From 77d5b1475aa6129d2f8a63e3e9b65d04075ace45 Mon Sep 17 00:00:00 2001
From: ExMix <rahuba.youri@mapswithme.com>
Date: Sun, 29 Nov 2015 15:15:10 +0300
Subject: [PATCH] [drape] send on reread only tiles that neighbour of outdated
 tiles

---
 drape_frontend/read_manager.cpp | 12 +++++++++++-
 drape_frontend/tile_utils.cpp   |  6 ++++++
 drape_frontend/tile_utils.hpp   |  2 ++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drape_frontend/read_manager.cpp b/drape_frontend/read_manager.cpp
index 39f91ff588..c68407978e 100755
--- a/drape_frontend/read_manager.cpp
+++ b/drape_frontend/read_manager.cpp
@@ -106,7 +106,17 @@ void ReadManager::UpdateCoverage(ScreenBase const & screen, TTilesCollection con
     IncreaseCounter(static_cast<int>(inputRects.size() + (m_tileInfos.size() - outdatedTiles.size())));
 
     for_each(outdatedTiles.begin(), outdatedTiles.end(), bind(&ReadManager::ClearTileInfo, this, _1));
-    for_each(m_tileInfos.begin(), m_tileInfos.end(), bind(&ReadManager::PushTaskFront, this, _1));
+    for (shared_ptr<TileInfo> const & tile : m_tileInfos)
+    {
+      for (shared_ptr<TileInfo> & outTile : outdatedTiles)
+      {
+        if (IsNeighbours(tile->GetTileKey(), outTile->GetTileKey()))
+        {
+            PushTaskFront(tile);
+            break;
+        }
+      }
+    }
     for_each(inputRects.begin(), inputRects.end(), bind(&ReadManager::PushTaskBackForTileKey, this, _1, texMng));
   }
   m_currentViewport = screen;
diff --git a/drape_frontend/tile_utils.cpp b/drape_frontend/tile_utils.cpp
index bc6f3ca67e..6407798c82 100755
--- a/drape_frontend/tile_utils.cpp
+++ b/drape_frontend/tile_utils.cpp
@@ -104,4 +104,10 @@ TileKey GetParentTile(TileKey const & tileKey, int targetZoom)
                  targetZoom);
 }
 
+bool IsNeighbours(TileKey const & tileKey1, TileKey const & tileKey2)
+{
+  return (abs(tileKey1.m_x - tileKey2.m_x) < 2) &&
+         (abs(tileKey1.m_y - tileKey2.m_y) < 2);
+}
+
 } // namespace df
diff --git a/drape_frontend/tile_utils.hpp b/drape_frontend/tile_utils.hpp
index c7bb1669ac..3bf05cc571 100755
--- a/drape_frontend/tile_utils.hpp
+++ b/drape_frontend/tile_utils.hpp
@@ -28,4 +28,6 @@ bool IsTileBelow(TileKey const & tileKey, TileKey const & targetTileKey);
 /// This function returns parent tile on specified zoom level.
 TileKey GetParentTile(TileKey const & tileKey, int targetZoom);
 
+bool IsNeighbours(TileKey const & tileKey1, TileKey const & tileKey2);
+
 } // namespace df