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/*
* Copyright (c) 2011-2015, Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "LinearParameterAdaptation.h"
#include <cmath>
#include <limits>
/**
* This class is used to perform a logarithmic adapation of type:
* (slopeNumerator / slopeDenominator) * log(parameter) + offset
* Since log(x) == -INFINITY , we can define FloorValue as a
* x -> 0
* a lower bound limit for the adaptation
*/
class CLogarithmicParameterAdaptation : public CLinearParameterAdaptation
{
public:
CLogarithmicParameterAdaptation();
/**
* Conversions must satisfy the following: f(f'(a)) = a
* Let f=fromUserValue and f'=toUserValue
* if y = f(log(x)/log(base)), then
* f'(y) * log(base) = log (x)
* exp(f'(y)*log(base)) = x
*/
int64_t fromUserValue(double dValue) const override;
double toUserValue(int64_t iValue) const override;
void showProperties(std::string &strResult) const override;
bool fromXml(const CXmlElement &xmlElement,
CXmlSerializingContext &serializingContext) override;
private:
/**
* _dLogarithmBase characterizes the new logarithm logB(x) with
* the following property: logB(x) = log(x) / log(_dLogarithmBase).
* log being the base-e logarithm.
*
* std::exp(1) == e^1 == e == natural logarithm base
* Make sure there is no precision lose by using std::exp overload that
* return the same type as _dLogarithmBase
*/
double _dLogarithmBase{std::exp(decltype(_dLogarithmBase){1})};
/**
* _dFloorValue reflects the lower bound for volume attenuation
*/
double _dFloorValue{-std::numeric_limits<double>::infinity()};
};