cairo:font-options-subpixel-order (options)

options -- a cairo:font-options-t instance
order -- a cairo:subpixel-order-t value

The cairo:font-options-subpixel-order function gets the subpixel order for the font options instance. The (setf cairo:font-options-subpixel-order) function sets the subpixel order. The subpixel order specifies the order of color elements within each pixel on the display device when rendering with an antialiasing mode of :subpixel. See the documentation for the cairo:subpixel-order-t enumeration for full details.