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module Game.Entities (Entities, mkEntities, mkPlayer, mkEffect, append, updateAll, render) where
import Data.Foldable (traverse_)
import Data.IORef
import qualified Game.Controller as C
import qualified Game.Sprites as S
import qualified SDL
data Dir = DirRight | DirLeft deriving (Eq)
data Type = TypePlayer | TypeEffect
toSpriteSet :: Dir -> Int
toSpriteSet DirRight = 0
toSpriteSet DirLeft = 1
frameDelay :: Int
frameDelay = 6
jumpFrame :: Int
jumpFrame = 3
gravityOff :: Int
gravityOff = -1
gravityUp :: Int
gravityUp = 0
gravityDown :: Int
gravityDown = 14
jumpLimit :: Int
jumpLimit = gravityDown + 7
gravityTable :: [Int]
gravityTable = [0, 6, 4, 4, 2, 2, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 4]
data Entities = Entities S.SpriteSheet [Entity]
data Spawn = DustEffectSpawn Int Int
data Entity = Entity
{ typ :: Type,
x :: Int,
y :: Int,
delay :: Int,
frame :: Int,
frameLimit :: Int,
jumping :: Bool,
gravity :: Int,
dir :: Dir,
sprite :: S.Sprite,
update :: Entity -> IO Entity,
isBlocked :: Int -> Int -> Bool,
destroy :: Bool,
spawns :: [Spawn]
}
mkEntities :: S.SpriteSheet -> Entities
mkEntities sprites = Entities sprites []
append :: Entity -> Entities -> Entities
append e (Entities sprites entities) = Entities sprites (entities ++ [e])
processSpawn :: S.SpriteSheet -> Spawn -> IO Entity
processSpawn sprites (DustEffectSpawn x y) = mkEffect sprites x y "dust"
updateAll :: Entities -> IO Entities
updateAll (Entities sprites entities) = do
updated <- traverse (\e -> e.update e) entities
new <- traverse (processSpawn sprites) (concatMap (\e -> e.spawns) updated)
pure $ Entities sprites $ map (\e -> e {spawns = []}) (filter (\e -> not e.destroy) updated) ++ new
render :: SDL.Renderer -> Entities -> IO ()
render renderer (Entities _ entities) = do
traverse_ renderOne entities
where
renderOne :: Entity -> IO ()
renderOne e =
S.render renderer e.sprite e.x e.y set e.frame
where
set = toSpriteSet e.dir
mkEffect :: S.SpriteSheet -> Int -> Int -> String -> IO Entity
mkEffect sprites x y name = do
s <- S.get sprites name
pure $
Entity
{ typ = TypeEffect,
x = x,
y = y,
delay = frameDelay,
frame = 0,
frameLimit = 3,
jumping = False,
gravity = gravityOff,
dir = DirRight,
sprite = s,
update = pure . updateEffect,
isBlocked = \_ _ -> False,
destroy = False,
spawns = []
}
updateEffect :: Entity -> Entity
updateEffect e
| e.delay > 0 = e {delay = e.delay - 1}
| e.frame + 1 < e.frameLimit = e {delay = e.frameLimit, frame = e.frame + 1}
| otherwise = e {destroy = True}
mkPlayer :: S.SpriteSheet -> Int -> Int -> IORef C.Controls -> (Int -> Int -> Bool) -> IO Entity
mkPlayer sprites x y controls isBlocked' = do
s <- S.get sprites "player"
pure $
Entity
{ typ = TypePlayer,
x = x,
y = y,
delay = 0,
frame = 0,
frameLimit = 3,
jumping = False,
gravity = gravityOff,
dir = DirRight,
sprite = s,
update = updatePlayer controls,
isBlocked = isBlocked',
destroy = False,
spawns = []
}
updateFrame :: Bool -> Entity -> Entity
updateFrame updated e
| isGravityOn = e
| e.delay > 0 = e {delay = e.delay - 1}
| e.frame < e.frameLimit = e {delay = frameDelay, frame = if updated then e.frame + 1 else 0}
| otherwise = e {delay = frameDelay, frame = 0}
where
isGravityOn = e.gravity > gravityOff
updateHorizontal :: Bool -> Bool -> Entity -> Entity
updateHorizontal left right e
-- prevent pressing both directions (kyboard)
| left && right = e
-- change direction first
| left && e.dir /= DirLeft = e {dir = DirLeft, delay = 0}
| right && e.dir /= DirRight = e {dir = DirRight, delay = 0}
| left && isGoingDown = if e.isBlocked (e.x - 1) (e.y + 23) then e else e {x = e.x - 1}
| left && not isGoingDown = if e.isBlocked (e.x - 1) (e.y + 23) && e.isBlocked (e.x - 1) (e.y + 17) then e else e {x = e.x - 1}
| right && isGoingDown = if e.isBlocked (e.x + 17) (e.y + 23) then e else e {x = e.x + 1}
| right && not isGoingDown = if e.isBlocked (e.x + 17) (e.y + 23) && e.isBlocked (e.x + 17) (e.y + 17) then e else e {x = e.x + 1}
| otherwise = e
where
isGoingDown = e.gravity == gravityOff || e.gravity >= gravityDown
updateVertical :: Bool -> Bool -> Entity -> Entity
updateVertical jump down e
| not jump
|| e.jumping
-- make jumping easier with "Coyote time"
|| (e.gravity /= gravityOff && (e.gravity < gravityDown || e.gravity > jumpLimit)) =
e
| not down = e {jumping = True, gravity = gravityUp, frame = jumpFrame, spawns = e.spawns ++ [DustEffectSpawn e.x (e.y + 8)]}
-- go down a 8 pixel tall platform; not ideal to have these values hardcoded here
-- but to be fair, the player height/width is hardcoded as well
| down
&& not (e.isBlocked (e.x + 2) (e.y + 24 + 8))
&& not (e.isBlocked (e.x + 12) (e.y + 24 + 8)) =
e {gravity = gravityDown, frame = jumpFrame, y = e.y + 1}
| otherwise = e
applyGravity :: Int -> Entity -> Entity
applyGravity v e
| v == 0 = e
-- hit the floor
| isGoingDown
&& (e.isBlocked (e.x + 2) (e.y + 24) || e.isBlocked (e.x + 12) (e.y + 24))
&& not (e.isBlocked (e.x + 2) (e.y + 23))
&& not (e.isBlocked (e.x + 12) (e.y + 23)) =
e {jumping = False, gravity = gravityOff, delay = 0}
| otherwise = applyGravity (v - 1) e {y = e.y + change}
where
isGoingDown = e.gravity >= gravityDown
change = if isGoingDown then 1 else -1
updateGravity :: Entity -> Entity
updateGravity e
| current > gravityOff = applyGravity (gravityTable !! current) e {gravity = new}
| not (e.isBlocked (e.x + 2) (e.y + 24) || e.isBlocked (e.x + 12) (e.y + 24)) = e {gravity = gravityDown, frame = jumpFrame}
| otherwise = e
where
current = e.gravity
new = if current > gravityOff && current < length gravityTable - 1 then current + 1 else current
updatePlayer :: IORef C.Controls -> Entity -> IO Entity
updatePlayer controls e = do
ctl <- readIORef controls
pure $
updateGravity $
updateVertical ctl.a ctl.down $
updateHorizontal ctl.left ctl.right $
-- left or right, but not both (keyboard)
updateFrame ((ctl.left || ctl.right) && (ctl.left /= ctl.right)) e
|
