Fixes #6401: Reload Lv2 plugin on SR change

This also includes banning blop's wavedata plugins, because they crash
on reloading. Reference: https://gitlab.com/drobilla/blop-lv2/-/issues/3

src/core/lv2/Lv2ControlBase.cpp

@@ -54,30 +54,7 @@ Lv2ControlBase::Lv2ControlBase(Model* that, const QString &uri) :
 {
 	if (m_plugin)
 	{
-		int channelsLeft = DEFAULT_CHANNELS; // LMMS plugins are stereo
-		while (channelsLeft > 0)
-		{
-			std::unique_ptr<Lv2Proc> newOne = std::make_unique<Lv2Proc>(m_plugin, that);
-			if (newOne->isValid())
-			{
-				channelsLeft -= std::max(
-					1 + static_cast<bool>(newOne->inPorts().m_right),
-					1 + static_cast<bool>(newOne->outPorts().m_right));
-				Q_ASSERT(channelsLeft >= 0);
-				m_procs.push_back(std::move(newOne));
-			}
-			else
-			{
-				qCritical() << "Failed instantiating LV2 processor";
-				m_valid = false;
-				channelsLeft = 0;
-			}
-		}
-		if (m_valid)
-		{
-			m_channelsPerProc = DEFAULT_CHANNELS / m_procs.size();
-			linkAllModels();
-		}
+		init(that);
 	}
 	else
 	{
@@ -94,6 +71,53 @@ Lv2ControlBase::~Lv2ControlBase() = default;
 
 
 
+void Lv2ControlBase::init(Model* meAsModel)
+{
+	int channelsLeft = DEFAULT_CHANNELS; // LMMS plugins are stereo
+	while (channelsLeft > 0)
+	{
+		std::unique_ptr<Lv2Proc> newOne = std::make_unique<Lv2Proc>(m_plugin, meAsModel);
+		if (newOne->isValid())
+		{
+			channelsLeft -= std::max(
+				1 + static_cast<bool>(newOne->inPorts().m_right),
+				1 + static_cast<bool>(newOne->outPorts().m_right));
+			Q_ASSERT(channelsLeft >= 0);
+			m_procs.push_back(std::move(newOne));
+		}
+		else
+		{
+			qCritical() << "Failed instantiating LV2 processor";
+			m_valid = false;
+			channelsLeft = 0;
+		}
+	}
+	if (m_valid)
+	{
+		m_channelsPerProc = DEFAULT_CHANNELS / m_procs.size();
+		linkAllModels();
+	}
+}
+
+
+
+
+void Lv2ControlBase::shutdown()
+{
+	// currently nothing to do here
+}
+
+
+
+
+void Lv2ControlBase::reload()
+{
+	for (const auto& c : m_procs) { c->reload(); }
+}
+
+
+
+
 LinkedModelGroup *Lv2ControlBase::getGroup(std::size_t idx)
 {
 	return (m_procs.size() > idx) ? m_procs[idx].get() : nullptr;
@@ -183,14 +207,6 @@ void Lv2ControlBase::loadFile(const QString &file)
 
 
 
-void Lv2ControlBase::reloadPlugin()
-{
-	// TODO
-}
-
-
-
-
 std::size_t Lv2ControlBase::controlCount() const {
 	std::size_t res = 0;
 	for (const auto& c : m_procs) { res += c->controlCount(); }

src/core/lv2/Lv2Features.cpp

@@ -105,6 +105,14 @@ void *&Lv2Features::operator[](const char *featName)
 }
 
 
+
+
+void Lv2Features::clear()
+{
+	m_featureByUri.clear();
+}
+
+
 } // namespace lmms
 
 #endif // LMMS_HAVE_LV2

src/core/lv2/Lv2Manager.cpp

@@ -60,6 +60,12 @@ const std::set<const char*, Lv2Manager::CmpStr> Lv2Manager::pluginBlacklist =
 	"http://calf.sourceforge.net/plugins/TransientDesigner",
 	"http://calf.sourceforge.net/plugins/Vinyl",
 
+	// https://gitlab.com/drobilla/blop-lv2/-/issues/3
+	"http://drobilla.net/plugins/blop/pulse",
+	"http://drobilla.net/plugins/blop/sawtooth",
+	"http://drobilla.net/plugins/blop/square",
+	"http://drobilla.net/plugins/blop/triangle",
+
 	// Visualization, meters, and scopes etc., won't work until we have gui support
 	"http://distrho.sf.net/plugins/ProM",
 	"http://distrho.sf.net/plugins/glBars",

src/core/lv2/Lv2Proc.cpp

@@ -31,6 +31,7 @@
 #include <lv2/lv2plug.in/ns/ext/atom/atom.h>
 #include <lv2/lv2plug.in/ns/ext/resize-port/resize-port.h>
 #include <QDebug>
+#include <QDomDocument>
 #include <QtGlobal>
 
 #include "AudioEngine.h"
@@ -175,6 +176,26 @@ Lv2Proc::~Lv2Proc() { shutdownPlugin(); }
 
 
 
+void Lv2Proc::reload()
+{
+	// save controls, which we want to keep
+	QDomDocument doc;
+	QDomElement controls = doc.createElement("controls");
+	saveValues(doc, controls);
+	// backup construction variables
+	const LilvPlugin* plugin = m_plugin;
+	Model* parent = Model::parentModel();
+	// destroy everything using RAII ...
+	this->~Lv2Proc();
+	// ... and reuse it ("placement new")
+	new (this) Lv2Proc(plugin, parent);
+	// reload the controls
+	loadValues(controls);
+}
+
+
+
+
 void Lv2Proc::dumpPorts()
 {
 	std::size_t num = 0;
@@ -424,7 +445,10 @@ void Lv2Proc::shutdownPlugin()
 		lilv_instance_deactivate(m_instance);
 		lilv_instance_free(m_instance);
 		m_instance = nullptr;
+
+		m_features.clear();
 	}
+	m_valid = true;
 }