/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield 
 * Copyright (C) 2003 3Dlabs Inc. Ltd.
 *
 * This application is open source and may be redistributed and/or modified   
 * freely and without restriction, both in commericial and non commericial
 * 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/osgGL2/ProgramObject
 * author:	Mike Weiblen 2003-10-03
 *
 * See http://www.3dlabs.com/opengl2/ for more information regarding
 * the OpenGL Shading Language.
*/


#ifndef OSGGL2_PROGRAMOBJECT
#define OSGGL2_PROGRAMOBJECT 1

#include <osg/State>
#include <osg/StateAttribute>
#include <osg/buffered_value>
#include <osg/ref_ptr>
#include <osg/Vec2>
#include <osg/Vec3>
#include <osg/Vec4>
#include <osg/Notify>

#include <osgGL2/Export>
#include <osgGL2/Extensions>
#include <osgGL2/UniformValue>

#include <string>
#include <vector>


namespace osgGL2 {

class ProgramObject;
typedef osg::ref_ptr<ProgramObject> ProgramObjectPtr;

class ShaderObject;
typedef osg::ref_ptr<ShaderObject> ShaderObjectPtr;

///////////////////////////////////////////////////////////////////////////

/** Encapsulates the OpenGL Shading Language ProgramObject */
class OSGGL2_EXPORT ProgramObject : public osg::StateAttribute
{
    public:
        ProgramObject();

        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
        ProgramObject(const ProgramObject& rhs, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);

        META_StateAttribute(osgGL2, ProgramObject, PROGRAMOBJECT);

        /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
        virtual int compare(const osg::StateAttribute& sa) const
        {
            // check the types are equal and then create the rhs variable
            // used by the COMPARE_StateAttribute_Paramter macro's below.
            COMPARE_StateAttribute_Types(ProgramObject,sa)

            // compare each parameter in turn against the rhs.
            COMPARE_StateAttribute_Parameter(_shaderObjectList);
            // COMPARE_StateAttribute_Parameter(_pcpoList);

            return 0; // passed all the above comparison macro's, must be equal.
        }

        virtual void getAssociatedModes(std::vector<GLMode>& ) const {}

	virtual void apply(osg::State& state) const;

	virtual void compile(osg::State& state) const { apply(state); }

        // data access methods.

	/** Force a relink on next apply() of associated glProgramObject. */
	void dirtyProgramObject();

	/** Force a recompile of all ShaderObjects on next apply(). */
	void dirtyShaderObjects();

	/** Set whether rendering of ProgramObject is enabled or disabled */
	void enable( bool enabled ) { _enabled = enabled; }

	/** Attach a ShaderObject to this ProgramObject */
	void addShader( ShaderObject* shadObj );

	void setUniform( const char* uniformName, int value );
	void setUniform( const char* uniformName, float value );
	void setUniform( const char* uniformName, osg::Vec2 value );
	void setUniform( const char* uniformName, osg::Vec3 value );
	void setUniform( const char* uniformName, osg::Vec4 value );

	inline void setSampler( const char* uniformName, int value )
	{
	    // emphatic alias for setUniform(int)
	    setUniform( uniformName, static_cast<int>(value) );
	}
        
        /** use deleteObject instead of glDeleteObject to allow
          * GL2 Objects to cached until they can be deleted
          * by the OpenGL context in which they were created, specified
          * by contextID.*/
        static void deleteObject(unsigned int contextID, GLhandleARB handle);

        /** flush all the cached glProgramObjects which need to be deleted
          * in the OpenGL context related to contextID.*/
        static void flushDeletedGL2Objects(unsigned int contextID,double currentTime, double& availableTime);


    protected:
	class PerContextProgObj : public osg::Referenced
	{
	    public:
		PerContextProgObj(const ProgramObject* progObj, unsigned int contextID);
		PerContextProgObj(const PerContextProgObj& rhs);

		GLhandleARB& getHandle() {return _glProgObjHandle;}

		bool isDirty() const {return _dirty;}
		void markAsDirty() {_dirty = true; }
		void build();
		void use() const;

		void updateUniforms( const UniformValueList& univalList );
		void applyUniformValues();

		void printInfoLog(osg::NotifySeverity severity) const;

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

	    protected:	/*data*/
		const ProgramObject* _progObj;
		osg::ref_ptr<Extensions> _extensions;
		GLhandleARB _glProgObjHandle;
		bool _dirty;
		UniformValueList _univalList;
		const unsigned int _contextID;
	};

    protected:	/*methods*/
        virtual ~ProgramObject();
        PerContextProgObj* getPCPO(unsigned int contextID) const;
	void updateUniforms( int frameNumber ) const;

    protected:	/*data*/
	bool _enabled;
	std::vector< ShaderObjectPtr > _shaderObjectList;
        mutable osg::buffered_value< osg::ref_ptr<PerContextProgObj> > _pcpoList;
	mutable int _frameNumberOfLastPCPOUpdate;
	mutable UniformValueList _univalList;
};

///////////////////////////////////////////////////////////////////////////

/** Encapsulates the OpenGL Shading Language ShaderObject */
class OSGGL2_EXPORT ShaderObject : public osg::Object
{
    public:

	enum Type {
	    VERTEX = GL_VERTEX_SHADER_ARB,
	    FRAGMENT = GL_FRAGMENT_SHADER_ARB,
	    UNKNOWN = -1
	};

        ShaderObject();
        ShaderObject(Type type);
        ShaderObject(Type type, const char* sourceText);

        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
        ShaderObject(const ShaderObject& rhs, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
        META_Object(osgGL2, ShaderObject);

        // data access methods.

	void setShaderSource( const char* sourceText );
	inline const std::string& getShaderSource() const {return _shaderSource; }
	bool loadShaderSourceFromFile( const char* fileName );
	inline Type getType() const { return _type; }
	const char* getTypename() const;

        /** Force a recompile on next apply() of associated glShaderObject. */
        void dirtyShaderObject();        

	void build(unsigned int contextID) const;
	void attach(unsigned int contextID, GLhandleARB progObj) const;


    protected:
	class PerContextShaderObj : public osg::Referenced
	{
	    public:
		PerContextShaderObj(const ShaderObject* shadObj, unsigned int contextID);
		PerContextShaderObj(const PerContextShaderObj& rhs);

		GLhandleARB& getHandle() {return _glShaderObjHandle;}

		bool isDirty() const {return _dirty;}
		void markAsDirty() {_dirty = true; }
		void build();

		void attach(GLhandleARB progObj) const;

		void printInfoLog(osg::NotifySeverity severity) const;

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

	    protected:	/*data*/
		const ShaderObject* _shadObj;
		osg::ref_ptr<Extensions> _extensions;
		GLhandleARB _glShaderObjHandle;
		bool _dirty;
		const unsigned int _contextID;
	};

    protected:	/*methods*/
        virtual ~ShaderObject();
        PerContextShaderObj* getPCSO(unsigned int contextID) const;

	friend void ProgramObject::addShader( ShaderObject* shadObj );	// to access addProgObjRef()
	void addProgObjRef( ProgramObject* progObj );

    protected:	/*data*/
	Type _type;
	std::string _shaderSource;
	std::vector< ProgramObjectPtr > _programObjectList;
        mutable osg::buffered_value< osg::ref_ptr<PerContextShaderObj> > _pcsoList;
};

}

#endif