Added objects to floor, ceiling, and back wall
objects draw according to scale given by the distance from the viewer
(or how close they are to the back wall) so far size, and x positions
are transformed according to this scale.
ability to figure out where objects are according to the current view
direction s added but untested.

Notes:
Uses alot of hardcoding (eg all images are assumed to be drawn full size
as a 200x200 image)
objects can be positioned right on the edge of the floor and so will
appear to go into/over the wall

ToDo:
remove hardcoding and 'magic numbers'
rotate the room and watch as objects change position on floor with
correct position and scale as if the room were 3D
add objects to side walls
return clicked objects