app: add boundary_offset() which offsets BoundSegs in place

and use it in gimp_region_select_tool_calculate().
Also fix boundary_transform() indentation.

app/base/boundary.c

@@ -363,19 +363,17 @@ boundary_simplify (BoundSeg *sorted_segs,
 
 /*Transform boundary based on a matrix*/
 
-BoundSeg * boundary_transform (const BoundSeg *segs,
+BoundSeg *
+boundary_transform (const BoundSeg *segs,
                     gint           *num_segs,
                     GimpMatrix3    *matrix)
 {
-
+  Boundary *boundary = boundary_new (NULL);
-  Boundary *boundary = boundary_new(NULL);
   gint      i;
 
   for (i = 0; i < *num_segs; i++)
     {
-
+      /* dont transform sorting sentinels */
-
-          /*dont transform sorting sentinels*/
       if (!(segs[i].x1 == -1 &&
             segs[i].y1 == -1 &&
             segs[i].x2 == -1 &&
@@ -393,15 +391,41 @@ BoundSeg * boundary_transform (const BoundSeg *segs,
         }
       else
         {
-              /*Keep the sorting sentinel*/
+          /* Keep the sorting sentinel */
           boundary_add_seg (boundary,
                             -1, -1,
                             -1, -1,
                             segs[i].open);
         }
     }
+
   *num_segs = boundary->num_segs;
-      return boundary_free(boundary, FALSE);
+
+  return boundary_free (boundary, FALSE);
+}
+
+void
+boundary_offset (BoundSeg *segs,
+                 gint      num_segs,
+                 gint      off_x,
+                 gint      off_y)
+{
+  gint i;
+
+  for (i = 0; i < num_segs; i++)
+    {
+      /* dont offset sorting sentinels */
+      if (!(segs[i].x1 == -1 &&
+            segs[i].y1 == -1 &&
+            segs[i].x2 == -1 &&
+            segs[i].y2 == -1))
+        {
+          segs[i].x1 += off_x;
+          segs[i].y1 += off_y;
+          segs[i].x2 += off_x;
+          segs[i].y2 += off_y;
+        }
+    }
 }
 
 

app/base/boundary.h

@@ -60,5 +60,11 @@ BoundSeg * boundary_transform (const BoundSeg *segs,
                                gint           *num_segs,
                                GimpMatrix3    *matrix);
 
+/* offsets in-place */
+void       boundary_offset    (BoundSeg       *segs,
+                               gint            num_segs,
+                               gint            off_x,
+                               gint            off_y);
+
 
 #endif  /*  __BOUNDARY_H__  */

app/tools/gimpregionselecttool.c

@@ -381,10 +381,20 @@ gimp_region_select_tool_calculate (GimpRegionSelectTool *region_sel,
                          BOUNDARY_HALF_WAY,
                          num_segs);
 
+  if (! options->sample_merged)
+    {
+      GimpImage    *image    = gimp_display_get_image (display);
+      GimpDrawable *drawable = gimp_image_get_active_drawable (image);
+      gint          off_x, off_y;
+
+      gimp_item_get_offset (GIMP_ITEM (drawable), &off_x, &off_y);
+
+      boundary_offset (bsegs, *num_segs, off_x, off_y);
+    }
+
   segs = g_new (GdkSegment, *num_segs);
 
-  gimp_display_shell_transform_segments (shell, bsegs, segs, *num_segs,
+  gimp_display_shell_transform_segments (shell, bsegs, segs, *num_segs, FALSE);
-                                         ! options->sample_merged);
   g_free (bsegs);
 
   gimp_display_shell_unset_override_cursor (shell);