add Limiter

Author: Brian Sorahan

limiter.go

@@ -0,0 +1,33 @@
+package sc
+
+// Limiter limits the input amplitude to the given level.
+// Limiter will not overshoot like Compander will,
+// but it needs to look ahead in the audio.
+// Thus there is a delay equal to twice the value of the dur parameter.
+// Limiter, unlike Compander, is completely transparent for an in range signal.
+// The Rate method of Limiter will panic if In is nil.
+type Limiter struct {
+	In    Input // The signal to be processed.
+	Level Input // The peak output amplitude level to which to normalize the input.
+	Dur   Input // The buffer delay time. Shorter times will produce smaller delays and quicker transient response times, but may introduce amplitude modulation artifacts.
+}
+
+func (limiter *Limiter) defaults() {
+	if limiter.In == nil {
+		panic("Limiter needs an input")
+	}
+	if limiter.Level == nil {
+		limiter.Level = C(1)
+	}
+	if limiter.Dur == nil {
+		limiter.Dur = C(0.01)
+	}
+}
+
+// Rate creates a new ugen at a specific rate.
+// If rate is an unsupported value this method will cause a runtime panic.
+func (limiter Limiter) Rate(rate int8) Input {
+	CheckRate(rate)
+	(&limiter).defaults()
+	return UgenInput("Limiter", rate, 0, 1, limiter.In, limiter.Level, limiter.Dur)
+}