diff options
Diffstat (limited to 'users/glittershark/xanthous/src/Xanthous/Game/Lenses.hs')
| -rw-r--r-- | users/glittershark/xanthous/src/Xanthous/Game/Lenses.hs | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/users/glittershark/xanthous/src/Xanthous/Game/Lenses.hs b/users/glittershark/xanthous/src/Xanthous/Game/Lenses.hs index 1f2d21665fdb..6242b855f1cc 100644 --- a/users/glittershark/xanthous/src/Xanthous/Game/Lenses.hs +++ b/users/glittershark/xanthous/src/Xanthous/Game/Lenses.hs @@ -12,6 +12,7 @@ module Xanthous.Game.Lenses , getInitialState , initialStateFromSeed , entitiesAtCharacter + , revealedEntitiesAtPosition -- * Collisions , Collision(..) @@ -129,3 +130,21 @@ entitiesAtCharacter = lens getter setter getter gs = gs ^. entities . EntityMap.atPosition (gs ^. characterPosition) setter gs ents = gs & entities . EntityMap.atPosition (gs ^. characterPosition) .~ ents + +-- | Returns all entities at the given position that are revealed to the +-- character. +-- +-- Concretely, this is either entities that are *currently* visible to the +-- character, or entities, that are immobile and that the character has seen +-- before +revealedEntitiesAtPosition :: Position -> GameState -> (VectorBag SomeEntity) +revealedEntitiesAtPosition p gs + | p `member` characterVisiblePositions gs + = entitiesAtPosition + | p `member` (gs ^. revealedPositions) + = immobileEntitiesAtPosition + | otherwise + = mempty + where + entitiesAtPosition = gs ^. entities . EntityMap.atPosition p + immobileEntitiesAtPosition = filter (not . entityCanMove) entitiesAtPosition |