// title: Abusing Convolution2 to make pitch
// author: jamshark70
// description:
// Inspired by Formlet, which does something like formant synthesis by outputting short sinusoidal grains in response to impulses, I thought, what if we replace the sine grains with an arbitrary impulse response?
// 
// You could do that with TGrains, but as the pitch goes up, so does the number of overlapping grains and CPU use along with it. But, convolution of a chain of impulses should be the same as granular synthesis, if the grain contents are used as the convolution kernel (impulse response).
// 
// The first example does this with a buffer containing BrownNoise (shaped by a Hanning envelope). The second example adds timbre control by crossfading between three different Convolution2 results. To avoid clicks in the output when crossing buffer boundaries, I had to ensure that even-numbered buffers always go into XFade2's leftmost input and odd ones into the second input.
// 
// (Note, the second example could be made more efficient/scalable by using just two Convolution2 units, and providing a trigger to the third input whenever its calculated buffer number changes. Exercise for the reader...)
// code:
// fixed (unchanging) impulse response
// cmd-. to stop

(
s.waitForBoot {
	var c = Condition.new, cleanfunc = { CmdPeriod.remove(cleanfunc); b.free };
	fork {
		b = Buffer.alloc(s, 2048, 1);
		CmdPeriod.add(cleanfunc);
		s.sync;
		a = {
			RecordBuf.ar(BrownNoise.ar * EnvGen.ar(Env(#[0, 1, 0], #[0.5, 0.5], \sin), timeScale: b.duration, doneAction: 2), b, loop: 0);
			0
		}.play;
		OSCpathResponder(s.addr, ['/n_end', a.nodeID], { |time, resp, msg|
			resp.remove;
			c.unhang;
		}).add;
		c.hang;
		a = {
			var freq = MouseX.kr(150, 450, warp: 1, lag: 0.1);
			LeakDC.ar(Convolution2.ar(Impulse.ar(freq), b, framesize: b.numFrames) * -35.dbamp) ! 2;
		}.play;
	};
};
)



// multiple impulse responses for timbre control
(
s.waitForBoot {
	var c = Condition.new, cleanfunc = { CmdPeriod.remove(cleanfunc); b.free };
	fork {
		b = Buffer.allocConsecutive(3, s, 2048, 1);
		CmdPeriod.add(cleanfunc);
		s.sync;
		a = {
			var sig = [BrownNoise.ar, PinkNoise.ar, WhiteNoise.ar];
			sig.do { |chan, i|
				RecordBuf.ar(chan * EnvGen.ar(Env(#[0, 1, 0], #[0.5, 0.5], \sin), timeScale: b[i].duration, doneAction: 2), b[i], loop: 0);
				0
			};
		}.play;
		OSCpathResponder(s.addr, ['/n_end', a.nodeID], { |time, resp, msg|
			resp.remove;
			c.unhang;
		}).add;
		c.hang;
		a = {
			var freq = MouseX.kr(150, 450, warp: 1, lag: 0.1),
				index = MouseY.kr(0, 1.99, lag: 0.1),
				iWhole = index.trunc(2),
				iFrac = index - iWhole,
				iAdjust = iFrac >= 1.0,
				trig = Impulse.ar(freq),
				convolvers = b.collect { |buf, i|
					LeakDC.ar(Convolution2.ar(trig, buf, framesize: buf.numFrames))
				};
			(
				XFade2.ar(
					Select.ar(iWhole + (2 * iAdjust), convolvers),
					Select.ar(iWhole + 1, convolvers),
					iFrac.fold(0, 1) * 2 - 1
				) * -30.dbamp
			) ! 2;
		}.play;
	};
};
)