Allow dropping items by dragging off inventory

src/Dodge/Update.hs

@@ -354,14 +354,13 @@ checkTermDist w = fromMaybe w $ do
 
 updateMouseContext :: Configuration -> Universe -> Universe
 updateMouseContext cfig u = case u ^. uvWorld . input . mouseContext of
-    OverInvDrag | lbheld -> u
+    OverInvDrag {} -> u & uvWorld . input . mouseContext .~ invdrag
     OverInvDragSelect{} -> u
     _ -> u & uvWorld . input . mouseContext
         .~ fromMaybe
             aimcontext
             (overmenu <|> overinv <|> overcomb <|> overterm)
   where
-    lbheld = ButtonLeft `M.member` (u ^. uvWorld . input . mouseButtons)
     overmenu = do
         screen <- u ^? uvScreenLayers . ix 0
         return $ case screen ^. scOptions of
@@ -384,6 +383,10 @@ updateMouseContext cfig u = case u ^. uvWorld . input . mouseContext of
         | ButtonRight `M.member` (w ^. input . mouseButtons) = MouseAiming
         | otherwise = MouseInGame
     mpos = w ^. input . mousePos
+    invdrag = fromMaybe (OverInvDrag Nothing) $ do
+        sss <- w ^? hud . hudElement . diSections
+        (0,j) <- inverseSelNumPos cfig (invDisplayParams w) sss mpos
+        return $ OverInvDrag $ Just j
     overinv = do
         sss <- w ^? hud . hudElement . diSections
         selpos <- inverseSelNumPos cfig (invDisplayParams w) sss mpos