bug 758236 - force non-spacing marks to have zero width (merged forwa…

…rd from bug 727736). r=jdaggett
Brli · Apr 21, 2012 · fcabd5f · fcabd5f
1 parent 1b4e759
commit fcabd5f
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Showing 3 changed files with 54 additions and 5 deletions.
diff --git a/gfx/harfbuzz/src/hb-ot-layout.cc b/gfx/harfbuzz/src/hb-ot-layout.cc
@@ -32,6 +32,7 @@
 #include "hb-ot-layout-gsub-table.hh"
 #include "hb-ot-layout-gpos-table.hh"
 #include "hb-ot-maxp-table.hh"
+#include "hb-ot-shape-private.hh"
 
 
 #include <stdlib.h>
@@ -506,8 +507,33 @@ hb_ot_layout_position_lookup   (hb_font_t    *font,
 }
 
 void
-hb_ot_layout_position_finish (hb_buffer_t  *buffer)
-{
+hb_ot_layout_position_finish (hb_face_t *face, hb_buffer_t *buffer)
+{
+  /* force diacritics to have zero width */
+  unsigned int count = buffer->len;
+  const hb_glyph_info_t *info = buffer->info;
+  hb_glyph_position_t *positions = buffer->pos;
+  /*
+   * Forcibly zero widths of chars with GC=Mn; we don't use the GDEF 'Mark' class
+   * because some fonts (e.g. C-DAC Yogesh) classify spacing Indic matras as 'Mark'
+   * but we don't want to force their width to zero.
+   */
+  if (buffer->props.direction == HB_DIRECTION_RTL) {
+    for (unsigned int i = 1; i < count; i++) {
+      if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
+        positions[i].x_advance = 0;
+      }
+    }
+  } else {
+    for (unsigned int i = 1; i < count; i++) {
+      if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
+        hb_glyph_position_t& pos = positions[i];
+        pos.x_offset -= pos.x_advance;
+        pos.x_advance = 0;
+      }
+    }
+  }
+
   GPOS::position_finish (buffer);
 }
 

diff --git a/gfx/harfbuzz/src/hb-ot-layout.h b/gfx/harfbuzz/src/hb-ot-layout.h
@@ -207,7 +207,7 @@ hb_ot_layout_position_lookup (hb_font_t    *font,
 
 /* Should be called after all the position_lookup's are done */
 void
-hb_ot_layout_position_finish (hb_buffer_t  *buffer);
+hb_ot_layout_position_finish (hb_face_t *face, hb_buffer_t  *buffer);
 
 
 HB_END_DECLS

diff --git a/gfx/harfbuzz/src/hb-ot-shape.cc b/gfx/harfbuzz/src/hb-ot-shape.cc
@@ -330,15 +330,38 @@ hb_ot_position_complex (hb_ot_shape_context_t *c)
     c->applied_position_complex = TRUE;
   }
 
-  hb_ot_layout_position_finish (c->buffer);
+  hb_ot_layout_position_finish (c->face, c->buffer);
 
   return;
 }
 
 static void
-hb_position_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
+hb_position_complex_fallback (hb_ot_shape_context_t *c)
 {
   /* TODO Mark pos */
+  unsigned int count = c->buffer->len;
+  const hb_glyph_info_t *info = c->buffer->info;
+  hb_glyph_position_t *positions = c->buffer->pos;
+  if (c->buffer->props.direction == HB_DIRECTION_RTL) {
+    for (unsigned int i = 1; i < count; i++) {
+      if (FLAG (_hb_glyph_info_get_general_category (&info[i])) &
+	  (FLAG (HB_UNICODE_GENERAL_CATEGORY_FORMAT) |
+	   FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) |
+	   FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
+        positions[i].x_advance = 0;
+    }
+  } else {
+    for (unsigned int i = 1; i < count; i++) {
+      if (FLAG (_hb_glyph_info_get_general_category (&info[i])) &
+	  (FLAG (HB_UNICODE_GENERAL_CATEGORY_FORMAT) |
+	   FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) |
+	   FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK))) {
+        hb_glyph_position_t& pos = positions[i];
+        pos.x_offset = -pos.x_advance;
+        pos.x_advance = 0;
+      }
+    }
+  }
 }
 
 static void