From de3bf8f68abea11fa5c71271bd3a4417b5dbb1c1 Mon Sep 17 00:00:00 2001
From: Ferran Sole <ferran.sole@samsung.com>
Date: Tue, 9 Aug 2016 16:07:35 +0100
Subject: [PATCH] [3.0] Bug fix in Transform manager, improve performance

* World matrices where not reordered in the sorting pass causing the
  application to get the wrong value if the world matrix was queried during
  component sorting.
  This bug was causing slider handle and value to jump to an erroneous position
  when panning

* Minor performance improvement to reduce the number of swaps when
  reordering transform components

Change-Id: Ifde6ef4aaa2052c70042ef46c8909c85c407588a
---
 dali/internal/update/manager/transform-manager.cpp | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/dali/internal/update/manager/transform-manager.cpp b/dali/internal/update/manager/transform-manager.cpp
index 5415778..b289bf4 100644
--- a/dali/internal/update/manager/transform-manager.cpp
+++ b/dali/internal/update/manager/transform-manager.cpp
@@ -312,6 +312,7 @@ void TransformManager::SwapComponents( unsigned int i, unsigned int j )
   std::swap( mLocal[i], mLocal[j] );
   std::swap( mComponentDirty[i], mComponentDirty[j] );
   std::swap( mBoundingSpheres[i], mBoundingSpheres[j] );
+  std::swap( mWorld[i], mWorld[j] );
 
   mIds[ mComponentId[i] ] = i;
   mIds[ mComponentId[j] ] = j;
@@ -335,10 +336,15 @@ void TransformManager::ReorderComponents()
     }
   }
 
-  std::sort( mOrderedComponents.Begin(), mOrderedComponents.End());
-  for( size_t i(0); i<mComponentCount-1; ++i )
+  std::stable_sort( mOrderedComponents.Begin(), mOrderedComponents.End());
+  unsigned int previousIndex = 0;
+  for( size_t newIndex(0); newIndex<mComponentCount-1; ++newIndex )
   {
-    SwapComponents( mIds[mOrderedComponents[i].id], i);
+    previousIndex = mIds[mOrderedComponents[newIndex].id];
+    if( previousIndex != newIndex )
+    {
+      SwapComponents( previousIndex, newIndex);
+    }
   }
 }
 
-- 
2.7.4