From ea431882a75b6b99868e5d57d4c8436ccf79b50a Mon Sep 17 00:00:00 2001
From: Andrew Belt <andrewpbelt@gmail.com>
Date: Mon, 31 May 2021 14:17:59 -0400
Subject: [PATCH] Add Engine meter to menu bar.

---
 include/engine/Engine.hpp |  4 ++++
 src/app/MenuBar.cpp       | 23 +++++++++++++++++++-
 src/engine/Engine.cpp     | 46 ++++++++++++++++++++++++++++++++++-----
 3 files changed, 66 insertions(+), 7 deletions(-)

diff --git a/include/engine/Engine.hpp b/include/engine/Engine.hpp
index 990e7d77..a919d9fd 100644
--- a/include/engine/Engine.hpp
+++ b/include/engine/Engine.hpp
@@ -85,6 +85,10 @@ struct Engine {
 	Calculated by `stepFrames / sampleRate`.
 	*/
 	double getBlockDuration();
+	/** Returns the average block processing time divided by block time in the last T seconds.
+	*/
+	double getMeterAverage();
+	double getMeterMax();
 
 	// Modules
 	size_t getNumModules();
diff --git a/src/app/MenuBar.cpp b/src/app/MenuBar.cpp
index f96ee694..01a71f83 100644
--- a/src/app/MenuBar.cpp
+++ b/src/app/MenuBar.cpp
@@ -1057,14 +1057,25 @@ struct HelpButton : MenuButton {
 // MenuBar
 ////////////////////
 
+struct MeterLabel : widget::OpaqueWidget {
+	void draw(const DrawArgs& args) override {
+		double meterAverage = APP->engine->getMeterAverage();
+		double meterMax = APP->engine->getMeterMax();
+		std::string text = string::f("%.1f%% avg / %.1f%% max", meterAverage * 100, meterMax * 100);
+		bndMenuLabel(args.vg, 0.0, 0.0, box.size.x, box.size.y, -1, text.c_str());
+	}
+};
+
 
 struct MenuBar : widget::OpaqueWidget {
+	MeterLabel* meterLabel;
+
 	MenuBar() {
 		const float margin = 5;
 		box.size.y = BND_WIDGET_HEIGHT + 2 * margin;
 
 		ui::SequentialLayout* layout = new ui::SequentialLayout;
-		layout->box.pos = math::Vec(margin, margin);
+		layout->margin = math::Vec(margin, margin);
 		layout->spacing = math::Vec(0, 0);
 		addChild(layout);
 
@@ -1095,6 +1106,11 @@ struct MenuBar : widget::OpaqueWidget {
 		MenuButton* alphaButton = new MenuButton;
 		alphaButton->text = "Pre-alpha build. Not for release.";
 		layout->addChild(alphaButton);
+
+		meterLabel = new MeterLabel;
+		meterLabel->box.pos.y = margin;
+		meterLabel->box.size.x = 160;
+		addChild(meterLabel);
 	}
 
 	void draw(const DrawArgs& args) override {
@@ -1103,6 +1119,11 @@ struct MenuBar : widget::OpaqueWidget {
 
 		Widget::draw(args);
 	}
+
+	void step() override {
+		meterLabel->box.pos.x = box.size.x - meterLabel->box.size.x;
+		Widget::step();
+	}
 };
 
 
diff --git a/src/engine/Engine.cpp b/src/engine/Engine.cpp
index b789bba4..915d9339 100644
--- a/src/engine/Engine.cpp
+++ b/src/engine/Engine.cpp
@@ -201,6 +201,7 @@ struct Engine::Internal {
 	std::vector<Module*> modules;
 	std::vector<Cable*> cables;
 	std::set<ParamHandle*> paramHandles;
+	Module* primaryModule = NULL;
 
 	// moduleId
 	std::map<int64_t, Module*> modulesCache;
@@ -216,7 +217,14 @@ struct Engine::Internal {
 	int64_t blockFrame = 0;
 	double blockTime = 0.0;
 	int blockFrames = 0;
-	Module* primaryModule = NULL;
+
+	// Meter
+	int meterCount = 0;
+	double meterTotal = 0.0;
+	double meterMax = 0.0;
+	double meterLastTime = -INFINITY;
+	double meterLastAverage = 0.0;
+	double meterLastMax = 0.0;
 
 	// Parameter smoothing
 	Module* smoothModule = NULL;
@@ -516,6 +524,9 @@ void Engine::clear_NoLock() {
 
 
 void Engine::stepBlock(int frames) {
+	// Start timer before locking
+	double startTime = system::getTime();
+
 	std::lock_guard<std::mutex> stepLock(internal->blockMutex);
 	ReadLock lock(internal->mutex);
 	// Configure thread
@@ -542,12 +553,25 @@ void Engine::stepBlock(int frames) {
 
 	yieldWorkers();
 
-	double endTime = system::getTime();
-	float duration = endTime - internal->blockTime;
-	float blockDuration = internal->blockFrames * internal->sampleTime;
-	// DEBUG("%d %f / %f = %f%%", internal->blockFrames, duration, blockDuration, duration / blockDuration * 100.f);
-
 	internal->block++;
+
+	// Stop timer
+	double endTime = system::getTime();
+	double meter = (endTime - startTime) / (frames * internal->sampleTime);
+	internal->meterTotal += meter;
+	internal->meterMax = std::fmax(internal->meterMax, meter);
+	internal->meterCount++;
+
+	// Update meter values
+	const double meterUpdateDuration = 1.0;
+	if (startTime - internal->meterLastTime >= meterUpdateDuration) {
+		internal->meterLastAverage = internal->meterTotal / internal->meterCount;
+		internal->meterLastMax = internal->meterMax;
+		internal->meterLastTime = startTime;
+		internal->meterCount = 0;
+		internal->meterTotal = 0.0;
+		internal->meterMax = 0.0;
+	}
 }
 
 
@@ -643,6 +667,16 @@ double Engine::getBlockDuration() {
 }
 
 
+double Engine::getMeterAverage() {
+	return internal->meterLastAverage;
+}
+
+
+double Engine::getMeterMax() {
+	return internal->meterLastMax;
+}
+
+
 size_t Engine::getNumModules() {
 	return internal->modules.size();
 }