Merge pull request #3407 from Be-ing/opengl_initialization_fix

fix initialization of QGLWidget waveform widgets & renderers 

26 files changed, 108 insertions, 91 deletions

diff --git a/src/preferences/dialog/dlgprefwaveform.cpp b/src/preferences/dialog/dlgprefwaveform.cpp
index 48ac7bae01..03113b816e 100644
--- a/src/preferences/dialog/dlgprefwaveform.cpp
+++ b/src/preferences/dialog/dlgprefwaveform.cpp
@@ -115,14 +115,10 @@ DlgPrefWaveform::DlgPrefWaveform(QWidget* pParent, MixxxMainWindow* pMixxx,
             &WaveformWidgetFactory::waveformMeasured,
             this,
             &DlgPrefWaveform::slotWaveformMeasured);
-    // Don't automatically reload the skin after changing the overview type to
-    // work around macOS skin change crash. https://bugs.launchpad.net/mixxx/+bug/1877487
-#ifndef __APPLE__
     connect(waveformOverviewComboBox,
             QOverload<int>::of(&QComboBox::currentIndexChanged),
             this,
             &DlgPrefWaveform::slotSetWaveformOverviewType);
-#endif
     connect(clearCachedWaveforms,
             &QAbstractButton::clicked,
             this,
@@ -182,15 +178,10 @@ void DlgPrefWaveform::slotUpdate() {
 }
 
 void DlgPrefWaveform::slotApply() {
-    // Require restarting Mixxx to apply the new overview type in order to work
-    // around macOS skin change crash. https://bugs.launchpad.net/mixxx/+bug/1877487
-#ifdef __APPLE__
     ConfigValue overviewtype = ConfigValue(waveformOverviewComboBox->currentIndex());
     if (overviewtype != m_pConfig->get(ConfigKey("[Waveform]", "WaveformOverviewType"))) {
         m_pConfig->set(ConfigKey("[Waveform]", "WaveformOverviewType"), overviewtype);
-        notifyRebootNecessary();
     }
-#endif
     WaveformSettings waveformSettings(m_pConfig);
     waveformSettings.setWaveformCachingEnabled(enableWaveformCaching->isChecked());
     waveformSettings.setWaveformGenerationWithAnalysisEnabled(
@@ -240,12 +231,6 @@ void DlgPrefWaveform::slotResetToDefaults() {
     playMarkerPositionSlider->setValue(50);
 }
 
-void DlgPrefWaveform::notifyRebootNecessary() {
-    // make the fact that you have to restart mixxx more obvious
-    QMessageBox::information(
-            this, tr("Information"), tr("Mixxx must be restarted to load the new overview type."));
-}
-
 void DlgPrefWaveform::slotSetFrameRate(int frameRate) {
     WaveformWidgetFactory::instance()->setFrameRate(frameRate);
 }
diff --git a/src/waveform/renderers/glslwaveformrenderersignal.cpp b/src/waveform/renderers/glslwaveformrenderersignal.cpp
index 0afb83a542..01d9465db1 100644
--- a/src/waveform/renderers/glslwaveformrenderersignal.cpp
+++ b/src/waveform/renderers/glslwaveformrenderersignal.cpp
@@ -19,7 +19,6 @@ GLSLWaveformRendererSignal::GLSLWaveformRendererSignal(WaveformWidgetRenderer* w
           m_bDumpPng(false),
           m_shadersValid(false),
           m_rgbShader(rgbShader) {
-    initializeOpenGLFunctions();
 }
 
 GLSLWaveformRendererSignal::~GLSLWaveformRendererSignal() {
@@ -191,7 +190,8 @@ void GLSLWaveformRendererSignal::createFrameBuffers() {
     }
 }
 
-bool GLSLWaveformRendererSignal::onInit() {
+void GLSLWaveformRendererSignal::onInitializeGL() {
+    initializeOpenGLFunctions();
     m_textureRenderedWaveformCompletion = 0;
 
     if (!m_frameShaderProgram) {
@@ -199,14 +199,13 @@ bool GLSLWaveformRendererSignal::onInit() {
     }
 
     if (!loadShaders()) {
-        return false;
+        return;
     }
+    createFrameBuffers();
     createGeometry();
     if (!loadTexture()) {
-        return false;
+        return;
     }
-
-    return true;
 }
 
 void GLSLWaveformRendererSignal::onSetup(const QDomNode& node) {
@@ -240,19 +239,23 @@ void GLSLWaveformRendererSignal::onSetTrack() {
 }
 
 void GLSLWaveformRendererSignal::onResize() {
+    // onInitializeGL not called yet
+    if (!m_frameShaderProgram) {
+        return;
+    }
     createFrameBuffers();
 }
 
 void GLSLWaveformRendererSignal::slotWaveformUpdated() {
     m_textureRenderedWaveformCompletion = 0;
+    // onInitializeGL not called yet
+    if (!m_frameShaderProgram) {
+        return;
+    }
     loadTexture();
 }
 
 void GLSLWaveformRendererSignal::draw(QPainter* painter, QPaintEvent* /*event*/) {
-    if (!m_framebuffer || !m_framebuffer->isValid() || !m_shadersValid) {
-        return;
-    }
-
     TrackPointer trackInfo = m_waveformRenderer->getTrackInfo();
     if (!trackInfo) {
         return;
@@ -273,6 +276,8 @@ void GLSLWaveformRendererSignal::draw(QPainter* painter, QPaintEvent* /*event*/)
         return;
     }
 
+    maybeInitializeGL();
+
     // save the GL state set for QPainter
     painter->beginNativePainting();
 
diff --git a/src/waveform/renderers/glslwaveformrenderersignal.h b/src/waveform/renderers/glslwaveformrenderersignal.h
index 8e5f3ca803..9ebfc7920d 100644
--- a/src/waveform/renderers/glslwaveformrenderersignal.h
+++ b/src/waveform/renderers/glslwaveformrenderersignal.h
@@ -1,6 +1,5 @@
 #pragma once
 
-#include <QOpenGLFunctions_2_1>
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
 
 #include <QGLFramebufferObject>
@@ -11,17 +10,17 @@
 #include "util/memory.h"
 #include "waveform/renderers/waveformrenderersignalbase.h"
 
-class GLSLWaveformRendererSignal: public QObject,
-        public WaveformRendererSignalBase,
-        protected QOpenGLFunctions_2_1 {
+class GLSLWaveformRendererSignal : public QObject,
+                                   public WaveformRendererSignalBase,
+                                   public GLWaveformRenderer {
     Q_OBJECT
   public:
     GLSLWaveformRendererSignal(WaveformWidgetRenderer* waveformWidgetRenderer,
                                bool rgbShader);
     ~GLSLWaveformRendererSignal() override;
 
-    bool onInit() override;
     void onSetup(const QDomNode& node) override;
+    void onInitializeGL() override;
     void draw(QPainter* painter, QPaintEvent* event) override;
 
     void onSetTrack() override;
diff --git a/src/waveform/renderers/glvsynctestrenderer.cpp b/src/waveform/renderers/glvsynctestrenderer.cpp
index dc5e42e966..6cbc85b454 100644
--- a/src/waveform/renderers/glvsynctestrenderer.cpp
+++ b/src/waveform/renderers/glvsynctestrenderer.cpp
@@ -11,7 +11,6 @@ GLVSyncTestRenderer::GLVSyncTestRenderer(
         WaveformWidgetRenderer* waveformWidgetRenderer)
     : WaveformRendererSignalBase(waveformWidgetRenderer),
       m_drawcount(0) {
-    initializeOpenGLFunctions();
 }
 
 GLVSyncTestRenderer::~GLVSyncTestRenderer() {
@@ -27,6 +26,7 @@ inline void setPoint(QPointF& point, qreal x, qreal y) {
 }
 
 void GLVSyncTestRenderer::draw(QPainter* painter, QPaintEvent* /*event*/) {
+    maybeInitializeGL();
 
     PerformanceTimer timer;
     //mixxx::Duration t5, t6, t7, t8, t9, t10, t11, t12, t13;
diff --git a/src/waveform/renderers/glvsynctestrenderer.h b/src/waveform/renderers/glvsynctestrenderer.h
index b9a31049eb..a74ef88e64 100644
--- a/src/waveform/renderers/glvsynctestrenderer.h
+++ b/src/waveform/renderers/glvsynctestrenderer.h
@@ -1,15 +1,14 @@
 #pragma once
 
-#include <QOpenGLFunctions_2_1>
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
 
 #include "waveformrenderersignalbase.h"
 
 class ControlObject;
 
-class GLVSyncTestRenderer: public WaveformRendererSignalBase,
-        protected QOpenGLFunctions_2_1 {
-public:
+class GLVSyncTestRenderer : public WaveformRendererSignalBase,
+                            public GLWaveformRenderer {
+  public:
     explicit GLVSyncTestRenderer(
             WaveformWidgetRenderer* waveformWidgetRenderer);
     virtual ~GLVSyncTestRenderer();
diff --git a/src/waveform/renderers/glwaveformrendererfilteredsignal.cpp b/src/waveform/renderers/glwaveformrendererfilteredsignal.cpp
index 8cb59e1e40..0ad618c0bd 100644
--- a/src/waveform/renderers/glwaveformrendererfilteredsignal.cpp
+++ b/src/waveform/renderers/glwaveformrendererfilteredsignal.cpp
@@ -12,7 +12,6 @@
 GLWaveformRendererFilteredSignal::GLWaveformRendererFilteredSignal(
         WaveformWidgetRenderer* waveformWidgetRenderer)
         : WaveformRendererSignalBase(waveformWidgetRenderer) {
-    initializeOpenGLFunctions();
 }
 
 GLWaveformRendererFilteredSignal::~GLWaveformRendererFilteredSignal() {
@@ -24,6 +23,7 @@ void GLWaveformRendererFilteredSignal::onSetup(const QDomNode& /*node*/) {
 }
 
 void GLWaveformRendererFilteredSignal::draw(QPainter* painter, QPaintEvent* /*event*/) {
+    maybeInitializeGL();
 
     TrackPointer pTrack = m_waveformRenderer->getTrackInfo();
     if (!pTrack) {
diff --git a/src/waveform/renderers/glwaveformrendererfilteredsignal.h b/src/waveform/renderers/glwaveformrendererfilteredsignal.h
index 807ee928ea..be4b30780b 100644
--- a/src/waveform/renderers/glwaveformrendererfilteredsignal.h
+++ b/src/waveform/renderers/glwaveformrendererfilteredsignal.h
@@ -1,6 +1,5 @@
 #pragma once
 
-#include <QOpenGLFunctions_2_1>
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
 
 #include <QDomNode>
@@ -9,9 +8,9 @@
 
 class ControlObject;
 
-class GLWaveformRendererFilteredSignal: public WaveformRendererSignalBase,
-        protected QOpenGLFunctions_2_1 {
-public:
+class GLWaveformRendererFilteredSignal : public WaveformRendererSignalBase,
+                                         public GLWaveformRenderer {
+  public:
     explicit GLWaveformRendererFilteredSignal(
             WaveformWidgetRenderer* waveformWidgetRenderer);
     virtual ~GLWaveformRendererFilteredSignal();
diff --git a/src/waveform/renderers/glwaveformrendererrgb.cpp b/src/waveform/renderers/glwaveformrendererrgb.cpp
index 8bfac3f5f4..708a139a43 100644
--- a/src/waveform/renderers/glwaveformrendererrgb.cpp
+++ b/src/waveform/renderers/glwaveformrendererrgb.cpp
@@ -16,7 +16,6 @@ const float kHeightScaleFactor = 255.0f / sqrtf(255 * 255 * 3);
 GLWaveformRendererRGB::GLWaveformRendererRGB(
         WaveformWidgetRenderer* waveformWidgetRenderer)
         : WaveformRendererSignalBase(waveformWidgetRenderer) {
-    initializeOpenGLFunctions();
 }
 
 GLWaveformRendererRGB::~GLWaveformRendererRGB() {
@@ -26,6 +25,8 @@ void GLWaveformRendererRGB::onSetup(const QDomNode& /* node */) {
 }
 
 void GLWaveformRendererRGB::draw(QPainter* painter, QPaintEvent* /*event*/) {
+    maybeInitializeGL();
+
     TrackPointer pTrack = m_waveformRenderer->getTrackInfo();
     if (!pTrack) {
         return;
diff --git a/src/waveform/renderers/glwaveformrendererrgb.h b/src/waveform/renderers/glwaveformrendererrgb.h
index 4b435d6746..8bbfd7fd93 100644
--- a/src/waveform/renderers/glwaveformrendererrgb.h
+++ b/src/waveform/renderers/glwaveformrendererrgb.h
@@ -1,14 +1,13 @@
 #pragma once
 
-#include <QOpenGLFunctions_2_1>
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
 
 #include "waveformrenderersignalbase.h"
 
 class ControlObject;
 
-class GLWaveformRendererRGB: public WaveformRendererSignalBase,
-        protected QOpenGLFunctions_2_1 {
+class GLWaveformRendererRGB : public WaveformRendererSignalBase,
+                              public GLWaveformRenderer {
   public:
     explicit GLWaveformRendererRGB(
             WaveformWidgetRenderer* waveformWidgetRenderer);
diff --git a/src/waveform/renderers/glwaveformrenderersimplesignal.cpp b/src/waveform/renderers/glwaveformrenderersimplesignal.cpp
index d9651356bf..041353ff7c 100644
--- a/src/waveform/renderers/glwaveformrenderersimplesignal.cpp
+++ b/src/waveform/renderers/glwaveformrenderersimplesignal.cpp
@@ -10,7 +10,6 @@
 GLWaveformRendererSimpleSignal::GLWaveformRendererSimpleSignal(
         WaveformWidgetRenderer* waveformWidgetRenderer)
         : WaveformRendererSignalBase(waveformWidgetRenderer) {
-    initializeOpenGLFunctions();
 }
 
 GLWaveformRendererSimpleSignal::~GLWaveformRendererSimpleSignal() {
@@ -26,6 +25,8 @@ inline void setPoint(QPointF& point, qreal x, qreal y) {
 }
 
 void GLWaveformRendererSimpleSignal::draw(QPainter* painter, QPaintEvent* /*event*/) {
+    maybeInitializeGL();
+
     TrackPointer pTrack = m_waveformRenderer->getTrackInfo();
     if (!pTrack) {
         return;
diff --git a/src/waveform/renderers/glwaveformrenderersimplesignal.h b/src/waveform/renderers/glwaveformrenderersimplesignal.h
index 48e698803d..ae3aae6111 100644
--- a/src/waveform/renderers/glwaveformrenderersimplesignal.h
+++ b/src/waveform/renderers/glwaveformrenderersimplesignal.h
@@ -1,14 +1,14 @@
 #pragma once
 
-#include <QOpenGLFunctions_2_1>
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
 
 #include "waveformrenderersignalbase.h"
 
 class ControlObject;
 
-class GLWaveformRendererSimpleSignal : public WaveformRendererSignalBase, protected QOpenGLFunctions_2_1 {
-public:
+class GLWaveformRendererSimpleSignal : public WaveformRendererSignalBase,
+                                       public GLWaveformRenderer {
+  public:
     explicit GLWaveformRendererSimpleSignal(WaveformWidgetRenderer* waveformWidgetRenderer);
     virtual ~GLWaveformRendererSimpleSignal();
 
diff --git a/src/waveform/renderers/waveformrendererabstract.h b/src/waveform/renderers/waveformrendererabstract.h
index a1856e70f2..9ccbfaa70d 100644
--- a/src/waveform/renderers/waveformrendererabstract.h
+++ b/src/waveform/renderers/waveformrendererabstract.h
@@ -1,6 +1,8 @@
 #pragma once
 
 #include <QDomNode>
+#include <QGLContext>
+#include <QOpenGLFunctions_2_1>
 #include <QPaintEvent>
 #include <QPainter>
 
@@ -45,3 +47,29 @@ class WaveformRendererAbstract {
 
     friend class WaveformWidgetRenderer;
 };
+
+/// GLWaveformRenderer is a WaveformRendererAbstract which directly calls OpenGL functions.
+///
+/// Note that the Qt OpenGL WaveformRendererAbstracts are not GLWaveformRenderers because
+/// they do not call OpenGL functions directly. Instead, they inherit QGLWidget and use the
+/// QPainter API which Qt translates to OpenGL under the hood.
+class GLWaveformRenderer : protected QOpenGLFunctions_2_1 {
+  public:
+    virtual void onInitializeGL() {
+        initializeOpenGLFunctions();
+    }
+
+  protected:
+    // Somehow QGLWidget does not call QGLWidget::initializeGL on macOS, so hack around that
+    // by calling this in `draw` when the QGLContext has been made current.
+    // TODO: remove this when upgrading to QOpenGLWidget
+    void maybeInitializeGL() {
+        if (QGLContext::currentContext() != m_pLastContext) {
+            onInitializeGL();
+            m_pLastContext = QGLContext::currentContext();
+        }
+    }
+
+  private:
+    const QGLContext* m_pLastContext;
+};
diff --git a/src/waveform/widgets/glrgbwaveformwidget.cpp b/src/waveform/widgets/glrgbwaveformwidget.cpp
index 40b54b4903..c483eca3d5 100644
--- a/src/waveform/widgets/glrgbwaveformwidget.cpp
+++ b/src/waveform/widgets/glrgbwaveformwidget.cpp
@@ -13,21 +13,17 @@
 #include "waveform/sharedglcontext.h"
 
 GLRGBWaveformWidget::GLRGBWaveformWidget(const QString& group, QWidget* parent)
-        : QGLWidget(parent, SharedGLContext::getWidget()),
-          WaveformWidgetAbstract(group) {
+        : GLWaveformWidgetAbstract(group, parent) {
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
-    if (QGLContext::currentContext() != context()) {
-        makeCurrent();
-    }
 
     addRenderer<WaveformRenderBackground>();
     addRenderer<WaveformRendererEndOfTrack>();
     addRenderer<WaveformRendererPreroll>();
     addRenderer<WaveformRenderMarkRange>();
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
-    addRenderer<GLWaveformRendererRGB>();
+    m_pGlRenderer = addRenderer<GLWaveformRendererRGB>();
 #endif // !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
     addRenderer<WaveformRenderBeat>();
     addRenderer<WaveformRenderMark>();
diff --git a/src/waveform/widgets/glrgbwaveformwidget.h b/src/waveform/widgets/glrgbwaveformwidget.h
index 8d6391ad79..bfd8cda72f 100644
--- a/src/waveform/widgets/glrgbwaveformwidget.h
+++ b/src/waveform/widgets/glrgbwaveformwidget.h
@@ -4,7 +4,7 @@
 
 #include "waveformwidgetabstract.h"
 
-class GLRGBWaveformWidget : public QGLWidget, public WaveformWidgetAbstract {
+class GLRGBWaveformWidget : public GLWaveformWidgetAbstract {
     Q_OBJECT
   public:
     GLRGBWaveformWidget(const QString& group, QWidget* parent);
diff --git a/src/waveform/widgets/glsimplewaveformwidget.cpp b/src/waveform/widgets/glsimplewaveformwidget.cpp
index c54482279e..a54cc5a76c 100644
--- a/src/waveform/widgets/glsimplewaveformwidget.cpp
+++ b/src/waveform/widgets/glsimplewaveformwidget.cpp
@@ -16,21 +16,17 @@
 #include "waveform/sharedglcontext.h"
 
 GLSimpleWaveformWidget::GLSimpleWaveformWidget(const QString& group, QWidget* parent)
-        : QGLWidget(parent, SharedGLContext::getWidget()),
-          WaveformWidgetAbstract(group) {
+        : GLWaveformWidgetAbstract(group, parent) {
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
-    if (QGLContext::currentContext() != context()) {
-        makeCurrent();
-    }
 
     addRenderer<WaveformRenderBackground>();
     addRenderer<WaveformRendererEndOfTrack>();
     addRenderer<WaveformRendererPreroll>();
     addRenderer<WaveformRenderMarkRange>();
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
-    addRenderer<GLWaveformRendererSimpleSignal>();
+    m_pGlRenderer = addRenderer<GLWaveformRendererSimpleSignal>();
 #endif // !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
     addRenderer<WaveformRenderBeat>();
     addRenderer<WaveformRenderMark>();
diff --git a/src/waveform/widgets/glsimplewaveformwidget.h b/src/waveform/widgets/glsimplewaveformwidget.h
index 1aacfaed80..16ed62aacc 100644
--- a/src/waveform/widgets/glsimplewaveformwidget.h
+++ b/src/waveform/widgets/glsimplewaveformwidget.h
@@ -4,7 +4,7 @@
 
 #include "waveformwidgetabstract.h"
 
-class GLSimpleWaveformWidget : public QGLWidget, public WaveformWidgetAbstract {
+class GLSimpleWaveformWidget : public GLWaveformWidgetAbstract {
     Q_OBJECT
   public:
     GLSimpleWaveformWidget(const QString& group, QWidget* parent);
diff --git a/src/waveform/widgets/glslwaveformwidget.cpp b/src/waveform/widgets/glslwaveformwidget.cpp
index a45e0a715b..faa22df84c 100644
--- a/src/waveform/widgets/glslwaveformwidget.cpp
+++ b/src/waveform/widgets/glslwaveformwidget.cpp
@@ -31,8 +31,7 @@ GLSLWaveformWidget::GLSLWaveformWidget(
         const QString& group,
         QWidget* parent,
         bool rgbRenderer)
-        : QGLWidget(parent, SharedGLContext::getWidget()),
-          WaveformWidgetAbstract(group) {
+        : GLWaveformWidgetAbstract(group, parent) {
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
@@ -46,9 +45,9 @@ GLSLWaveformWidget::GLSLWaveformWidget(
     addRenderer<WaveformRenderMarkRange>();
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
     if (rgbRenderer) {
-        m_signalRenderer = addRenderer<GLSLWaveformRendererRGBSignal>();
+        m_pGlRenderer = addRenderer<GLSLWaveformRendererRGBSignal>();
     } else {
-        m_signalRenderer = addRenderer<GLSLWaveformRendererFilteredSignal>();
+        m_pGlRenderer = addRenderer<GLSLWaveformRendererFilteredSignal>();
     }
 #else
     Q_UNUSED(rgbRenderer);
diff --git a/src/waveform/widgets/glslwaveformwidget.h b/src/waveform/widgets/glslwaveformwidget.h
index 85baf50dcd..229bbc2fca 100644
--- a/src/waveform/widgets/glslwaveformwidget.h
+++ b/src/waveform/widgets/glslwaveformwidget.h
@@ -6,7 +6,7 @@
 
 class GLSLWaveformRendererSignal;
 
-class GLSLWaveformWidget : public QGLWidget, public WaveformWidgetAbstract {
+class GLSLWaveformWidget : public GLWaveformWidgetAbstract {
     Q_OBJECT
   public:
     GLSLWaveformWidget(
diff --git a/src/waveform/widgets/glwaveformwidget.cpp b/src/waveform/widgets/glwaveformwidget.cpp
index 4b43658fd1..03e4849174 100644
--- a/src/waveform/widgets/glwaveformwidget.cpp
+++ b/src/waveform/widgets/glwaveformwidget.cpp
@@ -18,21 +18,17 @@
 #include "waveform/sharedglcontext.h"
 
 GLWaveformWidget::GLWaveformWidget(const QString& group, QWidget* parent)
-        : QGLWidget(parent, SharedGLContext::getWidget()),
-          WaveformWidgetAbstract(group) {
+        : GLWaveformWidgetAbstract(group, parent) {
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
-    if (QGLContext::currentContext() != context()) {
-        makeCurrent();
-    }
 
     addRenderer<WaveformRenderBackground>();
     addRenderer<WaveformRendererEndOfTrack>();
     addRenderer<WaveformRendererPreroll>();
     addRenderer<WaveformRenderMarkRange>();
 #if !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
-    addRenderer<GLWaveformRendererFilteredSignal>();
+    m_pGlRenderer = addRenderer<GLWaveformRendererFilteredSignal>();
 #endif // !defined(QT_NO_OPENGL) && !defined(QT_OPENGL_ES_2)
     addRenderer<WaveformRenderBeat>();
     addRenderer<WaveformRenderMark>();
diff --git a/src/waveform/widgets/glwaveformwidget.h b/src/waveform/widgets/glwaveformwidget.h
index fa27180e67..9073523ba6 100644
--- a/src/waveform/widgets/glwaveformwidget.h
+++ b/src/waveform/widgets/glwaveformwidget.h
@@ -4,7 +4,7 @@
 
 #include "waveformwidgetabstract.h"
 
-class GLWaveformWidget : public QGLWidget, public WaveformWidgetAbstract {
+class GLWaveformWidget : public GLWaveformWidgetAbstract {
     Q_OBJECT
   public:
     GLWaveformWidget(const QString& group, QWidget* parent);
diff --git a/src/waveform/widgets/qtrgbwaveformwidget.cpp b/src/waveform/widgets/qtrgbwaveformwidget.cpp
index 7a388ad813..f0ba3b0c36 100644
--- a/src/waveform/widgets/qtrgbwaveformwidget.cpp
+++ b/src/waveform/widgets/qtrgbwaveformwidget.cpp
@@ -21,9 +21,6 @@ QtRGBWaveformWidget::QtRGBWaveformWidget(const QString& group, QWidget* parent)
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
-    if (QGLContext::currentContext() != context()) {
-        makeCurrent();
-    }
 
     addRenderer<WaveformRenderBackground>();
     addRenderer<WaveformRendererEndOfTrack>();
diff --git a/src/waveform/widgets/qtsimplewaveformwidget.cpp b/src/waveform/widgets/qtsimplewaveformwidget.cpp
index 4978a6b848..866d37c308 100644
--- a/src/waveform/widgets/qtsimplewaveformwidget.cpp
+++ b/src/waveform/widgets/qtsimplewaveformwidget.cpp
@@ -23,9 +23,6 @@ QtSimpleWaveformWidget::QtSimpleWaveformWidget(
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
-    if (QGLContext::currentContext() != context()) {
-        makeCurrent();
-    }
 
     addRenderer<WaveformRenderBackground>();
     addRenderer<WaveformRendererEndOfTrack>();
diff --git a/src/waveform/widgets/qtvsynctestwidget.cpp b/src/waveform/widgets/qtvsynctestwidget.cpp
index c651d3655d..32f151af96 100644
--- a/src/waveform/widgets/qtvsynctestwidget.cpp
+++ b/src/waveform/widgets/qtvsynctestwidget.cpp
@@ -22,9 +22,6 @@ QtVSyncTestWidget::QtVSyncTestWidget(const QString& group, QWidget* parent)
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
-    if (QGLContext::currentContext() != context()) {
-        makeCurrent();
-    }
 
     addRenderer<QtVSyncTestRenderer>();
 
diff --git a/src/waveform/widgets/qtwaveformwidget.cpp b/src/waveform/widgets/qtwaveformwidget.cpp
index 904e03cc09..8cf493517e 100644
--- a/src/waveform/widgets/qtwaveformwidget.cpp
+++ b/src/waveform/widgets/qtwaveformwidget.cpp
@@ -22,9 +22,6 @@ QtWaveformWidget::QtWaveformWidget(const QString& group, QWidget* parent)
     qDebug() << "Created QGLWidget. Context"
              << "Valid:" << context()->isValid()
              << "Sharing:" << context()->isSharing();
-    if (QGLContext::currentContext() != context()) {
-        makeCurrent();
-    }
 
     addRenderer<WaveformRenderBackground>();
     addRenderer<WaveformRendererEndOfTrack>();
diff --git a/src/waveform/widgets/waveformwidgetabstract.cpp b/src/waveform/widgets/waveformwidgetabstract.cpp
index 7dc1d995e0..bec1e190a3 100644
--- a/src/waveform/widgets/waveformwidgetabstract.cpp
+++ b/src/waveform/widgets/waveformwidgetabstract.cpp
@@ -1,9 +1,11 @@
 #include "waveformwidgetabstract.h"
-#include "waveform/renderers/waveformwidgetrenderer.h"
-#include "util/compatibility.h"
 
-#include <QtDebug>
 #include <QWidget>
+#include <QtDebug>
+
+#include "util/compatibility.h"
+#include "waveform/renderers/waveformwidgetrenderer.h"
+#include "waveform/sharedglcontext.h"
 
 WaveformWidgetAbstract::WaveformWidgetAbstract(const QString& group)
         : WaveformWidgetRenderer(group),
@@ -46,3 +48,8 @@ void WaveformWidgetAbstract::resize(int width, int height) {
     }
     WaveformWidgetRenderer::resize(width, height, static_cast<float>(devicePixelRatio));
 }
+
+GLWaveformWidgetAbstract::GLWaveformWidgetAbstract(const QString& group, QWidget* parent)
+        : WaveformWidgetAbstract(group),
+          QGLWidget(parent, SharedGLContext::getWidget()) {
+}
diff --git a/src/waveform/widgets/waveformwidgetabstract.h b/src/waveform/widgets/waveformwidgetabstract.h
index 3b975c7189..d5b6ce23f3 100644
--- a/