This is to prepare so we don't recalculate the lookup cache map for color
tables on every clipped rect (which is expensive).
Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>