There is ome thing that I don't understand here: wouldn't implementing a custom square wave generator as an AudioWorkletProcessor be a more straightforward approach in this case?
I think long term I will be moving in that direction. For this initial exploration and experimentation I've been doing with the Web Audio API, the sawtooth oscillator + step function waveshaper node have been sufficient for my use case but I will need investigate whether I can produce a more authentic sound with an AudioWorkletProcessor approach
I did a little synth project recently that uses an AudioWorklet processor to morph between single-cycle waveforms, and it worked super well. When I tried to do this with the Web Audio API, the audio would stutter when I moved the controls. Switching to an AudioWorklet thread eliminated the stuttering issue. So, if you need real-time sound shaping controls, you may find that AudioWorklet is a better fit.
I’ve got a very simple project demonstrating how to use the newish pure C++ Emscripten Audio Worklet API if you’re interested. It’s a bit neater than the old way you’ll usually come across which also involves writing JS code, but there aren’t many docs online! https://github.com/tomduncalf/emscripten-audio-worklet-examp...
I agree. There’s a bit of mental overhead related to working with audio worklets (you have to load them from an URL or a blob URL, etc.) but for square waves in particular the logic should be fairly straighforward, the process function just needs to output 1 or -1 for any given sample.
It needs to do a lot more than that if you want to have something that doesn't alias like crazy. And significantly more if you want it to sound like a game boy.
Well, the output of the wave shaper approach in the article is exactly the same sharp digital square wave that you'd get from a trivial square wave generator.
But I overlooked the point that the GP mentions that the processor source code must be loaded from a separate JS file. That's some quite annoying overhead.
What I was trying to imply was that it's not enough to build a square wave generator to sound like a game boy. Even if that generator in the game boy was a perfect square wave generator, which I'm not sure it is.
The sound created by that generator passes through a fairly complicated filter known as The game boy's speaker. To properly create a game boy sound, you need to find or take an impulse response of that speaker and convolve it with the output of your oscillator.
Well, and a single recorded impulse response is probably not enough, either, if you want to be super accurate. The directivity pattern is probably awful and shaping the sound as well.
I know all of that. But I just didn't want to get into these details in this thread.
Yes... IMO, the WebAudio synthesis primitives are not particularly useful. You are so much better off discarding these primitives and rolling your own for an audio project of any significance.