/*
-----------------------------------------------------------------------------
This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2014 Torus Knot Software Ltd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
-----------------------------------------------------------------------------
*/
#ifndef __Ogre_Volume_CSGSource_H__
#define __Ogre_Volume_CSGSource_H__

#include "OgreVolumeSource.h"
#include "OgreVector.h"
#include "OgreAxisAlignedBox.h"
#include "OgreVolumePrerequisites.h"
#include "OgreVolumeSimplexNoise.h"

namespace Ogre {
namespace Volume {
    /** \addtogroup Optional
    *  @{
    */
    /** \addtogroup Volume
    *  @{
    */
    /** A sphere.
    */
    class _OgreVolumeExport CSGSphereSource : public Source
    {
    protected:
        /** The radius.
        */
        const Real mR;
        
        /** The center.
        */
        const Vector3 mCenter;
    public:
    
        /** Constructor.
        @param r
            The radius.
        @param center
            The center.
        */
        CSGSphereSource(const Real r, const Vector3 &center);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    /** A plane.
    */
    class _OgreVolumeExport CSGPlaneSource : public Source
    {
    protected:
        
        /// The distance to zero of the plane.
        const Real mD;
        
        /// The normal of the plane.
        Vector3 mNormal;

    public:
        
        /** Constructor.
        @param d
            The distance to zero of the plane.
        @param normal
            The planes normal.
        */
        CSGPlaneSource(const Real d, const Vector3 &normal);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    /** A not rotated cube.
    */
    class _OgreVolumeExport CSGCubeSource : public Source
    {
    protected:
    
        /// The six possible normals of the cube.
        static Vector3 mBoxNormals[6];
        
        /// The box.
        AxisAlignedBox mBox;

        /** Gets the distance of a point to the nearest cube element.
        @param position
            The point to test.
        @return
            The distance.
        */
        inline Real distanceTo(const Vector3 &position) const
        {
            Real distance;
            const Vector3 dMin = position - mBox.getMinimum();
            const Vector3 dMax = mBox.getMaximum() - position;

            // Check if inside of the box
            if (dMin.x >= (Real)0.0 && dMin.y >= (Real)0.0 && dMin.z >= (Real)0.0 &&
                dMax.x >= (Real)0.0 && dMax.y >= (Real)0.0 && dMax.z >= (Real)0.0)
            {
                const Real d[6] = {dMin.x, dMin.y, dMin.z, dMax.x, dMax.y, dMax.z};
                distance = Math::POS_INFINITY;
                for (size_t i = 0; i < 6; ++i)
                {
                    if (d[i] < distance)
                    {
                        distance = d[i];
                    }
                }
            }
            else
            {
                distance = -mBox.distance(position);
            }
            return distance;
        }

    public:
    
        /** Constructor.
        @param min
            The lower back left corner.
        @param max
            The upper front right corner.
        */
        CSGCubeSource(const Vector3 &min, const Vector3 &max);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    /** Abstract operation volume source holding two sources as operants.
    */
    class _OgreVolumeExport CSGOperationSource : public Source
    {
    protected:
    
        /// The first operant.
        const Source *mA;
        
        /// The second operant.
        const Source *mB;
        
        /** Constructor. Protected to be callable from child classes.
        @param a
            The first operator.
        @param b
            The second operator.
        */
        CSGOperationSource(const Source *a, const Source *b);

        /** Constructor, sets the sources to null.
        Protected to be callable from child classes.
        */
        CSGOperationSource(void);
    public:
        
        /** Gets the first operator source.
        @return
            The first operator source.
        */
        virtual const Source* getSourceA() const;
        
        /** Sets the first operator source.
        @param a
            The first operator source.
        */
        virtual void setSourceA(Source *a);

        /** Gets the second operator source.
        @return
            The second operator source.
        */
        virtual const Source* getSourceB(void) const;
        
        /** Sets the second operator source.
        @param b
            The second operator source.
        */
        virtual void setSourceB(Source *b);
    };

    /** Builds the intersection between two sources.
    */
    class _OgreVolumeExport CSGIntersectionSource : public CSGOperationSource
    {
    public:
    
        /** Constructor.
        @param a
            The first operator.
        @param b
            The second operator.
        */
        CSGIntersectionSource(const Source *a, const Source *b);

        /** Constructor, sets the sources to null.
        */
        CSGIntersectionSource(void);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    /** Builds the union between two sources.
    */
    class _OgreVolumeExport CSGUnionSource : public CSGOperationSource
    {
    public:
    
        /** Constructor.
        @param a
            The first operator.
        @param b
            The second operator.
        */
        CSGUnionSource(const Source *a, const Source *b);

        /** Constructor, sets the sources to null.
        */
        CSGUnionSource(void);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    /** Builds the difference between two sources.
    */
    class _OgreVolumeExport CSGDifferenceSource : public CSGOperationSource
    {
    public:
    
    
        /** Constructor.
        @param a
            The first operator.
        @param b
            The second operator.
        */
        CSGDifferenceSource(const Source *a, const Source *b);

        /** Constructor, sets the sources to null.
        */
        CSGDifferenceSource(void);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    /** Source which does a unary operation to another one.
    */
    class _OgreVolumeExport CSGUnarySource : public Source
    {
    protected:
    
        /// The first operant.
        const Source *mSrc;
        
        /** Constructor. Protected to be callable from child classes.
        @param src
            The operator.
        */
        CSGUnarySource(const Source *src);

        /** Constructor. Sets the source to null.
        Protected to be callable from child classes.
        */
        CSGUnarySource(void);

    public:

        /** Gets the source.
        @return
            The source.
        */
        virtual const Source* getSource(void) const;
        
        /** Sets the source.
        @param a
            The source.
        */
        virtual void setSource(Source *a);
    };

    /** Negates the given volume.
    */
    class _OgreVolumeExport CSGNegateSource : public CSGUnarySource
    {
    public:
    
        /** Constructor.
        @param src
            The source to negate.
        */
        explicit CSGNegateSource(const Source *src);
        
        /** Constructor. Sets the source to null.
        */
        CSGNegateSource(void);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    /** Scales the given volume source.
    */
    class _OgreVolumeExport CSGScaleSource : public CSGUnarySource
    {
    protected:
        
        /// Holds the dimensions of the volume.
        Real mScale;
    public:

        /** Constructor.
        @param src
            The source to scale.
        @param scale
            The scale of the source.
        */
        CSGScaleSource(const Source *src, const Real scale);
        
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
    };

    class _OgreVolumeExport CSGNoiseSource: public CSGUnarySource
    {
    protected:
        
        /// The frequencies of the octaves.
        Real *mFrequencies;

        /// The amplitudes of the octaves.
        Real *mAmplitudes;
        
        /// The amount of octaves.
        size_t mNumOctaves;
        
        /// To make some noise.
        SimplexNoise mNoise;

        /// To calculate the gradient.
        Real mGradientOff;

        /// The initial seed.
        long mSeed;

        /// Prepares the node members.
        void setData(void);

        /* Gets the density value.
        @param position
            The position of the value.
        @return
            The value.
        */
        inline Real getInternalValue(const Vector3 &position) const
        {
            Real toAdd = (Real)0.0;
            for (size_t i = 0; i < mNumOctaves; ++i)
            {
                toAdd += mNoise.noise(position.x * mFrequencies[i], position.y * mFrequencies[i], position.z * mFrequencies[i]) * mAmplitudes[i];
            }
            return mSrc->getValue(position) + toAdd;
        }

    public:
        
        /** Constructor.
        @param src
            The source to add the noise to.
        @param frequencies
            The frequencies of the added noise octaves.
        @param amplitudes
            The amplitudes of the added noise octaves.
        @param numOctaves
            The amount of octaves.
        @param seed
            The seed to initialize the random number generator with.
        */
        CSGNoiseSource(const Source *src, Real *frequencies, Real *amplitudes, size_t numOctaves, long seed);
                
        /** Constructor with current time as seed.
        @param src
            The source to add the noise to.
        @param frequencies
            The frequencies of the added noise octaves.
        @param amplitudes
            The amplitudes of the added noise octaves.
        @param numOctaves
            The amount of octaves.
        */
        CSGNoiseSource(const Source *src, Real *frequencies, Real *amplitudes, size_t numOctaves);
                
        /** Overridden from Source.
        */
        Vector4 getValueAndGradient(const Vector3 &position) const override;

        /** Overridden from Source.
        */
        Real getValue(const Vector3 &position) const override;
        
        /** Gets the initial seed.
        @return
            The initial seed.
        */
        long getSeed(void) const;
    };
    /** @} */
    /** @} */
}
}

#endif