Added SDL_PROP_WINDOW_CREATE_WIN32_STYLE_EX_NUMBER

include/SDL3/SDL_video.h

@@ -1399,6 +1399,7 @@ extern SDL_DECLSPEC SDL_Window * SDLCALL SDL_CreatePopupWindow(SDL_Window *paren
  *   window, if you want to wrap an existing window.
  * - `SDL_PROP_WINDOW_CREATE_WIN32_PIXEL_FORMAT_HWND_POINTER`: optional,
  *   another window to share pixel format with, useful for OpenGL windows
+ * - `SDL_PROP_WINDOW_CREATE_WIN32_STYLE_EX_NUMBER`: the window style (WS_EX_*) flags to use instead of the defaults.
  *
  * These are additional supported properties with X11:
  *
@@ -1494,6 +1495,7 @@ extern SDL_DECLSPEC SDL_Window * SDLCALL SDL_CreateWindowWithProperties(SDL_Prop
 #define SDL_PROP_WINDOW_CREATE_WAYLAND_WL_SURFACE_POINTER          "SDL.window.create.wayland.wl_surface"
 #define SDL_PROP_WINDOW_CREATE_WIN32_HWND_POINTER                  "SDL.window.create.win32.hwnd"
 #define SDL_PROP_WINDOW_CREATE_WIN32_PIXEL_FORMAT_HWND_POINTER     "SDL.window.create.win32.pixel_format_hwnd"
+#define SDL_PROP_WINDOW_CREATE_WIN32_STYLE_EX_NUMBER               "SDL.window.create.win32.style_ex"
 #define SDL_PROP_WINDOW_CREATE_X11_WINDOW_NUMBER                   "SDL.window.create.x11.window"
 #define SDL_PROP_WINDOW_CREATE_EMSCRIPTEN_CANVAS_ID_STRING         "SDL.window.create.emscripten.canvas_id"
 #define SDL_PROP_WINDOW_CREATE_EMSCRIPTEN_KEYBOARD_ELEMENT_STRING  "SDL.window.create.emscripten.keyboard_element"

src/video/windows/SDL_windowswindow.c

@@ -713,7 +713,7 @@ bool WIN_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window, SDL_Properties
         }
 
         style |= GetWindowStyle(window);
-        styleEx |= GetWindowStyleEx(window);
+        styleEx |= (DWORD)SDL_GetNumberProperty(create_props, SDL_PROP_WINDOW_CREATE_WIN32_STYLE_EX_NUMBER, GetWindowStyleEx(window));
 
         // Figure out what the window area will be
         WIN_ConstrainPopup(window, false);