_finish (c->font, c->buffer);
 
   return;
 }
 
+static inline void
+hb_ot_substitute (hb_ot_shape_context_t *c)
+{
+  hb_ot_substitute_default (c);
+  hb_ot_substitute_complex (c);
+}
 
 /* Position */
 
-static void
-hb_position_default (hb_ot_shape_context_t *c)
+static inline void
+hb_ot_position_default (hb_ot_shape_context_t *c)
 {
-  hb_ot_layout_position_start (c->buffer);
+  hb_ot_layout_position_start (c->font, c->buffer);
 
   unsigned int count = c->buffer->len;
   for (unsigned int i = 0; i < count; i++) {
-    hb_font_get_glyph_advance_for_direction (c->font, c->buffer->info[i].codepoint,
-                                             c->buffer->props.direction,
-                                             &c->buffer->pos[i].x_advance,
-                                             &c->buffer->pos[i].y_advance);
-    hb_font_subtract_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint,
-                                                 c->buffer->props.direction,
-                                                 &c->buffer->pos[i].x_offset,
-                                                 &c->buffer->pos[i].y_offset);
+    c->font->get_glyph_advance_for_direction (c->buffer->info[i].codepoint,
+                                              c->buffer->props.direction,
+                                              &c->buffer->pos[i].x_advance,
+                                              &c->buffer->pos[i].y_advance);
+    c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint,
+                                                  c->buffer->props.direction,
+                                                  &c->buffer->pos[i].x_offset,
+                                                  &c->buffer->pos[i].y_offset);
   }
 }
 
-static void
+static inline bool
 hb_ot_position_complex (hb_ot_shape_context_t *c)
 {
+  bool ret = false;
 
   if (hb_ot_layout_has_positioning (c->face))
   {
     /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */
 
     unsigned int count = c->buffer->len;
     for (unsigned int i = 0; i < count; i++) {
-      hb_font_add_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint,
-                                              HB_DIRECTION_LTR,
-                                              &c->buffer->pos[i].x_offset,
-                                              &c->buffer->pos[i].y_offset);
+      c->font->add_glyph_origin_for_direction (c->buffer->info[i].codepoint,
+                                               HB_DIRECTION_LTR,
+                                               &c->buffer->pos[i].x_offset,
+                                               &c->buffer->pos[i].y_offset);
     }
 
-    c->plan->map.position (c->font, c->buffer);
+    c->plan->position (c->font, c->buffer);
 
     for (unsigned int i = 0; i < count; i++) {
-      hb_font_subtract_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint,
-                                                   HB_DIRECTION_LTR,
-                                                   &c->buffer->pos[i].x_offset,
-                                                   &c->buffer->pos[i].y_offset);
+      c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint,
+                                                    HB_DIRECTION_LTR,
+                                                    &c->buffer->pos[i].x_offset,
+                                                    &c->buffer->pos[i].y_offset);
     }
 
-    c->applied_position_complex = true;
+    ret = true;
   }
 
-  hb_ot_layout_position_finish (c->buffer);
+  hb_ot_layout_position_finish (c->font, c->buffer, c->plan->shaper->zero_width_attached_marks);
 
-  return;
+  return ret;
 }
 
-static void
-hb_position_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
+static inline void
+hb_ot_position_complex_fallback (hb_ot_shape_context_t *c)
 {
-  /* TODO Mark pos */
+  _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer);
 }
 
-static void
-hb_truetype_kern (hb_ot_shape_context_t *c)
+static inline void
+hb_ot_truetype_kern (hb_ot_shape_context_t *c)
 {
   /* TODO Check for kern=0 */
   unsigned int count = c->buffer->len;
   for (unsigned int i = 1; i < count; i++) {
     hb_position_t x_kern, y_kern, kern1, kern2;
-    hb_font_get_glyph_kerning_for_direction (c->font,
-                                             c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint,
-                                             c->buffer->props.direction,
-                                             &x_kern, &y_kern);
+    c->font->get_glyph_kerning_for_direction (c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint,
+                                              c->buffer->props.direction,
+                                              &x_kern, &y_kern);
 
     kern1 = x_kern >> 1;
     kern2 = x_kern - kern1;
     c->buffer->pos[i - 1].x_advance += kern1;
     c->buffer->pos[i].x_advance += kern2;
     c->buffer->pos[i].x_offset += kern2;
 
     kern1 = y_kern >> 1;
     kern2 = y_kern - kern1;
     c->buffer->pos[i - 1].y_advance += kern1;
     c->buffer->pos[i].y_advance += kern2;
     c->buffer->pos[i].y_offset += kern2;
   }
 }
 
-static void
+static inline void
 hb_position_complex_fallback_visual (hb_ot_shape_context_t *c)
 {
-  hb_truetype_kern (c);
+  hb_ot_truetype_kern (c);
 }
 
+static inline void
+hb_ot_position (hb_ot_shape_context_t *c)
+{
+  hb_ot_position_default (c);
+
+  hb_bool_t fallback = !hb_ot_position_complex (c);
+
+  if (fallback)
+    hb_ot_position_complex_fallback (c);
+
+  if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
+    hb_buffer_reverse (c->buffer);
+
+  if (fallback)
+    hb_position_complex_fallback_visual (c);
+}
+
+
+/* Post-process */
+
 static void
-hb_hide_zerowidth (hb_ot_shape_context_t *c)
+hb_ot_hide_zerowidth (hb_ot_shape_context_t *c)
 {
-  /* TODO Save the space character in the font? */
-  hb_codepoint_t space;
-  if (!hb_font_get_glyph (c->font, ' ', 0, &space))
-    return; /* No point! */
+  hb_codepoint_t space = 0;
 
   unsigned int count = c->buffer->len;
   for (unsigned int i = 0; i < count; i++)
-    if (unlikely (_hb_glyph_info_is_zero_width (&c->buffer->info[i]))) {
+    if (unlikely (!is_a_ligature (c->buffer->info[i]) &&
+                  _hb_glyph_info_is_zero_width (&c->buffer->info[i])))
+    {
+      if (!space) {
+        /* We assume that the space glyph is not gid0. */
+        if (unlikely (!c->font->get_glyph (' ', 0, &space)) || !space)
+        return; /* No point! */
+      }
       c->buffer->info[i].codepoint = space;
       c->buffer->pos[i].x_advance = 0;
       c->buffer->pos[i].y_advance = 0;
     }
 }
 
 
-/* Do it! */
+/* Pull it all together! */
 
 static void
-hb_ot_shape_execute_internal (hb_ot_shape_context_t *c)
+hb_ot_shape_internal (hb_ot_shape_context_t *c)
 {
   c->buffer->deallocate_var_all ();
 
   /* Save the original direction, we use it later. */
   c->target_direction = c->buffer->props.direction;
 
   HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props0);
   HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props1);
 
+  c->buffer->clear_output ();
+
   hb_set_unicode_props (c->buffer);
-
+  hb_insert_dotted_circle (c->buffer, c->font);
   hb_form_clusters (c->buffer);
 
   hb_ensure_native_direction (c->buffer);
 
-  _hb_ot_shape_normalize (c->font, c->buffer, hb_ot_shape_complex_normalization_preference (c->plan->shaper));
+  hb_ot_substitute (c);
+  hb_ot_position (c);
 
-  hb_ot_shape_setup_masks (c);
-
-  /* SUBSTITUTE */
-  {
-    hb_substitute_default (c);
-
-    hb_ot_substitute_complex (c);
-  }
-
-  /* POSITION */
-  {
-    hb_position_default (c);
-
-    hb_ot_position_complex (c);
-
-    hb_bool_t position_fallback = !c->applied_position_complex;
-    if (position_fallback)
-      hb_position_complex_fallback (c);
-
-    if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
-      hb_buffer_reverse (c->buffer);
-
-    if (position_fallback)
-      hb_position_complex_fallback_visual (c);
-  }
-
-  hb_hide_zerowidth (c);
+  hb_ot_hide_zerowidth (c);
 
   HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props1);
   HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props0);
 
   c->buffer->props.direction = c->target_direction;
 
   c->buffer->deallocate_var_all ();
 }
 
-static void
-hb_ot_shape_plan_internal (hb_ot_shape_plan_t       *plan,
-                           hb_face_t                *face,
-                           const hb_segment_properties_t  *props,
-                           const hb_feature_t       *user_features,
-                           unsigned int              num_user_features)
-{
-  hb_ot_shape_planner_t planner;
-
-  assert (HB_DIRECTION_IS_VALID (props->direction));
-
-  planner.shaper = hb_ot_shape_complex_categorize (props);
-
-  hb_ot_shape_collect_features (&planner, props, user_features, num_user_features);
-
-  planner.compile (face, props, *plan);
-}
-
-static void
-hb_ot_shape_execute (hb_ot_shape_plan_t *plan,
-                     hb_font_t          *font,
-                     hb_buffer_t        *buffer,
-                     const hb_feature_t *user_features,
-                     unsigned int        num_user_features)
-{
-  hb_ot_shape_context_t c = {plan, font, font->face, buffer, user_features, num_user_features};
-  hb_ot_shape_execute_internal (&c);
-}
 
 hb_bool_t
-_hb_ot_shape (hb_font_t          *font,
+_hb_ot_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_ot_shape_plan_t plan;
-
-  buffer->guess_properties ();
-
-  hb_ot_shape_plan_internal (&plan, font->face, &buffer->props, features, num_features);
-  hb_ot_shape_execute (&plan, font, buffer, features, num_features);
+  hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features};
+  hb_ot_shape_internal (&c);
 
   return true;
 }
 
 
+
+static inline void
+hb_ot_map_glyphs_dumb (hb_font_t    *font,
+                       hb_buffer_t  *buffer)
+{
+  unsigned int count = buffer->len;
+  for (unsigned int i = 0; i < count; i++)
+    font->get_glyph (buffer->cur().codepoint, 0, &buffer->cur().codepoint);
+}
+
 void
 hb_ot_shape_glyphs_closure (hb_font_t          *font,
                             hb_buffer_t        *buffer,
                             const hb_feature_t *features,
                             unsigned int        num_features,
                             hb_set_t           *glyphs)
 {
   hb_ot_shape_plan_t plan;
 
   buffer->guess_properties ();
 
-  hb_ot_shape_plan_internal (&plan, font->face, &buffer->props, features, num_features);
+  /* TODO cache / ensure correct backend, etc. */
+  hb_shape_plan_t *shape_plan = hb_shape_plan_create (font->face, &buffer->props, features, num_features, NULL);
 
   /* TODO: normalization? have shapers do closure()? */
   /* TODO: Deal with mirrored chars? */
-  hb_map_glyphs (font, buffer);
+  hb_ot_map_glyphs_dumb (font, buffer);
 
   /* Seed it.  It's user's responsibility to have cleard glyphs
    * if that's what they desire. */
   unsigned int count = buffer->len;
   for (unsigned int i = 0; i < count; i++)
-    hb_set_add (glyphs, buffer->info[i].codepoint);
+    glyphs->add (buffer->info[i].codepoint);
 
   /* And find transitive closure. */
   hb_set_t copy;
   copy.init ();
 
   do {
     copy.set (glyphs);
-    plan.map.substitute_closure (font->face, glyphs);
+    HB_SHAPER_DATA_GET (shape_plan)->substitute_closure (font->face, glyphs);
   } while (!copy.equal (glyphs));
+
+  hb_shape_plan_destroy (shape_plan);
 }