Add selection box on left click drag

src/Dodge/Render/Picture.hs

@@ -2,6 +2,7 @@
 
 module Dodge.Render.Picture (fixedCoordPictures) where
 
+import qualified SDL
 import Control.Lens
 import qualified Data.Map.Strict as M
 import Data.Maybe
@@ -30,6 +31,7 @@ fixedCoordPictures u =
                 (u ^. uvWorld . cWorld . lWorld . lTestString)
             )
         <> displayFrameTicks u
+        <> drawAnySelectionBox u
         <> drawMouseCursor u
         <> toTopLeft
             cfig
@@ -44,7 +46,7 @@ fixedCoordPictures u =
     hw = halfWidth cfig
     hh = halfHeight cfig
     ttl = toTopLeft cfig
-    f (k, l) = (show k, foldMap _debugMessage l)
+    f (k, l) = (show k, map _debugMessage l)
 
 displayFrameTicks :: Universe -> Picture
 displayFrameTicks u
@@ -125,6 +127,13 @@ mouseCursorType u = case u ^. uvWorld . input . mouseContext of
             argV (w ^. cWorld . lWorld . lAimPos -.- cpos)
                 - w ^. wCam . camRot
 
+drawAnySelectionBox :: Universe -> Picture
+drawAnySelectionBox  u = case u ^. uvWorld . input . mouseContext of
+    OverInvDragSelect{} -> fold $ do
+        p <- u ^. uvWorld . input . clickPos . at SDL.ButtonLeft
+        return . color white . polygonWire $ rectVV (u ^. uvWorld . input . mousePos) p
+    _ -> mempty
+
 drawCursorByTerminalStatus :: TerminalStatus -> Picture
 drawCursorByTerminalStatus = \case
     TerminalPressTo "QUIT" -> drawQuitTerminal 5