Largely minizime the impacts of anti-aliasing being broken by post processing

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@10006 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/graphics/post_processing.cpp

@@ -91,6 +91,15 @@ void PostProcessing::beginCapture()
        race_manager->getNumPlayers() > 1)
         return;
     
+    // don't capture the input when we have no post-processing to add
+    // it will be faster and this ay we won't lose anti-aliasing
+    if (m_boost_amount <= 0.0f)
+    {
+        m_used_pp_this_frame = false;
+        return;
+    }
+    
+    m_used_pp_this_frame = true;
     irr_driver->getVideoDriver()->setRenderTarget(m_render_target, true, true);
 }
 
@@ -101,7 +110,10 @@ void PostProcessing::endCapture()
        race_manager->getNumPlayers() > 1)
         return;
     
-    irr_driver->getVideoDriver()->setRenderTarget(0, true, true, 0);
+    if (m_used_pp_this_frame)
+    {
+        irr_driver->getVideoDriver()->setRenderTarget(video::ERT_FRAME_BUFFER, true, true, 0);
+    }
 }
 
 void PostProcessing::update(float dt)
@@ -120,6 +132,11 @@ void PostProcessing::render()
        race_manager->getNumPlayers() > 1)
         return;
     
+    if (!m_used_pp_this_frame)
+    {
+        return;
+    }
+    
     // Draw the fullscreen quad while applying the corresponding post-processing shaders
     video::IVideoDriver*    video_driver = irr_driver->getVideoDriver();
     video::S3DVertex        vertices[6];

src/graphics/post_processing.hpp

@@ -36,6 +36,9 @@ private:
     
     /** Boost amount, used to tune the motion blur. Must be in the range 0.0 to 1.0 */
     float                       m_boost_amount;
+    
+    bool                        m_used_pp_this_frame;
+    
 public:
     PostProcessing();
     virtual ~PostProcessing();