[pango] [HB] Add hb_buffer_reverse()

[Behdad Esfahbod <behdad src gnome org>]

commit dfa2cfce0dac5ba1d9f87aea5ff3ab3ed36be6ce
Author: Behdad Esfahbod <behdad behdad org>
Date:   Mon Aug 10 20:59:25 2009 -0400

    [HB] Add hb_buffer_reverse()

 pango/opentype/hb-buffer.c |   32 +++++++++++++++++++++++++++++---
 pango/opentype/hb-buffer.h |    7 +++++++
 2 files changed, 36 insertions(+), 3 deletions(-)
---
diff --git a/pango/opentype/hb-buffer.c b/pango/opentype/hb-buffer.c
index c197b90..890a21b 100644
--- a/pango/opentype/hb-buffer.c
+++ b/pango/opentype/hb-buffer.c
@@ -65,7 +65,7 @@ hb_buffer_ensure_separate (hb_buffer_t *buffer, unsigned int size)
     if (!buffer->positions)
       buffer->positions = calloc (buffer->allocated, sizeof (buffer->positions[0]));
 
-    buffer->out_string = buffer->positions;
+    buffer->out_string = (hb_internal_glyph_info_t *) buffer->positions;
     memcpy (buffer->out_string, buffer->in_string, buffer->out_length * sizeof (buffer->out_string[0]));
   }
 }
@@ -136,7 +136,7 @@ hb_buffer_ensure (hb_buffer_t *buffer, unsigned int size)
     if (buffer->out_string != buffer->in_string)
     {
       buffer->in_string = realloc (buffer->in_string, new_allocated * sizeof (buffer->in_string[0]));
-      buffer->out_string = buffer->positions;
+      buffer->out_string = (hb_internal_glyph_info_t *) buffer->positions;
     }
     else
     {
@@ -212,7 +212,8 @@ _hb_buffer_swap (hb_buffer_t *buffer)
     hb_internal_glyph_info_t *tmp_string;
     tmp_string = buffer->in_string;
     buffer->in_string = buffer->out_string;
-    buffer->positions = buffer->out_string = tmp_string;
+    buffer->out_string = tmp_string;
+    buffer->positions = (hb_internal_glyph_position_t *) buffer->out_string;
   }
 
   tmp = buffer->in_length;
@@ -366,3 +367,28 @@ hb_buffer_get_glyph_positions (hb_buffer_t *buffer)
 
   return (hb_glyph_position_t *) buffer->positions;
 }
+
+
+void
+hb_buffer_reverse (hb_buffer_t *buffer)
+{
+  unsigned int i, j;
+
+  for (i = 0, j = buffer->in_length - 1; i < buffer->in_length / 2; i++, j--) {
+    hb_internal_glyph_info_t t;
+
+    t = buffer->in_string[i];
+    buffer->in_string[i] = buffer->in_string[j];
+    buffer->in_string[j] = t;
+  }
+
+  if (buffer->positions) {
+    for (i = 0, j = buffer->in_length - 1; i < buffer->in_length / 2; i++, j--) {
+      hb_internal_glyph_position_t t;
+
+      t = buffer->positions[i];
+      buffer->positions[i] = buffer->positions[j];
+      buffer->positions[j] = t;
+    }
+  }
+}
diff --git a/pango/opentype/hb-buffer.h b/pango/opentype/hb-buffer.h
index 57f56bd..4240f6a 100644
--- a/pango/opentype/hb-buffer.h
+++ b/pango/opentype/hb-buffer.h
@@ -99,6 +99,11 @@ void
 hb_buffer_ensure (hb_buffer_t  *buffer,
 		  unsigned int  size);
 
+void
+hb_buffer_reverse (hb_buffer_t *buffer);
+
+
+/* Filling the buffer in */
 
 void
 hb_buffer_add_glyph (hb_buffer_t    *buffer,
@@ -107,6 +112,8 @@ hb_buffer_add_glyph (hb_buffer_t    *buffer,
 		     unsigned int    cluster);
 
 
+/* Getting glyphs out of the buffer */
+
 /* Return value valid as long as buffer not modified */
 unsigned int
 hb_buffer_get_len (hb_buffer_t *buffer);