Convert generated levels to walls

Add support for converting generated levels to walls, and merge one into
the entity map at the beginning of the game.

There's nothing here that guarantees the character ends up *inside* the
level though (they almost always don't) so that'll have to be slotted
into the level generation process.

1 files changed, 12 insertions, 1 deletions

diff --git a/src/Xanthous/Data/EntityMap.hs b/src/Xanthous/Data/EntityMap.hs
index e3ceb6f651..401e395547 100644
--- a/src/Xanthous/Data/EntityMap.hs
+++ b/src/Xanthous/Data/EntityMap.hs
@@ -15,6 +15,7 @@ module Xanthous.Data.EntityMap
   , lookup
   , lookupWithPosition
   -- , positionedEntities
+  , neighbors
   ) where
 
 import Data.Monoid (Endo(..))
@@ -22,7 +23,14 @@ import Test.QuickCheck (Arbitrary(..))
 import Test.QuickCheck.Checkers (EqProp)
 
 import Xanthous.Prelude hiding (lookup)
-import Xanthous.Data (Position, Positioned(..), positioned, position)
+import Xanthous.Data
+  ( Position
+  , Positioned(..)
+  , positioned
+  , position
+  , Neighbors(..)
+  , neighborPositions
+  )
 import Xanthous.Orphans ()
 import Xanthous.Util (EqEqProp(..))
 
@@ -139,3 +147,6 @@ lookup eid = fmap (view positioned) . lookupWithPosition eid
 -- unlawful :(
 -- positionedEntities :: IndexedTraversal EntityID (EntityMap a) (EntityMap b) (Positioned a) (Positioned b)
 -- positionedEntities = byID . itraversed
+
+neighbors :: Position -> EntityMap a -> Neighbors (Vector a)
+neighbors pos em = (\p -> view (atPosition p) em) <$> neighborPositions pos