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module Game.Entities
( Entities,
Entity,
mkEntities,
addExit,
updateAll,
render,
renderVisible,
playerPosition,
)
where
import Control.Monad
import Data.Bits (Bits (..))
import Data.Foldable (find, traverse_)
import Data.IORef
import Data.List (sort)
import qualified Game.Controller as C
import Game.Entities.Common
import Game.Entities.Const
import Game.Entities.Effect
import Game.Entities.Exit
import Game.Entities.Pickup
import Game.Entities.Player
import Game.Entities.Robot
import Game.Entities.Slime
import Game.Entities.Types
import qualified Game.Map as M
import qualified Game.Sprites as S
import qualified Game.State as GS
import qualified SDL
mkEntities :: S.SpriteSheet -> M.Map -> IORef C.Controls -> IO Entities
mkEntities sprites m controls = do
player <- case find M.isPlayer (M.objects m) of
Just (M.PlayerEntity x y) -> mkPlayer sprites x y controls (M.isBlocked m)
_ -> error "No player entity in map"
playerRef <- newIORef player
entities <- traverse (toEntity playerRef) $ sort $ filter (not . M.isPlayer) (M.objects m)
-- the entities list has always player first
pure $ Entities sprites playerRef (player : entities)
where
toEntity :: IORef Entity -> M.Object -> IO Entity
toEntity playerRef (M.SlimeEntity x y) = mkSlime sprites x y (collision playerRef 16) (M.isBlocked m)
toEntity playerRef (M.RobotEntity x y) = mkRobot sprites x y (collision playerRef 24) (M.isBlocked m)
toEntity playerRef (M.BatteryEntity x y) = mkBattery sprites x y (collision playerRef 16)
toEntity _ (M.PlayerEntity _ _) = error "Player already processed"
-- | Return the player's entity position (x, y).
playerPosition :: Entities -> (Int, Int)
playerPosition (Entities _ _ entities) =
(player.x, player.y)
where
player = head entities
addExit :: Entities -> Int -> Int -> IO Entities
addExit es x y = do
exit <- mkExit es.sprites x y (collision es.player 24)
pure es {entities = head es.entities : exit : tail es.entities}
updateAll :: Entities -> GS.State -> IO (Entities, GS.State)
updateAll es state = do
-- update the player first (including the reference)
updatedPlayer <- player.update player
void $ writeIORef es.player updatedPlayer
-- then the other entities
updated <- (updatedPlayer :) <$> traverse (updateFilter $ state.hitDelay > 0) others
-- process actions
(state', updated') <- processActions (updateState state) updated (concatMap (\e -> e.actions) updated)
-- clear actions and filter out destroyed entities
pure (es {entities = map (\e -> e {actions = []}) (filter (\e -> not e.destroy) updated')}, state')
where
player = head es.entities
others = tail es.entities
-- update state counters
updateState :: GS.State -> GS.State
updateState s = if s.hitDelay > 0 then s {GS.hitDelay = s.hitDelay - 1} else s
-- the actions can change the game state, add new entities, and modify existing ones
processActions :: GS.State -> [Entity] -> [Action] -> IO (GS.State, [Entity])
processActions s ents (a : t) =
case a of
ActionAddEffect x y name -> do
effect <- mkEffect es.sprites x y name
processActions s (ents ++ [effect]) t
ActionAddBattery x y ->
processActions s {GS.batteries = s.batteries + 1, GS.lastBattery = (x, y)} ents t
ActionHitPlayer -> do
let (s', ents') =
if s.lives == 1
then
( s {GS.lives = 0, GS.gameOverDelay = gameOverDelay},
(head ents) {dir = Dying, gravity = gravityUp, frame = 0} : tail ents
)
else
( s {GS.lives = s.lives - 1, GS.hitDelay = hitDelay},
ents
)
processActions s' ents' t
ActionExitLevel -> processActions s {GS.levelCompleted = True} ents t
processActions s ents [] = pure (s, ents)
-- Update entities skipping enemies if the player was hit
updateFilter :: Bool -> Entity -> IO Entity
updateFilter False e = e.update e
updateFilter True e
| notEnemy e = e.update e
| otherwise = pure e
notEnemy :: Entity -> Bool
notEnemy ent = case ent.typ of
TypeEnemy -> False
_ -> True
-- | Render only visible entities according to the provided viewport and state.
renderVisible :: SDL.Renderer -> Entities -> M.Viewport -> GS.State -> IO ()
renderVisible renderer (Entities sprites player entities) v = render renderer (Entities sprites player visible)
where
-- FIXME: entities should have size so we can be exact here and
-- avoid the hardcoded size
visible = filter (\e -> isVisible v e.x e.y 16 16) entities
isVisible :: M.Viewport -> Int -> Int -> Int -> Int -> Bool
isVisible (M.Viewport vx vy vw vh) x y w h =
x < vx + vw && vx < x + w && y < vy + vh && vy < y + h
-- | Render all entities according to the provided state.
-- Use renderVisible to only render the entities that are in the viewport area.
render :: SDL.Renderer -> Entities -> GS.State -> IO ()
render renderer es state = do
-- if the player was hit, make the enemies wiggle before unfreezing
if state.hitDelay == 0 || state.hitDelay > hitDelay `div` 3
then traverse_ renderOne others
else traverse_ (renderWiggling ((.&.) 2 state.hitDelay)) others
-- always render player last
-- won't draw all the frames if the player was hit
if testBit state.hitDelay 2 then pure () else renderOne player
where
player = head es.entities
others = tail es.entities
renderWiggling :: Int -> Entity -> IO ()
renderWiggling m e = case e.typ of
TypeEnemy -> renderOne e {x = e.x + m}
_ -> renderOne e
renderOne :: Entity -> IO ()
renderOne e =
S.render renderer e.sprite e.x e.y set e.frame
where
set = toSpriteSet e.dir
|
