From 1d0dab45daa8c0ea430cd269ff1d2335cd41a6e7 Mon Sep 17 00:00:00 2001
From: BearOso <bearoso@gmail.com>
Date: Wed, 22 Feb 2023 19:14:05 -0600
Subject: [PATCH] win32: Flush message queue between driver changes.

---
 win32/COpenGL.cpp       | 14 +++++++++-----
 win32/win32_display.cpp | 14 +++++++++++---
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/win32/COpenGL.cpp b/win32/COpenGL.cpp
index 152eceb4..9e3ec394 100644
--- a/win32/COpenGL.cpp
+++ b/win32/COpenGL.cpp
@@ -104,7 +104,7 @@ bool COpenGL::Initialize(HWND hWnd)
 	LoadPBOFunctions();
 
 	wglSwapIntervalEXT = (PFNWGLSWAPINTERVALEXTPROC)wglGetProcAddress( "wglSwapIntervalEXT" );
-	
+
 	glEnableClientState(GL_VERTEX_ARRAY);
     glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 	glEnable(GL_BLEND);
@@ -113,7 +113,7 @@ bool COpenGL::Initialize(HWND hWnd)
 	glMatrixMode (GL_PROJECTION);
     glLoadIdentity ();
     glOrtho (0.0, 1.0, 0.0, 1.0, -1, 1);
-	
+
 	glVertexPointer(2, GL_FLOAT, 0, vertices);
 	glTexCoordPointer(2, GL_FLOAT, 0, texcoords);
 
@@ -147,7 +147,11 @@ void COpenGL::DeInitialize()
 		wglDeleteContext(hRC);
 		hRC = NULL;
 	}
-	hDC = NULL;
+	if (hDC)
+	{
+		ReleaseDC(hWnd, hDC);
+		hDC = NULL;
+	}
 	hWnd = NULL;
 	afterRenderWidth = 0;
 	afterRenderHeight = 0;
@@ -446,7 +450,7 @@ bool COpenGL::SetFullscreen(bool fullscreen)
 		ChangeDisplaySettings(NULL,0);
 	}
 
-	
+
 
 	return true;
 }
@@ -510,7 +514,7 @@ bool COpenGL::LoadPBOFunctions()
 		if(glGenBuffers && glBindBuffer && glBufferData && glDeleteBuffers && glMapBuffer) {
 			pboFunctionsLoaded = true;
 		}
-		 
+
 	}
 	return pboFunctionsLoaded;
 }
diff --git a/win32/win32_display.cpp b/win32/win32_display.cpp
index 12324697..f8b363b0 100644
--- a/win32/win32_display.cpp
+++ b/win32/win32_display.cpp
@@ -98,6 +98,15 @@ void WinChangeWindowSize(unsigned int newWidth, unsigned int newHeight)
 	S9xDisplayOutput->ChangeRenderSize(newWidth,newHeight);
 }
 
+static void FlushMessageQueue()
+{
+	for (MSG msg; PeekMessage(&msg, GUI.hWnd, 0, 0, PM_NOREMOVE);)
+	{
+		GetMessage(&msg, GUI.hWnd, 0, 0);
+		DispatchMessage(&msg);
+	}
+}
+
 /*  WinDisplayReset
 initializes the currently selected display output and
 reinitializes the core graphics rendering
@@ -107,8 +116,7 @@ returns true if successful, false otherwise
 bool WinDisplayReset(void)
 {
 	S9xDisplayOutput->DeInitialize();
-	if (S9xDisplayOutput == (IS9xDisplayOutput *)&VulkanDriver && GUI.outputMethod == OPENGL)
-		Sleep(500);
+	FlushMessageQueue();
 
 	switch(GUI.outputMethod) {
 		default:
@@ -238,7 +246,7 @@ bool8 S9xInitUpdate (void)
 bool8 S9xContinueUpdate(int Width, int Height)
 {
 	// called every other frame during interlace
-	
+
     Src.Width = Width;
 	if(Height%SNES_HEIGHT)
 	    Src.Height = Height;