From 8db453950469171e68b493cd1f2e5305ff22fc7d Mon Sep 17 00:00:00 2001
From: rachytski <siarhei.rachytski@gmail.com>
Date: Wed, 12 Sep 2012 13:30:07 +0300
Subject: [PATCH] pausing background rendering when animation is started, and
 resuming it back when it's finished.

---
 map/basic_tiling_render_policy.cpp | 38 ++++++++++++++++++++++++++----
 map/basic_tiling_render_policy.hpp |  5 ++++
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/map/basic_tiling_render_policy.cpp b/map/basic_tiling_render_policy.cpp
index 0db4acf39f..82001c35c8 100644
--- a/map/basic_tiling_render_policy.cpp
+++ b/map/basic_tiling_render_policy.cpp
@@ -40,7 +40,8 @@ BasicTilingRenderPolicy::BasicTilingRenderPolicy(Params const & p,
     m_DrawScale(0),
     m_IsEmptyModel(false),
     m_DoRecreateCoverage(false),
-    m_IsNavigating(false)
+    m_IsNavigating(false),
+    m_WasAnimatingLastFrame(false)
 {
   m_TileSize = CalculateTileSize(p.m_screenWidth, p.m_screenHeight);
 
@@ -58,6 +59,21 @@ void BasicTilingRenderPolicy::BeginFrame(shared_ptr<PaintEvent> const & e, Scree
     m_QueuedRenderer->BeginFrame();
 }
 
+void BasicTilingRenderPolicy::CheckAnimationTransition()
+{
+  // transition from non-animating to animating,
+  // should stop all background work
+  if (!m_WasAnimatingLastFrame && IsAnimating())
+    PauseBackgroundRendering();
+
+  // transition from animating to non-animating
+  // should resume all background work
+  if (m_WasAnimatingLastFrame && !IsAnimating())
+    ResumeBackgroundRendering();
+
+  m_WasAnimatingLastFrame = IsAnimating();
+}
+
 void BasicTilingRenderPolicy::DrawFrame(shared_ptr<PaintEvent> const & e, ScreenBase const & s)
 {
   if (m_QueuedRenderer)
@@ -66,6 +82,8 @@ void BasicTilingRenderPolicy::DrawFrame(shared_ptr<PaintEvent> const & e, Screen
     m_resourceManager->updatePoolState();
   }
 
+  CheckAnimationTransition();
+
   /// checking, whether we should add the CoverScreen command
 
   bool doForceUpdate = DoForceUpdate();
@@ -120,24 +138,34 @@ TileRenderer & BasicTilingRenderPolicy::GetTileRenderer()
   return *m_TileRenderer.get();
 }
 
-void BasicTilingRenderPolicy::StartNavigation()
+void BasicTilingRenderPolicy::PauseBackgroundRendering()
 {
   m_TileRenderer->SetIsPaused(true);
-  m_IsNavigating = true;
   m_TileRenderer->CancelCommands();
   if (m_QueuedRenderer)
     m_QueuedRenderer->SetPartialExecution(GetPlatform().CpuCores(), true);
 }
 
-void BasicTilingRenderPolicy::StopNavigation()
+void BasicTilingRenderPolicy::ResumeBackgroundRendering()
 {
   m_TileRenderer->SetIsPaused(false);
-  m_IsNavigating = false;
   m_DoRecreateCoverage = true;
   if (m_QueuedRenderer)
     m_QueuedRenderer->SetPartialExecution(GetPlatform().CpuCores(), false);
 }
 
+void BasicTilingRenderPolicy::StartNavigation()
+{
+  m_IsNavigating = true;
+  PauseBackgroundRendering();
+}
+
+void BasicTilingRenderPolicy::StopNavigation()
+{
+  m_IsNavigating = false;
+  ResumeBackgroundRendering();
+}
+
 void BasicTilingRenderPolicy::StartScale()
 {
   StartNavigation();
diff --git a/map/basic_tiling_render_policy.hpp b/map/basic_tiling_render_policy.hpp
index 06225188db..479e9a5a15 100644
--- a/map/basic_tiling_render_policy.hpp
+++ b/map/basic_tiling_render_policy.hpp
@@ -35,6 +35,7 @@ protected:
   string m_CountryName;
   bool m_DoRecreateCoverage;
   bool m_IsNavigating;
+  bool m_WasAnimatingLastFrame;
   size_t m_TileSize;
 
 protected:
@@ -44,6 +45,10 @@ protected:
   void StartNavigation();
   void StopNavigation();
 
+  void PauseBackgroundRendering();
+  void ResumeBackgroundRendering();
+  void CheckAnimationTransition();
+
 public:
 
   BasicTilingRenderPolicy(Params const & p,