design_decisions

I considered two options for getting samples from a Signal object:

1) A step() function that just returns one value after another and once that value is gone, it's gone. 

2) A getSampleAtTime(int t) function that gives the value of a signal at any particular increment.


The advantage of method 1 is that it allows for easy frequency modulation. An Oscillator's IncrementSignal
can be varied and the frequency of the sound will change. The downside is that there is no way to hook up one
Signal as the input of multiple other Signals, because each one will call the step() function separately,
messing stuff up. You can get around this by just copying Signals.

The advantage of method 2 is that you don't have to copy Signal objects to make one Signal the input of
multiple other signals. The disadvantage is that it makes frequency modulation very difficult. You won't know
how the waveTable was incremented previously, so if you changed the incrementSignal from 1 to 2, the wave may
skip foreward or backward in the wavetable.


Conclusion: method 1 is superior.