gdi32: Cache the font smoothing parameters.

dlls/gdi32/font.c

@@ -781,6 +781,7 @@ HFONT nulldrv_SelectFont( PHYSDEV dev, HFONT font, UINT *aa_flags )
 {
     static const WCHAR desktopW[] = { 'C','o','n','t','r','o','l',' ','P','a','n','e','l','\\',
                                       'D','e','s','k','t','o','p',0 };
+    static int orientation = -1, smoothing = -1;
     LOGFONTW lf;
     HKEY key;
 
@@ -797,14 +798,22 @@ HFONT nulldrv_SelectFont( PHYSDEV dev, HFONT font, UINT *aa_flags )
         break;
     case CLEARTYPE_QUALITY:
     case CLEARTYPE_NATURAL_QUALITY:
-        if (RegOpenKeyW( HKEY_CURRENT_USER, desktopW, &key )) break;
-        *aa_flags = get_subpixel_orientation( key );
-        RegCloseKey( key );
+        if (orientation == -1)
+        {
+            if (RegOpenKeyW( HKEY_CURRENT_USER, desktopW, &key )) break;
+            orientation = get_subpixel_orientation( key );
+            RegCloseKey( key );
+        }
+        *aa_flags = orientation;
         break;
     default:
-        if (RegOpenKeyW( HKEY_CURRENT_USER, desktopW, &key )) break;
-        *aa_flags = get_default_smoothing( key );
-        RegCloseKey( key );
+        if (smoothing == -1)
+        {
+            if (RegOpenKeyW( HKEY_CURRENT_USER, desktopW, &key )) break;
+            smoothing = get_default_smoothing( key );
+            RegCloseKey( key );
+        }
+        *aa_flags = smoothing;
         break;
     }
     return 0;