Refactor light source and wall shadow shaders

src/Picture/Tree.hs

@@ -138,3 +138,35 @@ rotate3 :: Float -> Point3 -> Point3
 rotate3 a (x,y,z) = (x',y',z)
     where (x',y') = rotateV a (x,y)
 
+--picToAlt :: (Ap.Alternative f, Monoid (f RenderType)) => Int -> Picture -> f RenderType
+--{-# INLINE picToAlt #-}
+--picToAlt x (Polygon i ps) 
+--    | i == x = Ap.pure $ RenderPoly $ zip (map zeroZ $ polyToTris ps) $ repeat black
+--    | otherwise = Ap.empty
+--picToAlt x (PolygonCol i vs) 
+--    | i /= x = Ap.empty 
+--    | otherwise = 
+--        let (ps,cs) = unzip vs
+--        in  Ap.pure $ RenderPoly $ zip (map zeroZ $ polyToTris ps) $ polyToTris cs
+--picToAlt x (Circle i r) 
+--    | i == x = Ap.pure $ RenderCirc $ ((0,0,0),black,r)
+--    | otherwise = Ap.empty
+--picToAlt x (Ellipse i (ax,ay) (bx,by) r) 
+--    | i == x = Ap.pure $ RenderEllipse [((ax,ay+r,0),black)
+--                                       ,((ax,ay-r,0),black)
+--                                       ,((bx,by-r,0),black)
+--                                       ]
+--    | otherwise = Ap.empty
+--picToAlt x (ThickArc i startA endA rad wdth) 
+--    | i == x = Ap.pure $ RenderArc $ ((0,0,0),black,(startA,endA,rad,wdth))
+--    | otherwise = Ap.empty
+--picToAlt x (Line i ps) 
+--    | i == x = Ap.pure $ RenderLine $ zip (map zeroZ $ doubleLine ps) $ repeat white
+--    | otherwise = Ap.empty
+--picToAlt x (Text i s) 
+--    | i == x = Ap.pure $ RenderText $ stringToList s
+--    | otherwise = Ap.empty
+--picToAlt j Blank = Ap.empty
+--picToAlt j (Pictures pics) = mconcat $ fmap (picToAlt j) pics
+
+