Implement floating camera

src/Dodge/Update/Camera.hs

@@ -5,6 +5,8 @@ module Dodge.Update.Camera (
     updateCamera,
 ) where
 
+import SDL (MouseButton (..))
+import Dodge.Base.Coordinate
 import Dodge.InputFocus
 import Bound
 import Dodge.Viewpoints
@@ -28,9 +30,32 @@ update where your avatar's view is from.  -}
 updateCamera :: Configuration -> World -> World
 updateCamera cfig w = case w ^. cWorld . cwCam . camControl of
     CamInGame -> updateInGameCamera cfig w
-    CamFloat -> w
+    CamFloat -> updateFloatingCamera cfig w
     CamPan -> w
 
+updateFloatingCamera :: Configuration -> World -> World
+updateFloatingCamera cfig w = w 
+    & updateBounds cfig
+    & cWorld . cwCam %~ setViewDistance cfig
+    & cWorld . cwCam %~ translateFloatingCamera theinput
+    & cWorld . cwCam %~ zoomFloatingCamera theinput
+  where
+    theinput = w ^. input
+
+translateFloatingCamera :: Input -> Camera -> Camera
+translateFloatingCamera theinput cam = fromMaybe cam $ do
+    presstime <- theinput ^. mouseButtons . at ButtonLeft
+    guard $ presstime > 1
+    hpos <- theinput ^? heldPos . ix ButtonLeft
+    let thetran = 
+            screenToWorldPos cam hpos
+            -.-
+            screenToWorldPos cam (theinput ^. mousePos) 
+    return $ cam & camCenter +~ thetran
+        & camViewFrom +~ thetran
+
+zoomFloatingCamera theinput cam = cam
+
 updateInGameCamera :: Configuration -> World -> World
 updateInGameCamera cfig w =
     w