From f51734d68ca7732575e8f35cecea60d0712796b6 Mon Sep 17 00:00:00 2001
From: Brandon Wright <bearoso@gmail.com>
Date: Sun, 6 May 2018 11:05:09 -0500
Subject: [PATCH] d3d: only lock a small region in case the driver tries to
 readback.

---
 win32/CDirect3D.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/win32/CDirect3D.cpp b/win32/CDirect3D.cpp
index da9ed590..eb75fa76 100644
--- a/win32/CDirect3D.cpp
+++ b/win32/CDirect3D.cpp
@@ -734,10 +734,11 @@ void CDirect3D::Render(SSurface Src)
 	if (GUI.ReduceInputLag)
 	{
 		IDirect3DSurface9 *surface;
+		RECT r = { 0, 0, 2, 2 };
 
 		if (pDevice->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &surface) == D3D_OK)
 		{
-			if (surface->LockRect(&lr, NULL, D3DLOCK_READONLY) == D3D_OK)
+			if (surface->LockRect(&lr, &r, D3DLOCK_READONLY) == D3D_OK)
 			{
 				surface->UnlockRect();
 			}