Windows: Correctly set the DPI-awareness of OpenGL worker threads

modules/juce_gui_basics/native/juce_win32_Windowing.cpp

@@ -4095,6 +4095,27 @@ JUCE_API bool shouldScaleGLWindow (void* hwnd)
  }
 #endif
 
+JUCE_API void setThreadDPIAwareness (void* hwnd)
+{
+    if (setThreadDPIAwarenessContext != nullptr)
+    {
+        if (! JUCEApplicationBase::isStandaloneApp())
+        {
+            if (hwnd != nullptr)
+                setThreadDPIAwarenessContext (isPerMonitorDPIAwareWindow ((HWND) hwnd) ? DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE
+                                                                                       : DPI_AWARENESS_CONTEXT_UNAWARE);
+        }
+        else
+        {
+           #if JUCE_WIN_PER_MONITOR_DPI_AWARE
+            setThreadDPIAwarenessContext (DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE);
+           #else
+            setThreadDPIAwarenessContext (DPI_AWARENESS_CONTEXT_UNAWARE);
+           #endif
+        }
+    }
+}
+
 JUCE_IMPLEMENT_SINGLETON (HWNDComponentPeer::WindowClassHolder)
 
 //==============================================================================

modules/juce_opengl/native/juce_OpenGL_win32.h

@@ -40,6 +40,8 @@ extern bool shouldScaleGLWindow (void* hwnd);
  void setProcessDPIAwarenessIfNecessary (void*);
 #endif
 
+ void setThreadDPIAwareness (void*);
+
 //==============================================================================
 class OpenGLContext::NativeContext
    #if JUCE_WIN_PER_MONITOR_DPI_AWARE
@@ -109,6 +111,8 @@ public:
         setProcessDPIAwarenessIfNecessary (nativeWindow->getNativeHandle());
        #endif
 
+        updateThreadDPIAwareness();
+
         context = &c;
         return true;
     }
@@ -116,7 +120,7 @@ public:
     void shutdownOnRenderThread()           { deactivateCurrentContext(); context = nullptr; }
 
     static void deactivateCurrentContext()  { wglMakeCurrent (0, 0); }
-    bool makeActive() const noexcept        { return isActive() || wglMakeCurrent (dc, renderContext) != FALSE; }
+    bool makeActive() const noexcept        { updateThreadDPIAwareness(); return isActive() || wglMakeCurrent (dc, renderContext) != FALSE; }
     bool isActive() const noexcept          { return wglGetCurrentContext() == renderContext; }
     void swapBuffers() const noexcept       { SwapBuffers (dc); }
 
@@ -336,6 +340,15 @@ private:
         return format;
     }
 
+    void updateThreadDPIAwareness() const
+    {
+        if (nativeWindow.get() != nullptr)
+            setThreadDPIAwareness (nativeWindow->getNativeHandle());
+        else
+            setThreadDPIAwareness (nullptr);
+
+    }
+
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (NativeContext)
 };