Pulse width modulation oscillator

[jpcima]

A pulse width modulation oscillator may be defined as follows.
sample=*pulse

• opcode oscillator_duty: range 0-100%, default 50% (square)
  the proportion of the period which has the pulse oscillator in 1 state

• oscillator_duty_onccN: range ±100% (also lfoN_oscillator_duty, egN_oscillator_duty, etc)
  the dynamic modulation of the pulse width

See also https://en.wikipedia.org/wiki/Pulse-width_modulation#Duty_cycle