#ifndef SHADOWGEOMETRY_H
#define SHADOWGEOMETRY_H

#define DEFAULT_SHADOW_COLOR (NiColor(0.7f, 0.7f, 0.7f))
class CShadowGeometry : public NiRefObject
{
public:
	enum ShadowType
	{
		ST_NULL,
		ST_STATIC,
		ST_DYNAMIC,
	};

    static CShadowGeometry* Create(ShadowType eShadowType = ST_DYNAMIC);

    virtual ~CShadowGeometry();
    
    // Render the shadow texture
    void Click(const NiPoint3& kPos);
	void RenderTexture();

    void ResetCaster(NiAVObject* pkCaster);

	NiTriShape* GetShadowGeometry() const { return m_spShadowGeometry; }
	bool IsDynamicShadow() const { return m_eShadowType == ST_DYNAMIC; }

	static void SetShadowColor(const NiColor& kColor);
	
	static bool _SDMInit();
	static void _SDMShutdown();

protected:
    CShadowGeometry(ShadowType eShadowType);

    void UpdateShadowCamera();
    void UpdateShadowGeometry();
    void UpdateShadowGeometryBound();

    void RecursiveStoreCasterObjects(NiAVObject* pkObject);
    bool GenerateCameraRay(unsigned int uiIndex, NiPoint3& kPt, NiPoint3& kDir);
    void CullTriAgainstCameraFrustum(const NiPoint3 akV[3]);
	void AddShadowTriangle(const NiPoint3 akV[3]);
	void TraverseGroundGeometry();

    // Initial max triangle and vertex counts allowed when generating the
    // set of geometry subtended by the shadown (i.e. shadow "recipient"
    // geometry).  This method is independent of "caster" geometry count, as
    // the system renders the shadow to a texture (or uses a loaded texture)
    enum { SHADOW_TRIANGLE_COUNT = 60, SHADOW_VERTEX_COUNT = 180 };

    // Leaf geometry objects in the shadow caster scene.  If the shadow is
    // dynamically rendered, we will render these as a flat list (a batch
    // rendering).  They are found by traversing the m_spCaster for leaf 
    // geometry
    NiTObjectSet<NiAVObjectPtr> m_kCastingObjects;
    NiTObjectSet<NiAVObjectPtr> m_kSkinnedCastingObjects;

    // The tree containing all objects that will cast a shadow upon the scene
    // Used only in the case that the shadow is dynamically rendered per frame
    NiAVObjectPtr m_spCaster;

    // A very distant camera, designed to represent an infinite light source
    NiCameraPtr m_spCamera;
	NiFrustumPlanes m_kPlanes;

    // The shadow texture, which will either be:
    // A) Rendered each frame to represent the shadow geometry as seen from 
    // the casting light's POV
    // B) Loaded from file at initialization time and used each frame
    NiTexturePtr m_spTexture;

    // The render target used by the system to render the shadow geometry
    NiRenderTargetGroupPtr m_spRenderTargetGroup;

    // Current recipient geometry, created from triangles in the m_spGround
    // scene that intersect the cast shadow volume.  This is a dynamic object
    // and will be refilled each frame
    NiTriShapePtr m_spShadowGeometry;

    NiPoint3 m_kLightDir;
    NiPoint3 m_kTranslate;
    float m_fRadius;

    // Limits on the amount of ground (recipient) geometry that can be added
    // to m_spShadowGeometry, to avoid overflowing (or having to resize) the
    // geometry arrays
    unsigned short m_usMaxTriangleCount;
    unsigned short m_usMaxVertexCount;

    ShadowType m_eShadowType;

	static NiMaterial* ms_pkShadowMaterial;
	static NiMaterial* ms_pkShadowSkinnedMaterial;

	static NiTexture* ms_pkStaticShadow;

    // A property state that causes the shadow caster to be rendered as dark
    // gray into the white background of the shadow image.  Used when drawing
    // the shadow caster geometry into the shadow texture (dynamically
    // rendered shadow image only - unused if the shadow is loaded from file)
    static NiPropertyState* ms_pkPropertyState;
    static NiMaterialProperty* ms_pkMaterialProperty;
};

NiSmartPointer(CShadowGeometry);

#endif // SHADOWGEOMETRY_H