Implement targeting launcher shells using separate item

src/Dodge/Projectile/Create.hs

@@ -2,15 +2,22 @@ module Dodge.Projectile.Create (
     createShell,
 ) where
 
+import Dodge.Item.Location
 import Data.Maybe
 import Dodge.Data.World
 import Geometry
 import qualified IntMapHelp as IM
 import LensHelp
 
+homingDrawType :: ProjectileHoming -> ProjectileDraw
+homingDrawType ht = case ht of
+    NoHoming -> DrawShell
+    HomeUsingRemoteScreen {} -> DrawRemoteShell
+    HomeUsingTargeting {} -> DrawRemoteShell
+
 -- assumes the mscreen is in your inventory
-createShell :: Maybe Item -> AmmoParams -> Muzzle -> Item -> Creature -> World -> World
-createShell mscreen aparams muz it cr w = w
+createShell :: ProjectileHoming -> AmmoParams -> Muzzle -> Item -> Creature -> World -> World
+createShell homing aparams muz it cr w = w
     & updatescreen
     & cWorld . lWorld . projectiles . at i
         ?~ Shell
@@ -18,7 +25,7 @@ createShell mscreen aparams muz it cr w = w
             , _prjZ = 20
             , _prjStartPos = pos
             , _prjVel = rotateV dir (V2 1 0)
-            , _prjDraw = maybe DrawShell (const DrawRemoteShell) mscreen
+            , _prjDraw = homingDrawType homing
             , _prjID = i
             , _prjAcc = rotateV dir (V2 3 0)
             , _prjDir = dir
@@ -26,10 +33,10 @@ createShell mscreen aparams muz it cr w = w
             , _prjPayload = _ampPayload aparams
             , _prjTimer = 350
             , _prjUpdates =
-                [ CollisionEffectPU (mscreen ^? _Just . itID) --Just screenid)
+                [ CollisionEffectPU (homing ^? phRemoteID) --Just screenid)
                 , TimePU
                 , StartSpinPU 335 (_crID cr) (_shellSpinAmount params)
-                , RemoteDirectionPU (350 - thrustdelay) 0 (mscreen ^? _Just . itID)
+                , RemoteDirectionPU (350 - thrustdelay) 0 homing
                 , ThrustPU (350 - thrustdelay) 0
                 , ReduceSpinPU (1 - fromIntegral (_shellSpinDrag params) * 2 / 200)
                 ]
@@ -38,10 +45,8 @@ createShell mscreen aparams muz it cr w = w
     thrustdelay = _shellThrustDelay params
     params = _itParams it
     updatescreen = fromMaybe id $ do
-        screeninvid <- mscreen ^? _Just . itLocation . ilInvID
-        return $
-            cWorld . lWorld . creatures . ix (_crID cr) . crInv . ix screeninvid
-                . itUse
+        screenid <- homing ^? phRemoteID
+        return $ pointerToItemID screenid . itUse
                 . atLinkedProjectile
                 ?~ i
     i = IM.newKey $ w ^. cWorld . lWorld . projectiles