#pragma once

//disable inheritance warning caused by multiple inheritance
#if _WIN32
#if _MSC_VER
#pragma warning(disable: 4250)
#endif
#endif

#include "OgreRenderTechnique.h"
#include "DepthShadowReceiverRenderTechnique.h"
#include "Ogre.h"

using namespace Ogre;

/**
	@brief DepthShadowReceiverRenderTechnique used in an OGRE environment.

	This technique defines that the object will recieve shadows with the help of depth shadow maps.
	Each lightsource can have a depth map assigned to it. These are going to be refreshed only 
	if shadow receivers are visible. It is the shadow receiver technique's resposibility
	to refresh them.

	The shadows from each light are calculated in separate passes. Each pass will
	modulate the shaded image, so thes should be the last passes (but before caustic passes).
	The given Pass* parameter n the constructor defines the pass after which new
	shadow recieving passes will be added by the technique.

*/
class __declspec( dllexport ) OgreDepthShadowReceiverRenderTechnique : public OgreRenderTechnique,
										public DepthShadowReceiverRenderTechnique
{
public:
	/**
		@brief Constructor.

		@param maxlights				the maximum number of light sources to recieve shadow from
		@param shadowVertexProgram		the vertex program to be used in the shadowing passes
		@param shadowFragmentProgram	the fragment program to be used in the shadowing passes
										It should have one pass and the depth map of a light will be bound to the first sampler unit. 
		@param WorldViewProjParamName   the name of the gpu program parameter the world-view-projection matrix should be bound to
		@param WorldParamName			the name of the gpu program parameter the world matrix should be bound to
		@param setLightViewMatrix		bound light space view matrix to a gpu program parameter
		@param setLightViewProjMatrix   bound light space view-projection matrix to a gpu program parameter
		@param setLightProjFarPlane		bound light space projection far plane to a gpu program parameter
		@param lightViewProjParamName   the name of the gpu program parameter the light space view-projection matrix should be bound to
		@param lightViewParamName       the name of the gpu program parameter the light space view matrix should be bound to
		@param lightFarPlaneParamName	the name of the gpu program parameter the light space projection far plane should be bound to
		@param passBlendingSRC				source blend factor of the new passes
		@param passBlendingDEST				destination blend factor of the new passes
		@param pass						the pass after which shadowing passes should be added
		@param parentRenderable			the object to operate on
		@param parentTechniqueGroup		the TechniqueGroup this RenderedTechnique is attached to
	*/
	OgreDepthShadowReceiverRenderTechnique(
							int maxlights,
							String shadowVertexProgram,
							String shadowFragmentProgram,
							String WorldViewProjParamName,
							String WorldParamName,
							bool setLightViewMatrix,
							bool setLightViewProjMatrix,
							bool setLightProjFarPlane,
							String lightViewProjParamName,
							String lightViewParamName,
							String lightFarPlaneParamName,
							SceneBlendFactor passBlendingSRC,
							SceneBlendFactor passBlendingDEST,
							bool createNewPasses,
							int startTextureUnitID,
							bool nearestLightsFromCamera,
							bool bindToVertexShader,
							Pass* pass,
							OgreRenderable* parentRenderable,
							OgreTechniqueGroup* parentTechniqueGroup
							);
	/**
		@brief Destructor.
	*/
	virtual ~OgreDepthShadowReceiverRenderTechnique();
	
	//inherited
	virtual void update(unsigned long frameNum);
	
protected:	
	/**
		@brief	the maximum number of light sources to recieve shadow from

		During update the nearest light sources will be found and used.
	*/
	int maxlights;
	/**
		@brief the vertex program to be used in the shadowing passes
	*/
	String shadowVertexProgram;
	/**
		@brief the fragment program to be used in the shadowing passes
										
		It should have one pass and the depth map of a light will be bound to the first sampler unit. 
	*/
	String shadowFragmentProgram;
	/**
		@breif new passes created by this technique
	*/
	std::vector<Pass*> passes;
	/**
		@brief bound light space view matrix to a gpu program parameter
	*/
	bool setLightViewMatrix;
	/**
		@brief bound light space view-projection matrix to a gpu program parameter
	*/
	bool setLightViewProjMatrix;
	/**
		@brief bound light space projection far plane to a gpu program parameter
	*/
	bool setLightProjFarPlane;
	/**
		@brief the name of the gpu program parameter the light space view-projection matrix should be bound to
	*/
	String lightViewProjParamName;
	/**
		@brief the name of the gpu program parameter the light space view matrix should be bound to
	*/
	String lightViewParamName;
	/**
		@brief the name of the gpu program parameter the light space projection far plane should be bound to
	*/
	String lightFarPlaneParamName;
	/**
		@brief the name of the gpu program parameter the world-view-projection matrix should be bound to
	*/	
	String WorldViewProjParamName;
	/**
		@brief the name of the gpu program parameter the world matrix should be bound to
	*/
	String WorldParamName;
	/**
		@brief source blend factor of the new passes
	*/
	SceneBlendFactor passBlendingSRC;
	/**
		@brief destination blend factor of the new passes
	*/
	SceneBlendFactor passBlendingDEST;	
	bool createNewPasses;
	int startTextureUnitID;
	bool nearestLightsFromCamera;
	bool bindToVertexShader;
};

/**
	@brief RenderTechniqueFactory to create OgreDepthShadowReceiverRenderTechnique instances.
*/
class __declspec( dllexport ) OgreDepthShadowReceiverRenderTechniqueFactory : public RenderTechniqueFactory
{
public:
	
	OgreDepthShadowReceiverRenderTechniqueFactory();

	OgreRenderTechnique* createInstance(IllumTechniqueParams* params,
										Pass* pass,
										OgreRenderable* parentRenderable,
										OgreTechniqueGroup* parentTechniqueGroup);

	virtual bool needMaterialCopy(IllumTechniqueParams* params);

	int maxlights;
	String shadowVertexProgram;
	String shadowFragmentProgram;
	bool setLightViewMatrix;
	bool setLightViewProjMatrix;
	bool setLightProjFarPlane;
	String lightViewProjParamName;
	String lightViewParamName;
	String lightFarPlaneParamName;
	String WorldViewProjParamName;
	String WorldParamName;
	SceneBlendFactor passBlendingSRC;
	SceneBlendFactor passBlendingDEST;
	bool createNewPasses;
	int startTextureUnitID;
	bool nearestLightsFromCamera;
	bool bindToVertexShader;
};