Roll HarfBuzz to 0.9.32

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

 /*
  * Copyright © 2009,2010  Red Hat, 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
@@ skipping 11 matching lines @@
  * 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-layout-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-ot-layout-private.hh"
 #include "hb-set-private.hh"
+#include "hb-shaper-impl-private.hh"
+
+#include "hb-unicode-private.hh"
 
 
 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'),
 };
@@ skipping 168 matching lines @@
 
 /* Main shaper */
 
 
 /* Prepare */
 
 static void
 hb_set_unicode_props (hb_buffer_t *buffer)
 {
   unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
   for (unsigned int i = 0; i < count; i++)
-    _hb_glyph_info_set_unicode_props (&buffer->info[i], buffer->unicode);
+    _hb_glyph_info_set_unicode_props (&info[i], buffer->unicode);
 }
 
 static void
 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
 {
   if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
       _hb_glyph_info_get_general_category (&buffer->info[0]) !=
       HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
     return;
 
-  if (!font->has_glyph (0x25CC))
+  if (!font->has_glyph (0x25CCu))
     return;
 
   hb_glyph_info_t dottedcircle;
-  dottedcircle.codepoint = 0x25CC;
+  dottedcircle.codepoint = 0x25CCu;
   _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;
+  hb_glyph_info_t *info = buffer->info;
   for (unsigned int i = 1; i < count; i++)
-    if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i])))
+    if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&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
@@ skipping 37 matching lines @@
   if (!c->plan->has_frac)
     return;
 
   hb_buffer_t *buffer = c->buffer;
 
   /* TODO look in pre/post context text also. */
   unsigned int count = buffer->len;
   hb_glyph_info_t *info = buffer->info;
   for (unsigned int i = 0; i < count; i++)
   {
-    if (info[i].codepoint == 0x2044) /* FRACTION SLASH */
+    if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
     {
       unsigned int start = i, end = i + 1;
       while (start &&
              _hb_glyph_info_get_general_category (&info[start - 1]) ==
              HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
         start--;
       while (end < count &&
              _hb_glyph_info_get_general_category (&info[end]) ==
              HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
         end++;
@@ skipping 39 matching lines @@
       buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
     }
   }
 }
 
 static inline void
 hb_ot_map_glyphs_fast (hb_buffer_t  *buffer)
 {
   /* Normalization process sets up glyph_index(), we just copy it. */
   unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
   for (unsigned int i = 0; i < count; i++)
-    buffer->info[i].codepoint = buffer->info[i].glyph_index();
+    info[i].codepoint = info[i].glyph_index();
 }
 
 static inline void
 hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
 {
   unsigned int count = c->buffer->len;
   hb_glyph_info_t *info = c->buffer->info;
   for (unsigned int i = 0; i < count; i++)
-    _hb_glyph_info_set_glyph_props (&info[i],
-                                    _hb_glyph_info_get_general_category (&info[i])
-                                    == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ?
-                                    HB_OT_LAYOUT_GLYPH_PROPS_MARK :
-                                    HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
+  {
+    hb_ot_layout_glyph_class_mask_t klass;
+
+    /* Never mark default-ignorables as marks.
+     * They won't get in the way of lookups anyway,
+     * but having them as mark will cause them to be skipped
+     * over if the lookup-flag says so, but at least for the
+     * Mongolian variation selectors, looks like Uniscribe
+     * marks them as non-mark.  Some Mongolian fonts without
+     * GDEF rely on this.  Another notable character that
+     * this applies to is COMBINING GRAPHEME JOINER. */
+    klass = (_hb_glyph_info_get_general_category (&info[i]) !=
+             HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
+             _hb_glyph_info_is_default_ignorable (&info[i])) ?
+            HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
+            HB_OT_LAYOUT_GLYPH_PROPS_MARK;
+    _hb_glyph_info_set_glyph_props (&info[i], klass);
+  }
 }
 
 static inline void
 hb_ot_substitute_default (hb_ot_shape_context_t *c)
 {
   hb_buffer_t *buffer = c->buffer;
 
   if (c->plan->shaper->preprocess_text)
     c->plan->shaper->preprocess_text (c->plan, buffer, c->font);
 
@@ skipping 36 matching lines @@
 static inline void
 hb_ot_substitute (hb_ot_shape_context_t *c)
 {
   hb_ot_substitute_default (c);
   hb_ot_substitute_complex (c);
 }
 
 /* Position */
 
 static inline void
-zero_mark_widths_by_unicode (hb_buffer_t *buffer)
+adjust_mark_offsets (hb_glyph_position_t *pos)
+{
+  pos->x_offset -= pos->x_advance;
+  pos->y_offset -= pos->y_advance;
+}
+
+static inline void
+zero_mark_width (hb_glyph_position_t *pos)
+{
+  pos->x_advance = 0;
+  pos->y_advance = 0;
+}
+
+static inline void
+zero_mark_widths_by_unicode (hb_buffer_t *buffer, bool adjust_offsets)
 {
   unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
   for (unsigned int i = 0; i < count; i++)
-    if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
+    if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
     {
-      buffer->pos[i].x_advance = 0;
-      buffer->pos[i].y_advance = 0;
+      if (adjust_offsets)
+        adjust_mark_offsets (&buffer->pos[i]);
+      zero_mark_width (&buffer->pos[i]);
     }
 }
 
 static inline void
-zero_mark_widths_by_gdef (hb_buffer_t *buffer)
+zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
 {
   unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
   for (unsigned int i = 0; i < count; i++)
-    if (_hb_glyph_info_is_mark (&buffer->info[i]))
+    if (_hb_glyph_info_is_mark (&info[i]))
     {
-      buffer->pos[i].x_advance = 0;
-      buffer->pos[i].y_advance = 0;
+      if (adjust_offsets)
+        adjust_mark_offsets (&buffer->pos[i]);
+      zero_mark_width (&buffer->pos[i]);
     }
 }
 
 static inline void
 hb_ot_position_default (hb_ot_shape_context_t *c)
 {
   hb_direction_t direction = c->buffer->props.direction;
   unsigned int count = c->buffer->len;
   hb_glyph_info_t *info = c->buffer->info;
   hb_glyph_position_t *pos = c->buffer->pos;
   for (unsigned int i = 0; i < count; i++)
   {
     c->font->get_glyph_advance_for_direction (info[i].codepoint,
                                               direction,
                                               &pos[i].x_advance,
                                               &pos[i].y_advance);
     c->font->subtract_glyph_origin_for_direction (info[i].codepoint,
                                                   direction,
                                                   &pos[i].x_offset,
                                                   &pos[i].y_offset);
 
   }
 }
 
 static inline bool
 hb_ot_position_complex (hb_ot_shape_context_t *c)
 {
   bool ret = false;
   unsigned int count = c->buffer->len;
+  bool has_positioning = hb_ot_layout_has_positioning (c->face);
+  /* If the font has no GPOS, AND, no fallback positioning will
+   * happen, AND, direction is forward, then when zeroing mark
+   * widths, we shift the mark with it, such that the mark
+   * is positioned hanging over the previous glyph.  When
+   * direction is backward we don't shift and it will end up
+   * hanging over the next glyph after the final reordering.
+   * If fallback positinoing happens or GPOS is present, we don't
+   * care.
+   */
+  bool adjust_offsets_when_zeroing = !(has_positioning || c->plan->shaper->fallback_position ||
+                                       HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction));
 
   switch (c->plan->shaper->zero_width_marks)
   {
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
-      zero_mark_widths_by_gdef (c->buffer);
+      zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
       break;
 
     /* Not currently used for any shaper:
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY:
-      zero_mark_widths_by_unicode (c->buffer);
+      zero_mark_widths_by_unicode (c->buffer, adjust_offsets_when_zeroing);
       break;
     */
 
     default:
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE:
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
       break;
   }
 
-  if (hb_ot_layout_has_positioning (c->face))
+  if (has_positioning)
   {
     hb_glyph_info_t *info = c->buffer->info;
     hb_glyph_position_t *pos = c->buffer->pos;
 
     /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */
 
     for (unsigned int i = 0; i < count; i++) {
       c->font->add_glyph_origin_for_direction (info[i].codepoint,
                                                HB_DIRECTION_LTR,
                                                &pos[i].x_offset,
                                                &pos[i].y_offset);
     }
 
     c->plan->position (c->font, c->buffer);
 
     for (unsigned int i = 0; i < count; i++) {
       c->font->subtract_glyph_origin_for_direction (info[i].codepoint,
                                                     HB_DIRECTION_LTR,
                                                     &pos[i].x_offset,
                                                     &pos[i].y_offset);
     }
 
     ret = true;
   }
 
   switch (c->plan->shaper->zero_width_marks)
   {
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE:
-      zero_mark_widths_by_unicode (c->buffer);
+      zero_mark_widths_by_unicode (c->buffer, adjust_offsets_when_zeroing);
       break;
 
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
-      zero_mark_widths_by_gdef (c->buffer);
+      zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
       break;
 
     default:
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
     //case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY:
     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
       break;
   }
 
   return ret;
@@ skipping 156 matching lines @@
 {
   hb_ot_shape_plan_t plan;
 
   const char *shapers[] = {"ot", NULL};
   hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
                                                              features, num_features, shapers);
 
   bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
 
   unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
   for (unsigned int i = 0; i < count; i++)
-    add_char (font, buffer->unicode, mirror, buffer->info[i].codepoint, glyphs);
+    add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
 
   hb_set_t lookups;
   lookups.init ();
   hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, &lookups);
 
   /* And find transitive closure. */
   hb_set_t copy;
   copy.init ();
   do {
     copy.set (glyphs);
     for (hb_codepoint_t lookup_index = -1; hb_set_next (&lookups, &lookup_index);)
       hb_ot_layout_lookup_substitute_closure (font->face, lookup_index, glyphs);
   } while (!copy.is_equal (glyphs));
 
   hb_shape_plan_destroy (shape_plan);
 }