1 files changed, 116 insertions, 0 deletions
diff --git a/Runtime/Camera/LODGroupManager.h b/Runtime/Camera/LODGroupManager.h
new file mode 100644
index 0000000..7623b63
--- /dev/null
+++ b/Runtime/Camera/LODGroupManager.h
@@ -0,0 +1,116 @@
+#pragma once
+
+#include "Runtime/Math/Vector3.h"
+#include "Runtime/Utilities/dynamic_array.h"
+#include "Runtime/Utilities/BitUtility.h"
+
+class LODGroup;
+struct CullingParameters;
+
+enum
+{
+	kMaximumLODLevels = 8,
+	kInvalidLODGroup = -1,
+
+	// When an LOD group is disabled, we want to make all renderers be disabled.
+	// For this purpose we have a single shared LODGroup index, with a mask that has all renderers always disabled.
+	kDisabledLODGroup = 0 
+};
+
+#if UNITY_EDITOR
+// LOD Visualization 
+// (NOTE: Keep LODUtilityBindings.txt struct in sync)
+struct LODVisualizationInformation
+{
+	int    triangleCount;
+	int    vertexCount;
+	int    rendererCount;
+	int    submeshCount;
+	
+	int    activeLODLevel;
+	float  activeLODFade;
+	float  activeDistance;
+	float  activeRelativeScreenSize;
+	float  activePixelSize;
+	float  activeWorldSpaceSize;
+};
+#endif
+
+class LODGroupManager
+{
+	struct LODSelectionData
+	{
+		// The point we measure the LOD distance against
+		Vector3f  worldReferencePoint;
+		float     maxDistanceSqr;
+		
+		// LOD maximum distance values
+		float     maxDistances[kMaximumLODLevels];
+		int       maxDistancesCount;
+		float     fadeDistance;
+		
+		// The associated lod group
+		LODGroup* lodGroup; 
+		
+		UInt32     forceLODLevelMask;
+	};
+	
+	dynamic_array<LODSelectionData>  m_SelectionData;
+	float                            m_LODBias;
+	UInt32                           m_MaximumLOD;
+	
+public:
+	
+	LODGroupManager (); 
+	
+	void   AddLODGroup (LODGroup& group, const Vector3f& position, float worldSpaceSize);
+	void   RemoveLODGroup (LODGroup& group);
+	
+	void   UpdateLODGroupParameters (int index, LODGroup& group, const Vector3f& position, float worldSpaceSize);
+	void   UpdateLODGroupPosition (int index, const Vector3f& position) { m_SelectionData[index].worldReferencePoint = position; }
+	
+	void   SetLODBias (float b)                                         { m_LODBias = b; }
+	float  GetLODBias () const                                          { return m_LODBias; }
+	
+	void   SetMaximumLODLevel (UInt32 b)                                { m_MaximumLOD = b; }
+	UInt32 GetMaximumLODLevel () const                                  { return m_MaximumLOD; }
+	
+	void   ResetLODBias ()                                              { SetLODBias(1.0F); }
+
+	int    GetLODGroupCount () const                                    { return m_SelectionData.size(); }
+	
+	
+	// Used by scene culling to determine 
+	// /lodGroupIndex/ is the index of LODGroup into m_SelectionData & m_ActiveLOD
+	// /activeLODMask/ is the LOD mask of the renderer. 
+	// m_ActiveLOD[lodGroupIndex].activeMask is a bitmask specifying which LOD levels should be rendered.
+	// When cross-fading between two LOD's multiple LOD's might be active in the same LODGroup
+	static bool IsLODVisible (UInt32 lodGroupIndex, UInt32 activeLODMask, const UInt8* activeLOD)
+	{
+		if (activeLODMask == 0)
+			return true;
+		
+		return activeLOD[lodGroupIndex] & activeLODMask;
+	}
+
+	void CalculateLODMasks (const CullingParameters& parameters, UInt8* outMasks, float* outFades);
+	static float CalculateLODFade (UInt32 lodGroupIndex, UInt32 rendererActiveLODMask, const UInt8* lodMasks, const float* lodFades);
+	
+	static void CalculatePerspectiveLODMask (const LODSelectionData& selection, const Vector3f& position, int maximumLOD, int currentMask, const float* fieldOfViewFudge, UInt8* output, float* outputFade);
+	static void CalculateOrthoLODMask (const LODSelectionData& selection, int maximumLOD, int currentMask, const float* fudge, UInt8* output, float* outputFade);
+
+#if UNITY_EDITOR
+	LODVisualizationInformation CalculateVisualizationData (const CullingParameters& cullingParameters, LODGroup& lodGroup, int lod);
+	
+#endif
+
+	void   SetForceLODMask (int index, UInt32 forceEditorLODMask)     { m_SelectionData[index].forceLODLevelMask = forceEditorLODMask; }
+	UInt32 GetForceLODMask (int index)                               { return m_SelectionData[index].forceLODLevelMask; }
+	void   ClearAllForceLODMask ();
+
+};
+
+LODGroupManager* GetLODGroupManagerPtr ();
+LODGroupManager& GetLODGroupManager ();
+void CleanupLODGroupManager ();
+void InitializeLODGroupManager ();