Merge branch 'master' into refactor-samplebuffer

CMakeLists.txt

@@ -35,7 +35,7 @@ INCLUDE(GenerateExportHeader)
 
 STRING(TOUPPER          "${CMAKE_PROJECT_NAME}" PROJECT_NAME_UCASE)
 
-SET(PROJECT_YEAR 2020)
+SET(PROJECT_YEAR 2023)
 
 SET(PROJECT_AUTHOR      "LMMS Developers")
 SET(PROJECT_URL         "https://lmms.io")

include/AudioEngine.h

@@ -197,6 +197,7 @@ public:
 
 	// audio-device-stuff
 
+	bool renderOnly() const { return m_renderOnly; }
 	// Returns the current audio device's name. This is not necessarily
 	// the user's preferred audio device, in case you were thinking that.
 	inline const QString & audioDevName() const

include/LmmsSemaphore.h

@@ -0,0 +1,93 @@
+/*
+ * Semaphore.h - Semaphore declaration
+ *
+ * Copyright (c) 2022-2022 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*
+ * This code has been copied and adapted from https://github.com/drobilla/jalv
+ * File src/zix/sem.h
+ */
+
+#ifndef LMMS_SEMAPHORE_H
+#define LMMS_SEMAPHORE_H
+
+#include "lmmsconfig.h"
+
+#ifdef LMMS_BUILD_APPLE
+#    include <mach/mach.h>
+#elif defined(LMMS_BUILD_WIN32)
+#    include <windows.h>
+#else
+#    include <semaphore.h>
+#endif
+
+#include <system_error>
+
+namespace lmms {
+
+/**
+   A counting semaphore.
+
+   This is an integer that is always positive, and has two main operations:
+   increment (post) and decrement (wait).  If a decrement can not be performed
+   (i.e. the value is 0) the caller will be blocked until another thread posts
+   and the operation can succeed.
+
+   Semaphores can be created with any starting value, but typically this will
+   be 0 so the semaphore can be used as a simple signal where each post
+   corresponds to one wait.
+
+   Semaphores are very efficient (much moreso than a mutex/cond pair).  In
+   particular, at least on Linux, post is async-signal-safe, which means it
+   does not block and will not be interrupted.  If you need to signal from
+   a realtime thread, this is the most appropriate primitive to use.
+
+   @note Likely outdated with C++20's std::counting_semaphore
+		 (though we have to check that this will be RT conforming on all platforms)
+*/
+class Semaphore
+{
+public:
+	Semaphore(unsigned initial);
+	Semaphore(const Semaphore&) = delete;
+	Semaphore& operator=(const Semaphore&) = delete;
+	Semaphore(Semaphore&&) = delete;
+	Semaphore& operator=(Semaphore&&) = delete;
+	~Semaphore();
+
+	void post();
+	void wait();
+	bool tryWait();
+
+private:
+#ifdef LMMS_BUILD_APPLE
+	semaphore_t m_sem;
+#elif defined(LMMS_BUILD_WIN32)
+	HANDLE m_sem;
+#else
+	sem_t m_sem;
+#endif
+};
+
+} // namespace lmms
+
+#endif // LMMS_SEMAPHORE_H

include/LocklessRingBuffer.h

@@ -51,13 +51,14 @@ public:
 	std::size_t capacity() const {return m_buffer.maximum_eventual_write_space();}
 	std::size_t free() const {return m_buffer.write_space();}
 	void wakeAll() {m_notifier.wakeAll();}
-	std::size_t write(const sampleFrame *src, std::size_t cnt, bool notify = false)
+	std::size_t write(const T *src, std::size_t cnt, bool notify = false)
 	{
 		std::size_t written = LocklessRingBuffer<T>::m_buffer.write(src, cnt);
 		// Let all waiting readers know new data are available.
 		if (notify) {LocklessRingBuffer<T>::m_notifier.wakeAll();}
 		return written;
 	}
+	void mlock() { m_buffer.mlock(); }
 
 protected:
 	ringbuffer_t<T> m_buffer;

include/Lv2Basics.h

@@ -47,8 +47,14 @@ struct LilvNodesDeleter
 	void operator()(LilvNodes* n) { lilv_nodes_free(n); }
 };
 
+struct LilvScalePointsDeleter
+{
+	void operator()(LilvScalePoints* s) { lilv_scale_points_free(s); }
+};
+
 using AutoLilvNode = std::unique_ptr<LilvNode, LilvNodeDeleter>;
 using AutoLilvNodes = std::unique_ptr<LilvNodes, LilvNodesDeleter>;
+using AutoLilvScalePoints = std::unique_ptr<LilvScalePoints, LilvScalePointsDeleter>;
 
 /**
 	Return QString from a plugin's node, everything will be freed automatically

include/Lv2Features.h

@@ -30,6 +30,7 @@
 #ifdef LMMS_HAVE_LV2
 
 #include <map>
+#include <string_view>
 #include <vector>
 #include "Lv2Manager.h"
 
@@ -78,7 +79,7 @@ private:
 	//! pointers to m_features, required for lilv_plugin_instantiate
 	std::vector<const LV2_Feature*> m_featurePointers;
 	//! features + data, ordered by URI
-	std::map<const char*, void*, Lv2Manager::CmpStr> m_featureByUri;
+	std::map<std::string_view, void*> m_featureByUri;
 };
 
 

include/Lv2Manager.h

@@ -31,6 +31,7 @@
 
 #include <map>
 #include <set>
+#include <string_view>
 #include <lilv/lilv.h>
 
 #include "Lv2Basics.h"
@@ -120,15 +121,9 @@ public:
 	Iterator begin() { return m_lv2InfoMap.begin(); }
 	Iterator end() { return m_lv2InfoMap.end(); }
 
-	//! strcmp based key comparator for std::set and std::map
-	struct CmpStr
-	{
-		bool operator()(char const *a, char const *b) const;
-	};
-
 	UridMap& uridMap() { return m_uridMap; }
 	const Lv2UridCache& uridCache() const { return m_uridCache; }
-	const std::set<const char*, CmpStr>& supportedFeatureURIs() const
+	const std::set<std::string_view>& supportedFeatureURIs() const
 	{
 		return m_supportedFeatureURIs;
 	}
@@ -136,17 +131,21 @@ public:
 	AutoLilvNodes findNodes(const LilvNode *subject,
 		const LilvNode *predicate, const LilvNode *object);
 
-	static const std::set<const char*, Lv2Manager::CmpStr>& getPluginBlacklist()
+	static const std::set<std::string_view>& getPluginBlacklist()
 	{
 		return pluginBlacklist;
 	}
+	static const std::set<std::string_view>& getPluginBlacklistBuffersizeLessThan32()
+	{
+		return pluginBlacklistBuffersizeLessThan32;
+	}
 
 private:
 	// general data
 	bool m_debug; //!< if set, debug output will be printed
 	LilvWorld* m_world;
 	Lv2InfoMap m_lv2InfoMap;
-	std::set<const char*, CmpStr> m_supportedFeatureURIs;
+	std::set<std::string_view> m_supportedFeatureURIs;
 
 	// feature data that are common for all Lv2Proc
 	UridMap m_uridMap;
@@ -155,7 +154,8 @@ private:
 	Lv2UridCache m_uridCache;
 
 	// static
-	static const std::set<const char*, Lv2Manager::CmpStr> pluginBlacklist;
+	static const std::set<std::string_view>
+		pluginBlacklist, pluginBlacklistBuffersizeLessThan32;
 
 	// functions
 	bool isSubclassOf(const LilvPluginClass *clvss, const char *uriStr);

include/Lv2Proc.h

@@ -1,7 +1,7 @@
 /*
  * Lv2Proc.h - Lv2 processor class
  *
- * Copyright (c) 2019-2020 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ * Copyright (c) 2019-2022 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
  *
  * This file is part of LMMS - https://lmms.io
  *
@@ -31,11 +31,14 @@
 
 #include <lilv/lilv.h>
 #include <memory>
+#include <optional>
 
+#include "LinkedModelGroups.h"
+#include "LmmsSemaphore.h"
 #include "Lv2Basics.h"
 #include "Lv2Features.h"
 #include "Lv2Options.h"
-#include "LinkedModelGroups.h"
+#include "Lv2Worker.h"
 #include "Plugin.h"
 #include "../src/3rdparty/ringbuffer/include/ringbuffer/ringbuffer.h"
 #include "TimePos.h"
@@ -174,8 +177,14 @@ private:
 	const LilvPlugin* m_plugin;
 	LilvInstance* m_instance;
 	Lv2Features m_features;
+
+	// options
 	Lv2Options m_options;
 
+	// worker
+	std::optional<Lv2Worker> m_worker;
+	Semaphore m_workLock; // this must be shared by different workers
+
 	// full list of ports
 	std::vector<std::unique_ptr<Lv2Ports::PortBase>> m_ports;
 	// quick reference to specific, unique ports

include/Lv2ViewBase.h

@@ -56,7 +56,7 @@ class Lv2ViewProc : public LinkedModelGroupView
 {
 public:
 	//! @param colNum numbers of columns for the controls
-	Lv2ViewProc(QWidget *parent, Lv2Proc *ctrlBase, int colNum);
+	Lv2ViewProc(QWidget *parent, Lv2Proc *proc, int colNum);
 	~Lv2ViewProc() override = default;
 
 private:

include/Lv2Worker.h

@@ -0,0 +1,93 @@
+/*
+ * Lv2Worker.h - Lv2Worker class
+ *
+ * Copyright (c) 2022-2022 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef LV2WORKER_H
+#define LV2WORKER_H
+
+#include "lmmsconfig.h"
+
+#ifdef LMMS_HAVE_LV2
+
+#include <lilv/lilv.h>
+#include <lv2/lv2plug.in/ns/ext/worker/worker.h>
+#include <thread>
+#include <vector>
+
+#include "LocklessRingBuffer.h"
+#include "LmmsSemaphore.h"
+
+namespace lmms
+{
+
+/**
+	Worker container
+*/
+class Lv2Worker
+{
+public:
+	// CTOR/DTOR/feature access
+	Lv2Worker(const LV2_Worker_Interface* iface, Semaphore* common_work_lock, bool threaded);
+	~Lv2Worker();
+	void setHandle(LV2_Handle handle) { m_handle = handle; }
+	LV2_Worker_Schedule* feature() { return &m_scheduleFeature; }
+
+	// public API
+	void emitResponses();
+	void notifyPluginThatRunFinished()
+	{
+		if(m_iface->end_run) { m_iface->end_run(m_scheduleFeature.handle); }
+	}
+
+	// to be called only by static functions
+	LV2_Worker_Status scheduleWork(uint32_t size, const void* data);
+	LV2_Worker_Status respond(uint32_t size, const void* data);
+
+private:
+	// functions
+	void workerFunc();
+	std::size_t bufferSize() const;  //!< size of internal buffers
+
+	// parameters
+	const LV2_Worker_Interface* m_iface;
+	bool m_threaded;
+	LV2_Handle m_handle;
+	LV2_Worker_Schedule m_scheduleFeature;
+
+	// threading/synchronization
+	std::thread m_thread;
+	std::vector<char> m_response;  //!< buffer where single requests from m_requests are unpacked
+	LocklessRingBuffer<char> m_requests, m_responses;  //!< ringbuffer to queue multiple requests
+	LocklessRingBufferReader<char> m_requestsReader, m_responsesReader;
+	std::atomic<bool> m_exit = false;  //!< Whether the worker function should keep looping
+	Semaphore m_sem;
+	Semaphore* m_workLock;
+};
+
+
+} // namespace lmms
+
+#endif // LMMS_HAVE_LV2
+
+#endif // LV2WORKER_H
+

include/SetupDialog.h

@@ -102,6 +102,7 @@ private slots:
 	// Audio settings widget.
 	void audioInterfaceChanged(const QString & driver);
 	void toggleHQAudioDev(bool enabled);
+	void updateBufferSizeWarning(int value);
 	void setBufferSize(int value);
 	void resetBufferSize();
 
@@ -179,6 +180,7 @@ private:
 	int m_bufferSize;
 	QSlider * m_bufferSizeSlider;
 	QLabel * m_bufferSizeLbl;
+	QLabel * m_bufferSizeWarnLbl;
 
 	// MIDI settings widgets.
 	QComboBox * m_midiInterfaces;

include/lmms_math.h

@@ -325,6 +325,32 @@ static inline T absMin( T a, T b )
 	return std::abs(a) < std::abs(b) ? a : b;
 }
 
+// @brief Calculate number of digits which LcdSpinBox would show for a given number
+// @note Once we upgrade to C++20, we could probably use std::formatted_size
+static inline int numDigitsAsInt(float f)
+{
+	// use rounding:
+	// LcdSpinBox sometimes uses roundf(), sometimes cast rounding
+	// we use rounding to be on the "safe side"
+	const float rounded = roundf(f);
+	int asInt = static_cast<int>(rounded);
+	int digits = 1; // always at least 1
+	if(asInt < 0)
+	{
+		++digits;
+		asInt = -asInt;
+	}
+	// "asInt" is positive from now
+	int32_t power = 1;
+	for(int32_t i = 1; i<10; ++i)
+	{
+		power *= 10;
+		if(static_cast<int32_t>(asInt) >= power) { ++digits; } // 2 digits for >=10, 3 for >=100
+		else { break; }
+	}
+	return digits;
+}
+
 
 } // namespace lmms
 

plugins/Compressor/Compressor.cpp

@@ -177,7 +177,8 @@ void CompressorEffect::calcRange()
 
 void CompressorEffect::resizeRMS()
 {
-	m_rmsTimeConst = exp(-1.f / (m_compressorControls.m_rmsModel.value() * 0.001f * m_sampleRate));
+	const float rmsValue = m_compressorControls.m_rmsModel.value();
+	m_rmsTimeConst = (rmsValue > 0) ? exp(-1.f / (rmsValue * 0.001f * m_sampleRate)) : 0;
 }
 
 void CompressorEffect::calcLookaheadLength()

plugins/Compressor/CompressorControlDialog.cpp

@@ -497,10 +497,12 @@ void CompressorControlDialog::redrawKnee()
 	float actualRatio = m_controls->m_limiterModel.value() ? 0 : m_controls->m_effect->m_ratioVal;
 
 	// Calculate endpoints for the two straight lines
-	float kneePoint1 = m_controls->m_effect->m_thresholdVal - m_controls->m_effect->m_kneeVal;
-	float kneePoint2X = m_controls->m_effect->m_thresholdVal + m_controls->m_effect->m_kneeVal;
-	float kneePoint2Y = (m_controls->m_effect->m_thresholdVal + (-m_controls->m_effect->m_thresholdVal * (actualRatio * (m_controls->m_effect->m_kneeVal / -m_controls->m_effect->m_thresholdVal))));
-	float ratioPoint = m_controls->m_effect->m_thresholdVal + (-m_controls->m_effect->m_thresholdVal * actualRatio);
+	const float thresholdVal = m_controls->m_effect->m_thresholdVal;
+	const float kneeVal = m_controls->m_effect->m_kneeVal;
+	float kneePoint1 = thresholdVal - kneeVal;
+	float kneePoint2X = thresholdVal + kneeVal;
+	float kneePoint2Y = thresholdVal + kneeVal * actualRatio;
+	float ratioPoint = thresholdVal + (-thresholdVal * actualRatio);
 
 	// Draw two straight lines
 	m_p.drawLine(0, m_kneeWindowSizeY, dbfsToXPoint(kneePoint1), dbfsToYPoint(kneePoint1));
@@ -510,7 +512,7 @@ void CompressorControlDialog::redrawKnee()
 	}
 
 	// Draw knee section
-	if (m_controls->m_effect->m_kneeVal)
+	if (kneeVal)
 	{
 		m_p.setPen(QPen(m_kneeColor2, 3));
 
@@ -522,8 +524,8 @@ void CompressorControlDialog::redrawKnee()
 		{
 			newPoint[0] = linearInterpolate(kneePoint1, kneePoint2X, (i + 1) / (float)COMP_KNEE_LINES);
 
-			const float temp = newPoint[0] - m_controls->m_effect->m_thresholdVal + m_controls->m_effect->m_kneeVal;
-			newPoint[1] = (newPoint[0] + (actualRatio - 1) * temp * temp / (4 * m_controls->m_effect->m_kneeVal));
+			const float temp = newPoint[0] - thresholdVal + kneeVal;
+			newPoint[1] = (newPoint[0] + (actualRatio - 1) * temp * temp / (4 * kneeVal));
 
 			m_p.drawLine(dbfsToXPoint(prevPoint[0]), dbfsToYPoint(prevPoint[1]), dbfsToXPoint(newPoint[0]), dbfsToYPoint(newPoint[1]));
 
@@ -768,4 +770,4 @@ void CompressorControlDialog::resetCompressorView()
 }
 
 
-} // namespace lmms::gui
+} // namespace lmms::gui

src/core/CMakeLists.txt

@@ -71,6 +71,7 @@ set(LMMS_SRCS
 	core/SamplePlayHandle.cpp
 	core/SampleRecordHandle.cpp
 	core/Scale.cpp
+	core/LmmsSemaphore.cpp
 	core/SerializingObject.cpp
 	core/Song.cpp
 	core/TempoSyncKnobModel.cpp
@@ -113,6 +114,7 @@ set(LMMS_SRCS
 	core/lv2/Lv2SubPluginFeatures.cpp
 	core/lv2/Lv2UridCache.cpp
 	core/lv2/Lv2UridMap.cpp
+	core/lv2/Lv2Worker.cpp
 
 	core/midi/MidiAlsaRaw.cpp
 	core/midi/MidiAlsaSeq.cpp

src/core/LmmsSemaphore.cpp

@@ -0,0 +1,143 @@
+/*
+ * Semaphore.cpp - Semaphore implementation
+ *
+ * Copyright (c) 2022-2022 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*
+ * This code has been copied and adapted from https://github.com/drobilla/jalv
+ * File src/zix/sem.h
+ */
+
+#include "LmmsSemaphore.h"
+
+#if defined(LMMS_BUILD_WIN32)
+#    include <limits.h>
+#else
+#    include <errno.h>
+#endif
+
+#include <system_error>
+
+namespace lmms {
+
+#ifdef LMMS_BUILD_APPLE
+Semaphore::Semaphore(unsigned val)
+{
+	kern_return_t rval = semaphore_create(mach_task_self(), &m_sem, SYNC_POLICY_FIFO, val);
+	if(rval != 0) {
+		throw std::system_error(rval, std::system_category(), "Could not create semaphore");
+	}
+}
+
+Semaphore::~Semaphore()
+{
+	semaphore_destroy(mach_task_self(), m_sem);
+}
+
+void Semaphore::post()
+{
+	semaphore_signal(m_sem);
+}
+
+void Semaphore::wait()
+{
+	kern_return_t rval = semaphore_wait(m_sem);
+	if (rval != KERN_SUCCESS) {
+		throw std::system_error(rval, std::system_category(), "Waiting for semaphore failed");
+	}
+}
+
+bool Semaphore::tryWait()
+{
+	const mach_timespec_t zero = { 0, 0 };
+	return semaphore_timedwait(m_sem, zero) == KERN_SUCCESS;
+}
+
+#elif defined(LMMS_BUILD_WIN32)
+
+Semaphore::Semaphore(unsigned initial)
+{
+	if(CreateSemaphore(nullptr, initial, LONG_MAX, nullptr) == nullptr) {
+		throw std::system_error(GetLastError(), std::system_category(), "Could not create semaphore");
+	}
+}
+
+Semaphore::~Semaphore()
+{
+	CloseHandle(m_sem);
+}
+
+void Semaphore::post()
+{
+	ReleaseSemaphore(m_sem, 1, nullptr);
+}
+
+void Semaphore::wait()
+{
+	if (WaitForSingleObject(m_sem, INFINITE) != WAIT_OBJECT_0) {
+		throw std::system_error(GetLastError(), std::system_category(), "Waiting for semaphore failed");
+	}
+}
+
+bool Semaphore::tryWait()
+{
+	return WaitForSingleObject(m_sem, 0) == WAIT_OBJECT_0;
+}
+
+#else  /* !defined(LMMS_BUILD_APPLE) && !defined(LMMS_BUILD_WIN32) */
+
+Semaphore::Semaphore(unsigned initial)
+{
+	if(sem_init(&m_sem, 0, initial) != 0) {
+		throw std::system_error(errno, std::generic_category(), "Could not create semaphore");
+	}
+}
+
+Semaphore::~Semaphore()
+{
+	sem_destroy(&m_sem);
+}
+
+void Semaphore::post()
+{
+	sem_post(&m_sem);
+}
+
+void Semaphore::wait()
+{
+	while (sem_wait(&m_sem) != 0) {
+		if (errno != EINTR) {
+			throw std::system_error(errno, std::generic_category(), "Waiting for semaphore failed");
+		}
+		/* Otherwise, interrupted, so try again. */
+	}
+}
+
+bool Semaphore::tryWait()
+{
+	return (sem_trywait(&m_sem) == 0);
+}
+
+#endif
+
+} // namespace lmms
+

src/core/lv2/Lv2Features.cpp

@@ -48,7 +48,7 @@ Lv2Features::Lv2Features()
 {
 	const Lv2Manager* man = Engine::getLv2Manager();
 	// create (yet empty) map feature URI -> feature
-	for(const char* uri : man->supportedFeatureURIs())
+	for(auto uri : man->supportedFeatureURIs())
 	{
 		m_featureByUri.emplace(uri, nullptr);
 	}
@@ -71,7 +71,7 @@ void Lv2Features::initCommon()
 void Lv2Features::createFeatureVectors()
 {
 	// create vector of features
-	for(std::pair<const char* const, void*>& pr : m_featureByUri)
+	for(const auto& [uri, feature] : m_featureByUri)
 	{
 		/*
 			If pr.second is nullptr here, this means that the LV2_feature
@@ -82,7 +82,7 @@ void Lv2Features::createFeatureVectors()
 			  vector creation (This can be done in
 			  Lv2Proc::initPluginSpecificFeatures or in Lv2Features::initCommon)
 		*/
-		m_features.push_back(LV2_Feature { pr.first, pr.second });
+		m_features.push_back(LV2_Feature{(const char*)uri.data(), (void*)feature});
 	}
 
 	// create pointer vector (for lilv_plugin_instantiate)

src/core/lv2/Lv2Manager.cpp

@@ -28,13 +28,14 @@
 
 #include <algorithm>
 #include <cstdlib>
-#include <cstring>
 #include <lilv/lilv.h>
 #include <lv2/lv2plug.in/ns/ext/buf-size/buf-size.h>
 #include <lv2/lv2plug.in/ns/ext/options/options.h>
+#include <lv2/lv2plug.in/ns/ext/worker/worker.h>
 #include <QDebug>
 #include <QElapsedTimer>
 
+#include "AudioEngine.h"
 #include "Engine.h"
 #include "Plugin.h"
 #include "Lv2ControlBase.h"
@@ -46,7 +47,7 @@ namespace lmms
 {
 
 
-const std::set<const char*, Lv2Manager::CmpStr> Lv2Manager::pluginBlacklist =
+const std::set<std::string_view> Lv2Manager::pluginBlacklist =
 {
 	// github.com/calf-studio-gear/calf, #278
 	"http://calf.sourceforge.net/plugins/Analyzer",
@@ -137,6 +138,26 @@ const std::set<const char*, Lv2Manager::CmpStr> Lv2Manager::pluginBlacklist =
 	"urn:juced:DrumSynth"
 };
 
+const std::set<std::string_view> Lv2Manager::pluginBlacklistBuffersizeLessThan32 =
+{
+	"http://moddevices.com/plugins/mod-devel/2Voices",
+	"http://moddevices.com/plugins/mod-devel/Capo",
+	"http://moddevices.com/plugins/mod-devel/Drop",
+	"http://moddevices.com/plugins/mod-devel/Harmonizer",
+	"http://moddevices.com/plugins/mod-devel/Harmonizer2",
+	"http://moddevices.com/plugins/mod-devel/HarmonizerCS",
+	"http://moddevices.com/plugins/mod-devel/SuperCapo",
+	"http://moddevices.com/plugins/mod-devel/SuperWhammy",
+	"http://moddevices.com/plugins/mod-devel/Gx2Voices",
+	"http://moddevices.com/plugins/mod-devel/GxCapo",
+	"http://moddevices.com/plugins/mod-devel/GxDrop",
+	"http://moddevices.com/plugins/mod-devel/GxHarmonizer",
+	"http://moddevices.com/plugins/mod-devel/GxHarmonizer2",
+	"http://moddevices.com/plugins/mod-devel/GxHarmonizerCS",
+	"http://moddevices.com/plugins/mod-devel/GxSuperCapo",
+	"http://moddevices.com/plugins/mod-devel/GxSuperWhammy"
+};
+
 
 
 
@@ -152,10 +173,15 @@ Lv2Manager::Lv2Manager() :
 	m_supportedFeatureURIs.insert(LV2_URID__map);
 	m_supportedFeatureURIs.insert(LV2_URID__unmap);
 	m_supportedFeatureURIs.insert(LV2_OPTIONS__options);
+	m_supportedFeatureURIs.insert(LV2_WORKER__schedule);
 	// min/max is always passed in the options
 	m_supportedFeatureURIs.insert(LV2_BUF_SIZE__boundedBlockLength);
 	// block length is only changed initially in AudioEngine CTOR
 	m_supportedFeatureURIs.insert(LV2_BUF_SIZE__fixedBlockLength);
+	if (const auto fpp = Engine::audioEngine()->framesPerPeriod(); (fpp & (fpp - 1)) == 0)  // <=> ffp is power of 2 (for ffp > 0)
+	{
+		m_supportedFeatureURIs.insert(LV2_BUF_SIZE__powerOf2BlockLength);
+	}
 
 	auto supportOpt = [this](Lv2UridCache::Id id)
 	{
@@ -288,14 +314,6 @@ void Lv2Manager::initPlugins()
 
 
 
-bool Lv2Manager::CmpStr::operator()(const char *a, const char *b) const
-{
-	return std::strcmp(a, b) < 0;
-}
-
-
-
-
 bool Lv2Manager::isFeatureSupported(const char *featName) const
 {
 	return m_supportedFeatureURIs.find(featName) != m_supportedFeatureURIs.end();

src/core/lv2/Lv2Proc.cpp

@@ -1,7 +1,7 @@
 /*
  * Lv2Proc.cpp - Lv2 processor class
  *
- * Copyright (c) 2019-2020 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ * Copyright (c) 2019-2022 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
  *
  * This file is part of LMMS - https://lmms.io
  *
@@ -30,6 +30,7 @@
 #include <lv2/lv2plug.in/ns/ext/midi/midi.h>
 #include <lv2/lv2plug.in/ns/ext/atom/atom.h>
 #include <lv2/lv2plug.in/ns/ext/resize-port/resize-port.h>
+#include <lv2/lv2plug.in/ns/ext/worker/worker.h>
 #include <QDebug>
 #include <QDomDocument>
 #include <QtGlobal>
@@ -75,11 +76,19 @@ Plugin::Type Lv2Proc::check(const LilvPlugin *plugin,
 	// TODO: manage a global blacklist outside of the code
 	//       for now, this will help
 	//       this is only a fix for the meantime
-	const auto& pluginBlacklist = Lv2Manager::getPluginBlacklist();
-	if (!Engine::ignorePluginBlacklist() &&
-		pluginBlacklist.find(pluginUri) != pluginBlacklist.end())
+	if (!Engine::ignorePluginBlacklist())
 	{
-		issues.emplace_back(PluginIssueType::Blacklisted);
+		const auto& pluginBlacklist = Lv2Manager::getPluginBlacklist();
+		const auto& pluginBlacklist32 = Lv2Manager::getPluginBlacklistBuffersizeLessThan32();
+		if(pluginBlacklist.find(pluginUri) != pluginBlacklist.end())
+		{
+			issues.emplace_back(PluginIssueType::Blacklisted);
+		}
+		else if(Engine::audioEngine()->framesPerPeriod() <= 32 &&
+			pluginBlacklist32.find(pluginUri) != pluginBlacklist32.end())
+		{
+			issues.emplace_back(PluginIssueType::Blacklisted);  // currently no special blacklist category
+		}
 	}
 
 	for (unsigned portNum = 0; portNum < maxPorts; ++portNum)
@@ -162,6 +171,7 @@ Plugin::Type Lv2Proc::check(const LilvPlugin *plugin,
 Lv2Proc::Lv2Proc(const LilvPlugin *plugin, Model* parent) :
 	LinkedModelGroup(parent),
 	m_plugin(plugin),
+	m_workLock(1),
 	m_midiInputBuf(m_maxMidiInputEvents),
 	m_midiInputReader(m_midiInputBuf)
 {
@@ -352,7 +362,19 @@ void Lv2Proc::copyBuffersToCore(sampleFrame* buf,
 
 void Lv2Proc::run(fpp_t frames)
 {
+	if (m_worker)
+	{
+		// Process any worker replies
+		m_worker->emitResponses();
+	}
+
 	lilv_instance_run(m_instance, static_cast<uint32_t>(frames));
+
+	if (m_worker)
+	{
+		// Notify the plugin the run() cycle is finished
+		m_worker->notifyPluginThatRunFinished();
+	}
 }
 
 
@@ -420,6 +442,9 @@ void Lv2Proc::initPlugin()
 
 	if (m_instance)
 	{
+		if(m_worker) {
+			m_worker->setHandle(lilv_instance_get_handle(m_instance));
+		}
 		for (std::size_t portNum = 0; portNum < m_ports.size(); ++portNum)
 			connectPort(portNum);
 		lilv_instance_activate(m_instance);
@@ -496,8 +521,20 @@ void Lv2Proc::initMOptions()
 
 void Lv2Proc::initPluginSpecificFeatures()
 {
+	// options
 	initMOptions();
 	m_features[LV2_OPTIONS__options] = const_cast<LV2_Options_Option*>(m_options.feature());
+
+	// worker (if plugin has worker extension)
+	Lv2Manager* mgr = Engine::getLv2Manager();
+	if (lilv_plugin_has_extension_data(m_plugin, mgr->uri(LV2_WORKER__interface).get())) {
+		const auto iface = static_cast<const LV2_Worker_Interface*>(
+			lilv_instance_get_extension_data(m_instance, LV2_WORKER__interface));
+		bool threaded = !Engine::audioEngine()->renderOnly();
+		m_worker.emplace(iface, &m_workLock, threaded);
+		m_features[LV2_WORKER__schedule] = m_worker->feature();
+		// Note: m_worker::setHandle will still need to be called later
+	}
 }
 
 
@@ -566,21 +603,35 @@ void Lv2Proc::createPort(std::size_t portNum)
 						break;
 					case Lv2Ports::Vis::Enumeration:
 					{
-						auto comboModel = new ComboBoxModel(nullptr, dispName);
-						LilvScalePoints* sps =
-							lilv_port_get_scale_points(m_plugin, lilvPort);
-						LILV_FOREACH(scale_points, i, sps)
+						ComboBoxModel* comboModel = new ComboBoxModel(nullptr, dispName);
+
 						{
-							const LilvScalePoint* sp = lilv_scale_points_get(sps, i);
-							ctrl->m_scalePointMap.push_back(lilv_node_as_float(
-											lilv_scale_point_get_value(sp)));
-							comboModel->addItem(
-								lilv_node_as_string(
-									lilv_scale_point_get_label(sp)));
+							AutoLilvScalePoints sps (static_cast<LilvScalePoints*>(lilv_port_get_scale_points(m_plugin, lilvPort)));
+							// temporary map, since lilv may return scale points in random order
+							std::map<float, const char*> scalePointMap;
+							LILV_FOREACH(scale_points, i, sps.get())
+							{
+								const LilvScalePoint* sp = lilv_scale_points_get(sps.get(), i);
+								const float f = lilv_node_as_float(lilv_scale_point_get_value(sp));
+								const char* s = lilv_node_as_string(lilv_scale_point_get_label(sp));
+								scalePointMap[f] = s;
+							}
+							for (const auto& [f,s] : scalePointMap)
+							{
+								ctrl->m_scalePointMap.push_back(f);
+								comboModel->addItem(s);
+							}
+						}
+						for(std::size_t i = 0; i < ctrl->m_scalePointMap.size(); ++i)
+						{
+							if(meta.def() == ctrl->m_scalePointMap[i])
+							{
+								comboModel->setValue(i);
+								comboModel->setInitValue(i);
+								break;
+							}
 						}
-						lilv_scale_points_free(sps);
 						ctrl->m_connectedModel.reset(comboModel);
-						// TODO: use default value on comboModel, too?
 						break;
 					}
 					case Lv2Ports::Vis::Toggled:

src/core/lv2/Lv2Worker.cpp

@@ -0,0 +1,203 @@
+/*
+ * Lv2Worker.cpp - Lv2Worker implementation
+ *
+ * Copyright (c) 2022-2022 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "Lv2Worker.h"
+
+#include <cassert>
+#include <QDebug>
+
+#ifdef LMMS_HAVE_LV2
+
+#include "Engine.h"
+
+
+namespace lmms
+{
+
+
+// static wrappers
+
+static LV2_Worker_Status
+staticWorkerRespond(LV2_Worker_Respond_Handle handle,
+	uint32_t size, const void* data)
+{
+	Lv2Worker* worker = static_cast<Lv2Worker*>(handle);
+	return worker->respond(size, data);
+}
+
+
+
+
+std::size_t Lv2Worker::bufferSize() const
+{
+	// ardour uses this fixed size for ALSA:
+	return 8192 * 4;
+	// for jack, they use 4 * jack_port_type_get_buffer_size (..., JACK_DEFAULT_MIDI_TYPE)
+	// (possible extension for AudioDevice)
+}
+
+
+
+
+Lv2Worker::Lv2Worker(const LV2_Worker_Interface* iface,
+	Semaphore* common_work_lock,
+	bool threaded) :
+	m_iface(iface),
+	m_threaded(threaded),
+	m_response(bufferSize()),
+	m_requests(bufferSize()),
+	m_responses(bufferSize()),
+	m_requestsReader(m_requests),
+	m_responsesReader(m_responses),
+	m_sem(0),
+	m_workLock(common_work_lock)
+{
+	assert(iface);
+	m_scheduleFeature.handle = static_cast<LV2_Worker_Schedule_Handle>(this);
+	m_scheduleFeature.schedule_work = [](LV2_Worker_Schedule_Handle handle,
+		uint32_t size, const void* data) -> LV2_Worker_Status
+		{
+			Lv2Worker* worker = static_cast<Lv2Worker*>(handle);
+			return worker->scheduleWork(size, data);
+		};
+
+	if (threaded) { m_thread = std::thread(&Lv2Worker::workerFunc, this); }
+
+	m_requests.mlock();
+	m_responses.mlock();
+}
+
+
+
+
+Lv2Worker::~Lv2Worker()
+{
+	m_exit = true;
+	if(m_threaded) {
+		m_sem.post();
+		m_thread.join();
+	}
+}
+
+
+
+
+// Let the worker send responses to the audio thread
+LV2_Worker_Status Lv2Worker::respond(uint32_t size, const void* data)
+{
+	if(m_threaded)
+	{
+		if(m_responses.free() < sizeof(size) + size)
+		{
+			return LV2_WORKER_ERR_NO_SPACE;
+		}
+		else
+		{
+			m_responses.write((const char*)&size, sizeof(size));
+			if(size && data) { m_responses.write((const char*)data, size); }
+		}
+	}
+	else
+	{
+		m_iface->work_response(m_handle, size, data);
+	}
+	return LV2_WORKER_SUCCESS;
+}
+
+
+
+
+// Let the worker receive work from the audio thread and "work" on it
+void Lv2Worker::workerFunc()
+{
+	std::vector<char> buf;
+	uint32_t size;
+	while (true) {
+		m_sem.wait();
+		if (m_exit) { break; }
+		const std::size_t readSpace = m_requestsReader.read_space();
+		if (readSpace <= sizeof(size)) { continue; } // (should not happen)
+
+		m_requestsReader.read(sizeof(size)).copy((char*)&size, sizeof(size));
+		assert(size <= readSpace - sizeof(size));
+		if(size > buf.size()) { buf.resize(size); }
+		if(size) { m_requestsReader.read(size).copy(buf.data(), size); }
+
+		m_workLock->wait();
+		m_iface->work(m_handle, staticWorkerRespond, this, size, buf.data());
+		m_workLock->post();
+	}
+}
+
+
+
+
+// Let the audio thread schedule work for the worker
+LV2_Worker_Status Lv2Worker::scheduleWork(uint32_t size, const void *data)
+{
+	if (m_threaded)
+	{
+		if(m_requests.free() < sizeof(size) + size)
+		{
+			return LV2_WORKER_ERR_NO_SPACE;
+		}
+		else
+		{
+			// Schedule a request to be executed by the worker thread
+			m_requests.write((const char*)&size, sizeof(size));
+			if(size && data) { m_requests.write((const char*)data, size); }
+			m_sem.post();
+		}
+	}
+	else
+	{
+		// Execute work immediately in this thread
+		m_workLock->wait();
+		m_iface->work(m_handle, staticWorkerRespond, this, size, data);
+		m_workLock->post();
+	}
+
+	return LV2_WORKER_SUCCESS;
+}
+
+
+
+
+// Let the audio thread read incoming worker responses, and process it
+void Lv2Worker::emitResponses()
+{
+	std::size_t read_space = m_responsesReader.read_space();
+	uint32_t size;
+	while (read_space > sizeof(size)) {
+		m_responsesReader.read(sizeof(size)).copy((char*)&size, sizeof(size));
+		if(size) { m_responsesReader.read(size).copy(m_response.data(), size); }
+		m_iface->work_response(m_handle, size, m_response.data());
+		read_space -= sizeof(size) + size;
+	}
+}
+
+
+} // namespace lmms
+
+#endif // LMMS_HAVE_LV2

src/gui/Lv2ViewBase.cpp

@@ -39,6 +39,7 @@
 #include "GuiApplication.h"
 #include "embed.h"
 #include "gui_templates.h"
+#include "lmms_math.h"
 #include "Lv2ControlBase.h"
 #include "Lv2Manager.h"
 #include "Lv2Proc.h"
@@ -51,13 +52,13 @@ namespace lmms::gui
 {
 
 
-Lv2ViewProc::Lv2ViewProc(QWidget* parent, Lv2Proc* ctrlBase, int colNum) :
-	LinkedModelGroupView (parent, ctrlBase, colNum)
+Lv2ViewProc::Lv2ViewProc(QWidget* parent, Lv2Proc* proc, int colNum) :
+	LinkedModelGroupView (parent, proc, colNum)
 {
-	class SetupWidget : public Lv2Ports::ConstVisitor
+	class SetupTheWidget : public Lv2Ports::ConstVisitor
 	{
 	public:
-		QWidget* m_par; // input
+		QWidget* m_parent; // input
 		const LilvNode* m_commentUri; // input
 		Control* m_control = nullptr; // output
 		void visit(const Lv2Ports::Control& port) override
@@ -69,20 +70,22 @@ Lv2ViewProc::Lv2ViewProc(QWidget* parent, Lv2Proc* ctrlBase, int colNum) :
 				switch (port.m_vis)
 				{
 					case PortVis::Generic:
-						m_control = new KnobControl(m_par);
+						m_control = new KnobControl(m_parent);
 						break;
 					case PortVis::Integer:
 					{
 						sample_rate_t sr = Engine::audioEngine()->processingSampleRate();
-						m_control = new LcdControl((port.max(sr) <= 9.0f) ? 1 : 2,
-													m_par);
+						auto pMin = port.min(sr);
+						auto pMax = port.max(sr);
+						int numDigits = std::max(numDigitsAsInt(pMin), numDigitsAsInt(pMax));
+						m_control = new LcdControl(numDigits, m_parent);
 						break;
 					}
 					case PortVis::Enumeration:
-						m_control = new ComboControl(m_par);
+						m_control = new ComboControl(m_parent);
 						break;
 					case PortVis::Toggled:
-						m_control = new CheckControl(m_par);
+						m_control = new CheckControl(m_parent);
 						break;
 				}
 				m_control->setText(port.name());
@@ -100,14 +103,14 @@ Lv2ViewProc::Lv2ViewProc(QWidget* parent, Lv2Proc* ctrlBase, int colNum) :
 	};
 
 	AutoLilvNode commentUri = uri(LILV_NS_RDFS "comment");
-	ctrlBase->foreach_port(
+	proc->foreach_port(
 		[this, &commentUri](const Lv2Ports::PortBase* port)
 		{
 			if(!lilv_port_has_property(port->m_plugin, port->m_port,
 										uri(LV2_PORT_PROPS__notOnGUI).get()))
 			{
-				SetupWidget setup;
-				setup.m_par = this;
+				SetupTheWidget setup;
+				setup.m_parent = this;
 				setup.m_commentUri = commentUri.get();
 				port->accept(setup);
 

src/gui/modals/SetupDialog.cpp

@@ -579,32 +579,39 @@ SetupDialog::SetupDialog(ConfigTab tab_to_open) :
 
 	// Buffer size tab.
 	auto bufferSize_tw = new TabWidget(tr("Buffer size"), audio_w);
-	bufferSize_tw->setFixedHeight(76);
+	auto bufferSize_layout = new QVBoxLayout(bufferSize_tw);
+	bufferSize_layout->setSpacing(10);
+	bufferSize_layout->setContentsMargins(10, 18, 10, 10);
 
 	m_bufferSizeSlider = new QSlider(Qt::Horizontal, bufferSize_tw);
 	m_bufferSizeSlider->setRange(1, 128);
 	m_bufferSizeSlider->setTickInterval(8);
 	m_bufferSizeSlider->setPageStep(8);
 	m_bufferSizeSlider->setValue(m_bufferSize / BUFFERSIZE_RESOLUTION);
-	m_bufferSizeSlider->setGeometry(10, 18, 340, 18);
 	m_bufferSizeSlider->setTickPosition(QSlider::TicksBelow);
 
+	m_bufferSizeLbl = new QLabel(bufferSize_tw);
+
+	m_bufferSizeWarnLbl = new QLabel(bufferSize_tw);
+	m_bufferSizeWarnLbl->setWordWrap(true);
+
 	connect(m_bufferSizeSlider, SIGNAL(valueChanged(int)),
 			this, SLOT(setBufferSize(int)));
 	connect(m_bufferSizeSlider, SIGNAL(valueChanged(int)),
 			this, SLOT(showRestartWarning()));
-
-	m_bufferSizeLbl = new QLabel(bufferSize_tw);
-	m_bufferSizeLbl->setGeometry(10, 40, 200, 24);
 	setBufferSize(m_bufferSizeSlider->value());
 
 	auto bufferSize_reset_btn = new QPushButton(embed::getIconPixmap("reload"), "", bufferSize_tw);
-	bufferSize_reset_btn->setGeometry(320, 40, 28, 28);
 	connect(bufferSize_reset_btn, SIGNAL(clicked()),
 			this, SLOT(resetBufferSize()));
 	bufferSize_reset_btn->setToolTip(
 			tr("Reset to default value"));
 
+	bufferSize_layout->addWidget(m_bufferSizeSlider);
+	bufferSize_layout->addWidget(m_bufferSizeLbl);
+	bufferSize_layout->addWidget(m_bufferSizeWarnLbl);
+	bufferSize_layout->addWidget(bufferSize_reset_btn);
+
 
 	// Audio layout ordering.
 	audio_layout->addWidget(audioiface_tw);
@@ -1172,6 +1179,24 @@ void SetupDialog::audioInterfaceChanged(const QString & iface)
 }
 
 
+void SetupDialog::updateBufferSizeWarning(int value)
+{
+	QString text = "<ul>";
+	if((value & (value - 1)) != 0)  // <=> value is not a power of 2 (for value > 0)
+	{
+		text += "<li>" + tr("The currently selected value is not a power of 2 "
+					"(32, 64, 128, 256, 512, 1024, ...). Some plugins may not be available.") + "</li>";
+	}
+	if(value <= 32)
+	{
+		text += "<li>" + tr("The currently selected value is less than or equal to 32. "
+					"Some plugins may not be available.") + "</li>";
+	}
+	text += "</ul>";
+	m_bufferSizeWarnLbl->setText(text);
+}
+
+
 void SetupDialog::setBufferSize(int value)
 {
 	const int step = DEFAULT_BUFFER_SIZE / BUFFERSIZE_RESOLUTION;
@@ -1197,6 +1222,7 @@ void SetupDialog::setBufferSize(int value)
 	m_bufferSize = value * BUFFERSIZE_RESOLUTION;
 	m_bufferSizeLbl->setText(tr("Frames: %1\nLatency: %2 ms").arg(m_bufferSize).arg(
 		1000.0f * m_bufferSize / Engine::audioEngine()->processingSampleRate(), 0, 'f', 1));
+	updateBufferSizeWarning(m_bufferSize);
 }
 
 

tests/CMakeLists.txt

@@ -21,6 +21,7 @@ ADD_EXECUTABLE(tests
 
 	src/core/ArrayVectorTest.cpp
 	src/core/AutomatableModelTest.cpp
+	src/core/MathTest.cpp
 	src/core/ProjectVersionTest.cpp
 	src/core/RelativePathsTest.cpp
 

tests/src/core/MathTest.cpp

@@ -0,0 +1,53 @@
+/*
+ * MathTest.cpp
+ *
+ * Copyright (c) 2023 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "QTestSuite.h"
+
+#include "lmms_math.h"
+
+#include <QDir>
+
+class MathTest : QTestSuite
+{
+	Q_OBJECT
+private slots:
+	void NumDigitsTest()
+	{
+		using namespace lmms;
+		QCOMPARE(numDigitsAsInt(1.f), 1);
+		QCOMPARE(numDigitsAsInt(9.9f), 2);
+		QCOMPARE(numDigitsAsInt(10.f), 2);
+		QCOMPARE(numDigitsAsInt(0.f), 1);
+		QCOMPARE(numDigitsAsInt(-100.f), 4);
+		QCOMPARE(numDigitsAsInt(-99.f), 3);
+		QCOMPARE(numDigitsAsInt(-0.4f), 1); // there is no "-0" for LED spinbox
+		QCOMPARE(numDigitsAsInt(-0.99f), 2);
+		QCOMPARE(numDigitsAsInt(1000000000), 10);
+		QCOMPARE(numDigitsAsInt(-1000000000), 11);
+		QCOMPARE(numDigitsAsInt(900000000), 9);
+		QCOMPARE(numDigitsAsInt(-900000000), 10);
+	}
+} MathTests;
+
+#include "MathTest.moc"