From a7e14b2065b6f1ee07aac3c6b936d968abfbd42c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Nusser?= <andre.nusser@googlemail.com>
Date: Sat, 21 Jul 2018 15:44:46 +0200
Subject: Fix visualization to be samplerate independent.

---
 plugingui/humaniservisualiser.cc | 13 ++++++-------
 plugingui/humaniservisualiser.h  |  6 +++---
 src/latencyfilter.cc             |  9 ++++++++-
 src/settings.h                   |  8 ++++----
 4 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/plugingui/humaniservisualiser.cc b/plugingui/humaniservisualiser.cc
index f0c016a..92da164 100644
--- a/plugingui/humaniservisualiser.cc
+++ b/plugingui/humaniservisualiser.cc
@@ -66,8 +66,7 @@ HumaniserVisualiser::Canvas::Canvas(GUI::Widget* parent,
                                     SettingsNotifier& settings_notifier)
 	: GUI::Widget(parent)
 	, settings_notifier(settings_notifier)
-	, latency_max_samples(settings.latency_max_ms.load() *
-	                      settings.samplerate.load() / 1000)
+	, latency_max_ms(settings.latency_max_ms.load())
 	, settings(settings)
 {
 	CONNECT(this, settings_notifier.enable_latency_modifier,
@@ -99,16 +98,16 @@ void HumaniserVisualiser::Canvas::repaintEvent(GUI::RepaintEvent *repaintEvent)
 
 	p.clear();
 
-	const int spx = latency_max_samples * 2 / width(); // samples pr. pixel
+	const float mspx = latency_max_ms * 2 / width(); // ms pr. pixel
 
-	int x = latency_offset / spx + width() / 2;
+	int x = latency_offset / mspx + width() / 2;
 	float v = (-1.0f * velocity_offset + 1.0f) * 0.8;
 	int y = height() * 0.2 + v * height();
 	y = std::max(0, y);
-	int w = 50.f * latency_stddev / spx * 3 * 2; // stddev is ~ +/- 3 span
+	int w = (3. * 2.) * latency_stddev / mspx; // stddev is ~ +/- 3 span
 	int h = velocity_stddev * height() / 4;
 
-	DEBUG(vis, "max: %d, spx: %d, x: %d, w: %d", latency_max_samples, spx, x, w);
+	DEBUG(vis, "max: %f, mspx: %f, x: %d, w: %d", latency_max_ms, mspx, x, w);
 
 	// Stddev squares
 	if(latency_enabled)
@@ -168,7 +167,7 @@ void HumaniserVisualiser::Canvas::velocityEnabledChanged(bool enabled)
 	redraw();
 }
 
-void HumaniserVisualiser::Canvas::latencyOffsetChanged(int offset)
+void HumaniserVisualiser::Canvas::latencyOffsetChanged(float offset)
 {
 	latency_offset = offset;
 	redraw();
diff --git a/plugingui/humaniservisualiser.h b/plugingui/humaniservisualiser.h
index 576ae6f..55e37d2 100644
--- a/plugingui/humaniservisualiser.h
+++ b/plugingui/humaniservisualiser.h
@@ -63,7 +63,7 @@ private:
 
 		void latencyEnabledChanged(bool enabled);
 		void velocityEnabledChanged(bool enabled);
-		void latencyOffsetChanged(int offset);
+		void latencyOffsetChanged(float offset);
 		void velocityOffsetChanged(float offset);
 		void latencyStddevChanged(float stddev);
 		void latencyLaidbackChanged(float laidback);
@@ -77,13 +77,13 @@ private:
 		bool latency_enabled{false};
 		bool velocity_enabled{false};
 
-		int latency_offset;
+		float latency_offset;
 		float velocity_offset;
 		float latency_stddev;
 		int laidback;
 		float velocity_stddev;
 		SettingsNotifier& settings_notifier;
-		const int latency_max_samples;
+		const float latency_max_ms;
 
 		Settings& settings;
 	};
diff --git a/src/latencyfilter.cc b/src/latencyfilter.cc
index 9410b50..0f3259b 100644
--- a/src/latencyfilter.cc
+++ b/src/latencyfilter.cc
@@ -44,6 +44,12 @@ static T1 getLatencySamples(T1 latency_ms, T2 samplerate)
 	return latency_ms * samplerate / 1000.;
 }
 
+template<typename T1, typename T2>
+static T1 getLatencyMs(T1 latency_samples, T2 samplerate)
+{
+	return 1000. * latency_samples / samplerate;
+}
+
 bool LatencyFilter::filter(event_t& event, std::size_t pos)
 {
 	auto enabled = settings.enable_latency_modifier.load();
@@ -86,7 +92,8 @@ bool LatencyFilter::filter(event_t& event, std::size_t pos)
 	event.offset += latency_laid_back; // laid back offset (user controlled)
 	event.offset += latency_offset; // current drift
 
-	settings.latency_current.store(latency_offset + latency_laid_back);
+	auto latency_current_ms = getLatencyMs(latency_offset + latency_laid_back, samplerate);
+	settings.latency_current.store(latency_current_ms);
 
 	return true;
 }
diff --git a/src/settings.h b/src/settings.h
index f37a810..e698d20 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -126,8 +126,8 @@ struct Settings
 	static float constexpr latency_regain_default = 0.9f;
 	Atomic<float> latency_regain{latency_regain_default};
 
-	// Current latency offset - for UI
-	Atomic<int> latency_current{0};
+	// Current latency offset in ms - for UI
+	Atomic<float> latency_current{0};
 };
 
 //! Settings getter class.
@@ -177,7 +177,7 @@ struct SettingsGetter
 	SettingRef<float> latency_laid_back_ms;
 	SettingRef<float> latency_stddev;
 	SettingRef<float> latency_regain;
-	SettingRef<int> latency_current;
+	SettingRef<float> latency_current;
 
 	SettingsGetter(Settings& settings)
 		: drumkit_file(settings.drumkit_file)
@@ -268,7 +268,7 @@ public:
 	Notifier<float> latency_laid_back_ms;
 	Notifier<float> latency_stddev;
 	Notifier<float> latency_regain;
-	Notifier<int> latency_current;
+	Notifier<float> latency_current;
 
 	void evaluate()
 	{
-- 
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