Re: [sc-users] BooleanUGens (was Re: conditional statement in SynthDef)

[Scott Wilson <sdwilson@xxxxxxxxxxxx>]

On 5 Sep 2005, at 21:22, James Harkins wrote:

> On Sep 5, 2005, at 1:04 PM, Joshua Parmenter wrote:
>
> > I first tried to add ==, but a recompile of the library threw all sorts of errors.  It seemed to me that, at least on a first look , adding == as a UGen would break code.  I really didn't spend much time trying different approaches. It seemed like it would be very simple to code in C, so IsEqual made sense to me.
>
> Here is the problem. There may be an alternate way to handle it, but it could be risky.
>
> Maybe a.asFloat === 0.0 etc.? But that would create and throw out a bunch of objects for UGens. Maybe have testA = a.asFloat; testB = b.asFloat;
>
> Dunno, maybe it's not worth it. Since BinaryOpUGen already supports == and != I think it could just be documented how to write the BinaryOpUGen yourself. Or implement IsEqual in terms of BinaryOpUGen. I don't think we need to lard it up with more plugins for things already included in the plugin lib.
>
> hjh
>
> <x-tad-smaller>		if (selector == </x-tad-smaller><x-tad-smaller>'*'</x-tad-smaller><x-tad-smaller>, {
> if (a == 0.0, { ^0.0 });
> if (b == 0.0, { ^0.0 });
> if (a == 1.0, { ^b });
> if (a == -1.0, { ^b.neg });
> if (b == 1.0, { ^a });
> if (b == -1.0, { ^a.neg });
> },{
> if (selector == </x-tad-smaller><x-tad-smaller>'+'</x-tad-smaller><x-tad-smaller>, {
> if (a == 0.0, { ^b });
> if (b == 0.0, { ^a });
> },{
> if (selector == </x-tad-smaller><x-tad-smaller>'-'</x-tad-smaller><x-tad-smaller>, {
> if (a == 0.0, { ^b.neg });
> if (b == 0.0, { ^a });
> },{
> if (selector == </x-tad-smaller><x-tad-smaller>'/'</x-tad-smaller><x-tad-smaller>, {
> if (b == 1.0, { ^a });
> if (b == -1.0, { ^a.neg });
> if (b.rate == </x-tad-smaller><x-tad-smaller>'scalar'</x-tad-smaller><x-tad-smaller>, { ^a * b.reciprocal });
> })})})});
> </x-tad-smaller>
If I understand these correctly, these tests will always prove false if a or b (as applicable) are UGens, and for UGens == and === are the same. So I think that they could be safely changed to === without the need to create extra objects, call asFloat, etc. On my machine === between Floats seems to bench slightly faster on average than == anyway.

nes pas?

S.