Roll HarfBuzz to 1.1.1

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

 /*
  * 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.
@@ skipping 206 matching lines @@
   {
     case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
     case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
       if (buffer->props.direction == HB_DIRECTION_LTR) {
         pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing;
         break;
       } else if (buffer->props.direction == HB_DIRECTION_RTL) {
         pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
         break;
       }
-      /* Fall through */
+      HB_FALLTHROUGH;
 
     default:
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
     case HB_UNICODE_COMBINING_CLASS_BELOW:
     case HB_UNICODE_COMBINING_CLASS_ABOVE:
       /* Center align. */
       pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing;
       break;
 
@@ skipping 14 matching lines @@
 
   /* Y positioning */
   switch (combining_class)
   {
     case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
     case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
     case HB_UNICODE_COMBINING_CLASS_BELOW:
     case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
       /* Add gap, fall-through. */
       base_extents.height -= y_gap;
+      HB_FALLTHROUGH;
 
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
       pos.y_offset = base_extents.y_bearing + base_extents.height - mark_extents.y_bearing;
       /* Never shift up "below" marks. */
       if ((y_gap > 0) == (pos.y_offset > 0))
       {
         base_extents.height -= pos.y_offset;
         pos.y_offset = 0;
       }
       base_extents.height += mark_extents.height;
       break;
 
     case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
     case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
     case HB_UNICODE_COMBINING_CLASS_ABOVE:
     case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
       /* Add gap, fall-through. */
       base_extents.y_bearing += y_gap;
       base_extents.height -= y_gap;
+      HB_FALLTHROUGH;
 
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
     case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
       pos.y_offset = base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
       /* Don't shift down "above" marks too much. */
       if ((y_gap > 0) != (pos.y_offset > 0))
       {
         unsigned int correction = -pos.y_offset / 2;
         base_extents.y_bearing += correction;
         base_extents.height -= correction;
@@ skipping 183 matching lines @@
       hb_position_t kern1 = y_kern >> 1;
       hb_position_t kern2 = y_kern - kern1;
       pos[idx].y_advance += kern1;
       pos[skippy_iter.idx].y_advance += kern2;
       pos[skippy_iter.idx].y_offset += kern2;
     }
 
     idx = skippy_iter.idx;
   }
 }
+
+
+/* Adjusts width of various spaces. */
+void
+_hb_ot_shape_fallback_spaces (const hb_ot_shape_plan_t *plan,
+                              hb_font_t *font,
+                              hb_buffer_t  *buffer)
+{
+  if (!HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
+    return;
+
+  hb_glyph_info_t *info = buffer->info;
+  hb_glyph_position_t *pos = buffer->pos;
+  unsigned int count = buffer->len;
+  for (unsigned int i = 0; i < count; i++)
+    if (_hb_glyph_info_is_unicode_space (&info[i]) && !_hb_glyph_info_ligated (&info[i]))
+    {
+      hb_unicode_funcs_t::space_t space_type = _hb_glyph_info_get_unicode_space_fallback_type (&info[i]);
+      hb_codepoint_t glyph;
+      typedef hb_unicode_funcs_t t;
+      switch (space_type)
+      {
+        case t::NOT_SPACE: /* Shouldn't happen. */
+        case t::SPACE:
+          break;
+
+        case t::SPACE_EM:
+        case t::SPACE_EM_2:
+        case t::SPACE_EM_3:
+        case t::SPACE_EM_4:
+        case t::SPACE_EM_5:
+        case t::SPACE_EM_6:
+        case t::SPACE_EM_16:
+          pos[i].x_advance = (font->x_scale + ((int) space_type)/2) / (int) space_type;
+          break;
+
+        case t::SPACE_4_EM_18:
+          pos[i].x_advance = font->x_scale * 4 / 18;
+          break;
+
+        case t::SPACE_FIGURE:
+          for (char u = '0'; u <= '9'; u++)
+            if (font->get_glyph (u, 0, &glyph))
+            {
+              pos[i].x_advance = font->get_glyph_h_advance (glyph);
+              break;
+            }
+          break;
+
+        case t::SPACE_PUNCTUATION:
+          if (font->get_glyph ('.', 0, &glyph))
+            pos[i].x_advance = font->get_glyph_h_advance (glyph);
+          else if (font->get_glyph (',', 0, &glyph))
+            pos[i].x_advance = font->get_glyph_h_advance (glyph);
+          break;
+
+        case t::SPACE_NARROW:
+          /* Half-space?
+           * Unicode doc http://www.unicode.org/charts/PDF/U2000.pdf says ~1/4 or 1/5 of EM.
+           * However, in my testing, many fonts have their regular space being about that
+           * size.  To me, a percentage of the space width makes more sense.  Half is as
+           * good as any. */
+          pos[i].x_advance /= 2;
+          break;
+      }
+    }
+}