Fix ANGLE/OpenGL swap buffer issues under Windows

CMakeLists.txt

@@ -1135,19 +1135,29 @@ install(
     "*.qm"
 )
 if(WIN32)
-install(
-  # I haven't seen a way to determine where the translations dir is, so I am making
-  # some assumptions here, and assuming that Qt5_DIR points to Qt-5.14.2/lib/cmake/Qt5
-  # which is what my configuration tells me.
-  DIRECTORY
-    "${Qt5_DIR}/../../../translations"
-  DESTINATION
-    "${MIXXX_INSTALL_DATADIR}"
-  # QT 5 translations have been separated into several files, and most of the qt_xx.qm files
-  # contain just shortcuts to load the qtbase, qtmultimedia etc files.
-  FILES_MATCHING REGEX
-    "qt_.+\.qm|qtbase_.*\.qm|qtmultimedia_.*\.qm|qtscript_.*\.qm|qtxmlpatterns_.*\.qm"
-)
+  install(
+    # I haven't seen a way to determine where the translations dir is, so I am making
+    # some assumptions here, and assuming that Qt5_DIR points to Qt-5.14.2/lib/cmake/Qt5
+    # which is what my configuration tells me.
+    DIRECTORY
+      "${Qt5_DIR}/../../../translations"
+    DESTINATION
+      "${MIXXX_INSTALL_DATADIR}"
+    # QT 5 translations have been separated into several files, and most of the qt_xx.qm files
+    # contain just shortcuts to load the qtbase, qtmultimedia etc files.
+    FILES_MATCHING REGEX
+      "qt_.+\.qm|qtbase_.*\.qm|qtmultimedia_.*\.qm|qtscript_.*\.qm|qtxmlpatterns_.*\.qm"
+  )
+
+  # Qt loads the ANGLE libraries dynamically, even when Qt itself is linked statically
+  install(
+    DIRECTORY
+      "${Qt5_DIR}/../../../bin"
+    DESTINATION
+      "${MIXXX_INSTALL_DATADIR}"
+    FILES_MATCHING REGEX
+      "libEGL.dll|libGLESv2.dll"
+  )
 endif()
 
 # Font files

src/waveform/waveformwidgetfactory.cpp

@@ -713,6 +713,9 @@ void WaveformWidgetFactory::swap() {
                 }
                 QGLWidget* glw = qobject_cast<QGLWidget*>(pWaveformWidget->getWidget());
                 if (glw != nullptr) {
+                    if (QGLContext::currentContext() != glw->context()) {
+                        glw->makeCurrent();
+                    }
                     glw->swapBuffers();
                 }
                 //qDebug() << "swap x" << m_vsyncThread->elapsed();

src/widget/wspinny.cpp

@@ -403,6 +403,9 @@ void WSpinny::swap() {
     if (window == nullptr || !window->isExposed()) {
         return;
     }
+    if (QGLContext::currentContext() != context()) {
+        makeCurrent();
+    }
     swapBuffers();
 }