Built-in turf vars:
turf/var
- appearance
- appearance_flags
- blend_mode
- color
- contents
- density
- desc
- dir
- filters
- gender
- icon
- icon_state
- icon_w
- icon_z
- invisibility
- underlays
- overlays
- loc
- layer
- luminosity
- mouse_over_pointer
- mouse_drag_pointer
- mouse_drop_pointer
- mouse_drop_zone var
- mouse_opacity var
- name
- opacity
- parent_type
- pixel_x
- pixel_y
- pixel_w
- pixel_z
- plane
- render_source
- render_target
- suffix
- tag
- text
- transform
- type
- vars
- verbs
- vis_contents
- vis_flags
- vis_locs
- x
- y
- z