Refactor shapes, prepare for different normals at single vertex pos

src/ShapePicture.hs

@@ -21,7 +21,7 @@ import Geometry
 import Data.Bifunctor
 import Control.Lens
 
-shMap :: (ShapeObj -> ShapeObj) -> Shape -> Shape
+shMap :: (Surface -> Surface) -> Shape -> Shape
 shMap = map
 
 -- should all this be inlined/inlinable?
@@ -63,12 +63,12 @@ rotateSP a = bimap (rotateSH a) (rotate a)
 
 mirrorSPxz :: SPic -> SPic
 {-# INLINE mirrorSPxz #-}
-mirrorSPxz = bimap (shMap (over shVs reverse) . overPosSH flipy) mirrorxz
+mirrorSPxz = bimap (shMap (over sfVs reverse) . overPosSH flipy) mirrorxz
   where
     flipy (V3 x y z) = V3 x (negate y) z
 
 mirrorSPyz :: SPic -> SPic
 {-# INLINE mirrorSPyz #-}
-mirrorSPyz = bimap (shMap (over shVs reverse) . overPosSH flipx) mirroryz
+mirrorSPyz = bimap (shMap (over sfVs reverse) . overPosSH flipx) mirroryz
   where
     flipx (V3 x y z) = V3 (negate x) y z