From b46f929178c638ee44b82c3c8faa58130f37ea88 Mon Sep 17 00:00:00 2001
From: glitchbear <161911268+glitchybear@users.noreply.github.com>
Date: Wed, 27 Nov 2024 11:57:19 -0600
Subject: [PATCH] Fixed display settings and refresh rate selection for
 exclusive fullscreen mode. Now applies the selected settings to the preferred
 display instead of the primary display.

---
 src/archutils/Win32/Crash.cpp          | 40 +++++++++++++++++++++++---
 src/archutils/Win32/GraphicsWindow.cpp | 14 ++++-----
 2 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/src/archutils/Win32/Crash.cpp b/src/archutils/Win32/Crash.cpp
index a87e54ad18..faf7bc7d08 100644
--- a/src/archutils/Win32/Crash.cpp
+++ b/src/archutils/Win32/Crash.cpp
@@ -349,13 +349,45 @@ static DWORD WINAPI MainExceptionHandler( LPVOID lpParameter )
 		/* The thread that crashed was the thread that created the main window.
 		 * Hide the window. This will also restore the video mode, if necessary. */
 		ShowWindow( g_hForegroundWnd, SW_HIDE );
-	} else {
+	}
+	else {
 		/* A different thread crashed. Simply kill all other windows. We can't
 		 * safely call ShowWindow; the main thread might be deadlocked. */
-		RageThread::HaltAllThreads( true );
-		ChangeDisplaySettings( nullptr, 0 );
-	}
+		RageThread::HaltAllThreads(true);
+		auto deviceModeIsValid = [=](const DEVMODE& mode) {
+			return (mode.dmFields & DM_PELSWIDTH) && (mode.dmFields & DM_PELSHEIGHT)
+				&& (mode.dmFields & DM_DISPLAYFREQUENCY)
+				&& (mode.dmBitsPerPel >= 32 || !(mode.dmFields & DM_BITSPERPEL));
+			};
 
+		DEVMODE devmode;
+		ZeroMemory(&devmode, sizeof(DEVMODE));
+		devmode.dmSize = sizeof(DEVMODE);
+		devmode.dmDriverExtra = 0;
+
+		DWORD deviceIter = 0;
+		DISPLAY_DEVICE dd;
+		ZeroMemory(&dd, sizeof(dd));
+		dd.cb = sizeof(dd);
+
+		/* Since we don't know which display was modified for fullscreen exclusive mode,
+		 * loop through all displays it could have been to restore the video mode. */
+		while (EnumDisplayDevices(NULL, deviceIter++, &dd, 0))
+		{
+			while (EnumDisplaySettingsEx(dd.DeviceName, ENUM_CURRENT_SETTINGS, &devmode, 0))
+			{
+				if (deviceModeIsValid(devmode))
+				{
+					ChangeDisplaySettingsEx(dd.DeviceName, nullptr, nullptr, 0, nullptr);
+				}
+				ZeroMemory(&devmode, sizeof(DEVMODE));
+				devmode.dmSize = sizeof(DEVMODE);
+				devmode.dmDriverExtra = 0;
+			}
+		}
+		ZeroMemory(&dd, sizeof(dd));
+		dd.cb = sizeof(dd);
+	}
 	InHere = false;
 
 	SetUnhandledExceptionFilter(nullptr);
diff --git a/src/archutils/Win32/GraphicsWindow.cpp b/src/archutils/Win32/GraphicsWindow.cpp
index 27ce1968bc..b2ebd0d722 100644
--- a/src/archutils/Win32/GraphicsWindow.cpp
+++ b/src/archutils/Win32/GraphicsWindow.cpp
@@ -87,13 +87,13 @@ static LRESULT CALLBACK GraphicsWindow_WndProc( HWND hWnd, UINT msg, WPARAM wPar
 				 * because that's where most other apps seem to do it. */
 				if( g_bHasFocus && !bHadFocus )
 				{
-					ChangeDisplaySettings( &g_FullScreenDevMode, CDS_FULLSCREEN );
+					ChangeDisplaySettingsEx( g_CurrentParams.sDisplayId, &g_FullScreenDevMode, nullptr, CDS_FULLSCREEN, nullptr );
 					ShowWindow( g_hWndMain, SW_SHOWNORMAL );
 					SetWindowPos( g_hWndMain, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE );
 				}
 				else if( !g_bHasFocus && bHadFocus )
 				{
-					ChangeDisplaySettings( nullptr, 0 );
+					ChangeDisplaySettingsEx(g_CurrentParams.sDisplayId, nullptr, nullptr, 0, nullptr);
 				}
 			}
 
@@ -228,7 +228,7 @@ RString GraphicsWindow::SetScreenMode( const VideoModeParams &p )
 	if( p.windowed )
 	{
 		// We're going windowed. If we were previously fullscreen, reset.
-		ChangeDisplaySettings( nullptr, 0 );
+		ChangeDisplaySettingsEx( p.sDisplayId, nullptr, nullptr, 0, nullptr );
 
 		return RString();
 	}
@@ -246,13 +246,13 @@ RString GraphicsWindow::SetScreenMode( const VideoModeParams &p )
 		DevMode.dmDisplayFrequency = p.rate;
 		DevMode.dmFields |= DM_DISPLAYFREQUENCY;
 	}
-	ChangeDisplaySettings( nullptr, 0 );
+	ChangeDisplaySettingsEx(p.sDisplayId, nullptr, nullptr, 0, nullptr);
 
-	int ret = ChangeDisplaySettings( &DevMode, CDS_FULLSCREEN );
+	int ret = ChangeDisplaySettingsEx( p.sDisplayId, &DevMode, nullptr, CDS_FULLSCREEN, nullptr );
 	if( ret != DISP_CHANGE_SUCCESSFUL && (DevMode.dmFields & DM_DISPLAYFREQUENCY) )
 	{
 		DevMode.dmFields &= ~DM_DISPLAYFREQUENCY;
-		ret = ChangeDisplaySettings( &DevMode, CDS_FULLSCREEN );
+		ret = ChangeDisplaySettingsEx( p.sDisplayId, &DevMode, nullptr, CDS_FULLSCREEN, nullptr );
 	}
 
 	// XXX: append error
@@ -514,7 +514,7 @@ void GraphicsWindow::Shutdown()
 	 * It'd be nice to not do this: Windows will do it when we quit, and if
 	 * we're shutting down OpenGL to try D3D, this will cause extra mode
 	 * switches. However, we need to do this before displaying dialogs. */
-	ChangeDisplaySettings( nullptr, 0 );
+	ChangeDisplaySettingsEx( g_CurrentParams.sDisplayId, nullptr, nullptr, 0, nullptr );
 
 	AppInstance inst;
 	UnregisterClass( g_sClassName, inst );