Shader.h

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/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 * Copyright (C) 2003-2005 3Dlabs Inc. Ltd.
 * Copyright (C) 2004-2005 Nathan Cournia
 * Copyright (C) 2008 Zebra Imaging
 * Copyright (C) 2010 VIRES Simulationstechnologie GmbH
 *
 * This application is open source and may be redistributed and/or modified
 * freely and without restriction, both in commercial and non commercial
 * applications, as long as this copyright notice is maintained.
 *
 * This application 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.
*/

/* file:   include/osg/Shader
 * author: Mike Weiblen 2008-01-02
 *         Holger Helmich 2010-10-21
*/

#ifndef OSG_SHADER
#define OSG_SHADER 1


#include <osg/GLExtensions>
#include <osg/Object>
#include <osg/buffered_value>

#include <set>
#include <map>

namespace osg {

class Program;

// set of shader define strings that the shader is dependent upon.
typedef std::set<std::string> ShaderDefines;

class OSG_EXPORT ShaderBinary : public osg::Object
{
    public:

        ShaderBinary();

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

        META_Object(osg, ShaderBinary);

        void allocate(unsigned int size);

        void assign(unsigned int size, const unsigned char* data);

        unsigned int getSize() const { return static_cast<unsigned int>(_data.size()); }

        unsigned char* getData() { return _data.empty() ? 0 : &(_data.front()); }

        const unsigned char* getData() const { return _data.empty() ? 0 : &(_data.front()); }

        static ShaderBinary* readShaderBinaryFile(const std::string& fileName);

    protected:

        typedef std::vector<unsigned char> Data;
        Data _data;
};



class OSG_EXPORT Shader : public osg::Object
{
    public:

        enum Type {
            VERTEX = GL_VERTEX_SHADER,
            TESSCONTROL = GL_TESS_CONTROL_SHADER,
            TESSEVALUATION = GL_TESS_EVALUATION_SHADER,
            GEOMETRY = GL_GEOMETRY_SHADER,
            FRAGMENT = GL_FRAGMENT_SHADER,
            COMPUTE = GL_COMPUTE_SHADER,
            UNDEFINED = -1
        };

        Shader(Type type = UNDEFINED);
        Shader(Type type, const std::string& source );
        Shader(Type type, ShaderBinary* shaderBinary );

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

        META_Object(osg, Shader);

        int compare(const Shader& rhs) const;

        bool setType(Type t);

        inline Type getType() const { return _type; }

        const char* getTypename() const;


        inline void setFileName(const std::string& fileName) { _shaderFileName = fileName; }

        inline const std::string& getFileName() const { return _shaderFileName; }


        void setShaderSource(const std::string& sourceText);

        inline const std::string& getShaderSource() const { return _shaderSource; }


        enum ShaderDefinesMode
        {
            USE_SHADER_PRAGMA,
            USE_MANUAL_SETTINGS
        };

        void setShaderDefinesMode(ShaderDefinesMode sdm) { _shaderDefinesMode = sdm; }
        ShaderDefinesMode getShaderDefinesMode() const { return _shaderDefinesMode; }


        void setShaderDefines(const ShaderDefines& shaderDefs) { _shaderDefines = shaderDefs; }
        ShaderDefines& getShaderDefines() { return _shaderDefines; }
        const ShaderDefines& getShaderDefines() const { return _shaderDefines; }

        void setShaderRequirements(const ShaderDefines& shaderDefs) { _shaderRequirements = shaderDefs; }
        ShaderDefines& getShaderRequirements() { return _shaderRequirements; }
        const ShaderDefines& getShaderRequirements() const { return _shaderRequirements; }


        void setShaderBinary(ShaderBinary* shaderBinary) { _shaderBinary = shaderBinary; }

        ShaderBinary* getShaderBinary() { return _shaderBinary.get(); }

        const ShaderBinary* getShaderBinary() const { return _shaderBinary.get(); }


        static Shader* readShaderFile( Type type, const std::string& fileName );

        bool loadShaderSourceFromFile( const std::string& fileName );


        typedef std::multimap<float, std::string> CodeInjectionMap;

        void addCodeInjection(float position, const std::string& code) { _codeInjectionMap.insert(CodeInjectionMap::value_type(position, code)); }

        CodeInjectionMap& getCodeInjectionMap() { return _codeInjectionMap; }

        const CodeInjectionMap& getCodeInjectionMap() const { return _codeInjectionMap; }



        virtual void resizeGLObjectBuffers(unsigned int maxSize);

        void releaseGLObjects(osg::State* state=0) const;

        void dirtyShader();

        void compileShader(osg::State& state) const;


        static void deleteGlShader(unsigned int contextID, GLuint shader);

        static void flushDeletedGlShaders(unsigned int contextID,double currentTime, double& availableTime);

        static void discardDeletedGlShaders(unsigned int contextID);

        static Shader::Type getTypeId( const std::string& tname );

    public:
        class OSG_EXPORT PerContextShader : public osg::Referenced
        {
            public:
                PerContextShader(const Shader* shader, unsigned int contextID);

                void setDefineString(const std::string& defStr) { _defineStr = defStr; }
                const std::string& getDefineString() const { return _defineStr; }

                GLuint getHandle() const {return _glShaderHandle;}

                void requestCompile();
                void compileShader(osg::State& state);
                bool needsCompile() const {return _needsCompile;}
                bool isCompiled() const {return _isCompiled;}
                bool getInfoLog( std::string& infoLog ) const;

                void attachShader(GLuint program) const;

                void detachShader(GLuint program) const;

            protected:        /*methods*/
                ~PerContextShader();

            protected:        /*data*/
                const Shader* _shader;

                osg::ref_ptr<osg::GLExtensions> _extensions;

                GLuint _glShaderHandle;

                std::string _defineStr;

                bool _needsCompile;

                bool _isCompiled;

                const unsigned int _contextID;

            private:
                PerContextShader();        // disallowed
                PerContextShader(const PerContextShader&);        // disallowed
                PerContextShader& operator=(const PerContextShader&);        // disallowed
        };


        struct OSG_EXPORT ShaderObjects : public osg::Referenced
        {
            typedef std::vector< osg::ref_ptr<PerContextShader> > PerContextShaders;

            ShaderObjects(const Shader* shader, unsigned int contextID);

            unsigned int        _contextID;
            const Shader*       _shader;
            mutable PerContextShaders  _perContextShaders;

            PerContextShader* getPCS(const std::string& defineStr) const;
            PerContextShader* createPerContextShader(const std::string& defineStr);
            void requestCompile();
        };

        PerContextShader* getPCS(osg::State& state) const;

    protected:        /*methods*/
        virtual ~Shader();


        friend class osg::Program;
        bool addProgramRef( osg::Program* program );
        bool removeProgramRef( osg::Program* program );

        void _computeShaderDefines();
        void _parseShaderDefines(const std::string& str, ShaderDefines& defines);


        protected:        /*data*/
        Type                            _type;
        std::string                     _shaderFileName;
        std::string                     _shaderSource;
        osg::ref_ptr<ShaderBinary>      _shaderBinary;

        CodeInjectionMap                _codeInjectionMap;

        // ShaderDefines variables
        ShaderDefinesMode               _shaderDefinesMode;
        ShaderDefines                   _shaderDefines;
        ShaderDefines                   _shaderRequirements;

        typedef std::set< osg::Program* > ProgramSet;
        ProgramSet                      _programSet;
        mutable osg::buffered_value< osg::ref_ptr<ShaderObjects> > _pcsList;

    private:
        Shader& operator=(const Shader&);        // disallowed
};


class OSG_EXPORT ShaderComponent : public osg::Object
{
    public:

        ShaderComponent();
        ShaderComponent(const ShaderComponent& sc,const CopyOp& copyop=CopyOp::SHALLOW_COPY);

        META_Object(osg, ShaderComponent)

        unsigned int addShader(osg::Shader* shader);
        void removeShader(unsigned int i);

        osg::Shader* getShader(unsigned int i) { return _shaders[i].get(); }
        const osg::Shader* getShader(unsigned int i) const { return _shaders[i].get(); }

        unsigned int getNumShaders() const { return static_cast<unsigned int>(_shaders.size()); }

        virtual void compileGLObjects(State& state) const;
        virtual void resizeGLObjectBuffers(unsigned int maxSize);
        virtual void releaseGLObjects(State* state=0) const;

    protected:

       typedef std::vector< osg::ref_ptr<osg::Shader> >  Shaders;
       Shaders _shaders;
};


}

#endif