A Phase Accumulator / Sine wave generator in Faust

phase_accumulator.dsp

import("math.lib");
Tau = 6.283185307179586;
Pi  = 3.141592653589793;
Fs  = SR;


oscillator(f, amplitude) = phase_accumulator(w) : sinf * amplitude with {
	w = f / Fs * Tau;
	sinf = ffunction(float sinf(float), <math.h>, "");
};


phase_accumulator(w) = (accumulator(w) ~ _) - w with {
	accumulator(w, phase) = output with {
		if = (w + phase) >= Tau;
		reset = w + phase - Tau;
		add = w + phase;
		output = (if,add,reset) : select2;
	};
};


process = oscillator(440, 0.7) , oscillator(440, 0.7) ;