bool32.risingfalling gate
frac32 attack time
frac32 decay time
frac32.positive envelope output
int32_t val;
val = 0;
if (inlet_gate > 0)
val = ___SMMLA((1 << 27) - val, (1 << 26) - (inlet_a >> 1), val);
else
val = ___SMMLA(val, (-1 << 26) + (inlet_d >> 1), val);
outlet_env = val;