[PATCH v2 3/3] gdi32: Report real VREFRESH values for GetDeviceCaps() with display DCs.

[Zhiyi Zhang]

Even though MSDN says 0 and 1 are both valid and they represent the default refresh rate of display
hardware. Some games rely on the value being the real refresh rate and use it to cap frame rates.

Fix an issue that Sakuna: Of Rice and Ruin reports monitors of 1Hz and cap to 1fps.

Signed-off-by: Zhiyi Zhang <zzhang at codeweavers.com>
---
 dlls/gdi32/driver.c         | 25 ++++++++++++++++++++++++-
 dlls/user32/tests/monitor.c |  2 +-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/dlls/gdi32/driver.c b/dlls/gdi32/driver.c
index bb98c554238..e146a3a4f85 100644
--- a/dlls/gdi32/driver.c
+++ b/dlls/gdi32/driver.c
@@ -82,6 +82,7 @@ static CRITICAL_SECTION_DEBUG critsect_debug =
 static CRITICAL_SECTION driver_section = { &critsect_debug, -1, 0, 0, 0, 0 };
 
 static BOOL (WINAPI *pEnumDisplayMonitors)(HDC, LPRECT, MONITORENUMPROC, LPARAM);
+static BOOL (WINAPI *pEnumDisplaySettingsW)(LPCWSTR, DWORD, LPDEVMODEW);
 static HWND (WINAPI *pGetDesktopWindow)(void);
 static BOOL (WINAPI *pGetMonitorInfoW)(HMONITOR, LPMONITORINFO);
 static INT (WINAPI *pGetSystemMetrics)(INT);
@@ -245,6 +246,7 @@ void CDECL __wine_set_display_driver( HMODULE module )
     pGetMonitorInfoW = (void *)GetProcAddress( user32, "GetMonitorInfoW" );
     pGetSystemMetrics = (void *)GetProcAddress( user32, "GetSystemMetrics" );
     pEnumDisplayMonitors = (void *)GetProcAddress( user32, "EnumDisplayMonitors" );
+    pEnumDisplaySettingsW = (void *)GetProcAddress( user32, "EnumDisplaySettingsW" );
     pSetThreadDpiAwarenessContext = (void *)GetProcAddress( user32, "SetThreadDpiAwarenessContext" );
 }
 
@@ -471,7 +473,28 @@ static INT CDECL nulldrv_GetDeviceCaps( PHYSDEV dev, INT cap )
     case PHYSICALOFFSETY: return 0;
     case SCALINGFACTORX:  return 0;
     case SCALINGFACTORY:  return 0;
-    case VREFRESH:        return GetDeviceCaps( dev->hdc, TECHNOLOGY ) == DT_RASDISPLAY ? 1 : 0;
+    case VREFRESH:
+    {
+        DEVMODEW devmode;
+        WCHAR *display;
+        DC *dc;
+
+        if (GetDeviceCaps( dev->hdc, TECHNOLOGY ) != DT_RASDISPLAY)
+            return 0;
+
+        if (pEnumDisplaySettingsW)
+        {
+            dc = get_nulldrv_dc( dev );
+
+            memset( &devmode, 0, sizeof(devmode) );
+            devmode.dmSize = sizeof(devmode);
+            display = dc->display[0] ? dc->display : NULL;
+            if (pEnumDisplaySettingsW( display, ENUM_CURRENT_SETTINGS, &devmode ))
+                return devmode.dmDisplayFrequency ? devmode.dmDisplayFrequency : 1;
+        }
+
+        return 1;
+    }
     case DESKTOPHORZRES:
         if (GetDeviceCaps( dev->hdc, TECHNOLOGY ) == DT_RASDISPLAY && pGetSystemMetrics)
         {
diff --git a/dlls/user32/tests/monitor.c b/dlls/user32/tests/monitor.c
index 08557867566..58b3f0d5e0c 100644
--- a/dlls/user32/tests/monitor.c
+++ b/dlls/user32/tests/monitor.c
@@ -2020,7 +2020,7 @@ static void _check_display_dc(INT line, HDC hdc, const DEVMODEA *dm, BOOL allow_
             dm->dmPelsHeight, value);
 
     value = GetDeviceCaps(hdc, VREFRESH);
-    todo_wine_if(value != dm->dmDisplayFrequency && value == 1)
+    todo_wine_if(allow_todo)
     ok_(__FILE__, line)(value == dm->dmDisplayFrequency, "Expected VREFRESH %d, got %d.\n",
             dm->dmDisplayFrequency, value);
 }
-- 
2.27.0