Add num_shadow_casters graphics parameter, allow cycle down enum options

src/Dodge/Render/Lights.hs

@@ -2,6 +2,7 @@ module Dodge.Render.Lights (
     lightsToRender,
 ) where
 
+import Data.List (sortOn)
 import Data.Maybe
 import Dodge.Data.LWorld
 import Dodge.Data.CamPos
@@ -11,7 +12,9 @@ import qualified IntMapHelp as IM
 import Control.Lens
 
 lightsToRender :: Configuration -> CamPos -> LWorld -> [(Point3, Float, Point3)]
-lightsToRender cfig campos w =
+{-# INLINE lightsToRender #-}
+lightsToRender cfig campos w =  take (fromEnum $ cfig ^. graphics_num_shadow_casters) $
+    sortOn (\(_,x,_) -> negate x) $
     mapMaybe getLS (IM.elems $ w ^. lightSources)
         ++ mapMaybe getTLS (w ^. tempLightSources)
   where