From 65495a1297a4cc8eb4f4d569fc283bfb0b1f569f Mon Sep 17 00:00:00 2001
From: Jules Blok <jules.blok@gmail.com>
Date: Mon, 10 Jul 2017 14:03:38 +0200
Subject: [PATCH] D3D: Resize the swapchain when the fullscreen state is
 changed

---
 Source/Core/VideoBackends/D3D/D3DBase.cpp |  6 ++----
 Source/Core/VideoBackends/D3D/Render.cpp  | 11 ++++++++---
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/Source/Core/VideoBackends/D3D/D3DBase.cpp b/Source/Core/VideoBackends/D3D/D3DBase.cpp
index 68b90d1f21..40ae9d0c95 100644
--- a/Source/Core/VideoBackends/D3D/D3DBase.cpp
+++ b/Source/Core/VideoBackends/D3D/D3DBase.cpp
@@ -52,8 +52,6 @@ unsigned int xres, yres;
 
 bool bFrameInProgress = false;
 
-#define NUM_SWAPCHAIN_BUFFERS 2
-
 HRESULT LoadDXGI()
 {
   if (dxgi_dll_ref++ > 0)
@@ -294,7 +292,7 @@ HRESULT Create(HWND wnd)
   }
 
   DXGI_SWAP_CHAIN_DESC1 swap_chain_desc = {};
-  swap_chain_desc.BufferCount = NUM_SWAPCHAIN_BUFFERS;
+  swap_chain_desc.BufferCount = 2;
   swap_chain_desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
   swap_chain_desc.SampleDesc.Count = 1;
   swap_chain_desc.SampleDesc.Quality = 0;
@@ -548,7 +546,7 @@ void Reset()
   GetClientRect(hWnd, &client);
   xres = client.right - client.left;
   yres = client.bottom - client.top;
-  D3D::swapchain->ResizeBuffers(NUM_SWAPCHAIN_BUFFERS, xres, yres, DXGI_FORMAT_R8G8B8A8_UNORM, 0);
+  D3D::swapchain->ResizeBuffers(0, xres, yres, DXGI_FORMAT_R8G8B8A8_UNORM, 0);
 
   // recreate back buffer texture
   ID3D11Texture2D* buf;
diff --git a/Source/Core/VideoBackends/D3D/Render.cpp b/Source/Core/VideoBackends/D3D/Render.cpp
index 027c3611c0..df4aad0e28 100644
--- a/Source/Core/VideoBackends/D3D/Render.cpp
+++ b/Source/Core/VideoBackends/D3D/Render.cpp
@@ -66,6 +66,7 @@ struct GXPipelineState
 static u32 s_last_multisamples = 1;
 static bool s_last_stereo_mode = false;
 static bool s_last_xfb_mode = false;
+static bool s_last_fullscreen_mode = false;
 
 static Television s_television;
 
@@ -240,6 +241,7 @@ Renderer::Renderer() : ::Renderer(D3D::GetBackBufferWidth(), D3D::GetBackBufferH
   s_last_multisamples = g_ActiveConfig.iMultisamples;
   s_last_stereo_mode = g_ActiveConfig.iStereoMode > 0;
   s_last_xfb_mode = g_ActiveConfig.bUseRealXFB;
+  s_last_fullscreen_mode = D3D::GetFullscreenState();
 
   g_framebuffer_manager = std::make_unique<FramebufferManager>(m_target_width, m_target_height);
   SetupDeviceObjects();
@@ -838,7 +840,9 @@ void Renderer::SwapImpl(u32 xfbAddr, u32 fbWidth, u32 fbStride, u32 fbHeight,
 
   SetWindowSize(fbStride, fbHeight);
 
-  const bool windowResized = CheckForResize();
+  const bool window_resized = CheckForResize();
+  const bool fullscreen = D3D::GetFullscreenState();
+  const bool fs_changed = s_last_fullscreen_mode != fullscreen;
 
   bool xfbchanged = s_last_xfb_mode != g_ActiveConfig.bUseRealXFB;
 
@@ -856,15 +860,16 @@ void Renderer::SwapImpl(u32 xfbAddr, u32 fbWidth, u32 fbStride, u32 fbHeight,
   D3D::Present();
 
   // Resize the back buffers NOW to avoid flickering
-  if (CalculateTargetSize() || xfbchanged || windowResized ||
+  if (CalculateTargetSize() || xfbchanged || window_resized || fs_changed ||
       s_last_multisamples != g_ActiveConfig.iMultisamples ||
       s_last_stereo_mode != (g_ActiveConfig.iStereoMode > 0))
   {
     s_last_xfb_mode = g_ActiveConfig.bUseRealXFB;
     s_last_multisamples = g_ActiveConfig.iMultisamples;
+    s_last_fullscreen_mode = fullscreen;
     PixelShaderCache::InvalidateMSAAShaders();
 
-    if (windowResized)
+    if (window_resized || fs_changed)
     {
       // TODO: Aren't we still holding a reference to the back buffer right now?
       D3D::Reset();