1 files changed, 30 insertions, 5 deletions
diff --git a/src/Xanthous/Game.hs b/src/Xanthous/Game.hs
index 6a46896106..ed65217e62 100644
--- a/src/Xanthous/Game.hs
+++ b/src/Xanthous/Game.hs
@@ -1,10 +1,11 @@
-{-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE MultiWayIf      #-}
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE RecordWildCards #-}
 --------------------------------------------------------------------------------
 module Xanthous.Game
   ( GameState(..)
   , entities
+  , revealedEntities
   , messageHistory
   , randomGen
 
@@ -13,6 +14,7 @@ module Xanthous.Game
   , positionedCharacter
   , character
   , characterPosition
+  , updateCharacterVision
 
   , MessageHistory(..)
   , pushMessage
@@ -33,8 +35,10 @@ import           Test.QuickCheck
 import           Test.QuickCheck.Arbitrary.Generic
 import           Control.Monad.State.Class
 --------------------------------------------------------------------------------
+import           Xanthous.Util (appendVia)
 import           Xanthous.Data.EntityMap (EntityMap, EntityID)
 import qualified Xanthous.Data.EntityMap as EntityMap
+import           Xanthous.Data.EntityMap.Graphics
 import           Xanthous.Data (Positioned, Position(..), positioned, position)
 import           Xanthous.Entities (SomeEntity(..), downcastEntity, entityIs)
 import           Xanthous.Entities.Character
@@ -68,6 +72,8 @@ hideMessage (MessageHistory msgs _) = MessageHistory msgs False
 
 data GameState = GameState
   { _entities          :: EntityMap SomeEntity
+    -- | A subset of the overall set of entities
+  , _revealedEntities  :: EntityMap SomeEntity
   , _characterEntityID :: EntityID
   , _messageHistory    :: MessageHistory
   , _randomGen         :: StdGen
@@ -76,10 +82,12 @@ data GameState = GameState
 makeLenses ''GameState
 
 instance Eq GameState where
-  (GameState es₁ ceid₁ mh₁ _) == (GameState es₂ ceid₂ mh₂ _)
-    = es₁ == es₂
-    && ceid₁ == ceid₂
-    && mh₁ == mh₂
+  (==) = (==) `on` \gs ->
+    ( gs ^. entities
+    , gs ^. revealedEntities
+    , gs ^. characterEntityID
+    , gs ^. messageHistory
+    )
 
 instance Arbitrary GameState where
   arbitrary = do
@@ -88,6 +96,11 @@ instance Arbitrary GameState where
     _messageHistory <- arbitrary
     (_characterEntityID, _entities) <- arbitrary <&>
       EntityMap.insertAtReturningID charPos (SomeEntity char)
+    revealedPositions <- sublistOf $ EntityMap.positions _entities
+    let _revealedEntities = mempty &~ do
+          for_ revealedPositions $ \pos -> do
+            let ents = _entities ^. EntityMap.atPosition pos
+            EntityMap.atPosition pos <>= ents
     _randomGen <- mkStdGen <$> arbitrary
     pure $ GameState {..}
 
@@ -101,6 +114,7 @@ getInitialState = do
           (SomeEntity char)
           mempty
       _messageHistory = NoMessageHistory
+      _revealedEntities = _entities
   pure GameState {..}
 
 positionedCharacter :: Lens' GameState (Positioned Character)
@@ -130,6 +144,17 @@ character = positionedCharacter . positioned
 characterPosition :: Lens' GameState Position
 characterPosition = positionedCharacter . position
 
+visionRadius :: Word
+visionRadius = 12 -- TODO make this dynamic
+
+-- | Update the revealed entities at the character's position based on their vision
+updateCharacterVision :: GameState -> GameState
+updateCharacterVision game =
+  let charPos = game ^. characterPosition
+      visible = visibleEntities charPos visionRadius $ game ^. entities
+  in game & revealedEntities %~ appendVia EntityMap.Deduplicate visible
+
+
 --------------------------------------------------------------------------------
 
 data Collision