add basic waveform caching
This adds a really basic version of waveform caching. Basically, if the parameters being passed through to the source model are unchanged, the waveform generator will just return a cached version of the previous waveform.
This adds a really basic version of waveform caching. Basically, if the parameters being passed through to the source model are unchanged, the waveform generator will just return a cached version of the previous waveform.