/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library 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
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSGUTIL_RENDERSTAGE
#define OSGUTIL_RENDERSTAGE 1

#include <osg/ColorMask>
#include <osg/Viewport>
#include <osg/Texture>
#include <osg/FrameBufferObject>
#include <osg/Camera>

#include <osgUtil/RenderBin>
#include <osgUtil/PositionalStateContainer>

namespace osgUtil {

/**
 * RenderStage base class. Used for encapsulate a complete stage in
 * rendering - setting up of viewport, the projection and model
 * matrices and rendering the RenderBin's enclosed with this RenderStage.
 * RenderStage also has a dependency list of other RenderStages, each
 * of which must be called before the rendering of this stage.  These
 * 'pre' rendering stages are used for advanced rendering techniques
 * like multistage pixel shading or impostors.
 */
class OSGUTIL_EXPORT RenderStage : public RenderBin
{
    public:


        RenderStage();
        RenderStage(SortMode mode);

        RenderStage(const RenderStage& rhs,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);

        virtual osg::Object* cloneType() const { return new RenderStage(); }
        virtual osg::Object* clone(const osg::CopyOp& copyop) const { return new RenderStage(*this,copyop); } // note only implements a clone of type.
        virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const RenderStage*>(obj)!=0L; }
        virtual const char* className() const { return "RenderStage"; }

        virtual void reset();


        /** Set the draw buffer used at the start of each frame draw. */
        void setDrawBuffer(GLenum buffer, bool applyMask = true ) { _drawBuffer = buffer; setDrawBufferApplyMask( applyMask ); }

        /** Get the draw buffer used at the start of each frame draw. */
        GLenum getDrawBuffer() const { return _drawBuffer; }

        /** Get the apply mask defining whether glDrawBuffer is called at each frame draw. */
        bool getDrawBufferApplyMask() const { return _drawBufferApplyMask; }

        /** Set the apply mask defining whether glDrawBuffer is called at each frame draw. */
        void setDrawBufferApplyMask( bool applyMask ) { _drawBufferApplyMask = applyMask; }



        /** Set the read buffer for any required copy operations to use. */
        void setReadBuffer(GLenum buffer, bool applyMask = true) { _readBuffer = buffer; setReadBufferApplyMask( applyMask ); }

        /** Get the read buffer for any required copy operations to use. */
        GLenum getReadBuffer() const { return _readBuffer; }

        /** Get the apply mask defining whether glReadBuffer is called at each frame draw. */
        bool getReadBufferApplyMask() const { return _readBufferApplyMask; }

        /** Set the apply mask defining whether glReadBuffer is called at each frame draw. */
        void setReadBufferApplyMask( bool applyMask ) { _readBufferApplyMask = applyMask; }


        /** Set the viewport.*/
        void setViewport(osg::Viewport* viewport) { _viewport = viewport; }

        /** Get the const viewport. */
        const osg::Viewport* getViewport() const { return _viewport.get(); }

        /** Get the viewport. */
        osg::Viewport* getViewport() { return _viewport.get(); }

        /** Set the initial view matrix.*/
        void setInitialViewMatrix(const osg::RefMatrix* matrix) { _initialViewMatrix = matrix; }

        /** Get the initial view matrix.*/
        const osg::RefMatrix* getInitialViewMatrix() { return _initialViewMatrix.get(); }

        /** Set the clear mask used in glClear(..).
          * Defaults to GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT. */
        void setClearMask(GLbitfield mask) { _clearMask = mask; }

        /** Get the clear mask.*/
        GLbitfield getClearMask() const { return _clearMask; }


        void setColorMask(osg::ColorMask* cm) { _colorMask = cm; }
        osg::ColorMask* getColorMask() { return _colorMask.get(); }
        const osg::ColorMask* getColorMask() const { return _colorMask.get(); }


        /** Set the clear color used in glClearColor(..).
          * glClearColor is only called if mask & GL_COLOR_BUFFER_BIT is true*/
        void setClearColor(const osg::Vec4& color) { _clearColor=color; }

        /** Get the clear color.*/
        const osg::Vec4& getClearColor() const { return _clearColor; }

        /** Set the clear accum used in glClearAccum(..).
          * glClearAcumm is only called if mask & GL_ACCUM_BUFFER_BIT is true. */
        void setClearAccum(const osg::Vec4& color) { _clearAccum=color; }

        /** Get the clear accum.*/
        const osg::Vec4& getClearAccum() const { return _clearAccum; }

        /** Set the clear depth used in glClearDepth(..). Defaults to 1.0
          * glClearDepth is only called if mask & GL_DEPTH_BUFFER_BIT is true. */
        void setClearDepth(double depth) { _clearDepth=depth; }

        /** Get the clear depth.*/
        double getClearDepth() const { return _clearDepth; }

        /** Set the clear stencil value used in glClearStencil(). Defaults to 0;
          * glClearStencil is only called if mask & GL_STENCIL_BUFFER_BIT is true*/
        void setClearStencil(int stencil) { _clearStencil=stencil; }

        /** Get the clear color.*/
        int getClearStencil() const { return _clearStencil; }


        void setCamera(osg::Camera* camera) { if (_camera!=camera) { _camera = camera; _cameraRequiresSetUp = true; } }
        osg::Camera* getCamera() { return _camera.get(); }
        const osg::Camera* getCamera() const { return _camera.get(); }

        void setCameraRequiresSetUp(bool flag) { _cameraRequiresSetUp = flag; }
        bool getCameraRequiresSetUp() const { return _cameraRequiresSetUp; }

        /** Attempt the set the RenderStage from the Camera settings.*/
        void runCameraSetUp(osg::RenderInfo& renderInfo);

        void setTexture(osg::Texture* texture, unsigned int level = 0, unsigned int face=0) { _texture = texture; _level = level; _face = face; }
        osg::Texture* getTexture() { return _texture.get(); }

        void setImage(osg::Image* image) { _image = image; }
        osg::Image* getImage() { return _image.get(); }

        void setImageReadPixelFormat(GLenum format) { _imageReadPixelFormat = format; }
        GLenum getImageReadPixelFormat() const { return _imageReadPixelFormat; }

        void setImageReadPixelDataType(GLenum type) { _imageReadPixelDataType = type; }
        GLenum getImageReadPixelDataType() const { return _imageReadPixelDataType; }

        /** Set a framebuffer object to render into. It is permissible for the
          * framebuffer object to be multisampled, in which case you should also
          * set a resolve framebuffer object - see setMultisampleResolveFramebufferObject(). */
        void setFrameBufferObject(osg::FrameBufferObject* fbo) { _fbo = fbo; }
        osg::FrameBufferObject* getFrameBufferObject() { return _fbo.get(); }
        const osg::FrameBufferObject* getFrameBufferObject() const { return _fbo.get(); }

        /** Sets the destination framebuffer object for glBlitFramebufferEXT to
          * resolve a multisampled framebuffer object after the RenderStage is
          * drawn. The resolve framebuffer object must not be multisampled. The
          * resolve framebuffer object is only necessary if the primary framebuffer
          * object is multisampled, if not then leave it set to null. */
        void setMultisampleResolveFramebufferObject(osg::FrameBufferObject* fbo);
        osg::FrameBufferObject* getMultisampleResolveFramebufferObject() { return _resolveFbo.get(); }
        const osg::FrameBufferObject* getMultisampleResolveFramebufferObject() const { return _resolveFbo.get(); }

        /** Set whether the framebuffer object should be unbound after
          * rendering. By default this is set to true. Set it to false if the
          * unbinding is not required. */
        void setDisableFboAfterRender(bool disable) {_disableFboAfterRender = disable;}
        bool getDisableFboAfterRender() const {return _disableFboAfterRender;}

        void setGraphicsContext(osg::GraphicsContext* context) { _graphicsContext = context; }
        osg::GraphicsContext* getGraphicsContext() { return _graphicsContext.get(); }
        const osg::GraphicsContext* getGraphicsContext() const { return _graphicsContext.get(); }




        void setInheritedPositionalStateContainerMatrix(const osg::Matrix& matrix) { _inheritedPositionalStateContainerMatrix = matrix; }
        const osg::Matrix& getInheritedPositionalStateContainerMatrix() const { return _inheritedPositionalStateContainerMatrix; }

        void setInheritedPositionalStateContainer(PositionalStateContainer* rsl) { _inheritedPositionalStateContainer = rsl; }
        PositionalStateContainer* getInheritedPositionalStateContainer() { return _inheritedPositionalStateContainer.get(); }

        void setPositionalStateContainer(PositionalStateContainer* rsl) { _renderStageLighting = rsl; }

        PositionalStateContainer* getPositionalStateContainer() const
        {
            if (!_renderStageLighting.valid()) _renderStageLighting = new PositionalStateContainer;
            return _renderStageLighting.get();
        }

        virtual void addPositionedAttribute(osg::RefMatrix* matrix,const osg::StateAttribute* attr)
        {
            getPositionalStateContainer()->addPositionedAttribute(matrix,attr);
        }

        virtual void addPositionedTextureAttribute(unsigned int textureUnit, osg::RefMatrix* matrix,const osg::StateAttribute* attr)
        {
            getPositionalStateContainer()->addPositionedTextureAttribute(textureUnit, matrix,attr);
        }

        void copyTexture(osg::RenderInfo& renderInfo);

        virtual void sort();

        virtual void drawPreRenderStages(osg::RenderInfo& renderInfo,RenderLeaf*& previous);

        virtual void draw(osg::RenderInfo& renderInfo,RenderLeaf*& previous);

        virtual void drawInner(osg::RenderInfo& renderInfo,RenderLeaf*& previous, bool& doCopyTexture);

        virtual void drawPostRenderStages(osg::RenderInfo& renderInfo,RenderLeaf*& previous);

        virtual void drawImplementation(osg::RenderInfo& renderInfo,RenderLeaf*& previous);


        void addToDependencyList(RenderStage* rs) { addPreRenderStage(rs); }

        void addPreRenderStage(RenderStage* rs, int order = 0);

        void addPostRenderStage(RenderStage* rs, int order = 0);

        /** Extract stats for current draw list. */
        bool getStats(Statistics& stats) const;

        /** Compute the number of dynamic RenderLeaves.*/
        virtual unsigned int computeNumberOfDynamicRenderLeaves() const;

        struct Attachment
        {
            osg::ref_ptr<osg::Image>                _image;
            GLenum                                  _imageReadPixelFormat;
            GLenum                                  _imageReadPixelDataType;
        };

        void attach(osg::Camera::BufferComponent buffer, osg::Image* image);

        /** search through any pre and post RenderStage that reference a Camera, and take a reference to each of these cameras to prevent them being deleted while they are still be used by the drawing thread.*/
        void collateReferencesToDependentCameras();

        /** clear the references to any dependent cameras.*/
        void clearReferencesToDependentCameras();

        /** If State is non-zero, this function releases any associated OpenGL objects for
           * the specified graphics context. Otherwise, releases OpenGL objexts
           * for all graphics contexts. */
        virtual void releaseGLObjects(osg::State* state= 0) const;

protected:

        virtual ~RenderStage();

        typedef std::pair< int , osg::ref_ptr<RenderStage> > RenderStageOrderPair;
        typedef std::list< RenderStageOrderPair > RenderStageList;
        typedef std::vector< osg::ref_ptr<osg::Camera> > Cameras;

        bool                                _stageDrawnThisFrame;
        RenderStageList                     _preRenderList;
        RenderStageList                     _postRenderList;

        Cameras                             _dependentCameras;

        // viewport x,y,width,height.
        osg::ref_ptr<osg::Viewport>         _viewport;
        osg::ref_ptr<const osg::RefMatrix>  _initialViewMatrix;

        GLenum                              _drawBuffer;
        bool                                _drawBufferApplyMask;
        GLenum                              _readBuffer;
        bool                                _readBufferApplyMask;
        GLbitfield                          _clearMask;
        osg::ref_ptr<osg::ColorMask>        _colorMask;
        osg::Vec4                           _clearColor;
        osg::Vec4                           _clearAccum;
        double                              _clearDepth;
        int                                 _clearStencil;

        bool                                _cameraRequiresSetUp;
        osg::observer_ptr<osg::Camera>      _camera;

        osg::ref_ptr<osg::Texture>              _texture;
        unsigned int                            _level;
        unsigned int                            _face;

        osg::ref_ptr<osg::Image>                _image;
        GLenum                                  _imageReadPixelFormat;
        GLenum                                  _imageReadPixelDataType;

        std::map< osg::Camera::BufferComponent, Attachment> _bufferAttachmentMap;

        osg::ref_ptr<osg::FrameBufferObject>    _fbo;
        osg::ref_ptr<osg::FrameBufferObject>    _resolveFbo;
        osg::ref_ptr<osg::GraphicsContext>      _graphicsContext;
        bool                                    _disableFboAfterRender;

        mutable osg::Matrix                         _inheritedPositionalStateContainerMatrix;
        mutable osg::ref_ptr<PositionalStateContainer>   _inheritedPositionalStateContainer;
        mutable osg::ref_ptr<PositionalStateContainer>   _renderStageLighting;


};

}

#endif

