However, if the window manager is also able to supply an application with an updated image of what the screen looked like before the foreground window was drawn but after all other windows were already drawn more possibilities open up. This would allow the one window in the foreground to appear semi-transparent, by using the before image as a texture filter on the final output. This was possible in Windows XP with software included with many NVidia GeForce video cards as well as from third party sources, using a hardware texture overlay.