Adding Effects

This help file is based on a file found in the SuperDirt GitHub repository. Report to the original version to get more information or add your improved workflow to this page to help other users. Adding new effects for Tidal and SuperDirt is a three-step process:

1. add the desired parameters to Tidal
2. add a module definition to SuperDirt, so it can be found when the parameter is not nil
3. add the SynthDef to SuperDirt, so it can be played

Adding a spectral delay

We are going to add a weird spectral delay to SuperDirt. This assumes that you have an instance of SuperDirt accessible via ~dirt in the SuperCollider interactive editor.

Tidal Side

We are going to add two parameters: tsdelay (float, delay time) and xsdelay (int, delay structure). Run the following Tidal Code (as if it was a tidal pattern):

let tsdelay = pF "tsdelay"
    xsdelay = pI "xsdelay"

If you want this the above be automatically available every time you start tidal, then add it to the definitions in your BootTidal.hs boot file.

SuperCollider Side

Add a module for SuperDirt. This adds a responder for the parameters.

(
~dirt.addModule('spectral-delay', { |dirtEvent|
    dirtEvent.sendSynth('spectral-delay' ++ ~dirt.numChannels,
        // OPTIONAL
        // passing this array of parameters could be left out,
        // but it makes it clear what happens
        [
            xsdelay: ~xsdelay,
            tsdelay: ~tsdelay,
            sustain: ~sustain,
            out: ~out
        ]
    )
}, { ~tsdelay.notNil or: { ~xsdelay.notNil } }); // play synth only if at least one of the two was given
)

You can previsualise the effect order using this command in SuperCollider:

~dirt.modules;

You can reorder the effects if you need to. For instance, if you want the low pass filter to come after the delay, run the following line:

~dirt.orderModules(['spectral-delay', 'hpf', 'klm']);

Make a SynthDef

The last step is to declare our spectral delay itself, that will be declared in a classic SuperCollider SynthDef:

(

var numChannels =  ~dirt.numChannels;

SynthDef("spectral-delay" ++ numChannels, { |out, tsdelay, xsdelay = 1, sustain|

    var signal, delayTime, delays, freqs, filtered;
    var size = 16;
    var maxDelayTime = 0.2;

    signal = In.ar(out, numChannels);
    delayTime = tsdelay * maxDelayTime;
    filtered = (1..size).sum { |i|
        var filterFreq = i.linexp(1, size, 40, 17000);
        var sig = BPF.ar(signal, filterFreq, 0.005);
        // the delay pattern is determined from xsdelay by bitwise-and:
        DelayN.ar(sig, maxDelayTime, i & xsdelay * (1/size) * delayTime )
    };
    signal = signal * 0.2 + (filtered * 4); // this controls wet/dry
    ReplaceOut.ar(out, signal)

}).add;
)

Final result

Now you should be able to write the following in Tidal:

d1 $ sound "can*4" # tsdelay "0 0.25 0.5 0.75 1" # xsdelay "3 124 3 12 62 2"