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Diffstat (limited to 'users/grfn/xanthous/src/Xanthous/Game/Lenses.hs')
| -rw-r--r-- | users/grfn/xanthous/src/Xanthous/Game/Lenses.hs | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/users/grfn/xanthous/src/Xanthous/Game/Lenses.hs b/users/grfn/xanthous/src/Xanthous/Game/Lenses.hs new file mode 100644 index 0000000000..6242b855f1 --- /dev/null +++ b/users/grfn/xanthous/src/Xanthous/Game/Lenses.hs @@ -0,0 +1,150 @@ +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE QuantifiedConstraints #-} +{-# LANGUAGE AllowAmbiguousTypes #-} +-------------------------------------------------------------------------------- +module Xanthous.Game.Lenses + ( positionedCharacter + , character + , characterPosition + , updateCharacterVision + , characterVisiblePositions + , characterVisibleEntities + , getInitialState + , initialStateFromSeed + , entitiesAtCharacter + , revealedEntitiesAtPosition + + -- * Collisions + , Collision(..) + , entitiesCollision + , collisionAt + ) where +-------------------------------------------------------------------------------- +import Xanthous.Prelude +-------------------------------------------------------------------------------- +import System.Random +import Control.Monad.State +import Control.Monad.Random (getRandom) +-------------------------------------------------------------------------------- +import Xanthous.Game.State +import Xanthous.Data +import Xanthous.Data.Levels +import qualified Xanthous.Data.EntityMap as EntityMap +import Xanthous.Data.EntityMap.Graphics + (visiblePositions, visibleEntities) +import Xanthous.Data.VectorBag +import Xanthous.Entities.Character (Character, mkCharacter) +import {-# SOURCE #-} Xanthous.Entities.Entities () +-------------------------------------------------------------------------------- + +getInitialState :: IO GameState +getInitialState = initialStateFromSeed <$> getRandom + +initialStateFromSeed :: Int -> GameState +initialStateFromSeed seed = + let _randomGen = mkStdGen seed + chr = mkCharacter + _upStaircasePosition = Position 0 0 + (_characterEntityID, _levelEntities) + = EntityMap.insertAtReturningID + _upStaircasePosition + (SomeEntity chr) + mempty + _levelRevealedPositions = mempty + level = GameLevel {..} + _levels = oneLevel level + _messageHistory = mempty + _promptState = NoPrompt + _activePanel = Nothing + _debugState = DebugState + { _allRevealed = False + } + _autocommand = NoAutocommand + in GameState {..} + + +positionedCharacter :: Lens' GameState (Positioned Character) +positionedCharacter = lens getPositionedCharacter setPositionedCharacter + where + setPositionedCharacter :: GameState -> Positioned Character -> GameState + setPositionedCharacter game chr + = game + & entities . at (game ^. characterEntityID) + ?~ fmap SomeEntity chr + + getPositionedCharacter :: GameState -> Positioned Character + getPositionedCharacter game + = over positioned + ( fromMaybe (error "Invariant error: Character was not a character!") + . downcastEntity + ) + . fromMaybe (error "Invariant error: Character not found!") + $ EntityMap.lookupWithPosition + (game ^. characterEntityID) + (game ^. entities) + + +character :: Lens' GameState Character +character = positionedCharacter . positioned + +characterPosition :: Lens' GameState Position +characterPosition = positionedCharacter . position + +visionRadius :: Word +visionRadius = 12 -- TODO make this dynamic + +-- | Update the revealed entities at the character's position based on their +-- vision +updateCharacterVision :: GameState -> GameState +updateCharacterVision game + = game & revealedPositions <>~ characterVisiblePositions game + +characterVisiblePositions :: GameState -> Set Position +characterVisiblePositions game = + let charPos = game ^. characterPosition + in visiblePositions charPos visionRadius $ game ^. entities + +characterVisibleEntities :: GameState -> EntityMap.EntityMap SomeEntity +characterVisibleEntities game = + let charPos = game ^. characterPosition + in visibleEntities charPos visionRadius $ game ^. entities + +entitiesCollision + :: ( Functor f + , forall xx. MonoFoldable (f xx) + , Element (f SomeEntity) ~ SomeEntity + , Element (f (Maybe Collision)) ~ Maybe Collision + , Show (f (Maybe Collision)) + , Show (f SomeEntity) + ) + => f SomeEntity + -> Maybe Collision +entitiesCollision = join . maximumMay . fmap entityCollision + +collisionAt :: MonadState GameState m => Position -> m (Maybe Collision) +collisionAt p = uses (entities . EntityMap.atPosition p) entitiesCollision + +entitiesAtCharacter :: Lens' GameState (VectorBag SomeEntity) +entitiesAtCharacter = lens getter setter + where + 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 |