Class BasicReverb

reverb-example-code.h:209–243

template<int channels=8, int diffusionSteps=4>
struct BasicReverb {
	using Array = std::array<double, channels>;
	
	MultiChannelMixedFeedback<channels> feedback;
	DiffuserHalfLengths<channels, diffusionSteps> diffuser;
	double dry, wet;

	BasicReverb(double roomSizeMs, double rt60, double dry=0, double wet=1) : diffuser(roomSizeMs), dry(dry), wet(wet) {
		feedback.delayMs = roomSizeMs;

		// How long does our signal take to go around the feedback loop?
		double typicalLoopMs = roomSizeMs*1.5;
		// How many times will it do that during our RT60 period?
		double loopsPerRt60 = rt60/(typicalLoopMs*0.001);
		// This tells us how many dB to reduce per loop
		double dbPerCycle = -60/loopsPerRt60;

		feedback.decayGain = std::pow(10, dbPerCycle*0.05);
	}
	
	void configure(double sampleRate) {
		feedback.configure(sampleRate);
		diffuser.configure(sampleRate);
	}
	
	Array process(Array input) {
		Array diffuse = diffuser.process(input);
		Array longLasting = feedback.process(diffuse);
		Array output;
		for (int c = 0; c < channels; ++c) {
			output[c] = dry*input[c] + wet*longLasting[c];
		}
		return output;
	}
};