Remove ssaTri, bullet movement is broken

src/Dodge/Particle/Bullet/Update.hs

@@ -1,4 +1,4 @@
-{-# LANGUAGE TupleSections #-}
+--{-# LANGUAGE TupleSections #-}
 {- Bullet update.  -}
 module Dodge.Particle.Bullet.Update
     ( mvBullet
@@ -15,15 +15,15 @@ import Control.Lens
 {- Update for a generic bullet.  -}
 mvBullet :: World -> Particle -> (World, Maybe Particle)
 mvBullet w bt' 
-    | t <= 0 || magV (_btVel' bt) < 1 = (w,Nothing)
+    | t <= 0 || magV (_ptVel bt) < 1 = (w,Nothing)
     | otherwise = second (fmap dodrag) $ 
         hiteff bt (thingsHitExceptCr mcr p (p +.+ vel) w) w
   where
     bt = foldr (\mg b -> _mgField mg mg b) bt' $ _magnets w
-    dodrag = btVel' %~ (drag *.*)
+    dodrag = ptVel %~ (drag *.*)
     drag = _btDrag bt
     mcr     = _btPassThrough' bt
     (p:_)  = _btTrail' bt
-    vel     = _btVel' bt
+    vel     = _ptVel bt
     hiteff  = _btHitEffect' bt
     t       = _btTimer' bt