Add the SDL_HasWindowSurface function

Author: suve

units/sdlvideo.inc

@@ -935,6 +935,19 @@ procedure SDL_RestoreWindow(window: PSDL_Window); cdecl;
 function SDL_SetWindowFullscreen(window: PSDL_Window; flags: TSDL_WindowFlags): cint; cdecl;
   external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_SetWindowFullscreen' {$ENDIF} {$ENDIF};
 
+  {**
+   * Return whether the window has a surface associated with it.
+   *
+   * \returns SDL_TRUE if there is a surface associated with the window, or
+   *          SDL_FALSE otherwise.
+   *
+   * \since This function is available since SDL 2.28.0.
+   *
+   * \sa SDL_GetWindowSurface
+   *}
+function SDL_HasWindowSurface(window: PSDL_Window): TSDL_Bool; cdecl;
+  external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_HasWindowSurface' {$ENDIF} {$ENDIF};
+
   {**
    *  Get the SDL surface associated with the window.
    *