[unsafe-to-break] Copy flag to all glyphs in a cluster

Makes consumption easier.

src/hb-buffer-private.hh

@@ -57,6 +57,8 @@ enum hb_buffer_scratch_flags_t {
   HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES		= 0x00000002u,
   HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK		= 0x00000004u,
   HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT		= 0x00000008u,
+  HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK		= 0x00000010u,
+
   /* Reserved for complex shapers' internal use. */
   HB_BUFFER_SCRATCH_FLAG_COMPLEX0			= 0x01000000u,
   HB_BUFFER_SCRATCH_FLAG_COMPLEX1			= 0x02000000u,
@@ -301,9 +303,53 @@ struct hb_buffer_t {
     }
     info.cluster = cluster;
   }
+
+  int
+  _unsafe_to_break_find_min_cluster (const hb_glyph_info_t *info,
+				     unsigned int start, unsigned int end,
+				     unsigned int cluster) const
+  {
+    for (unsigned int i = start; i < end; i++)
+      cluster = MIN (cluster, info[i].cluster);
+    return cluster;
+  }
+  void
+  _unsafe_to_break_set_mask (hb_glyph_info_t *info,
+			     unsigned int start, unsigned int end,
+			     unsigned int cluster)
+  {
+    for (unsigned int i = start; i < end; i++)
+      if (cluster != info[i].cluster)
+      {
+	scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK;
+	info[i].mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
+      }
+  }
 };
 
 
+/* Loop over clusters. Duplicated in foreach_syllable(). */
+#define foreach_cluster(buffer, start, end) \
+  for (unsigned int \
+       _count = buffer->len, \
+       start = 0, end = _count ? _next_cluster (buffer, 0) : 0; \
+       start < _count; \
+       start = end, end = _next_cluster (buffer, start))
+
+static inline unsigned int
+_next_cluster (hb_buffer_t *buffer, unsigned int start)
+{
+  hb_glyph_info_t *info = buffer->info;
+  unsigned int count = buffer->len;
+
+  unsigned int cluster = info[start].cluster;
+  while (++start < count && cluster == info[start].cluster)
+    ;
+
+  return start;
+}
+
+
 #define HB_BUFFER_XALLOCATE_VAR(b, func, var) \
   b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \
 	   sizeof (b->info[0].var))

src/hb-buffer.cc

@@ -643,28 +643,12 @@ done:
   skip_glyph ();
 }
 
-static int
-unsafe_to_break_find_min (const hb_glyph_info_t *info, unsigned int start, unsigned int end,
-			  unsigned int cluster)
-{
-  for (unsigned int i = start; i < end; i++)
-    cluster = MIN (cluster, info[i].cluster);
-  return cluster;
-}
-static void
-unsafe_to_break_set_mask (hb_glyph_info_t *info, unsigned int start, unsigned int end,
-			  unsigned int cluster)
-{
-  for (unsigned int i = start; i < end; i++)
-    if (cluster != info[i].cluster)
-      info[i].mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
-}
 void
 hb_buffer_t::unsafe_to_break_impl (unsigned int start, unsigned int end)
 {
   unsigned int cluster = (unsigned int) -1;
-  cluster = unsafe_to_break_find_min (info, start, end, cluster);
-  unsafe_to_break_set_mask (info, start, end, cluster);
+  cluster = _unsafe_to_break_find_min_cluster (info, start, end, cluster);
+  _unsafe_to_break_set_mask (info, start, end, cluster);
 }
 void
 hb_buffer_t::unsafe_to_break_from_outbuffer (unsigned int start, unsigned int end)
@@ -679,10 +663,10 @@ hb_buffer_t::unsafe_to_break_from_outbuffer (unsigned int start, unsigned int en
   assert (idx <= end);
 
   unsigned int cluster = (unsigned int) -1;
-  cluster = unsafe_to_break_find_min (out_info, start, out_len, cluster);
-  cluster = unsafe_to_break_find_min (info, idx, end, cluster);
-  unsafe_to_break_set_mask (out_info, start, out_len, cluster);
-  unsafe_to_break_set_mask (info, idx, end, cluster);
+  cluster = _unsafe_to_break_find_min_cluster (out_info, start, out_len, cluster);
+  cluster = _unsafe_to_break_find_min_cluster (info, idx, end, cluster);
+  _unsafe_to_break_set_mask (out_info, start, out_len, cluster);
+  _unsafe_to_break_set_mask (info, idx, end, cluster);
 }
 
 void

src/hb-ot-layout-private.hh

@@ -197,8 +197,7 @@ _hb_ot_layout_destroy (hb_ot_layout_t *layout);
 #define syllable()		var1.u8[3] /* GSUB/GPOS shaping boundaries */
 
 
-/* loop over syllables */
-
+/* Loop over syllables. Based on foreach_cluster(). */
 #define foreach_syllable(buffer, start, end) \
   for (unsigned int \
        _count = buffer->len, \

src/hb-ot-shape.cc

@@ -783,6 +783,31 @@ hb_ot_position (hb_ot_shape_context_t *c)
   _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
 }
 
+static inline void
+hb_propagate_flags (hb_buffer_t *buffer)
+{
+  /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
+   * Simplifies using them. */
+
+  if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK))
+    return;
+
+  hb_glyph_info_t *info = buffer->info;
+
+  foreach_cluster (buffer, start, end)
+  {
+    unsigned int mask = 0;
+    for (unsigned int i = start; i < end; i++)
+      if (info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
+      {
+	 mask = HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
+	 break;
+      }
+    if (mask)
+      for (unsigned int i = start; i < end; i++)
+	info[i].mask |= mask;
+  }
+}
 
 /* Pull it all together! */
 
@@ -826,6 +851,8 @@ hb_ot_shape_internal (hb_ot_shape_context_t *c)
   if (c->plan->shaper->postprocess_glyphs)
     c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
 
+  hb_propagate_flags (c->buffer);
+
   _hb_buffer_deallocate_unicode_vars (c->buffer);
 
   c->buffer->props.direction = c->target_direction;