Fix render states spillover (PR #3412)

Fixes issue reported in comment: #3402 (comment)

Author: tederis

Client/core/CCore.cpp

@@ -2012,11 +2012,21 @@ void CCore::OnPreHUDRender()
 {
     IDirect3DDevice9* pDevice = CGraphics::GetSingleton().GetDevice();
 
-    CGraphics::GetSingleton().EnteringMTARenderZone();
+    if (CGraphics::GetSingleton().HasLine3DPostFXQueueItems() || CGraphics::GetSingleton().HasPrimitive3DPostFXQueueItems())
+    {
+        /*
+            Although MTA render zones are expensive, we should use them twice in the bounds of the function
+            because some of render states from PostFX drain to the 2D part of the frame.
+        */
+        CGraphics::GetSingleton().EnteringMTARenderZone();
+
+        CGraphics::GetSingleton().DrawPrimitive3DPostFXQueue();
+        CGraphics::GetSingleton().DrawLine3DPostFXQueue();
+
+        CGraphics::GetSingleton().LeavingMTARenderZone();
+    }
 
-    // Draw post-fx 3D primitives
-    CGraphics::GetSingleton().DrawPrimitive3DPostFXQueue();
-    CGraphics::GetSingleton().DrawLine3DPostFXQueue();
+    CGraphics::GetSingleton().EnteringMTARenderZone();    
 
     // Maybe capture screen and other stuff
     CGraphics::GetSingleton().GetRenderItemManager()->DoPulse();

Client/core/Graphics/CGraphics.cpp

@@ -1651,6 +1651,11 @@ bool CGraphics::HasLine3DPreGUIQueueItems(void)
     return m_pLine3DBatcherPreGUI->HasItems() || m_pMaterialLine3DBatcherPreGUI->HasItems();
 }
 
+bool CGraphics::HasLine3DPostFXQueueItems()
+{
+    return m_pLine3DBatcherPostFX->HasItems() || m_pMaterialLine3DBatcherPostFX->HasItems();
+}
+
 void CGraphics::DrawPrimitive3DPostFXQueue(void)
 {
     m_pPrimitive3DBatcherPostFX->Flush();
@@ -1662,6 +1667,11 @@ bool CGraphics::HasPrimitive3DPreGUIQueueItems(void)
     return m_pMaterialPrimitive3DBatcherPreGUI->HasItems() || m_pPrimitive3DBatcherPreGUI->HasItems();
 }
 
+bool CGraphics::HasPrimitive3DPostFXQueueItems()
+{
+    return m_pMaterialPrimitive3DBatcherPostFX->HasItems() || m_pPrimitive3DBatcherPostFX->HasItems();
+}
+
 void CGraphics::DrawQueue(std::vector<sDrawQueueItem>& Queue)
 {
     BeginDrawBatch();

Client/core/Graphics/CGraphics.h

@@ -190,9 +190,11 @@ class CGraphics : public CGraphicsInterface, public CSingleton<CGraphics>
     void DrawLine3DPreGUIQueue(void);
     void DrawLine3DPostFXQueue(void);
     bool HasLine3DPreGUIQueueItems(void);
+    bool HasLine3DPostFXQueueItems();
     void DrawPrimitive3DPostFXQueue(void);
     void DrawPrimitive3DPreGUIQueue(void);
     bool HasPrimitive3DPreGUIQueueItems(void);
+    bool HasPrimitive3DPostFXQueueItems();
 
     void DidRenderScene();
     void SetProgressMessage(const SString& strMessage);