/*
* 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.

#pragma once

#include "FIR-Windows.h"

namespace ImageProcessing
{
    /* ####################################################################################################################
     */
    template<class DataType>
    static inline DataType abs    (const DataType& ths) { return (ths < 0 ? -ths : ths); }
    template<class DataType>
    static inline void     minmax (const DataType& ths, DataType& mn, DataType& mx) { mn = (mn > ths ? ths : mn); mx = (mx < ths ? ths : mx); }
    template<class DataType>
    static inline DataType minimum(const DataType& ths, const DataType& tht) { return (ths < tht ? ths : tht); }
    template<class DataType>
    static inline DataType maximum(const DataType& ths, const DataType& tht) { return (ths > tht ? ths : tht); }

    /* ####################################################################################################################
     */

    template<class T>
    class FilterWeights
    {
    public:
        FilterWeights()
            : weights(nullptr)
        {
        }

        ~FilterWeights()
        {
            delete[] weights;
        }

    public:
        // window-position
        int first, last;

        // do we encounter positive as well as negative weights
        bool hasNegativeWeights;

        /* weights, summing up to -(1 << 15),
         * means weights are given negative
         * that enables us to use signed short
         * multiplication while occupying 0x8000
         */
        T* weights;
    };

    /* ####################################################################################################################
     */

    void               calculateFilterRange (unsigned int srcFactor, int& srcFirst, int& srcLast,
        unsigned int dstFactor, int  dstFirst, int  dstLast,
        double blurFactor, class IWindowFunction<double>* windowFunction);

    template<typename T>
    FilterWeights<T>* calculateFilterWeights(unsigned int srcFactor, int  srcFirst, int  srcLast,
        unsigned int dstFactor, int  dstFirst, int  dstLast, signed short int numRepetitions,
        double blurFactor, class IWindowFunction<double>* windowFunction,
            bool peaknorm, bool& plusminus);
    
    template<>
    FilterWeights<signed short int>* calculateFilterWeights<signed short int>(unsigned int srcFactor, int srcFirst, int srcLast,
        unsigned int dstFactor, int dstFirst, int dstLast, signed short int numRepetitions,
        double blurFactor, class IWindowFunction<double>* windowFunction,
        bool peaknorm, bool& plusminus);


} //end namespace ImageProcessing