Building a closet in an odd shaped room?

Okay, so I'm moving my room into an odd shaped room because its bigger. It doesn't have a closet which is a HUGE problem for me because I have so much clothes. We have a one story house, but this is an upstairs room, so it's kind of like 1 1/2 stories. This room has slanted walls because that's where the roof it. So I can't really build a closet without it being a huge project. There's only one wall that would be big enough to build a closet on it, but it has a window and slanted walls on either side. I've come up with different ideas to build one, but they all end up that it wont work. So, my question is do you know of any ideas that I could build a good sized closet in here? Also, the slanted walls end about half way down the wall. Sorry if this was confusing but if you could give me ANY ideas, I'd love it ♥ thank you.