Rémi Bernon : win32u: Return the current display mode depth with nulldrv.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 8531f23a41956dcc3c68d6b02401f5c78db8ec60
URL:    https://gitlab.winehq.org/wine/wine/-/commit/8531f23a41956dcc3c68d6b02401f5c...

Author: Rémi Bernon <rbernon(a)codeweavers.com>
Date:   Fri Mar  3 10:26:37 2023 +0100

win32u: Return the current display mode depth with nulldrv.

---

 dlls/win32u/driver.c    |  2 +-
 dlls/win32u/sysparams.c | 13 +++++++++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/dlls/win32u/driver.c b/dlls/win32u/driver.c
index 1c0708461a1..3f676dc5796 100644
--- a/dlls/win32u/driver.c
+++ b/dlls/win32u/driver.c
@@ -761,7 +761,7 @@ static BOOL nulldrv_GetCurrentDisplaySettings( LPCWSTR name, BOOL is_primary, LP
 
 static INT nulldrv_GetDisplayDepth( LPCWSTR name, BOOL is_primary )
 {
-    return 32;
+    return -1; /* use default implementation */
 }
 
 static BOOL nulldrv_UpdateDisplayDevices( const struct gdi_device_manager *manager, BOOL force, void *param )
diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c
index bcdb8c5103b..60b12321953 100644
--- a/dlls/win32u/sysparams.c
+++ b/dlls/win32u/sysparams.c
@@ -2727,6 +2727,7 @@ static unsigned int active_monitor_count(void)
 INT get_display_depth( UNICODE_STRING *name )
 {
     struct display_device *device;
+    BOOL is_primary;
     INT depth;
 
     if (!lock_display_devices())
@@ -2743,8 +2744,16 @@ INT get_display_depth( UNICODE_STRING *name )
         return 32;
     }
 
-    depth = user_driver->pGetDisplayDepth( device->device_name,
-                                           !!(device->state_flags & DISPLAY_DEVICE_PRIMARY_DEVICE) );
+    is_primary = !!(device->state_flags & DISPLAY_DEVICE_PRIMARY_DEVICE);
+    if ((depth = user_driver->pGetDisplayDepth( device->device_name, is_primary )) < 0)
+    {
+        struct adapter *adapter = CONTAINING_RECORD( device, struct adapter, dev );
+        DEVMODEW current_mode = {.dmSize = sizeof(DEVMODEW)};
+
+        if (!adapter_get_current_settings( adapter, ¤t_mode )) depth = 32;
+        else depth = current_mode.dmBitsPerPel;
+    }
+
     unlock_display_devices();
     return depth;
 }