FrequencyDetector.h

#pragma once

#include "ofUtils.h"

class SimpleFrequencyDetector : public vector<float>
{
public:
	SimpleFrequencyDetector():buffer_size_(0) {
		timestamp_ = ofGetElapsedTimef();
	}
	void setBufferSize(int max) {
		if(max > 0) {
			reserve(max);
		}
		buffer_size_ = max;
	}
	void mark() {
		float prev = timestamp_;
		timestamp_ = ofGetElapsedTimef();
		while(buffer_size_ > 0 && size() >= buffer_size_) {
			erase(begin());
		}
		push_back(timestamp_-prev);
	}
	float getFrequency(float duration) {
		int count = 0;
		float marked = 0;
		for(reverse_iterator it = rbegin(); it != rend(); ++it) {
			marked += *it;
			++count;
			if(marked > duration) {
				break;
			}
		}
		if(marked == 0) {
			return 0;
		}
		return count/marked;
	}
private:
	int buffer_size_;
	float timestamp_;
};