Allow for assigning attach items orientations

src/Dodge/Data/ComposedItem.hs

@@ -41,8 +41,9 @@ data ItemStructuralFunction
     deriving (Eq, Ord, Show, Read)
 
 type PartiallyComposedItem lt = (Item, ItemStructuralFunction, LinkTest lt)
+type ComposedItem = (Item, ItemStructuralFunction)
 
-data ItemAttachment = IAttach
+data ItemLink = ILink
     { _iatType :: ComposeLinkType
     , _iatOrient :: Item -> Item -> Maybe (Point3, Quaternion Float)
     }
@@ -58,6 +59,7 @@ data LinkUpdate lt = LUpdate
     , _luChildUpdate :: PartiallyComposedItem lt -> PartiallyComposedItem lt
     }
 
+makeLenses ''ItemLink
 makeLenses ''LinkTest
 makeLenses ''LinkUpdate
 deriveJSON defaultOptions ''ComposeLinkType

src/Dodge/Data/DoubleTree.hs

@@ -49,6 +49,11 @@ instance Foldable DoubleTree where
 instance Functor (LabelDoubleTree b) where
     fmap f (LDT x l r) = LDT (f x) (fmap (second $ fmap f) l) (fmap (second $ fmap f) r)
 
+instance Bifunctor LabelDoubleTree where
+    second = fmap
+    first f (LDT x l r) = LDT x (map (first f . second (first f)) l)
+        (map (first f . second (first f)) r)
+
 makeLenses ''DoubleTree
 makeLenses ''LabelDoubleTree
 deriveJSON defaultOptions ''DoubleTree