If the room is wide enough, place the tub along the window wall shown and switch to casement windows. Place the toilet where the sink is, and a larger vanity on the opposite wall.

Thanks! I'll have to look into the costs of that. That, of course, would be ideal. I'm looking for the most budget friendly remodel.

A floor plan would be helpful in space reconfiguration ideas.

You might be able to add a shower fixture to the half wall and surround the tub in glass.
https://www.houzz.com/photos/3300-linde-residence-modern-bathroom-phoenix-phvw-vp~570705

Or simply build up the wall and add traditional glass doors or a curtain. The current floor plan seems to be the best fit for your window placement.

I would suggest you leave the tub, toilet, and windows where they are. In keeping with this idea, I would suggest you borrow some space from the room behind the sink and have the sink and vanity cabinet recessed into this space. There might be additional space you can enclose for storage on each side of the sink. This arrangement will give you a straight path through the bathroom. If there is anything I personally dislike, it is having a sink jutting out, especially if the counter top has sharp or square corners, and having to walk around it.