I'm trying to put together a simple oscilloscope abstraction that imitates the "trigger" function of a real one, so that the waveform can be seen from its starting point. In other words, a [tabwrite~] would graph on the upward swing of a zero crossing. To do this, I'd like to know if there is an audio object which gives a bang at a zero crossing, or perhaps even only at a crossing from the negative to the positive domain of the signal. I've thought of something with [expr~ $v1 < 0], but what comes out is still in the audio domain and isn't the bang which [tabwrite~] needs.
Other suggestions welcome.
best! Derek