Add intro message when the rack is empty. Round zoom level to nearest percent.

include/app/RackScrollWidget.hpp

@@ -8,6 +8,7 @@ namespace rack {
 
 struct RackScrollWidget : ScrollWidget {
 	void step() override;
+	void draw(NVGcontext *vg) override;
 };
 
 

include/app/RackWidget.hpp

@@ -50,6 +50,7 @@ struct RackWidget : OpaqueWidget {
 	/** Moves a module to the closest non-colliding position */
 	bool requestModuleBoxNearest(ModuleWidget *mw, math::Rect requestedBox);
 	ModuleWidget *getModule(int moduleId);
+	bool isEmpty();
 
 	// Cable methods
 

src/app/RackScrollWidget.cpp

@@ -27,4 +27,22 @@ void RackScrollWidget::step() {
 }
 
 
+void RackScrollWidget::draw(NVGcontext *vg) {
+	ScrollWidget::draw(vg);
+
+	if (app()->scene->rackWidget->isEmpty()) {
+		math::Rect b;
+		b.size = math::Vec(600, 300);
+		b.pos = box.size.minus(b.size).div(2);
+		NVGcolor bg = nvgRGBAf(0, 0, 0, 0.4);
+		bndInnerBox(vg, b.pos.x, b.pos.y, b.size.x, b.size.y,
+			0, 0, 0, 0, bg, bg);
+
+		NVGcolor fg = nvgRGBAf(1, 1, 1, 0.25);
+		std::string text = "Right-click or press Enter to add modules";
+		bndIconLabelValue(vg, b.pos.x, b.pos.y + 80, b.size.x, b.size.y, -1, fg, BND_CENTER, 80, text.c_str(), NULL);
+	}
+}
+
+
 } // namespace rack

src/app/RackWidget.cpp

@@ -416,6 +416,10 @@ ModuleWidget *RackWidget::getModule(int moduleId) {
 	return NULL;
 }
 
+bool RackWidget::isEmpty() {
+	return moduleContainer->children.empty();
+}
+
 void RackWidget::clearCables() {
 	for (Widget *w : cableContainer->children) {
 		CableWidget *cw = dynamic_cast<CableWidget*>(w);

src/app/Scene.cpp

@@ -64,7 +64,7 @@ void Scene::step() {
 
 	// Set zoom every few frames
 	if (app()->window->frame % 10 == 0)
-		zoomWidget->setZoom(settings::zoom);
+		zoomWidget->setZoom(std::round(settings::zoom * 100) / 100);
 
 	// Request latest version from server
 	if (!devMode && checkVersion && !checkedVersion) {

src/app/Toolbar.cpp

@@ -187,8 +187,8 @@ struct ZoomQuantity : Quantity {
 	float getMinValue() override {return 0.25;}
 	float getMaxValue() override {return 2.0;}
 	float getDefaultValue() override {return 1.0;}
-	float getDisplayValue() override {return getValue() * 100.0;}
-	void setDisplayValue(float displayValue) override {setValue(displayValue / 100.0);}
+	float getDisplayValue() override {return std::round(getValue() * 100);}
+	void setDisplayValue(float displayValue) override {setValue(displayValue / 100);}
 	std::string getLabel() override {return "Zoom";}
 	std::string getUnit() override {return "%";}
 };
@@ -202,8 +202,8 @@ struct CableOpacityQuantity : Quantity {
 		return settings::cableOpacity;
 	}
 	float getDefaultValue() override {return 0.5;}
-	float getDisplayValue() override {return getValue() * 100.0;}
-	void setDisplayValue(float displayValue) override {setValue(displayValue / 100.0);}
+	float getDisplayValue() override {return getValue() * 100;}
+	void setDisplayValue(float displayValue) override {setValue(displayValue / 100);}
 	std::string getLabel() override {return "Cable opacity";}
 	std::string getUnit() override {return "%";}
 };
@@ -225,7 +225,7 @@ struct CableTensionQuantity : Quantity {
 
 struct PowerMeterItem : MenuItem {
 	PowerMeterItem() {
-		text = "Power meter";
+		text = "CPU meter";
 		rightText = CHECKMARK(settings::powerMeter);
 	}
 	void onAction(const event::Action &e) override {

src/engine/Engine.cpp

@@ -1,6 +1,7 @@
 #include "engine/Engine.hpp"
 #include "settings.hpp"
 #include "system.hpp"
+#include "random.hpp"
 
 #include <algorithm>
 #include <chrono>
@@ -150,6 +151,16 @@ static void Engine_step(Engine *engine) {
 		}
 	}
 
+#if 0
+	if (random::u32() % 1000 == 0 && settings::powerMeter) {
+		float cpuTotal = 0.f;
+		for (Module *module : engine->modules) {
+			cpuTotal += module->cpuTime;
+		}
+		DEBUG("%fus %f%% CPU", cpuTotal * 1e6, cpuTotal * engine->internal->sampleRate * 100);
+	}
+#endif
+
 	// Step cables
 	for (Cable *cable : engine->cables) {
 		cable->step();