/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
// Original file Copyright Crytek GMBH or its affiliates, used under license.

#ifndef CRYINCLUDE_TOOLS_SPHERICALHARMONICS_PRT_ISAMPLEGENERATOR_H
#define CRYINCLUDE_TOOLS_SPHERICALHARMONICS_PRT_ISAMPLEGENERATOR_H
#pragma once

#include <PRT/PRTTypes.h>
#include "BasicUtils.h"


namespace NSH
{
    namespace NSampleGen
    {
        typedef std::vector<TVec2D, CSHAllocator<TVec2D> >  TRandomSampleVec;           //!< sample vector for random x,y coordinates

        /************************************************************************************************************************************************/

        //!< unit sphere sample generation policy
        struct ISampleGenPolicy
        {
            virtual void GenerateSamples(TRandomSampleVec& rSamples, const uint32 cMaxSamples) = 0; //!< sample generation
            //!< resets organizer, default impl sufficient
            virtual void Reset(){};
        };

        /************************************************************************************************************************************************/

        struct ISampleOrganizer
        {
            //!< converts NOT NORMALIZED random samples into SH sample and reorganizes all samples, returns number of successfully generated samples
            virtual const uint32 ConvertIntoSHAndReOrganize
            (
                const TVec2D* cpRandomSamples,
                const uint32 cRandomSampleCount,
                const SDescriptor& rSHDescriptor
            ) = 0;
            //!< retrieves all samples
            virtual void GetSamples(TScalarVecVec&) const = 0;
            //!< returns a reference to a sample from a handle
            virtual const CSample_tpl<SCoeffList_tpl<TScalarCoeff> >& GetSample(const TSampleHandle& crHandle) const = 0;
            //!< resets organizer
            virtual void Reset() = 0;
            //!< returns max capacity of samples according to sample handle type
            virtual const uint32 Capacity() = 0;
            //!< returns min capacity of samples according to sample handle type
            virtual const uint32 MinCapacity() = 0;
        };

        /************************************************************************************************************************************************/

        //!< unit sphere sample generator interface
        struct ISampleGenerator
        {
            //!< generates cSampleCount SH samples according to sample distribution policy
            //!< reorganizes the vector of SH samples into bins to be able to only work only on a certain hemisphere(defined through vertex normal later on)
            virtual void GenerateSamples(const uint32 cSampleCount) = 0;
            virtual void GenerateSamples(const uint32 cSampleCount, const SDescriptor& crNewDescriptor) = 0;
            //!< retrieves the number of constructed samples
            virtual const uint32 Size() const = 0;
            //!< retrieves the number of ordered constructed samples
            virtual const uint32 OrderedSize() const = 0;
            //!< retrieves all samples
            virtual void GetSamples(TScalarVecVec&) const = 0;
            //!< returns the descritpor the sample generator is built with
            virtual const SDescriptor& SHDescriptor() const = 0;
            //!< virtual destructor
            virtual ~ISampleGenerator() {}
            //!< resets and restarts sample generator
            virtual void Restart(const uint32 cSampleCount, const SDescriptor& crDescriptor) = 0;
            //!< returns a reference to a sample from a handle
            virtual const CSample_tpl<SCoeffList_tpl<TScalarCoeff> >& ReturnSampleFromHandle(const TSampleHandle& crHandle) const = 0;
        };
    }
}
#endif // CRYINCLUDE_TOOLS_SPHERICALHARMONICS_PRT_ISAMPLEGENERATOR_H