Re: input error(?) on plugin

On Aug 22, 2004, at 12:04 PM, adam overton wrote:

> hello there.
>
> i think i might be going crazy...
>
> so below is a super tiny plugin that just prints out the input samples 
> that it's given to the message window. i'm just giving the Ugen a 
> static input value of 0.0, yet it reports a value of 8.0000000 on the 
> 5th sample and the 17th sample ... for every block...

If the input is a scalar there will be only one value at the input, 
there will be no 5th sample or 17th sample. You're lucky you didn't 
just crash.

> // A Ctor usually does 3 things.
> // 1. set the calculation function.
> // 2. initialize the unit generator state variables.
> // 3. calculate one sample of output.
> void TestInput_Ctor(TestInput* unit)
> {
>
>         // 1. set the calculation function.
>         SETCALC(TestInput_next);

You need to have a separate calculation function for whether the input 
is a buffer (audio rate) or a scalar (control rate, scalar rate).
Look to see how other ugens test the input rates and select a 
calculation function this. For example:
        if (unit->mCalcRate == calc_FullRate && INRATE(0) != calc_FullRate) {
                SETCALC(Trig_next_k);
        } else {
                SETCALC(Trig_next);
        }


Or alternately you can implement a checkInputs method in your SC class 
to disallow scalar inputs if the ugen is audio rate. For example:

        checkInputs {
                if (rate == 'audio' and: {inputs.at(1).rate != 'audio'}, {
 			^("phase input is not audio rate: " + inputs.at(1) + 
inputs.at(1).rate);
                });
                ^nil
        }



--
--- james mccartney   james-M9HdPQXNfxq9Zq0HfjR8jw@xxxxxxxxxxxxxxxx   
<http://www.audiosynth.com>
SuperCollider - a real time audio synthesis programming language