Tweak "magnets" that affect bullet movement

src/Dodge/Bullet.hs

@@ -10,7 +10,6 @@ import Data.Maybe
 import Dodge.Creature.Test
 import Dodge.Data.World
 import Dodge.EnergyBall
-import Dodge.MagnetBuBu
 import Dodge.Movement.Turn
 import Dodge.WorldEvent.SpawnParticle
 import Dodge.WorldEvent.ThingsHit
@@ -35,7 +34,22 @@ updateBullet w bu
 
 applyMagnetsToBul :: Bullet -> World -> Bullet
 applyMagnetsToBul bu =
-    foldl' (flip doMagnetBuBu) bu . _magnets . _lWorld . _cWorld
+    foldl' (flip doMagnetBuBu) bu . _oldMagnets . _lWorld . _cWorld
+
+doMagnetBuBu :: Magnet -> Bullet -> Bullet
+doMagnetBuBu mg bu = case _mgField mg of
+    MagnetAlign | isclose -> bu
+    MagnetDeflect | isclose -> bu & buVel %~ vecTurnTo (50 * pi / d) bpos mgdeflectpos
+    _ -> bu
+  where
+    bvel = bu ^. buVel
+    mpos = mg ^. mgPos
+    bpos = bu ^. buPos
+    mgdeflectpos
+        | isLHS mpos (mpos + bvel) bpos = bpos + vNormal (bpos - mpos)
+        | otherwise = bpos - vNormal (bpos - mpos)
+    d = dist (bu ^. buPos) (mg ^. mgPos)
+    isclose = d < 100
 
 updateBulVel :: Bullet -> Bullet
 updateBulVel bt = case _buTrajectory bt of