Add support for left click actions

src/Dodge/Default/Shell.hs

@@ -0,0 +1,17 @@
+module Dodge.Default.Shell
+    where
+import Dodge.Data
+import Picture
+
+defaultShell :: Projectile
+defaultShell = Shell
+    { _pjPos = (0,0)
+    , _pjStartPos = (0,0)
+    , _pjVel = (0,0)
+    , _pjDir = 0
+    , _pjSpin = 0
+    , _pjDraw = \_ -> blank
+    , _pjID = 0
+    , _pjUpdate = \_ -> id
+    , _pjPayload = \_ -> id
+    }