#ifndef OSG_TRANSPARENCY
#define OSG_TRANSPARENCY 1

#include <osg/StateAttribute>
#include <osg/StateSet>

namespace osg {

/** Transparancy - encapsulates the OpenGL transparancy state.*/
class SG_EXPORT Transparency : public StateAttribute
{
    public :

        Transparency();
        virtual Object* clone() const { return new Transparency(); }
        virtual bool isSameKindAs(const Object* obj) const { return dynamic_cast<const Transparency*>(obj)!=0L; }
        virtual const char* className() const { return "Transparency"; }

        virtual const Type getType() const { return TRANSPARENCY; }
        
        virtual void setStateSetModes(StateSet& ds,const GLModeValue value) const
        {
            ds.setMode(GL_BLEND,value);
        }

        enum TransparencyMode {
            DST_ALPHA            = GL_DST_ALPHA,
            DST_COLOR            = GL_DST_COLOR,
            ONE                  = GL_ONE,
            ONE_MINUS_DST_ALPHA  = GL_ONE_MINUS_DST_ALPHA,
            ONE_MINUS_DST_COLOR  = GL_ONE_MINUS_DST_COLOR,
            ONE_MINUS_SRC_ALPHA  = GL_ONE_MINUS_SRC_ALPHA,
            ONE_MINUS_SRC_COLOR  = GL_ONE_MINUS_SRC_COLOR,
            SRC_ALPHA            = GL_SRC_ALPHA,
            SRC_ALPHA_SATURATE   = GL_SRC_ALPHA_SATURATE,
            SRC_COLOR            = GL_SRC_COLOR,
            ZERO                 = GL_ZERO
        };

        inline void setFunction( const int source, const int destination )
        {
            _source_factor = source;
            _destination_factor = destination;
        }

        void setSource(const int source) { _source_factor = source; }
        inline const int getSource() const { return _source_factor; }
        
        void setDestination(const int destination) { _destination_factor = destination; }
        inline const int getDestination() const { return _destination_factor; }

        virtual void apply(State& state) const;

    protected :

        virtual ~Transparency();

        int _source_factor;
        int _destination_factor;
};

};

#endif