Tweak bullet bouncing and spawning

src/Dodge/Default/Wall.hs

@@ -4,6 +4,8 @@ import Dodge.Data
 import Dodge.Block.Debris -- this dependency is (directly) for dirtColor
 import Picture
 import Geometry.Data
+
+import Control.Lens
 {- Indestructible wall.  -}
 defaultWall :: Wall
 defaultWall = Wall 
@@ -23,6 +25,7 @@ defaultWall = Wall
     , _wlWalkable = False
     , _wlHeight = 100
     , _wlMaterial = Stone
+    , _wlBouncy = True
     }
 defaultDoorWall' :: Wall
 defaultDoorWall' = defaultWall
@@ -44,6 +47,8 @@ defaultMachineWall = defaultWall
     , _wlMaterial  = Metal
     , _wlPenetrable = True
     }
+defaultSensorWall :: Wall
+defaultSensorWall = defaultMachineWall & wlBouncy .~ False
 defaultDirtWall :: Wall
 defaultDirtWall = defaultWall
     { _wlLine = (V2 0 0,V2 50 0)