Normally, Shower Doors tend to be in one side. In case your bathroom is a different case, consider as many openings as you require based on the number of glass' sides. For instance, a 90-degree enclosure (L-shape) would have 2 openings. Please see the image for reference.
Each opening should be the total area of Glass for each side of the enclosure. Doors are included in the glass area. Therefore, do not add extra area of doors. Also, you can type all the details in the comments field; our specialists will be in touch with all the information you provide.