Allow for items to cast shadows

src/ShapePicture.hs

@@ -9,9 +9,18 @@ import Picture
 import Geometry
 
 emptyBlank :: SPic
-emptyBlank = SPic empty blank
+emptyBlank = SPic emptySH blank
 
-translateSP :: Float -> Float -> SPic -> SPic
-translateSP x y (SPic sh pic) = SPic
+translateSPf :: Float -> Float -> SPic -> SPic
+translateSPf x y (SPic sh pic) = SPic
     (translateSH (V3 x y 0) sh)
     (translate x y pic)
+
+-- TODO make this uniform: currently the shape translates and the picture is set to a constant
+translateSPz :: Float -> SPic -> SPic
+translateSPz z (SPic sh pic) = SPic
+    (translateSH (V3 0 0 z) sh)
+    (setDepth z pic)
+
+rotateSP :: Float -> SPic -> SPic
+rotateSP a (SPic sh pic) = SPic (rotateSH a sh) (rotate a pic)