97b7130bb9
we switched to GPLv3 a long time ago, but neglected to update the per-file license headers
112 lines
4.4 KiB
C++
112 lines
4.4 KiB
C++
// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
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/*
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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//
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/// @file AverageFilter.h
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/// @brief A class to provide the average of a number of samples
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#ifndef __AVERAGE_FILTER_H__
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#define __AVERAGE_FILTER_H__
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#include "FilterClass.h"
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#include "FilterWithBuffer.h"
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// 1st parameter <T> is the type of data being filtered.
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// 2nd parameter <U> is a larger data type used during summation to prevent overflows
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// 3rd parameter <FILTER_SIZE> is the number of elements in the filter
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template <class T, class U, uint8_t FILTER_SIZE>
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class AverageFilter : public FilterWithBuffer<T,FILTER_SIZE>
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{
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public:
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// constructor
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AverageFilter() : FilterWithBuffer<T,FILTER_SIZE>(), _num_samples(0) {
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};
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// apply - Add a new raw value to the filter, retrieve the filtered result
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virtual T apply(T sample);
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// reset - clear the filter
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virtual void reset();
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private:
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uint8_t _num_samples; // the number of samples in the filter, maxes out at size of the filter
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};
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// Typedef for convenience (1st argument is the data type, 2nd is a larger datatype to handle overflows, 3rd is buffer size)
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typedef AverageFilter<int8_t,int16_t,2> AverageFilterInt8_Size2;
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typedef AverageFilter<int8_t,int16_t,3> AverageFilterInt8_Size3;
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typedef AverageFilter<int8_t,int16_t,4> AverageFilterInt8_Size4;
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typedef AverageFilter<int8_t,int16_t,5> AverageFilterInt8_Size5;
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typedef AverageFilter<uint8_t,uint16_t,2> AverageFilterUInt8_Size2;
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typedef AverageFilter<uint8_t,uint16_t,3> AverageFilterUInt8_Size3;
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typedef AverageFilter<uint8_t,uint16_t,4> AverageFilterUInt8_Size4;
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typedef AverageFilter<uint8_t,uint16_t,5> AverageFilterUInt8_Size5;
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typedef AverageFilter<int16_t,int32_t,2> AverageFilterInt16_Size2;
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typedef AverageFilter<int16_t,int32_t,3> AverageFilterInt16_Size3;
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typedef AverageFilter<int16_t,int32_t,4> AverageFilterInt16_Size4;
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typedef AverageFilter<int16_t,int32_t,5> AverageFilterInt16_Size5;
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typedef AverageFilter<uint16_t,uint32_t,2> AverageFilterUInt16_Size2;
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typedef AverageFilter<uint16_t,uint32_t,3> AverageFilterUInt16_Size3;
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typedef AverageFilter<uint16_t,uint32_t,4> AverageFilterUInt16_Size4;
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typedef AverageFilter<uint16_t,uint32_t,5> AverageFilterUInt16_Size5;
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typedef AverageFilter<int32_t,float,2> AverageFilterInt32_Size2;
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typedef AverageFilter<int32_t,float,3> AverageFilterInt32_Size3;
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typedef AverageFilter<int32_t,float,4> AverageFilterInt32_Size4;
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typedef AverageFilter<int32_t,float,5> AverageFilterInt32_Size5;
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typedef AverageFilter<uint32_t,float,2> AverageFilterUInt32_Size2;
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typedef AverageFilter<uint32_t,float,3> AverageFilterUInt32_Size3;
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typedef AverageFilter<uint32_t,float,4> AverageFilterUInt32_Size4;
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typedef AverageFilter<uint32_t,float,5> AverageFilterUInt32_Size5;
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typedef AverageFilter<float,float,5> AverageFilterFloat_Size5;
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// Public Methods //////////////////////////////////////////////////////////////
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template <class T, class U, uint8_t FILTER_SIZE>
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T AverageFilter<T,U,FILTER_SIZE>:: apply(T sample)
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{
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U result = 0;
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// call parent's apply function to get the sample into the array
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FilterWithBuffer<T,FILTER_SIZE>::apply(sample);
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// increment the number of samples so far
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_num_samples++;
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if( _num_samples > FILTER_SIZE || _num_samples == 0 )
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_num_samples = FILTER_SIZE;
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// get sum of all values - there is a risk of overflow here that we ignore
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for(uint8_t i=0; i<FILTER_SIZE; i++)
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result += FilterWithBuffer<T,FILTER_SIZE>::samples[i];
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return (T)(result / _num_samples);
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}
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// reset - clear all samples
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template <class T, class U, uint8_t FILTER_SIZE>
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void AverageFilter<T,U,FILTER_SIZE>:: reset()
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{
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// call parent's apply function to get the sample into the array
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FilterWithBuffer<T,FILTER_SIZE>::reset();
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// clear our variable
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_num_samples = 0;
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}
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#endif // __AVERAGE_FILTER_H__
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