AudioKit - AKOperationGenerator with AKParameters - CPU Issue - ios

Question

I need help with sending AKParameters to the AKOperationGenerator. My current solution use a lot of CPU. Is there a better way how to do it?
Here is my example code:
import AudioKit
class SynthVoice: AKNode {
override init() {
let synth = AKOperationGenerator { p in
//(1) - 30% CPU
let osc: AKOperation = AKOperation.squareWave(frequency: p[0], amplitude: p[1], pulseWidth: p[2])
//(2) - 9% CPU
//let osc: AKOperation = AKOperation.squareWave(frequency: 440, amplitude: 1, pulseWidth: 0.5)
return osc
}
synth.parameters[0] = 880
synth.parameters[1] = 1
synth.parameters[2] = 0.5
super.init()
self.avAudioNode = synth.avAudioNode
synth.start()
}
}
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let mixer: AKMixer = AKMixer([SynthVoice(), SynthVoice(), SynthVoice(), SynthVoice(), SynthVoice(), SynthVoice()])
AudioKit.output = mixer
AudioKit.start()
}
}
I need 6 voice osc bank with envelope filter for each voice. I did not find any OSC-bank with envelope filter in AudioKit, so I started to write my own via AKOperationGenerator... But the CPU is too high. (About 100% in my project - 6 AKOperationGenerator with PWM square osc and envelope filter and a lot of AKParameters that can be changed via UI)
Thanks for any response.

Answer 1

I'd definitely do this at the DSP Kernel level. Its C/C++ but its really not too bad. Use one of the AKOscillatorBank type nodes as your model, but in addition to having an amplitude envelope, put in a filter envelope the same way. We're releasing an open source synth that does this exact thing in a few months if you can wait.