/* -*-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_MULTISAMPLE
#define OSG_MULTISAMPLE 1


#include <osg/GL>
#include <osg/StateAttribute>
#include <osg/ref_ptr>


#ifndef GL_ARB_multisample
#define GL_MULTISAMPLE_ARB                0x809D
#define GL_SAMPLE_ALPHA_TO_COVERAGE_ARB   0x809E
#define GL_SAMPLE_ALPHA_TO_ONE_ARB        0x809F
#define GL_SAMPLE_COVERAGE_ARB            0x80A0
#define GL_SAMPLE_BUFFERS_ARB             0x80A8
#define GL_SAMPLES_ARB                    0x80A9
#define GL_SAMPLE_COVERAGE_VALUE_ARB      0x80AA
#define GL_SAMPLE_COVERAGE_INVERT_ARB     0x80AB
#define GL_MULTISAMPLE_BIT_ARB            0x20000000
#endif
#ifndef GL_NV_multisample_filter_hint
#define GL_MULTISAMPLE_FILTER_HINT_NV     0x8534
#endif


namespace osg {

/** Multisample - encapsulates the OpenGL Multisample state.*/
class OSG_EXPORT Multisample : public StateAttribute
{
    public :

        enum Mode
        {
            FASTEST = GL_FASTEST,
            NICEST = GL_NICEST,
            DONT_CARE = GL_DONT_CARE
        };

        Multisample();

        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
        Multisample(const Multisample& trans,const CopyOp& copyop=CopyOp::SHALLOW_COPY):
            StateAttribute(trans,copyop),
            _coverage(trans._coverage),
            _invert(trans._invert),
            _mode(trans._mode) {}

        META_StateAttribute(osg, Multisample,MULTISAMPLE);

        /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
        virtual int compare(const StateAttribute& sa) const
        {
            // check the types are equal and then create the rhs variable
            // used by the COMPARE_StateAttribute_Parameter macros below.
            COMPARE_StateAttribute_Types(Multisample,sa)

            // compare each parameter in turn against the rhs.
            COMPARE_StateAttribute_Parameter(_coverage)
            COMPARE_StateAttribute_Parameter(_invert)
            COMPARE_StateAttribute_Parameter(_mode)

            return 0; // passed all the above comparison macros, must be equal.
        }

        void setSampleCoverage(float coverage, bool invert)
        {
            _coverage = coverage;
            _invert = invert;
        }
        inline void setCoverage(float coverage) { _coverage=coverage; }
        inline float getCoverage() const { return _coverage; }

        inline void setInvert(bool invert) { _invert=invert; }
        inline bool getInvert() const { return _invert; }

        inline void setHint(Mode mode) { _mode = mode; }
        inline Mode getHint() const { return _mode; }

        virtual void apply(State& state) const;

    protected :

        virtual ~Multisample();

        float _coverage;
        bool _invert;
        Mode _mode;
};

}

#endif