#pragma once

#include <cstdint>

class DDS {
    private:
        uint32_t phase = 0;
    public:
        uint32_t ftw = 0;
        void set_frequency(double f) {
            ftw = f*(double)UINT32_MAX;
        }
        double get() {
            phase += ftw;  // wraps on overflow
            return sin(phase*2.0*M_PI/(double)UINT32_MAX);
        }
};

template<typename T, unsigned int N>
class Lowpass {
    private:
        double k = 0.0;
        T s[N] = {};
    public:
        void set_bandwidth(double f) {
            k = 2.0*M_PI*f;
        }
        T update(T x) {
            T a = x;
            for(int i=0;i<N;i++) {
                s[i] += (a - s[i])*k;
                a = s[i];
            }
            return a;
        }
};