src/java.desktop/macosx/classes/sun/awt/CGraphicsDevice.java

@@ -30,11 +30,11 @@
 import java.awt.GraphicsConfiguration;
 import java.awt.GraphicsDevice;
 import java.awt.Insets;
 import java.awt.Window;
 import java.util.Objects;
-
+import sun.java2d.SunGraphicsEnvironment;
 import sun.java2d.opengl.CGLGraphicsConfig;
 
 public final class CGraphicsDevice extends GraphicsDevice
         implements DisplayChangedListener {
 

@@ -138,11 +138,11 @@
 
     @Override
     public void displayChanged() {
         xResolution = nativeGetXResolution(displayID);
         yResolution = nativeGetYResolution(displayID);
-        scale = (int) nativeGetScaleFactor(displayID);
+        initScaleFactor();
         //TODO configs/fullscreenWindow/modes?
     }
 
     @Override
     public void paletteChanged() {

@@ -247,10 +247,21 @@
     @Override
     public DisplayMode[] getDisplayModes() {
         return nativeGetDisplayModes(displayID);
     }
 
+    private void initScaleFactor() {
+        if (SunGraphicsEnvironment.isUIScaleEnabled()) {
+            double debugScale = SunGraphicsEnvironment.getDebugScale();
+            scale = (int) (debugScale >= 1
+                    ? Math.round(debugScale)
+                    : nativeGetScaleFactor(displayID));
+        } else {
+            scale = 1;
+        }
+    }
+
     private static native double nativeGetScaleFactor(int displayID);
 
     private static native void nativeSetDisplayMode(int displayID, int w, int h, int bpp, int refrate);
 
     private static native DisplayMode nativeGetDisplayMode(int displayID);