Wrap entities operations on a type

1 files changed, 35 insertions, 20 deletions

diff --git a/src/Game/Entities.hs b/src/Game/Entities.hs
index 0cfdb47..66d2da6 100644
--- a/src/Game/Entities.hs
+++ b/src/Game/Entities.hs
@@ -1,5 +1,8 @@
-module Game.Entities (Entity (..), toSpriteSet, mkPlayer, mkEffect, update, render) where
+{-# OPTIONS_GHC -Wno-unused-top-binds #-}
 
+module Game.Entities (Entities, mkEntities, mkPlayer, mkEffect, append, update, render) where
+
+import Data.Foldable (traverse_)
 import Data.IORef
 import qualified Game.Controller as C
 import qualified Game.Sprites as S
@@ -31,6 +34,8 @@ gravityDown = 16
 gravityTable :: [Int]
 gravityTable = [0, 6, 4, 4, 2, 2, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 4]
 
+data Entities = Entities S.SpriteSheet [Entity]
+
 data Spawn = DustEffectSpawn Int Int
 
 data Entity = Entity
@@ -49,6 +54,35 @@ data Entity = Entity
     eSpawns :: [Spawn]
   }
 
+mkEntities :: S.SpriteSheet -> Entities
+mkEntities sprites = Entities sprites []
+
+append :: Entity -> Entities -> Entities
+append e (Entities sprites entities) = Entities sprites (entities ++ [e])
+
+processSpawn :: S.SpriteSheet -> Spawn -> IO Entity
+processSpawn sprites (DustEffectSpawn x y) = mkEffect sprites x y "dust"
+
+update :: Entities -> IO Entities
+update (Entities sprites entities) = do
+  updated <- traverse (\e -> eUpdate e e) entities
+  new <- traverse (processSpawn sprites) (concatMap eSpawns updated)
+  pure $ Entities sprites $ map (\e -> e {eSpawns = []}) (filter (not . eDestroy) updated) ++ new
+
+render :: SDL.Renderer -> Entities -> IO ()
+render renderer (Entities _ entities) = do
+  traverse_ renderOne entities
+  where
+    renderOne :: Entity -> IO ()
+    renderOne e =
+      S.render renderer sp x y set frame
+      where
+        sp = eSprite e
+        x = eX e
+        y = eY e
+        set = toSpriteSet $ eDir e
+        frame = eFrame e
+
 mkEffect :: S.SpriteSheet -> Int -> Int -> String -> IO Entity
 mkEffect sprites x y name = do
   s <- S.get sprites name
@@ -157,22 +191,3 @@ updatePlayer controls e = do
         updateHorizontal (C.cLeft ctl) (C.cRight ctl) $
           -- left or right, but not both (keyboard)
           updateFrame ((C.cLeft ctl || C.cRight ctl) && (C.cLeft ctl /= C.cRight ctl)) e
-
-processSpawn :: S.SpriteSheet -> Spawn -> IO Entity
-processSpawn sprites (DustEffectSpawn x y) = mkEffect sprites x y "dust"
-
-update :: S.SpriteSheet -> [Entity] -> IO [Entity]
-update sprites entities = do
-  updated <- traverse (\e -> eUpdate e e) entities
-  new <- traverse (processSpawn sprites) (concatMap eSpawns updated)
-  pure $ map (\e -> e {eSpawns = []}) (filter (not . eDestroy) updated) ++ new
-
-render :: SDL.Renderer -> Entity -> IO ()
-render renderer ent =
-  S.render renderer sp x y set frame
-  where
-    sp = eSprite ent
-    x = eX ent
-    y = eY ent
-    set = toSpriteSet $ eDir ent
-    frame = eFrame ent