display server window position bug fix (#37323)

platform/linuxbsd/display_server_x11.cpp

@@ -3603,8 +3603,10 @@ DisplayServerX11::DisplayServerX11(const String &p_rendering_driver, WindowMode
 		}
 	}
 #endif
-
-	WindowID main_window = _create_window(p_mode, p_flags, Rect2i(Point2(), p_resolution));
+	Point2i window_position(
+			(screen_get_size(0).width - p_resolution.width) / 2,
+			(screen_get_size(0).height - p_resolution.height) / 2);
+	WindowID main_window = _create_window(p_mode, p_flags, Rect2i(window_position, p_resolution));
 	for (int i = 0; i < WINDOW_FLAG_MAX; i++) {
 		if (p_flags & (1 << i)) {
 			window_set_flag(WindowFlags(i), true, main_window);

platform/osx/display_server_osx.mm

@@ -3524,7 +3524,10 @@ DisplayServerOSX::DisplayServerOSX(const String &p_rendering_driver, WindowMode
 	}
 #endif
 
-	WindowID main_window = _create_window(p_mode, Rect2i(Point2i(), p_resolution));
+	Point2i window_position(
+			(screen_get_size(0).width - p_resolution.width) / 2,
+			(screen_get_size(0).height - p_resolution.height) / 2);
+	WindowID main_window = _create_window(p_mode, Rect2i(window_position, p_resolution));
 	for (int i = 0; i < WINDOW_FLAG_MAX; i++) {
 		if (p_flags & (1 << i)) {
 			window_set_flag(WindowFlags(i), true, main_window);

platform/windows/display_server_windows.cpp

@@ -2897,7 +2897,10 @@ DisplayServerWindows::DisplayServerWindows(const String &p_rendering_driver, Win
 		}
 	}
 #endif
-	WindowID main_window = _create_window(p_mode, 0, Rect2i(Point2i(), p_resolution));
+	Point2i window_position(
+			(screen_get_size(0).width - p_resolution.width) / 2,
+			(screen_get_size(0).height - p_resolution.height) / 2);
+	WindowID main_window = _create_window(p_mode, 0, Rect2i(window_position, p_resolution));
 	for (int i = 0; i < WINDOW_FLAG_MAX; i++) {
 		if (p_flags & (1 << i)) {
 			window_set_flag(WindowFlags(i), true, main_window);