view Source/Utility/Accumulator.h @ 20:dfff66c07936

Lots of minor changes to support building on Visual Studio. A few MSVC-specific #ifdefs to eliminate things Visual Studio doesn't like. This version now compiles on Windows (provided liblo, Juce and pthread are present) but the TouchKeys device support is not yet enabled. Also, the code now needs to be re-checked on Mac and Linux.

/*
  TouchKeys: multi-touch musical keyboard control software
  Copyright (c) 2013 Andrew McPherson

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
 
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
  =====================================================================

  Accumulator.h: template class that accumulates (adds) samples coming into
  a given Node.
*/

#ifndef KEYCONTROL_ACCUMULATOR_H
#define KEYCONTROL_ACCUMULATOR_H

#include <iostream>
#include <exception>
#include "Node.h"

/*
 * Accumulator
 *
 * Calculate the running sum of the last N points of a signal.  Unlike Integral, it does not
 * take into account the timestamps, and so is signficantly faster but less flexible.
 *
 * The output type of this class is a pair, the first of which indicates how many samples are
 * included in the accumulated result, and the second of which is the result itself.  This handles
 * transient startup conditions where all N samples are not yet available.
 *
 */

template<typename DataType, int N>
class Accumulator : public Node<std::pair<int, DataType> > {
public:
	typedef typename std::pair<int, DataType> return_type;
	typedef typename Node<return_type>::capacity_type capacity_type;
	//typedef typename Node<return_type>::size_type size_type;
	
	// ***** Constructors *****
		
	Accumulator(capacity_type capacity, Node<DataType>& input) : Node<return_type>(capacity), input_(input), samples_(N+1) {
		if(capacity <= N)			// Need to have at least N points in history to accumulate
			throw new std::bad_alloc();
		//std::cout << "Registering Accumulator\n";
		this->registerForTrigger(&input_);
		//std::cout << "Accumulator: this_source = " << (TriggerSource*)this << "this_dest = " << (TriggerDestination*)this << " input_ = " << &input_ << std::endl;
	}
				
	// Copy constructor
	Accumulator(Accumulator<DataType,N> const& obj) : Node<return_type>(obj), input_(obj.input_), samples_(obj.samples_) {
		this->registerForTrigger(&input_);
	}
	
	// ***** Modifiers *****
	//
	// Override this method to clear the samples_ buffer
	
	void clear() {
		Node<std::pair<int, DataType> >::clear();
		samples_.clear();
	}
	
	// ***** Evaluator *****
	//
	// This is called when the input gets a new data point.  Accumulate its value and store it in our buffer.
	// Storing it will also cause a trigger to be sent to anyone who's listening.
	
	void triggerReceived(TriggerSource* who, timestamp_type timestamp) {
		//std::cout << "Accumulator::triggerReceived\n";
		
		if(who != &input_)
			return;
		
		//std::cout << "Accumulator::triggerReceived2\n";		
		
		DataType newSample = input_.latest();
		samples_.push_back(newSample);		
		
		if(this->empty()) {
			this->insert(return_type(1, newSample), timestamp);
		}
		else {
			// Get the last point (both sample count and its accumulated value)
			return_type previousAccum = this->latest();
			
			// Add the current sample
			DataType accumulatedValue = newSample + previousAccum.second;
			int numPoints = previousAccum.first;
			
			// If necessary, subtract off the oldest sample, which by the size of samples_
			// is guaranteed to be its first point.
			if(samples_.full())
				accumulatedValue -= samples_.front();
			else
				numPoints++;
			
			this->insert(return_type(numPoints, accumulatedValue), timestamp);
		}
	}
	
	// Reset the integral to a given value at a given sample.  All samples
	// after this one are marked "missing" to force a recalculation of the integral next time
	// the value is requested.

	/*void reset(size_type index) {
		if(index < this->beginIndex() || index >= this->endIndex())
			return;
		this->rawValueAt(index) = std::pair<int, DataType>(0,DataType());
		size_type i = index + 1;
		while(i < this->endIndex())
			this->rawValueAt(index) = missing_value<std::pair<int, DataType> >::missing();
	}*/
	
private:
	Node<DataType>& input_;
	
	// Buffer holding the individual samples.  We need to be able to drop the last sample out of the
	// accumulated buffer, and including our own sample buffer means we don't need to rely on the
	// length of the input to store old samples.
	boost::circular_buffer<DataType> samples_;
};


#endif /* KEYCONTROL_ACCUMULATOR_H */