feat(rt_interp): enable file locations for include

scenes/demo-2.lisp

@@ -1,40 +1,4 @@
-(set 'red
-     (material
-      (color 1 0 0)
-      (color 1 0 0)
-      (color 0.5 0 0)
-      50 0.25))
-(set 'blue
-     (material
-      (color 0 0 1)
-      (color 0 0 1)
-      (color 0 0 0.6)
-      50 0.25))
-(set 'green
-     (material
-      (color 0 1 0)
-      (color 0 1 0)
-      (color 0 0.6 0)
-      50 0.25))
-(set 'white
-     (material
-      (color 1 1 1)
-      (color 1 1 1)
-      (color 0.6 0.6 0.6)
-      100 0.5))
-(set 'black
-     (material
-      (color 0 0 0)
-      (color 0 0 0)
-      (color 0.6 0.6 0.6)
-      100 0.5))
-
-(set 'dark-mirror
-     (material
-      (color 0 0 0)
-      (color 0 0 0)
-      (color 0.2 0.2 0.2)
-      20 0.6))
+(include "./materials.lisp")
 
 (set 's1
      (sphere