PV_SoftWipe		combine low and high bins from two inputs with interpolation

PV_SoftWipe.ar(bufferA,  bufferB, wipe)

Copies low bins from one input and the high bins of the other.  Interpolates.
bufferA - fft buffer A.
bufferB - fft buffer B.
wipe - can range between -1 and +1.
if wipe == 0 then the output is the same as inA.
if  wipe > 0 then it begins replacing with bins from inB from the bottom up. 
if  wipe < 0 then it begins replacing with bins from inB from the top down.

s.boot;
(
b = Buffer.alloc(s,2048,1);
c = Buffer.alloc(s,2048,1);
d = Buffer.read(s,"sounds/a11wlk01.wav");
)

(
SynthDef("help-SoftWipe", { arg out=0,bufnumA=0, bufnumB=1;
	var inA, chainA, inB, chainB, chain;
	inA = WhiteNoise.ar(0.2);
	inB = LFSaw.ar(100, 0, 0.2);
	chainA = FFT(bufnumA, inA);
	chainB = FFT(bufnumB, inB);
	chain = PV_SoftWipe(chainA, chainB, MouseX.kr(-1, 1)); 
	Out.ar(out, 0.5 * IFFT(chain).dup);
}).play(s,[\out, 0, \bufnumA, b.bufnum, \bufnumB, c.bufnum ]);
)

(
SynthDef("help-SoftWipe2", { arg out=0,bufnumA=0, bufnumB=1, soundBufnum=2;
	var inA, chainA, inB, chainB, chain;
	inA = WhiteNoise.ar(0.2);
	inB = PlayBuf.ar(1, soundBufnum, BufRateScale.kr(soundBufnum), loop: 1);
	chainA = FFT(bufnumA, inA);
	chainB = FFT(bufnumB, inB);
	chain = PV_SoftWipe(chainA, chainB, LFCub.kr(0.05)); 
	Out.ar(out, 0.5 * IFFT(chain).dup);
}).play(s,[\out, 0, \bufnumA, b.bufnum, \bufnumB, c.bufnum, \soundBufnum, d.bufnum]);
)