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gamma.h
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/******************************************************************************
The MIT License(MIT)
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
Copyright(c) 2021 John Wellbelove
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 ETL_GAMMA_INCLUDED
#define ETL_GAMMA_INCLUDED
#include "platform.h"
#include "functional.h"
#include "type_traits.h"
#include <math.h>
namespace etl
{
//***************************************************************************
//***************************************************************************
template <typename TInput>
class gamma_encode : public etl::unary_function<TInput, TInput>
{
public:
//*********************************
//*********************************
gamma_encode(double gamma_, TInput maximum_)
: one_over_gamma(1.0 / gamma_)
, maximum(maximum_)
{
}
//*********************************
//*********************************
TInput operator()(TInput value) const
{
// Calculate intermediate result because rounding + optimization
// lead to wrong values when returning directly (test on i386)
const double result = maximum * pow(double(value) / maximum, one_over_gamma);
return TInput(result);
}
private:
const double one_over_gamma;
const double maximum;
};
//***************************************************************************
//***************************************************************************
template <typename TInput>
class gamma_decode : public etl::unary_function<TInput, TInput>
{
public:
//*********************************
//*********************************
gamma_decode(double gamma_, TInput maximum_)
: gamma(gamma_)
, maximum(maximum_)
{
}
//*********************************
//*********************************
TInput operator()(TInput value) const
{
// Calculate intermediate result because rounding + optimization
// lead to wrong values when returning directly (test on i386)
const double result = maximum * pow(double(value) / maximum, gamma);
return TInput(result);
}
private:
const double gamma;
const double maximum;
};
} // namespace etl
#endif
etl::gamma_decode::gamma_decode
gamma_decode(double gamma_, TInput maximum_)
Constructor.
Definition gamma.h:89
etl::gamma_decode::operator()
TInput operator()(TInput value) const
Definition gamma.h:99
etl::gamma_encode::operator()
TInput operator()(TInput value) const
Definition gamma.h:63
etl::gamma_encode::gamma_encode
gamma_encode(double gamma_, TInput maximum_)
Constructor.
Definition gamma.h:53
functional.h
math.h
etl
Definition absolute.h:40
platform.h
etl::unary_function
unary_function
Definition functional.h:182
type_traits.h