Added engine pausing/resuming (in sample rate choose menu)

include/engine.hpp

@@ -55,6 +55,7 @@ void engineRemoveWire(Wire *wire);
 void engineSetParamSmooth(Module *module, int paramId, float value);
 
 extern float gSampleRate;
+extern bool gPaused;
 
 
 } // namespace rack

src/app/Toolbar.cpp

@@ -57,6 +57,12 @@ struct FileChoice : ChoiceButton {
 };
 
 
+struct PauseItem : MenuItem {
+	void onAction() {
+		gPaused = !gPaused;
+	}
+};
+
 struct SampleRateItem : MenuItem {
 	float sampleRate;
 	void onAction() {
@@ -70,6 +76,10 @@ struct SampleRateChoice : ChoiceButton {
 		menu->box.pos = getAbsolutePos().plus(Vec(0, box.size.y));
 		menu->box.size.x = box.size.x;
 
+		PauseItem *pauseItem = new PauseItem();
+		pauseItem->text = gPaused ? "Resume Engine" : "Pause Engine";
+		menu->pushChild(pauseItem);
+
 		float sampleRates[] = {44100, 48000, 88200, 96000, 176400, 192000};
 		int sampleRatesLen = sizeof(sampleRates) / sizeof(sampleRates[0]);
 		for (int i = 0; i < sampleRatesLen; i++) {

src/engine.cpp

@@ -15,6 +15,7 @@
 namespace rack {
 
 float gSampleRate;
+bool gPaused = false;
 
 
 static bool running = false;
@@ -85,7 +86,7 @@ static void engineRun() {
 	while (running) {
 		vipMutex.wait();
 
-		{
+		if (!gPaused) {
 			std::lock_guard<std::mutex> lock(mutex);
 			for (int i = 0; i < mutexSteps; i++) {
 				engineStep();