Implement generalised storing of position for mouse presses

src/Dodge/Update/Input/InGame.hs

@@ -69,22 +69,24 @@ updatePressedButtonsCarte w = updatePressedButtonsCarte' (_mouseButtons (_input
 updatePressedButtonsCarte' :: M.Map MouseButton Int -> World -> World
 updatePressedButtonsCarte' pkeys w
     | isDown ButtonRight =
-        w
-            & input . clickMousePos .~ _mousePos (_input w)
-            & hud . carteCenter %~ (-.- trans)
+        w & hud . carteCenter %~ (-.- trans)
     | isDown ButtonLeft =
         w
-            & input . clickMousePos .~ _mousePos (_input w)
             & hud . carteRot -~ rot
             & hud . carteZoom *~ czoom
     | otherwise = w
   where
     isDown but = but `M.member` pkeys
-    rot = angleBetween (_mousePos (_input w)) (_clickMousePos (_input w))
-    czoom = magV (_mousePos (_input w)) / magV (_clickMousePos (_input w))
-    trans =
-        rotateV (w ^. hud . carteRot) $
-            1 / (w ^. hud . carteZoom) *.* (_mousePos (_input w) -.- _clickMousePos (_input w))
+    mbutpos but = theinput ^. heldPos . at but
+    rot = fromMaybe 0 $ angleBetween (_mousePos (_input w)) <$> mbutpos SDL.ButtonLeft
+    czoom = fromMaybe 1 $ do
+        p <- mbutpos SDL.ButtonLeft
+        return $ magV (_mousePos theinput) / magV p
+    theinput = w ^. input
+    trans = fromMaybe 0 $ do
+        p <- mbutpos SDL.ButtonRight
+        return . rotateV (w ^. hud . carteRot) $
+            1 / (w ^. hud . carteZoom) *.* (_mousePos (_input w) -.- p)
 
 updateKeysInTerminal :: Int -> Universe -> Universe
 updateKeysInTerminal tmid u =