source: GTP/trunk/App/Demos/Geom/OgreStuff/include/OgreCompositorChain.h @ 1812

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

Copyright (c) 2000-2005 The OGRE Team
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.
-----------------------------------------------------------------------------
*/
#ifndef __CompositorChain_H__
#define __CompositorChain_H__

#include "OgrePrerequisites.h"
#include "OgreRenderTargetListener.h"
#include "OgreRenderQueueListener.h"
#include "OgreCompositorInstance.h"
#include "OgreCompositor.h"
namespace Ogre {
    
    /** Chain of compositor effects applying to one viewport.
     */
    class _OgreExport CompositorChain: public RenderTargetListener
    {
    public:
        CompositorChain(Viewport *vp);
        /** Another gcc warning here, which is no problem because RenderTargetListener is never used
            to delete an object.
            warning: `class Ogre::CompositorChain' has virtual functions but non-virtual destructor
        */
        virtual ~CompositorChain();
        
        /// Data types
        typedef std::vector<CompositorInstance*> Instances;
        typedef VectorIterator<Instances> InstanceIterator;
        
        /// Identifier for "last" compositor in chain
        static const size_t LAST = (size_t)-1;
        /// Identifier for best technique
        static const size_t BEST = 0;
        
        /** Apply a compositor. Initially, the filter is enabled.
        @param filter     Filter to apply
        @param addPosition    Position in filter chain to insert this filter at; defaults to the end (last applied filter)
        @param technique      Technique to use; CompositorChain::BEST (default) chooses to the best one 
                            available (first technique supported)
        */
        CompositorInstance* addCompositor(CompositorPtr filter, size_t addPosition=LAST, size_t technique=BEST);
    
        /** Remove a compositor.
        @param position    Position in filter chain of filter to remove; defaults to the end (last applied filter)
        */
        void removeCompositor(size_t position=LAST);
        
        /** Get the number of compositors.
        */
        size_t getNumCompositors();
        
        /** Remove all compositors.
        */
        void removeAllCompositors();
        
        /** Get compositor instance by position.
         */
        CompositorInstance *getCompositor(size_t index);

                /** Get the original scene compositor instance for this chain (internal use). 
                */
                CompositorInstance* _getOriginalSceneCompositor(void) { return mOriginalScene; }
    
        /** Get an iterator over the compositor instances. The first compositor in this list is applied first, the last one is applied last.
        */
        InstanceIterator getCompositors();
    
        /** Enable or disable a compositor, by position. Disabling a compositor stops it from rendering
            but does not free any resources. This can be more efficient than using removeCompositor and 
                        addCompositor in cases the filter is switched on and off a lot.
        @param position    Position in filter chain of filter
        */
        void setCompositorEnabled(size_t position, bool state);
    
        /** @see RenderTargetListener::preRenderTargetUpdate */
                virtual void preRenderTargetUpdate(const RenderTargetEvent& evt);
                /** @see RenderTargetListener::preViewportUpdate */
        virtual void preViewportUpdate(const RenderTargetViewportEvent& evt);
        /** @see RenderTargetListener::postViewportUpdate */
        virtual void postViewportUpdate(const RenderTargetViewportEvent& evt);
                /** @see RenderTargetListener::viewportRemoved */
                virtual void viewportRemoved(const RenderTargetViewportEvent& evt);
        
        /** Mark state as dirty, and to be recompiled next frame.
         */
        void _markDirty();
        
        /** Get viewport that is the target of this chain
         */
        Viewport *getViewport();

                /** Remove a compositor by pointer. This is internally used by CompositionTechnique to
                        "weak" remove any instanced of a deleted technique.
        */
        void _removeInstance(CompositorInstance *i);

                /** Internal method for registering a queued operation for deletion later **/
                void _queuedOperation(CompositorInstance::RenderSystemOperation* op);

    protected:    
        /// Viewport affected by this CompositorChain
        Viewport *mViewport;
        
        /** Plainly renders the scene; implicit first compositor in the chain.
        */
        CompositorInstance *mOriginalScene;
        
        /// Postfilter instances in this chain
        Instances mInstances;
        
        /// State needs recompile
        bool mDirty;
                /// Any compositors enabled?
                bool mAnyCompositorsEnabled;

        /// Compiled state (updated with _compile)
        CompositorInstance::CompiledState mCompiledState;
        CompositorInstance::TargetOperation mOutputOperation;
                /// Render System operations queued by last compile, these are created by this
                /// instance thus managed and deleted by it. The list is cleared with 
                /// clearCompilationState()
                typedef std::vector<CompositorInstance::RenderSystemOperation*> RenderSystemOperations;
                RenderSystemOperations mRenderSystemOperations;

        
                /** Clear compiled state */
                void clearCompiledState();

                /** Compile this Composition chain into a series of RenderTarget operations.
        */
        void _compile();
        
        /** Prepare a viewport, the camera and the scene for a rendering operation
         */
        void preTargetOperation(CompositorInstance::TargetOperation &op, Viewport *vp, Camera *cam);
        
        /** Restore a viewport, the camera and the scene after a rendering operation
         */
        void postTargetOperation(CompositorInstance::TargetOperation &op, Viewport *vp, Camera *cam);

                /// destroy internal resources
                void destroyResources(void);

                /** Render queue listener used to set up rendering events. */
                class RQListener: public RenderQueueListener
                {
                public:
                        /** @copydoc RenderQueueListener::renderQueueStarted
                        */
                        virtual void renderQueueStarted(uint8 id, const String& invocation, bool& skipThisQueue);
                        /** @copydoc RenderQueueListener::renderQueueEnded
                        */
                        virtual void renderQueueEnded(uint8 id, const String& invocation, bool& repeatThisQueue);

                        /** Set current operation and target */
                        void setOperation(CompositorInstance::TargetOperation *op,SceneManager *sm,RenderSystem *rs);

                        /** Notify current destination viewport  */
                        void notifyViewport(Viewport* vp) { mViewport = vp; }

                        /** Flush remaining render system operations */
                        void flushUpTo(uint8 id);
                private:
                        CompositorInstance::TargetOperation *mOperation;
                        SceneManager *mSceneManager;
                        RenderSystem *mRenderSystem;
                        Viewport* mViewport;
                        CompositorInstance::RenderSystemOpPairs::iterator currentOp, lastOp;
                };
                RQListener mOurListener;
                /// Old viewport settings
                unsigned int mOldClearEveryFrameBuffers;
                /// Store old scene visibility mask
                uint32 mOldVisibilityMask;
                /// Store old find visible objects
                bool mOldFindVisibleObjects;
        /// Store old camera LOD bias      
        float mOldLodBias;     
                ///     Store old viewport material scheme
                String mOldMaterialScheme;
    };
}

#endif