GraphicsContext.h

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/* -*-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 OSG_GRAPHICSCONTEXT
#define OSG_GRAPHICSCONTEXT 1

#include <osg/State>
#include <osg/GraphicsThread>
#include <osg/Timer>

#include <vector>

namespace osg {

// forward declare osg::Camera
class Camera;

class OSG_EXPORT GraphicsContext : public Object
{
    public:

        struct OSG_EXPORT ScreenIdentifier
        {
            ScreenIdentifier();

            ScreenIdentifier(int in_screenNum);

            ScreenIdentifier(const std::string& in_hostName,int in_displayNum, int in_screenNum);

            std::string displayName() const;

            void readDISPLAY();

            void setScreenIdentifier(const std::string& displayName);

            void setUndefinedScreenDetailsToDefaultScreen()
            {
                if (displayNum<0) displayNum = 0;
                if (screenNum<0) screenNum = 0;
            }

            std::string  hostName;
            int displayNum;
            int screenNum;
        };

        struct OSG_EXPORT Traits : public osg::Referenced, public ScreenIdentifier
        {
            Traits(DisplaySettings* ds=0);

            // graphics context original and size
            int x;
            int y;
            int width;
            int height;

            // window decoration and behaviour
            std::string windowName;
            bool        windowDecoration;
            bool        supportsResize;

            // buffer depths, 0 equals off.
            unsigned int red;
            unsigned int blue;
            unsigned int green;
            unsigned int alpha;
            unsigned int depth;
            unsigned int stencil;

            // multi sample parameters
            unsigned int sampleBuffers;
            unsigned int samples;

            // buffer configuration
            bool pbuffer;
            bool quadBufferStereo;
            bool doubleBuffer;

            // render to texture
            GLenum          target;
            GLenum          format;
            unsigned int    level;
            unsigned int    face;
            unsigned int    mipMapGeneration;

            // V-sync
            bool            vsync;

            // Swap Group
            bool            swapGroupEnabled;
            GLuint          swapGroup;
            GLuint          swapBarrier;

            // use multithreaded OpenGL-engine (OS X only)
            bool            useMultiThreadedOpenGLEngine;

            // enable cursor
            bool            useCursor;

            // settings used in set up of graphics context, only presently used by GL3 build of OSG.
            std::string     glContextVersion;
            unsigned int    glContextFlags;
            unsigned int    glContextProfileMask;

            bool getContextVersion(unsigned int& major, unsigned int& minor) const;

            // shared context
            osg::observer_ptr<GraphicsContext> sharedContext;

            osg::ref_ptr<osg::Referenced> inheritedWindowData;

            // ask the GraphicsWindow implementation to set the pixel format of an inherited window
            bool setInheritedWindowPixelFormat;

            // X11 hint whether to override the window managers window size/position redirection
            bool overrideRedirect;

            DisplaySettings::SwapMethod swapMethod;
        };

        struct ScreenSettings {
            ScreenSettings() :
                width(0),
                height(0),
                refreshRate(0),
                colorDepth(0)
            {}
            ScreenSettings(int width, int height, double refreshRate=0, unsigned int colorDepth=0) :
                width(width),
                height(height),
                refreshRate(refreshRate),
                colorDepth(colorDepth)
            {}

            int width;
            int height;
            double refreshRate;         
            unsigned int colorDepth;    
        };

        typedef std::vector<ScreenSettings> ScreenSettingsList;

        struct WindowingSystemInterface : public osg::Referenced
        {
            virtual unsigned int getNumScreens(const ScreenIdentifier& screenIdentifier = ScreenIdentifier()) = 0;

            virtual void getScreenSettings(const ScreenIdentifier& screenIdentifier, ScreenSettings & resolution) = 0;

            virtual bool setScreenSettings(const ScreenIdentifier& /*screenIdentifier*/, const ScreenSettings & /*resolution*/) { return false; }

            virtual void enumerateScreenSettings(const ScreenIdentifier& screenIdentifier, ScreenSettingsList & resolutionList) = 0;

            virtual void setDisplaySettings(DisplaySettings*) {}

            virtual osg::DisplaySettings* getDisplaySettings() const { return 0; }

            virtual GraphicsContext* createGraphicsContext(Traits* traits) = 0;

            virtual ~WindowingSystemInterface() {}


            inline void getScreenResolution(const ScreenIdentifier& screenIdentifier, unsigned int& width, unsigned int& height)
            {
                ScreenSettings settings;
                getScreenSettings(screenIdentifier, settings);
                width = settings.width;
                height = settings.height;
            }

            inline bool setScreenResolution(const ScreenIdentifier& screenIdentifier, unsigned int width, unsigned int height)
            {
                return setScreenSettings(screenIdentifier, ScreenSettings(width, height));
            }

            inline bool setScreenRefreshRate(const ScreenIdentifier& screenIdentifier, double refreshRate)
            {
                ScreenSettings settings;
                getScreenSettings(screenIdentifier, settings);
                settings.refreshRate = refreshRate;
                return setScreenSettings(screenIdentifier, settings);
            }

        };


        static void setWindowingSystemInterface(WindowingSystemInterface* wsInterface);

        static WindowingSystemInterface* getWindowingSystemInterface();

        static GraphicsContext* createGraphicsContext(Traits* traits);

        static unsigned int createNewContextID();

        static unsigned int getMaxContextID();

        static void incrementContextIDUsageCount(unsigned int contextID);

        static void decrementContextIDUsageCount(unsigned int contextID);

        typedef std::vector<GraphicsContext*> GraphicsContexts;

        static GraphicsContexts getAllRegisteredGraphicsContexts();

        static GraphicsContexts getRegisteredGraphicsContexts(unsigned int contextID);

        static void setCompileContext(unsigned int contextID, GraphicsContext* gc);

        static  GraphicsContext* getOrCreateCompileContext(unsigned int contextID);

        static GraphicsContext* getCompileContext(unsigned int contextID);

    public:

        void add(Operation* operation);

        void remove(Operation* operation);

        void remove(const std::string& name);

        void removeAllOperations();

        virtual void runOperations();

        typedef std::list< ref_ptr<Operation> > GraphicsOperationQueue;

        GraphicsOperationQueue& getOperationsQueue() { return _operations; }

        OpenThreads::Mutex* getOperationsMutex() { return &_operationsMutex; }

        osg::RefBlock* getOperationsBlock() { return _operationsBlock.get(); }

        Operation* getCurrentOperation() { return _currentOperation.get(); }


    public:

        inline const Traits* getTraits() const { return _traits.get(); }

        virtual bool valid() const = 0;


        inline void setState(State* state) { _state = state; }

        inline State* getState() { return _state.get(); }

        inline const State* getState() const { return _state.get(); }


        inline void setClearColor(const Vec4& color) { _clearColor = color; }

        inline const Vec4& getClearColor() const { return _clearColor; }

        inline void setClearMask(GLbitfield mask) { _clearMask = mask; }

        inline GLbitfield getClearMask() const { return _clearMask; }

        virtual void clear();

        double getTimeSinceLastClear() const { return osg::Timer::instance()->delta_s(_lastClearTick, osg::Timer::instance()->tick()); }


        bool realize();

        void close(bool callCloseImplementation=true);

        void swapBuffers();

        inline bool isRealized() const { return isRealizedImplementation(); }


        bool makeCurrent();

        bool makeContextCurrent(GraphicsContext* readContext);

        bool releaseContext();

        inline bool isCurrent() const { return _threadOfLastMakeCurrent == OpenThreads::Thread::CurrentThread(); }

        inline void bindPBufferToTexture(GLenum buffer) { bindPBufferToTextureImplementation(buffer); }



        void createGraphicsThread();

        void setGraphicsThread(GraphicsThread* gt);

        GraphicsThread* getGraphicsThread() { return _graphicsThread.get(); }

        const GraphicsThread* getGraphicsThread() const { return _graphicsThread.get(); }


        virtual bool realizeImplementation() = 0;

        virtual bool isRealizedImplementation() const = 0;

        virtual void closeImplementation() = 0;

        virtual bool makeCurrentImplementation() = 0;

        virtual bool makeContextCurrentImplementation(GraphicsContext* readContext) = 0;

        virtual bool releaseContextImplementation() = 0;

        virtual void bindPBufferToTextureImplementation(GLenum buffer) = 0;

        struct SwapCallback : public osg::Referenced
        {
            virtual void swapBuffersImplementation(GraphicsContext* gc) = 0;
        };
        void setSwapCallback(SwapCallback* rc) { _swapCallback = rc; }

        SwapCallback* getSwapCallback() { return _swapCallback.get(); }

        const SwapCallback* getSwapCallback() const { return _swapCallback.get(); }

        void swapBuffersCallbackOrImplemenation()
        {
            if (_state.valid()) _state->frameCompleted();

            if (_swapCallback.valid()) _swapCallback->swapBuffersImplementation(this);
            else swapBuffersImplementation();
        }

        virtual void swapBuffersImplementation() = 0;



        void resized(int x, int y, int width, int height)
        {
            if (_resizedCallback.valid()) _resizedCallback->resizedImplementation(this, x, y, width, height);
            else resizedImplementation(x, y, width, height);
        }

        struct ResizedCallback : public osg::Referenced
        {
            virtual void resizedImplementation(GraphicsContext* gc, int x, int y, int width, int height) = 0;
        };

        void setResizedCallback(ResizedCallback* rc) { _resizedCallback = rc; }

        ResizedCallback* getResizedCallback() { return _resizedCallback.get(); }

        const ResizedCallback* getResizedCallback() const { return _resizedCallback.get(); }

        virtual void resizedImplementation(int x, int y, int width, int height);


        typedef std::list< osg::Camera* > Cameras;

        Cameras& getCameras() { return _cameras; }

        const Cameras& getCameras() const { return _cameras; }

        void setDefaultFboId(GLuint i) { _defaultFboId = i; }

        GLuint getDefaultFboId() const { return _defaultFboId; }

    public:

        virtual bool isSameKindAs(const Object* object) const { return dynamic_cast<const GraphicsContext*>(object)!=0; }
        virtual const char* libraryName() const { return "osg"; }
        virtual const char* className() const { return "GraphicsContext"; }

    protected:

        GraphicsContext();
        GraphicsContext(const GraphicsContext&, const osg::CopyOp&);

        virtual ~GraphicsContext();

        virtual Object* cloneType() const { return 0; }
        virtual Object* clone(const CopyOp&) const { return 0; }

        static void registerGraphicsContext(GraphicsContext* gc);

        static void unregisterGraphicsContext(GraphicsContext* gc);


        void addCamera(osg::Camera* camera);
        void removeCamera(osg::Camera* camera);

        Cameras _cameras;

        friend class osg::Camera;

        ref_ptr<Traits>         _traits;
        ref_ptr<State>          _state;

        Vec4                    _clearColor;
        GLbitfield              _clearMask;

        OpenThreads::Thread*    _threadOfLastMakeCurrent;

        OpenThreads::Mutex                  _operationsMutex;
        osg::ref_ptr<osg::RefBlock>         _operationsBlock;
        GraphicsOperationQueue              _operations;
        osg::ref_ptr<Operation>             _currentOperation;

        ref_ptr<GraphicsThread>             _graphicsThread;

        ref_ptr<ResizedCallback>            _resizedCallback;
        ref_ptr<SwapCallback>               _swapCallback;

        Timer_t                             _lastClearTick;

        GLuint                              _defaultFboId;
};

//#include <osg/GLExtensions>


class OSG_EXPORT SyncSwapBuffersCallback : public GraphicsContext::SwapCallback
{
public:
    SyncSwapBuffersCallback();

    virtual void swapBuffersImplementation(GraphicsContext* gc);

    GLsync _previousSync;
};

}

#endif