/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

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 __CompositorInstance_H__
#define __CompositorInstance_H__

#include "OgrePrerequisites.h"
#include "OgreMaterial.h"
#include "OgreTexture.h"
#include "OgreRenderQueue.h"
namespace Ogre {
    const size_t RENDER_QUEUE_COUNT = RENDER_QUEUE_OVERLAY+1;       
            
    /** An instance of a Compositor object for one Viewport. It is part of the CompositorChain
		for a Viewport.
     */
    class _OgreExport CompositorInstance
    {
    public:
        CompositorInstance(Compositor *filter, CompositionTechnique *technique, CompositorChain *chain);
        virtual ~CompositorInstance();
		/** Provides an interface to "listen in" to to render system operations executed by this 
			CompositorInstance.
		*/
		class _OgreExport Listener
		{
		public:
			virtual ~Listener();

			/** Notification of when a render target operation involving a material (like
				rendering a quad) is compiled, so that miscelleneous parameters that are different
				per Compositor instance can be set up.
				@param pass_id	Pass identifier within Compositor instance, this is speficied 
								by the user by CompositionPass::setIdentifier().
				@param mat		Material, this may be changed at will and will only affect
								the current instance of the Compositor, not the global material
								it was cloned from.
			 */
			virtual void notifyMaterialSetup(uint32 pass_id, MaterialPtr &mat);

			/** Notification before a render target operation involving a material (like
				rendering a quad), so that material parameters can be varied.
				@param pass_id	Pass identifier within Compositor instance, this is speficied 
								by the user by CompositionPass::setIdentifier().
				@param mat		Material, this may be changed at will and will only affect
								the current instance of the Compositor, not the global material
								it was cloned from.
			 */
			virtual void notifyMaterialRender(uint32 pass_id, MaterialPtr &mat);
		};
        /** Specific render system operation. A render target operation does special operations
		    between render queues like rendering a quad, clearing the frame buffer or 
			setting stencil state.
		*/
		class RenderSystemOperation
		{
		public:
			virtual ~RenderSystemOperation();
			/// Set state to SceneManager and RenderSystem
			virtual void execute(SceneManager *sm, RenderSystem *rs) = 0;
		};
		typedef std::map<int, MaterialPtr> QuadMaterialMap;
		typedef std::pair<int, RenderSystemOperation*> RenderSystemOpPair;
		typedef std::vector<RenderSystemOpPair> RenderSystemOpPairs;
        /** Operation setup for a RenderTarget (collected).
        */
        class TargetOperation
        {
        public:
            TargetOperation()
            { 
            }
            TargetOperation(RenderTarget *target):
                target(target), currentQueueGroupID(0), visibilityMask(0xFFFFFFFF),
                lodBias(1.0f),
                onlyInitial(false), hasBeenRendered(false), findVisibleObjects(false)
            { 
            }
            /// Target
            RenderTarget *target;

			/// Current group ID
			int currentQueueGroupID;

			/// RenderSystem operations to queue into the scene manager, by
			/// uint8
			RenderSystemOpPairs renderSystemOperations;

			/// Scene visibility mask
            /// If this is 0, the scene is not rendered at all
            uint32 visibilityMask;
            
            /// LOD offset. This is multiplied with the camera LOD offset
            /// 1.0 is default, lower means lower detail, higher means higher detail
            float lodBias;
            
            /** A set of render queues to either include or exclude certain render queues.
	 		*/
            typedef std::bitset<RENDER_QUEUE_COUNT> RenderQueueBitSet;

			/// Which renderqueues to render from scene
			RenderQueueBitSet renderQueues;
            
            /** @see CompositionTargetPass::mOnlyInitial
            */
            bool onlyInitial;
            /** "Has been rendered" flag; used in combination with
                onlyInitial to determine whether to skip this target operation.
            */
            bool hasBeenRendered;
            /** Whether this op needs to find visible scene objects or not 
            */
            bool findVisibleObjects;
			/** Which material scheme this op will use */
			String materialScheme;
        };
        typedef std::vector<TargetOperation> CompiledState;
        
        /** Set enabled flag. The compositor instance will only render if it is
            enabled, otherwise it is pass-through.
        */
        void setEnabled(bool value);
        
        /** Get enabled flag.
        */
        bool getEnabled();

		/** Get the instance name for a local texture.
		@note It is only valid to call this when local textures have been loaded, 
			which in practice means that the compositor instance is active. Calling
			it at other times will cause an exception. Note that since textures
			are cleaned up aggressively, this name is not guaranteed to stay the
			same if you disable and renable the compositor instance.
		@param name The name of the texture in the original compositor definition
		@returns The instance name for the texture, corresponds to a real texture
		*/
		const String& getTextureInstanceName(const String& name);

       
        /** Recursively collect target states (except for final Pass).
            @param compiledState    This vector will contain a list of TargetOperation objects
        */
        virtual void _compileTargetOperations(CompiledState &compiledState);
        
        /** Compile the final (output) operation. This is done seperately because this
            is combined with the input in chained filters.
        */
        virtual void _compileOutputOperation(TargetOperation &finalState);
        
        /** Get Compositor of which this is an instance
        */
        Compositor *getCompositor();
        
        /** Get CompositionTechnique used by this instance
        */
        CompositionTechnique *getTechnique();

		/** Get Chain that this instance is part of
        */
        CompositorChain *getChain();

		/** Add a listener. Listeners provide an interface to "listen in" to to render system 
			operations executed by this CompositorInstance so that materials can be 
			programmatically set up.
			@see CompositorInstance::Listener
		*/
		void addListener(Listener *l);

		/** Remove a listener.
			@see CompositorInstance::Listener
		*/
		void removeListener(Listener *l);

		/** Notify listeners of a material compilation.
		*/
		void _fireNotifyMaterialSetup(uint32 pass_id, MaterialPtr &mat);

		/** Notify listeners of a material render.
		*/
		void _fireNotifyMaterialRender(uint32 pass_id, MaterialPtr &mat);
	private:
        /// Compositor of which this is an instance
        Compositor *mCompositor;
        /// Composition technique used by this instance
        CompositionTechnique *mTechnique;
        /// Composition chain of which this instance is part
        CompositorChain *mChain;
        /// Is this instance enabled?
        bool mEnabled;
        /// Map from name->local texture
        typedef std::map<String,TexturePtr> LocalTextureMap;
        LocalTextureMap mLocalTextures;

		/// Vector of listeners
		typedef std::vector<Listener*> Listeners;
		Listeners mListeners;
        
        /// Previous instance (set by chain)
        CompositorInstance *mPreviousInstance;
		
		/** Collect rendering passes. Here, passes are converted into render target operations
			and queued with queueRenderSystemOp.
        */
        virtual void collectPasses(TargetOperation &finalState, CompositionTargetPass *target);
        
        /** Create a local dummy material with one technique but no passes.
            The material is detached from the Material Manager to make sure it is destroyed
			when going out of scope.
        */
        MaterialPtr createLocalMaterial();
        
        /** Create local rendertextures and other resources. Builds mLocalTextures.
        */
        void createResources();
        
        /** Destroy local rendertextures and other resources.
        */
        void freeResources();

        /** Get RenderTarget for a named local texture.
        */
        RenderTarget *getTargetForTex(const String &name);
        
        /** Get source texture name for a named local texture.
        */
        const String &getSourceForTex(const String &name);

		/** Queue a render system operation.
			@returns destination pass
		 */
		void queueRenderSystemOp(TargetOperation &finalState, RenderSystemOperation *op);
        
        friend class CompositorChain;
    };
}

#endif
