[sc-dev] Dust variant

[Rohan Drape <rd@xxxxxxxxxxxxxxx>]

Hello All,

I have a what I think of as a Dust variant and am wondering if:

a) this UGen exists already,
b) it is possible to write using existing UGens, or 
c) failing that what the rules are for suggesting UGens

I mention c) because I am trying to rewrite a semi-complicated UGen as
a UGen graph and am wanting to use only 'standard' UGens.

DustR(lo,hi) generates triggers where the inter-offset times are
generated randomly in the specified range (seconds) with linear
distribution.

It is trivial but I can't see how to do this using existing UGens
(TRand & Impulse look likely but require a cycle) and it has quite
different properties to Dust (perhaps it is misnamed, R is for range,
though it pronounces well, B is for bound?).

For instance, compare:

Dust.ar(1)
DustR.ar(0,2)

Impulse.ar(1,0)*WhiteNoise.ar
DustR.ar(1,1)

Dust.ar(0.025.reciprocal)
DustR.ar(0, 0.1)

Regards,
Rohan

struct DustR : public Unit
{
        int32 mCounter;
};

void DustR_next(DustR *unit, int inNumSamples);
void DustR_Ctor(DustR *unit);

void DustR_Ctor(DustR *unit)
{	
	SETCALC(DustR_next);
	
	unit->mCounter = 0;
	DustR_next(unit, 1);
}

void DustR_next(DustR *unit, int inNumSamples)
{
	float *out = ZOUT(0);
	float iot_min = ZIN0(0);
	float iot_max = ZIN0(1);
	int32 counter = unit->mCounter;
	
	RGET
	
	LOOP(inNumSamples, 
                if (counter <= 0) {
			float z = frand(s1,s2,s3);
			ZXP(out) = z;
			z = (z * (iot_max - iot_min)) + iot_min;
			counter = (int32) (z * unit->mRate->mSampleRate);
		} else  {
			ZXP(out) = 0.f;
		}
		counter -= 1;
	);
	unit->mCounter = counter;

	RPUT
	
}

DefineSimpleUnit(DustR);

DustR : UGen {
	*ar { arg lo = 0.0, hi = 1.0, mul = 1.0, add = 0.0;
		^this.multiNew('audio', lo, hi).madd(mul, add)
	}
	*kr { arg lo = 0.0, hi = 1.0, mul = 1.0, add = 0.0;
		^this.multiNew('control', lo, hi).madd(mul, add)
	}
}