Magnets

src/Dodge/Item/Equipment.hs

@@ -8,21 +8,39 @@ import Dodge.Item.Weapon.BatteryGuns
 import Dodge.Creature.Test
 import Dodge.Wall.Reflect
 import Dodge.Wall
+import Dodge.Magnet
 import Picture
 import Geometry
 import ShapePicture
 import Shape
+import qualified IntMapHelp as IM
 
-import qualified Data.IntMap.Strict as IM
 import Control.Lens
 
 magShield :: Item
 magShield = defaultEquipment
     { _itType = MAGSHIELD
     , _itName = "MAGSHIELD"
+    , _itUse = EquipUse useMagShield
     , _itEquipPict = \_ _ -> (,) emptySH blank
     , _itID = Nothing
+    , _itAttachment = ItMInt Nothing
     }
+useMagShield :: Creature -> Int -> World -> World
+useMagShield cr invid w = w & magnets . at mgid ?~ themagnet
+  where
+    themagnet = Magnet
+        {_mgID = mgid
+        ,_mgUpdate = Just . (mgUpdate .~ const Nothing)
+        ,_mgPos = _crPos cr
+        ,_mgField = curveAroundField
+        }
+    mgid = case it ^? itAttachment . itMInt . _Just of
+        Just mgid' -> mgid'
+        Nothing -> IM.newKey $ _magnets w
+    it = _crInv cr IM.! invid
+
+
 flameShield :: Item 
 flameShield = defaultEquipment
     { _itType = FLAMESHIELD