Add `smooth` variable for ParamWidgets

include/app.hpp

@@ -217,6 +217,8 @@ struct ParamWidget : OpaqueWidget, QuantityWidget {
 	To permanently disable or change randomization behavior, override the randomize() method instead of changing this.
 	*/
 	bool randomizable = true;
+	/** Apply per-sample smoothing in the engine */
+	bool smooth = false;
 
 	json_t *toJson();
 	void fromJson(json_t *rootJ);
@@ -243,11 +245,10 @@ struct Knob : ParamWidget {
 	/** Multiplier for mouse movement to adjust knob value */
 	float speed = 1.0;
 	float dragValue;
+	Knob();
 	void onDragStart(EventDragStart &e) override;
 	void onDragMove(EventDragMove &e) override;
 	void onDragEnd(EventDragEnd &e) override;
-	/** Tell engine to smoothly vary this parameter */
-	void onChange(EventChange &e) override;
 };
 
 struct SpriteKnob : virtual Knob, SpriteWidget {

include/componentlibrary.hpp

@@ -62,6 +62,7 @@ struct RoundHugeBlackKnob : RoundBlackKnob {
 struct RoundSmallBlackSnapKnob : RoundSmallBlackKnob {
 	RoundSmallBlackSnapKnob() {
 		snap = true;
+		smooth = false;
 	}
 };
 
@@ -312,6 +313,7 @@ struct BefacoBigKnob : SVGKnob {
 struct BefacoBigSnapKnob : BefacoBigKnob {
 	BefacoBigSnapKnob() {
 		snap = true;
+		smooth = false;
 	}
 };
 

src/app/Knob.cpp

@@ -10,6 +10,10 @@ namespace rack {
 #define KNOB_SENSITIVITY 0.0015
 
 
+Knob::Knob() {
+	smooth = true;
+}
+
 void Knob::onDragStart(EventDragStart &e) {
 	windowCursorLock();
 	dragValue = value;
@@ -37,15 +41,5 @@ void Knob::onDragEnd(EventDragEnd &e) {
 	randomizable = true;
 }
 
-void Knob::onChange(EventChange &e) {
-	if (!module)
-		return;
-
-	if (snap)
-		engineSetParam(module, paramId, value);
-	else
-		engineSetParamSmooth(module, paramId, value);
-}
-
 
 } // namespace rack

src/app/ParamWidget.cpp

@@ -39,7 +39,10 @@ void ParamWidget::onChange(EventChange &e) {
 	if (!module)
 		return;
 
-	engineSetParam(module, paramId, value);
+	if (smooth)
+		engineSetParamSmooth(module, paramId, value);
+	else
+		engineSetParam(module, paramId, value);
 }