diff --git a/source/backend/native/3bandeq/DistrhoPlugin3BandEQ.cpp b/source/backend/native/3bandeq/DistrhoPlugin3BandEQ.cpp
index e0d991cbf..e85ac5784 100644
--- a/source/backend/native/3bandeq/DistrhoPlugin3BandEQ.cpp
+++ b/source/backend/native/3bandeq/DistrhoPlugin3BandEQ.cpp
@@ -209,11 +209,11 @@ void DistrhoPlugin3BandEQ::d_setProgram(uint32_t index)
 
 void DistrhoPlugin3BandEQ::d_activate()
 {
-    xLP  = exp(-2.0 * cfPI * freqLP / d_sampleRate());
+    xLP  = std::exp(-2.0 * cfPI * freqLP / d_sampleRate());
     a0LP = 1.0f - xLP;
     b1LP = -xLP;
 
-    xHP  = exp(-2.0 * cfPI * freqHP / d_sampleRate());
+    xHP  = std::exp(-2.0 * cfPI * freqHP / d_sampleRate());
     a0HP = 1.0f - xHP;
     b1HP = -xHP;
 }
@@ -226,8 +226,8 @@ void DistrhoPlugin3BandEQ::d_deactivate()
 
 void DistrhoPlugin3BandEQ::d_run(float** inputs, float** outputs, uint32_t frames, uint32_t, const MidiEvent*)
 {
-    const float* in1 = inputs[0];
-    const float* in2 = inputs[1];
+    float* in1  = inputs[0];
+    float* in2  = inputs[1];
     float* out1 = outputs[0];
     float* out2 = outputs[1];
 
diff --git a/source/backend/native/3bandeq/DistrhoPluginInfo.h b/source/backend/native/3bandeq/DistrhoPluginInfo.h
index 6e73edffe..e40fdb3a3 100644
--- a/source/backend/native/3bandeq/DistrhoPluginInfo.h
+++ b/source/backend/native/3bandeq/DistrhoPluginInfo.h
@@ -33,11 +33,10 @@
 
 #ifdef QTCREATOR_TEST
 // TESTING
-#include "3bandeq/DistrhoPluginInfo.h"
 # undef DISTRHO_PLUGIN_IS_SYNTH
 # undef DISTRHO_PLUGIN_WANT_LATENCY
 # undef DISTRHO_PLUGIN_WANT_STATE
-# define DISTRHO_PLUGIN_IS_SYNTH 1
+# define DISTRHO_PLUGIN_IS_SYNTH     1
 # define DISTRHO_PLUGIN_WANT_LATENCY 1
 # define DISTRHO_PLUGIN_WANT_STATE   1
 #endif
diff --git a/source/backend/native/3bandsplitter/DistrhoPlugin3BandSplitter.cpp b/source/backend/native/3bandsplitter/DistrhoPlugin3BandSplitter.cpp
index 9b0e17f1e..ced55e10b 100644
--- a/source/backend/native/3bandsplitter/DistrhoPlugin3BandSplitter.cpp
+++ b/source/backend/native/3bandsplitter/DistrhoPlugin3BandSplitter.cpp
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Lesser General Public License for more details.
  *
  * For a full copy of the license see the LGPL.txt file
@@ -209,11 +209,11 @@ void DistrhoPlugin3BandSplitter::d_setProgram(uint32_t index)
 
 void DistrhoPlugin3BandSplitter::d_activate()
 {
-    xLP  = exp(-2.0 * cfPI * freqLP / d_sampleRate());
+    xLP  = std::exp(-2.0 * cfPI * freqLP / d_sampleRate());
     a0LP = 1.0f - xLP;
     b1LP = -xLP;
 
-    xHP  = exp(-2.0 * cfPI * freqHP / d_sampleRate());
+    xHP  = std::exp(-2.0 * cfPI * freqHP / d_sampleRate());
     a0HP = 1.0f - xHP;
     b1HP = -xHP;
 }
@@ -226,8 +226,8 @@ void DistrhoPlugin3BandSplitter::d_deactivate()
 
 void DistrhoPlugin3BandSplitter::d_run(float** inputs, float** outputs, uint32_t frames, uint32_t, const MidiEvent*)
 {
-    const float* in1 = inputs[0];
-    const float* in2 = inputs[1];
+    float* in1  = inputs[0];
+    float* in2  = inputs[1];
     float* out1 = outputs[0];
     float* out2 = outputs[1];
     float* out3 = outputs[2];
diff --git a/source/backend/native/Makefile b/source/backend/native/Makefile
new file mode 100644
index 000000000..329823706
--- /dev/null
+++ b/source/backend/native/Makefile
@@ -0,0 +1,83 @@
+#!/usr/bin/make -f
+# Makefile for carla-native #
+# ------------------------------------ #
+# Created by falkTX
+#
+
+include ../../Makefile.mk
+
+# --------------------------------------------------------------
+
+BUILD_C_FLAGS   += -fvisibility=hidden -fPIC -I. -I.. -I../../includes
+BUILD_CXX_FLAGS += -fvisibility=hidden -fPIC -I. -I.. -I../../includes -I../../utils -I../../libs/distrho-plugin-toolkit
+BUILD_CXX_FLAGS += $(shell pkg-config --cflags QtCore QtGui)
+
+LINK_FLAGS      += -shared
+LINK_FLAGS      += $(shell pkg-config --libs QtCore QtGui)
+
+ifeq ($(HAVE_ZYN_DEPS),true)
+ZYN_CXX_FLAGS    = $(BUILD_CXX_FLAGS)
+ZYN_CXX_FLAGS   += $(shell pkg-config --cflags fftw3 mxml)
+LINK_FLAGS      += $(shell pkg-config --libs fftw3 mxml)
+endif
+
+# --------------------------------------------------------------
+
+# Simple plugins
+OBJS  = \
+	bypass.c.o \
+	midi-split.c.o \
+	midi-through.c.o
+
+# DISTRHO plugins
+OBJS += \
+	distrho-3bandeq.cpp.o \
+	distrho-3bandsplitter.cpp.o \
+	distrho-pingpongpan.cpp.o
+
+# ZynAddSubFX
+ifeq ($(HAVE_ZYN_DEPS),true)
+OBJS += \
+	zynaddsubfx.cpp.o \
+	zynaddsubfx-src.cpp.o
+endif
+
+TARGET = ../carla_native.so
+
+# --------------------------------------------------------------
+
+all: $(TARGET)
+
+clean:
+	rm -f $(OBJS) $(TARGET)
+
+# --------------------------------------------------------------
+
+%.c.o: %.c
+	$(CC) $< $(BUILD_C_FLAGS) -c -o $@
+
+%.cpp.o: %.cpp
+	$(CXX) $< $(BUILD_CXX_FLAGS) -c -o $@
+
+$(TARGET): $(OBJS)
+	$(CXX) $^ $(LINK_FLAGS) -o $@
+
+# --------------------------------------------------------------
+
+distrho-3bandeq.cpp.o: distrho-3bandeq.cpp
+	$(CXX) $< $(BUILD_CXX_FLAGS) -I3bandeq -DDISTRHO_NAMESPACE=DISTRHO_3BandEQ -c -o $@
+
+distrho-3bandsplitter.cpp.o: distrho-3bandsplitter.cpp
+	$(CXX) $< $(BUILD_CXX_FLAGS) -I3bandsplitter -DDISTRHO_NAMESPACE=DISTRHO_3BandSplitter -c -o $@
+
+distrho-pingpongpan.cpp.o: distrho-pingpongpan.cpp
+	$(CXX) $< $(BUILD_CXX_FLAGS) -Ipingpongpan -DDISTRHO_NAMESPACE=DISTRHO_PingPongPan -c -o $@
+
+# distrho-pugl.o: distrho-pugl.cpp
+# 	$(CXX) $< $(BUILD_CXX_FLAGS) -c -o $@
+
+zynaddsubfx.cpp.o: zynaddsubfx.cpp
+	$(CXX) $< $(ZYN_CXX_FLAGS) -c -o $@
+
+zynaddsubfx-src.cpp.o: zynaddsubfx-src.cpp
+	$(CXX) $< $(ZYN_CXX_FLAGS) -c -o $@
diff --git a/source/backend/native/distrho-3bandeq.cpp b/source/backend/native/distrho-3bandeq.cpp
index adaafe1f4..b49dbc0a3 100644
--- a/source/backend/native/distrho-3bandeq.cpp
+++ b/source/backend/native/distrho-3bandeq.cpp
@@ -1,6 +1,6 @@
 /*
  * Carla Native Plugins
- * Copyright (C) 2012 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2013 Filipe Coelho <falktx@falktx.com>
  *
  * 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
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the GNU General Public License see the COPYING file
@@ -31,7 +31,7 @@ START_NAMESPACE_DISTRHO
 
 static PluginDescriptor tBandEqDesc = {
     /* category  */ ::PLUGIN_CATEGORY_EQ,
-    /* hints     */ ::PLUGIN_IS_RTSAFE | ::PLUGIN_HAS_GUI,
+    /* hints     */ static_cast<PluginHints>(::PLUGIN_IS_RTSAFE | ::PLUGIN_HAS_GUI),
     /* audioIns  */ DISTRHO_PLUGIN_NUM_INPUTS,
     /* audioOuts */ DISTRHO_PLUGIN_NUM_OUTPUTS,
     /* midiIns   */ 0,
diff --git a/source/backend/native/distrho-3bandsplitter.cpp b/source/backend/native/distrho-3bandsplitter.cpp
index 4c509362d..44ce49eec 100644
--- a/source/backend/native/distrho-3bandsplitter.cpp
+++ b/source/backend/native/distrho-3bandsplitter.cpp
@@ -1,6 +1,6 @@
 /*
  * Carla Native Plugins
- * Copyright (C) 2012 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2013 Filipe Coelho <falktx@falktx.com>
  *
  * 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
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the GNU General Public License see the COPYING file
@@ -31,7 +31,7 @@ START_NAMESPACE_DISTRHO
 
 static PluginDescriptor tBandSplitterDesc = {
     /* category  */ ::PLUGIN_CATEGORY_EQ,
-    /* hints     */ ::PLUGIN_HAS_GUI,
+    /* hints     */ static_cast<PluginHints>(::PLUGIN_IS_RTSAFE | ::PLUGIN_HAS_GUI),
     /* audioIns  */ DISTRHO_PLUGIN_NUM_INPUTS,
     /* audioOuts */ DISTRHO_PLUGIN_NUM_OUTPUTS,
     /* midiIns   */ 0,
diff --git a/source/backend/native/distrho-pingpongpan.cpp b/source/backend/native/distrho-pingpongpan.cpp
index 3315d362e..78b9e5ae2 100644
--- a/source/backend/native/distrho-pingpongpan.cpp
+++ b/source/backend/native/distrho-pingpongpan.cpp
@@ -1,6 +1,6 @@
 /*
  * Carla Native Plugins
- * Copyright (C) 2012 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2013 Filipe Coelho <falktx@falktx.com>
  *
  * 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
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the GNU General Public License see the COPYING file
@@ -31,7 +31,7 @@ START_NAMESPACE_DISTRHO
 
 static PluginDescriptor tBandEqDesc = {
     /* category  */ ::PLUGIN_CATEGORY_UTILITY,
-    /* hints     */ ::PLUGIN_HAS_GUI,
+    /* hints     */ static_cast<PluginHints>(::PLUGIN_IS_RTSAFE | ::PLUGIN_HAS_GUI),
     /* audioIns  */ DISTRHO_PLUGIN_NUM_INPUTS,
     /* audioOuts */ DISTRHO_PLUGIN_NUM_OUTPUTS,
     /* midiIns   */ 0,
diff --git a/source/backend/native/distrho/DistrhoPluginCarla.cpp b/source/backend/native/distrho/DistrhoPluginCarla.cpp
index aa88ff4a3..43f9d1ef8 100644
--- a/source/backend/native/distrho/DistrhoPluginCarla.cpp
+++ b/source/backend/native/distrho/DistrhoPluginCarla.cpp
@@ -1,6 +1,6 @@
 /*
  * DISTHRO Plugin Toolkit (DPT)
- * Copyright (C) 2012 Filipe Coelho <falktx@gmail.com>
+ * Copyright (C) 2012-2013 Filipe Coelho <falktx@gmail.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the license see the GPL.txt file
@@ -40,26 +40,16 @@ public:
         : QDialog(nullptr),
           m_host(host),
           m_plugin(plugin),
-          ui(this, realWinId(), setParameterCallback, setStateCallback, uiEditParameterCallback, uiSendNoteCallback, uiResizeCallback)
+          ui(this, (intptr_t)winId(), setParameterCallback, setStateCallback, uiEditParameterCallback, uiSendNoteCallback, uiResizeCallback)
     {
         setFixedSize(ui.getWidth(), ui.getHeight());
-        setWindowTitle("TEST GUI");
+        setWindowTitle(DISTRHO_PLUGIN_NAME);
     }
 
     ~UICarla()
     {
     }
 
-    intptr_t realWinId() const
-    {
-        WId wId = winId();
-#if DISTRHO_OS_WINDOWS
-        return (intptr_t)static_cast<HWND>(wId);
-#else
-        return wId;
-#endif
-    }
-
     // ---------------------------------------------
 
     void carla_show(const bool yesNo)
@@ -142,20 +132,19 @@ private:
 
     static void setParameterCallback(void* ptr, uint32_t rindex, float value)
     {
-        UICarla* _this_ = (UICarla*)ptr;
-        CARLA_ASSERT(_this_);
-
-        _this_->setParameterValue(rindex, value);
+        if (UICarla* _this_ = (UICarla*)ptr)
+            _this_->setParameterValue(rindex, value);
     }
 
     static void setStateCallback(void* ptr, const char* key, const char* value)
     {
 # if DISTRHO_PLUGIN_WANT_STATE
-        UICarla* _this_ = (UICarla*)ptr;
-        CARLA_ASSERT(_this_);
-
-        _this_->setState(key, value);
+        if (UICarla* _this_ = (UICarla*)ptr)
+            _this_->setState(key, value);
 # else
+        return;
+
+        // unused
         Q_UNUSED(ptr);
         Q_UNUSED(key);
         Q_UNUSED(value);
@@ -164,20 +153,19 @@ private:
 
     static void uiEditParameterCallback(void* ptr, uint32_t index, bool started)
     {
-        UICarla* _this_ = (UICarla*)ptr;
-        CARLA_ASSERT(_this_);
-
-        _this_->uiEditParameter(index, started);
+        if (UICarla* _this_ = (UICarla*)ptr)
+            _this_->uiEditParameter(index, started);
     }
 
     static void uiSendNoteCallback(void* ptr, bool onOff, uint8_t channel, uint8_t note, uint8_t velocity)
     {
 # if DISTRHO_PLUGIN_IS_SYNTH
-        UICarla* _this_ = (UICarla*)ptr;
-        CARLA_ASSERT(_this_);
-
-        _this_->uiSendNote(onOff, channel, note, velocity);
+        if (UICarla* _this_ = (UICarla*)ptr)
+            _this_->uiSendNote(onOff, channel, note, velocity);
 # else
+        return;
+
+        // unused
         Q_UNUSED(ptr);
         Q_UNUSED(onOff);
         Q_UNUSED(channel);
@@ -188,10 +176,8 @@ private:
 
     static void uiResizeCallback(void* ptr, unsigned int width, unsigned int height)
     {
-        UICarla* _this_ = (UICarla*)ptr;
-        CARLA_ASSERT(_this_);
-
-        _this_->uiResize(width, height);
+        if (UICarla* _this_ = (UICarla*)ptr)
+            _this_->uiResize(width, height);
     }
 };
 #endif
@@ -236,21 +222,24 @@ protected:
 
         {
             const uint32_t paramHints = plugin.parameterHints(index);
+            int nativeparamHints = 0;
 
             if (paramHints & PARAMETER_IS_AUTOMABLE)
-                param.hints |= ::PARAMETER_IS_AUTOMABLE;
+                nativeparamHints |= ::PARAMETER_IS_AUTOMABLE;
             if (paramHints & PARAMETER_IS_BOOLEAN)
-                param.hints |= ::PARAMETER_IS_BOOLEAN;
+                nativeparamHints |= ::PARAMETER_IS_BOOLEAN;
             if (paramHints & PARAMETER_IS_INTEGER)
-                param.hints |= ::PARAMETER_IS_INTEGER;
+                nativeparamHints |= ::PARAMETER_IS_INTEGER;
             if (paramHints & PARAMETER_IS_LOGARITHMIC)
-                param.hints |= ::PARAMETER_IS_LOGARITHMIC;
+                nativeparamHints |= ::PARAMETER_IS_LOGARITHMIC;
             if (paramHints & PARAMETER_IS_OUTPUT)
-                param.hints |= ::PARAMETER_IS_OUTPUT;
+                nativeparamHints |= ::PARAMETER_IS_OUTPUT;
+
+            param.hints = static_cast<ParameterHints>(nativeparamHints);
         }
 
-        param.name  = plugin.parameterName(index);
-        param.unit  = plugin.parameterUnit(index);
+        param.name = plugin.parameterName(index);
+        param.unit = plugin.parameterUnit(index);
 
         {
             const ParameterRanges& ranges(plugin.parameterRanges(index));
diff --git a/source/backend/native/pingpongpan/DistrhoPluginPingPongPan.cpp b/source/backend/native/pingpongpan/DistrhoPluginPingPongPan.cpp
index 2b4f51a47..08a785a40 100644
--- a/source/backend/native/pingpongpan/DistrhoPluginPingPongPan.cpp
+++ b/source/backend/native/pingpongpan/DistrhoPluginPingPongPan.cpp
@@ -136,8 +136,8 @@ void DistrhoPluginPingPongPan::d_deactivate()
 
 void DistrhoPluginPingPongPan::d_run(float** inputs, float** outputs, uint32_t frames, uint32_t, const MidiEvent*)
 {
-    const float* in1 = inputs[0];
-    const float* in2 = inputs[1];
+    float* in1  = inputs[0];
+    float* in2  = inputs[1];
     float* out1 = outputs[0];
     float* out2 = outputs[1];
 
diff --git a/source/libs/distrho-plugin-toolkit/DistrhoPlugin.h b/source/libs/distrho-plugin-toolkit/DistrhoPlugin.h
index 32b6633fb..b966160ea 100644
--- a/source/libs/distrho-plugin-toolkit/DistrhoPlugin.h
+++ b/source/libs/distrho-plugin-toolkit/DistrhoPlugin.h
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the license see the GPL.txt file
@@ -90,10 +90,7 @@ struct Parameter {
     ParameterRanges ranges;
 
     Parameter()
-        : hints(0x0),
-          name(nullptr),
-          symbol(nullptr),
-          unit(nullptr) {}
+        : hints(0x0) {}
 };
 
 // -------------------------------------------------
@@ -104,8 +101,9 @@ struct MidiEvent {
     uint8_t  buffer[3];
 
     MidiEvent()
-        : frame(0),
-          buffer{0} {}
+    {
+        clear();
+    }
 
     void clear()
     {
diff --git a/source/libs/distrho-plugin-toolkit/DistrhoPluginMain.cpp b/source/libs/distrho-plugin-toolkit/DistrhoPluginMain.cpp
index 22da58036..26403a7d5 100644
--- a/source/libs/distrho-plugin-toolkit/DistrhoPluginMain.cpp
+++ b/source/libs/distrho-plugin-toolkit/DistrhoPluginMain.cpp
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the license see the GPL.txt file
diff --git a/source/libs/distrho-plugin-toolkit/DistrhoUtils.h b/source/libs/distrho-plugin-toolkit/DistrhoUtils.h
index d1d0a313b..ef334e06a 100644
--- a/source/libs/distrho-plugin-toolkit/DistrhoUtils.h
+++ b/source/libs/distrho-plugin-toolkit/DistrhoUtils.h
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the license see the GPL.txt file
diff --git a/source/libs/distrho-plugin-toolkit/src/DistrhoDefines.h b/source/libs/distrho-plugin-toolkit/src/DistrhoDefines.h
index a35d4c890..39e0633eb 100644
--- a/source/libs/distrho-plugin-toolkit/src/DistrhoDefines.h
+++ b/source/libs/distrho-plugin-toolkit/src/DistrhoDefines.h
@@ -15,8 +15,8 @@
  * For a full copy of the license see the GPL.txt file
  */
 
-#ifndef __DISTRHO_DEFINES_HPP__
-#define __DISTRHO_DEFINES_HPP__
+#ifndef __DISTRHO_DEFINES_H__
+#define __DISTRHO_DEFINES_H__
 
 #if defined(__WIN32__) || defined(__WIN64__)
 # define DISTRHO_PLUGIN_EXPORT extern "C" __declspec (dllexport)
@@ -53,4 +53,4 @@
 # define USE_NAMESPACE_DISTRHO
 #endif
 
-#endif // __DISTRHO_DEFINES_HPP__
+#endif // __DISTRHO_DEFINES_H__
diff --git a/source/libs/distrho-plugin-toolkit/src/DistrhoMacros.h b/source/libs/distrho-plugin-toolkit/src/DistrhoMacros.h
index 447d1e422..d45881f98 100644
--- a/source/libs/distrho-plugin-toolkit/src/DistrhoMacros.h
+++ b/source/libs/distrho-plugin-toolkit/src/DistrhoMacros.h
@@ -15,8 +15,8 @@
  * For a full copy of the license see the GPL.txt file
  */
 
-#ifndef __DISTRHO_MACROS_HPP__
-#define __DISTRHO_MACROS_HPP__
+#ifndef __DISTRHO_MACROS_H__
+#define __DISTRHO_MACROS_H__
 
 #include "DistrhoDefines.h"
 #include "DistrhoPluginInfo.h"
@@ -59,4 +59,4 @@
 
 #define DISTRHO_UI_URI DISTRHO_PLUGIN_URI "#UI"
 
-#endif // __DISTRHO_MACROS_HPP__
+#endif // __DISTRHO_MACROS_H__
diff --git a/source/libs/distrho-plugin-toolkit/src/DistrhoPlugin.cpp b/source/libs/distrho-plugin-toolkit/src/DistrhoPlugin.cpp
index b28dee653..e3717ee5a 100644
--- a/source/libs/distrho-plugin-toolkit/src/DistrhoPlugin.cpp
+++ b/source/libs/distrho-plugin-toolkit/src/DistrhoPlugin.cpp
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the license see the GPL.txt file
@@ -41,14 +41,14 @@ Plugin::Plugin(uint32_t parameterCount, uint32_t programCount, uint32_t stateCou
     if (parameterCount > 0)
     {
         data->parameterCount = parameterCount;
-        data->parameters = new Parameter [parameterCount];
+        data->parameters = new Parameter[parameterCount];
     }
 
     if (programCount > 0)
     {
 #if DISTRHO_PLUGIN_WANT_PROGRAMS
         data->programCount = programCount;
-        data->programNames = new d_string [programCount];
+        data->programNames = new d_string[programCount];
 #endif
     }
 
@@ -56,7 +56,7 @@ Plugin::Plugin(uint32_t parameterCount, uint32_t programCount, uint32_t stateCou
     {
 #if DISTRHO_PLUGIN_WANT_STATE
         data->stateCount = stateCount;
-        data->stateKeys  = new d_string [stateCount];
+        data->stateKeys  = new d_string[stateCount];
 #endif
     }
 }
diff --git a/source/libs/distrho-plugin-toolkit/src/DistrhoPluginInternal.h b/source/libs/distrho-plugin-toolkit/src/DistrhoPluginInternal.h
index 89f8081af..3f16bf459 100644
--- a/source/libs/distrho-plugin-toolkit/src/DistrhoPluginInternal.h
+++ b/source/libs/distrho-plugin-toolkit/src/DistrhoPluginInternal.h
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the license see the GPL.txt file
@@ -42,12 +42,10 @@ struct PluginPrivateData {
     uint32_t  programCount;
     d_string* programNames;
 #endif
-
 #if DISTRHO_PLUGIN_WANT_STATE
     uint32_t  stateCount;
     d_string* stateKeys;
 #endif
-
 #if DISTRHO_PLUGIN_WANT_LATENCY
     uint32_t latency;
 #endif
@@ -308,10 +306,10 @@ public:
 
         if (data)
         {
-            data->bufferSize = bufferSize;
-
             if (callback && data->bufferSize == bufferSize)
                 callback = false;
+
+            data->bufferSize = bufferSize;
         }
 
         if (plugin && callback)
@@ -328,10 +326,10 @@ public:
 
         if (data)
         {
-            data->sampleRate = sampleRate;
-
             if (callback && data->sampleRate == sampleRate)
                 callback = false;
+
+            data->sampleRate = sampleRate;
         }
 
         if (plugin && callback)
diff --git a/source/libs/distrho-plugin-toolkit/src/DistrhoUIInternal.h b/source/libs/distrho-plugin-toolkit/src/DistrhoUIInternal.h
index 033849dc9..daf3f7b6a 100644
--- a/source/libs/distrho-plugin-toolkit/src/DistrhoUIInternal.h
+++ b/source/libs/distrho-plugin-toolkit/src/DistrhoUIInternal.h
@@ -9,7 +9,7 @@
  *
  * 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * For a full copy of the license see the GPL.txt file
@@ -41,9 +41,9 @@ START_NAMESPACE_DISTRHO
 // -------------------------------------------------
 
 #ifdef DISTRHO_UI_OPENGL
-typedef PuglView* NativeWidget;
+typedef PuglView NativeWidget;
 #else
-typedef QWidget*  NativeWidget;
+typedef QWidget  NativeWidget;
 #endif
 
 typedef void (*setParamFunc)    (void* ptr, uint32_t index, float value);
@@ -80,8 +80,8 @@ struct UIPrivateData {
     uint32_t parameterOffset;
 
     // UI
-    void*        ptr;
-    NativeWidget widget;
+    void*         ptr;
+    NativeWidget* widget;
 
     // Callbacks
     setParamFunc    setParamCallbackFunc;
@@ -261,7 +261,12 @@ public:
     void createWindow(intptr_t parent)
     {
 #ifdef DISTRHO_UI_QT4
-        assert(ui && ! qt_widget);
+        assert(ui && data && ! qt_widget);
+
+        if (qt_widget || ! (ui && data))
+            return;
+
+        qt_mouseDown = false;
 
         // create embedable widget
         qt_widget = new QEmbedWidget;
@@ -293,9 +298,9 @@ public:
         // show it
         qt_widget->show();
 #else
-        assert(ui);
+        assert(ui && data && ! data->widget);
 
-        if ((data && data->widget) || ! ui)
+        if ((! data) || data->widget || ! ui)
             return;
 
         data->widget = puglCreate(parent, DISTRHO_PLUGIN_NAME, ui->d_width(), ui->d_height(), false);
@@ -331,9 +336,13 @@ public:
             qt_widget->close();
 
             if (qt_grip)
+            {
                 delete qt_grip;
+                qt_grip = nullptr;
+            }
 
             delete qt_widget;
+            qt_widget = nullptr;
         }
 #else
         ((OpenGLUI*)ui)->d_onClose();
@@ -351,46 +360,31 @@ public:
 #ifdef DISTRHO_UI_OPENGL
     void gl_onDisplay()
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
             uiGL->d_onDisplay();
     }
 
     void gl_onKeyboard(bool press, uint32_t key)
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
             uiGL->d_onKeyboard(press, key);
     }
 
     void gl_onMotion(int x, int y)
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
             uiGL->d_onMotion(x, y);
     }
 
     void gl_onMouse(int button, bool press, int x, int y)
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
             uiGL->d_onMouse(button, press, x, y);
     }
 
     void gl_onReshape(int width, int height)
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
         {
             if (! gl_initiated)
             {
@@ -404,32 +398,24 @@ public:
 
     void gl_onScroll(float dx, float dy)
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
             uiGL->d_onScroll(dx, dy);
     }
 
     void gl_onSpecial(bool press, Key key)
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
             uiGL->d_onSpecial(press, key);
     }
 
     void gl_onClose()
     {
-        OpenGLUI* uiGL = (OpenGLUI*)ui;
-        assert(uiGL);
-
-        if (uiGL)
+        if (OpenGLUI* uiGL = (OpenGLUI*)ui)
             uiGL->d_onClose();
     }
 
     // ---------------------------------------------
+private:
 
     static void gl_onDisplayCallback(PuglView* view)
     {