I have been trying to improve my pixel art so I joined pixel joint. I have recently been working on a movie theater. I started coloring it in when I ran into a problem, which brings me to my question...

"How do I accurately determine where one object casts a shadow on another?"

• This is my picture so far --->Click Here<---
• The program I used to make the pixel art is Corel Paint Shop Pro 4x
• Please note where the light source in the picture.

            If there is any information I missed please let me know, and things such as tips you might suggest, or flaws you may find, please point them out to me, they will be greatly appreciated. 

Thank you for your help
                - KWVance