From 3649570e0cfcf175cc256082170d369d366e263e Mon Sep 17 00:00:00 2001
From: L0laapk3 <L0laapk3@gmail.com>
Date: Sun, 5 May 2024 20:28:11 +0200
Subject: [PATCH] fix borderless flicker

---
 src/SFML/Window/Win32/WindowImplWin32.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/SFML/Window/Win32/WindowImplWin32.cpp b/src/SFML/Window/Win32/WindowImplWin32.cpp
index 059b39dba..89a978589 100644
--- a/src/SFML/Window/Win32/WindowImplWin32.cpp
+++ b/src/SFML/Window/Win32/WindowImplWin32.cpp
@@ -179,7 +179,8 @@ m_cursorGrabbed(m_fullscreen)
     DWORD win32Style = WS_VISIBLE;
     if (style == Style::None)
     {
-        win32Style |= WS_POPUP;
+        // You cannot spawn a window as a true borderless window. Remove the caption after creation.
+        win32Style |= WS_CAPTION;
     }
     else
     {
@@ -235,6 +236,14 @@ m_cursorGrabbed(m_fullscreen)
     if (m_fullscreen)
         switchToFullscreen(mode);
 
+    if (style == Style::None)
+    {
+        // For a true borderless window, remove the titlebar now.
+        // from: https://github.com/Codeusa/Borderless-Gaming/blob/3cc4dc6bd580b263287be45981f1e36036daf4eb/BorderlessGaming.Logic/Windows/Manipulation.cs#L71-L94
+        constexpr long long borderlessStyleRemove = WS_CAPTION | WS_THICKFRAME | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX;
+        SetWindowLongPtr(m_handle, GWL_STYLE, GetWindowLongPtr(m_handle, GWL_STYLE) & ~borderlessStyleRemove);
+    }
+
     // Increment window count
     ++windowCount;
 }