The Bed - Lighting and Shadows

I have returned to a previous project that was started and then left behind to explore other avenues. Mainly sketching, but now back to full drawings.

The original post for "The Bed" can be found here:1000 Hours of Drawing: The Bed - In Progress 1

In order to continue with this drawing (fill in the rest of the space) I need to figure out where the light sources are. The bed was first drawn without consideration for the rest of the room. That was the point, if you go back and read the original post. Let the drawing dictate the space. With shadows already established in the bedding and as a result, the bed is dictating the light sources for the room. Below is my way of figuring out those sources.