/*-------------------------------------------------------------------------
This source file is a part of OGRE
(Object-oriented Graphics Rendering Engine)

For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2012 Torus Knot Software Ltd
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-------------------------------------------------------------------------*/
#ifndef __ShadowTextureManager_H__
#define __ShadowTextureManager_H__

// Precompiler options
#include "OgrePrerequisites.h"
#include "OgreSingleton.h"
#include "OgrePixelFormat.h"
#include "OgreTexture.h"
#include "OgreIteratorWrappers.h"


namespace Ogre
{
	/** \addtogroup Core
	*  @{
	*/
	/** \addtogroup Scene
	*  @{
	*/
	typedef vector<TexturePtr>::type ShadowTextureList;

	/** Structure containing the configuration for one shadow texture. */
	struct ShadowTextureConfig
	{
		unsigned int width;
		unsigned int height;
		PixelFormat format;
        unsigned int fsaa;
		uint16		depthBufferPoolId;

		ShadowTextureConfig()
			: width(512), height(512), format(PF_X8R8G8B8), fsaa(0), depthBufferPoolId(1) {}
	};

	typedef vector<ShadowTextureConfig>::type ShadowTextureConfigList;
	typedef ConstVectorIterator<ShadowTextureConfigList> ConstShadowTextureConfigIterator;

	inline _OgreExport bool operator== ( const ShadowTextureConfig& lhs, const ShadowTextureConfig& rhs );
	inline _OgreExport bool operator!= ( const ShadowTextureConfig& lhs, const ShadowTextureConfig& rhs );


	/** Class to manage the available shadow textures which may be shared between
		many SceneManager instances if formats agree.
	@remarks
		The management of the list of shadow textures has been separated out into
		a dedicated class to enable the clean management of shadow textures
		across many scene manager instances. Where multiple scene managers are
		used with shadow textures, the configuration of those shadows may or may
		not be consistent - if it is, it is good to centrally manage the textures
		so that creation and destruction responsibility is clear.
	*/
	class _OgreExport ShadowTextureManager : public Singleton<ShadowTextureManager>, public ShadowDataAlloc
	{
	protected:
		ShadowTextureList mTextureList;
		ShadowTextureList mNullTextureList;
		size_t mCount;

	public:
		ShadowTextureManager();
		virtual ~ShadowTextureManager();

		/** Populate an incoming list with shadow texture references as requested
			in the configuration list.
		*/
		virtual void getShadowTextures(const ShadowTextureConfigList& config, 
			ShadowTextureList& listToPopulate);

		/** Get an appropriately defined 'null' texture, i.e. one which will always
			result in no shadows.
		*/
		virtual TexturePtr getNullShadowTexture(PixelFormat format);

		/** Remove any shadow textures that are no longer being referenced.
		@remarks
			This should be called fairly regularly since references may take a 
			little while to disappear in some cases (if referenced by materials)
		*/
		virtual void clearUnused();
		/** Dereference all the shadow textures kept in this class and remove them
			from TextureManager; note that it is up to the SceneManagers to clear 
			their local references.
		*/
		virtual void clear();

        /** Override standard Singleton retrieval.
        @remarks
        Why do we do this? Well, it's because the Singleton
        implementation is in a .h file, which means it gets compiled
        into anybody who includes it. This is needed for the
        Singleton template to work, but we actually only want it
        compiled into the implementation of the class based on the
        Singleton, not all of them. If we don't change this, we get
        link errors when trying to use the Singleton-based class from
        an outside dll.
        @par
        This method just delegates to the template version anyway,
        but the implementation stays in this single compilation unit,
        preventing link errors.
        */
        static ShadowTextureManager& getSingleton(void);
        /** Override standard Singleton retrieval.
        @remarks
        Why do we do this? Well, it's because the Singleton
        implementation is in a .h file, which means it gets compiled
        into anybody who includes it. This is needed for the
        Singleton template to work, but we actually only want it
        compiled into the implementation of the class based on the
        Singleton, not all of them. If we don't change this, we get
        link errors when trying to use the Singleton-based class from
        an outside dll.
        @par
        This method just delegates to the template version anyway,
        but the implementation stays in this single compilation unit,
        preventing link errors.
        */
        static ShadowTextureManager* getSingletonPtr(void);

	};

	/** @} */
	/** @} */
}


#endif