Implement the start of creature AI

Add a Brain class, which determines for an entity the set of moves it
makes every step of the game, and begin to implement that for gormlaks.
The idea here is that every step of the game, a gormlak will move
towards the furthest-away wall it can see.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/Xanthous/Entities/Creature.hs b/src/Xanthous/Entities/Creature.hs
index 5151f78b3061..accf0c42e2ad 100644
--- a/src/Xanthous/Entities/Creature.hs
+++ b/src/Xanthous/Entities/Creature.hs
@@ -8,6 +8,7 @@ module Xanthous.Entities.Creature
   , newWithType
   , damage
   , isDead
+  , visionRadius
   ) where
 --------------------------------------------------------------------------------
 import           Xanthous.Prelude
@@ -17,8 +18,7 @@ import           Data.Aeson.Generic.DerivingVia
 import           Data.Aeson (ToJSON, FromJSON)
 --------------------------------------------------------------------------------
 import           Xanthous.Entities.RawTypes hiding (Creature, description)
-import qualified Xanthous.Entities.RawTypes as Raw
-import           Xanthous.Entities (Draw(..), Entity(..), DrawRawChar(..))
+import           Xanthous.Entities (Draw(..), DrawRawChar(..))
 --------------------------------------------------------------------------------
 
 data Creature = Creature
@@ -35,9 +35,7 @@ makeLenses ''Creature
 instance Arbitrary Creature where
   arbitrary = genericArbitrary
 
-instance Entity Creature where
-  blocksVision _ = False
-  description = view $ creatureType . Raw.description
+--------------------------------------------------------------------------------
 
 newWithType :: CreatureType -> Creature
 newWithType _creatureType =
@@ -52,3 +50,6 @@ damage amount = hitpoints %~ \hp ->
 
 isDead :: Creature -> Bool
 isDead = views hitpoints (== 0)
+
+visionRadius :: Creature -> Word
+visionRadius = const 12 -- TODO