It's easy to cover your bay or corner window with Special Shape curtain rods. Bay or corner rods are available as single or double and come in a size that fit many standard bays. Special shape rods are designed for stationary panels or curtains with a rod pocket. If you want your drapes to open and close with a cord, then you'll need to have a heavy-duty curtain rod made to fit the shape of your bay or corner.
Curtain rods for arches, circles and octagons are made from a light weight flexible tubing. This tubing can be easily bent to conform to just about any shape. Plus, if you can't find a size that matches your window, you can easily use two or more pieces of tubing. The rod attaches to the wall using barrel brackets. These brackets have clips for the tube to snap in to. You must use a rod pocket style curtain with this type of rod. You won't be able to attach rings.
Flexible special shape tubing and barrel brackets are made for very light weight fabrics or sheers. If you have a thick fabric or lined or interlined fabric, it will be too heavy for the rod. For a more durable option for heavier fabrics, a custom heavy-duty curtain rod would be a better choice.