Additive Synthesis Actor

The Additive Synthesis Actor performs harmonic-spectrum additive synthesis. At most 30 harmonics ("partials") are computed.

To use the Additive Synthesis Actor, load add.so and create an actor of type AddActor.

AddActor messages

In addition to the messages understood by all generator actors, the AddActor understands the following messages:
SetFreq hActor x
Set the default fundamental frequency for new instances created by this actor to x Hz.
SetAllFreq hActor x time
Set the fundamental frequency of all children to x Hz, and also set the default fundamental frequency for all future children to x Hz. If time is specified, children will modulate to the new frequency over the specified duration. Default frequency is always set immediately regardless of time.
SetAmplPartials hActor array
Set the default amplitudes of the first few partials (however many are specified) for new instances created by this actor to array.
SetIthAmpl hActor i x
Set the default amplitude of the i'th partial (starting from 0 as the base partial) for new instances created by this actor to x.
SetAllIthAmpl hActor i x time
Set the amplitude of the i'th partial of all children to x, and set the default amplitude of the i'th partial for all future children. If time is specified, children will modulate to the new amplitude over the specified duration. Default amplitude is always set immediately regardless of time.
SetFDPartials hActor array
Set the default frequency deviations of the first few partials (however many are specified) for new instances created by this actor to array.
As the FD value for the i'th partial ranges from -1 to 1, the i'th partial will have a frequency ranging from that of the (i-1)'th to that of the (i+1)'th.
In other words: Frequency deviation is expressed in deviated portion of fundamental frequency with range of [-1, +1]. New partial frequency = original harmonic frequency + FD*fundamental frequency. So FD=-1 brings the partial down to the partial below it, FD=1 up.
SetIthFD hActor x
Set the default frequency deviation of the i'th partial for new instances created by this actor to x.
SetAllIthFD hActor i x time
Set the frequency deviation of the i'th partial of all children to x, and set the default amplitude of the i'th partial for all future children. If time is specified, children will modulate to the new value over the specified duration. Default value is always set immediately regardless of time.

AddActor handler messages

In addition to the messages understood by all handlers, the handler for the additive synthesis algorithm understands the following messages:
SetFreq hSound x time
Set the fundamental frequency to x Hz. If time is specified, move to the new frequency over the specified duration.
SetAmplPartials hSound array time
Set the amplitudes of the first few partials (however many are specified) to array. If time is specified, move to the new amplitudes over the specified duration.
SetIthAmpl hSound i x time
Set the i'th partial's amplitude to x. If time is specified, move to the new amplitude over the specified duration. (Note: as of this writing, overlapping SetIthAmpl messages for different partials with different times may cause unexpected results.)
SetFDPartials hSound array
Set the frequency deviations of the first few partials (however many are specified) to array.
SetIthFD hSound x
Set the frequency deviation of the i'th partial to x.
As x ranges from -1 to 1, the i'th partial will have a frequency ranging from that of the (i-1)'th to that of the (i+1)'th.
SetFreqPartials hSound array
Set the absolute frequency (in Hz) of the first few partials (however many are specified) to array. Valid range is [0, 24000].
SetIthFreq hSound x
Set the absolute frequency of the i'th partial to x.

Examples

LoadDSO add.so;
a = Create AddActor;
Play a fairly quiet pure sine wave at 200 Hz for 5 seconds:

s = BeginSound a SetFreq 200 SetAmp .1;
sleep 5;

The same, but with another louder sine wave at 1000 Hz:

SetIthAmpl a 0 .1;
SetIthAmpl a 4 .3;
s = BeginSound a SetFreq 200 SetAmp 1;
sleep 5;

Another way to get the same result:

s = BeginSoundPaused a SetFreq 200 SetAmp 1;
SetIthAmpl s 0 .1;
SetIthAmpl s 4 .3;
SetPause s 0;
sleep 5;

Yet another way to get the same result:

s = BeginSoundPaused a SetFreq 200 SetAmp 1;
SetAmplPartials s [.1 0 0 0 .3];
SetPause s 0;
sleep 5;

This time, fade out the 200 Hz sine wave and fade in a 400 Hz one:

s = BeginSoundPaused a SetFreq 200 SetAmp 1;
SetAmplPartials s [.1 0 0 0 .3];
SetPause s 0;
SetAmplPartials s [0 .1 0 0 .3] 5;
sleep 5;

How to play an arbitrary collection of frequencies:

s = BeginSoundPaused a SetFreq 200 SetAmp 1;
SetAmplPartials s [.3 .1 .4 .1 .5 .9 ];
SetFreqPartials s [200 700 100 800 200 800];
SetPause s 0;
sleep 5;