assimp/tools/assimp_view/MeshRenderer.h

/*
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Free Asset Import Library (ASSIMP)
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#if (!defined AV_MESH_RENDERER_H_INCLUDED)
#define AV_MESH_RENDERER_H_INCLUDED


#define AI_VIEW_ALPHA_SORT_DELTA 3

//-------------------------------------------------------------------------------
/* Helper class tp render meshes
*/
//-------------------------------------------------------------------------------
class CMeshRenderer
{
private:

	// default constructor
	CMeshRenderer() 
		:	m_bRotationChanged(true),
			m_iFrameCount(AI_VIEW_ALPHA_SORT_DELTA-1)
	{
		// no other members to initialize
	}

public:

	//------------------------------------------------------------------
	// Singleton accessors
	static CMeshRenderer s_cInstance;
	inline static CMeshRenderer& Instance ()
	{
		return s_cInstance;
	}


	//------------------------------------------------------------------
	// Draw a mesh in the global mesh list using the current pipeline state
	// iIndex Index of the mesh to be drawn
	//
	// The function draws all faces in order, regardless of their distance
	int DrawUnsorted(unsigned int iIndex);

	//------------------------------------------------------------------
	// Draw a mesh in the global mesh list using the current pipeline state
	// iIndex Index of the mesh to be drawn
	//
	// The method sorts all vertices by their distance (back to front)
	//
	// mWorld World matrix for the node
	int DrawSorted(unsigned int iIndex,
		const aiMatrix4x4& mWorld);


	//------------------------------------------------------------------
	// Indicate that the rotation of the object or the camera has
	// been changed, thus the alpha order tree must be updated
	inline void SetRotationChangedFlag()
	{
		this->m_bRotationChanged = true;
	}

	//------------------------------------------------------------------
	// Reset the state of the class
	// Called whenever a new asset is loaded
	inline void Reset()
	{
		this->m_bRotationChanged = true;
		this->m_iFrameCount = 2;
	}

	//------------------------------------------------------------------
	// Called at the beginning of the frame. Reset the state
	// of the instance
	inline void OnBeginFrame()
	{
		if (0 == this->m_iFrameCount)
		{
			this->m_bRotationChanged = false;
		}
	}

private:

	// true if the rotation of the object or camera has changed
	// in the last frame. If there were no changes it should
	// not be necessary to update the alpha ordering tree
	bool m_bRotationChanged;

	// only update the alpha order each AI_VIEW_ALPHA_SORT_DELTA frames
	unsigned int m_iFrameCount;
};

#endif //!! include guard