-module Sim ( ChunkData, initSimSpace, defaultChunkData ) where
+module Sim (
+ Simulation, simSpace,
+ ChunkType, ChunkData, chunkType,
+ initSimSpace, testSim, physStep, validDirects,
+ simToString, stringToSim
+) where
+import Debug.Trace
+import Data.Vector ((!), (//))
import qualified Data.Vector as V
+import Data.List as L
-data ChunkData = ChunkData
- { velocity :: (Float, Float)
- , density :: Float
+data Simulation = Simulation
+ { simSpace :: V.Vector ChunkData
+ , simW :: Int
+ , simH :: Int
} deriving (Show)
-defaultChunkData = ChunkData
- { velocity = (0,0)
- , density = 0
+data ChunkType = Air
+ | Water
+ | Wall
+ | Pump
+ | Drain deriving (Show, Enum)
+
+data ChunkData = ChunkData
+ { chunkType :: ChunkType
+ } deriving (Show)
+
+-- vec accessors
+simGet Simulation{simSpace=s,simW=w} x y = s ! (y*w+x)
+simSet sim@Simulation{simSpace=s,simW=w,simH=h} c x y = sim { simSpace = (s // [(y*w+x,c)]) }
+simGetChunkType sim x y = chunkType $ simGet sim x y
+
+initSimSpace x y = Simulation
+ { simSpace = V.replicate (y*x) ChunkData { chunkType=Air }
+ , simW = x
+ , simH = y
}
-initSimSpace :: Int -> Int -> V.Vector ChunkData
-initSimSpace x y = V.replicate (y*x) defaultChunkData
+testSim = let a = simSet (initSimSpace 10 10) (ChunkData Water) 5 5
+ in simSet a (ChunkData Wall) 5 6
+
+physStep sim@Simulation{simW=w,simH=h} = _physStep [(x, y) | x <- [0..w-1], y <- [0..h-1]] sim sim
+-- _physStep grid acc sim@Simulation{simSpace=s,simW=w,simH=h} | trace ("" ++ show h) False = undefined
+_physStep grid acc sim@Simulation{simSpace=s,simW=w,simH=h} =
+ if null grid then acc
+ else _physStep (tail grid) next sim
+ where x = fst $ head grid
+ y = snd $ head grid
+ valid = validDirects x y w h
+ next = case simGetChunkType sim x y of
+ Water -> updateWaterChunk x y valid acc
+ Pump -> updatePumpChunk x y valid acc
+ Drain -> updateDrainChunk x y valid acc
+ _ -> acc
+
+-- template for update functions
+updateScaffolder x y valid sim directs cond exec =
+ if null directs then sim
+ else if cond (head directs) then exec (head directs)
+ else updateScaffolder x y valid sim (tail directs) cond exec
+
+updateWaterChunk x y valid sim = updateScaffolder x y valid sim
+ ((0,1) : (waterRandom [(-1,1),(1,1),(-1,0),(1,0)] x y))
+ (\qd ->
+ elem qd valid &&
+ fromEnum (simGetChunkType sim ((+) x $ fst qd) ((+) y $ snd qd)) == fromEnum Air
+ )
+ (\qd -> simSet
+ (simSet sim ChunkData { chunkType=Air } x y)
+ ChunkData { chunkType=Water }
+ ((+) x $ fst qd)
+ ((+) y $ snd qd)
+ )
+
+-- really stupid pure psuedorandom
+waterRandom d x y =
+ let perm = L.permutations d
+ in perm !! ((x^y+x*y^x+x) `mod` (length perm))
+
+updatePumpChunk x y valid sim = updateScaffolder x y valid sim
+ [(0,1),(-1,0),(1,0)]
+ (\qd ->
+ elem qd valid &&
+ fromEnum (simGetChunkType sim ((+) x $ fst qd) ((+) y $ snd qd)) == fromEnum Air
+ )
+ (\qd -> simSet sim ChunkData { chunkType=Water } ((+) x $ fst qd) ((+) y $ snd qd))
+
+updateDrainChunk x y valid sim = updateScaffolder x y valid sim
+ [(0,1),(0,-1),(-1,0),(1,0)]
+ (\qd ->
+ elem qd valid &&
+ fromEnum (simGetChunkType sim ((+) x $ fst qd) ((+) y $ snd qd)) == fromEnum Water
+ )
+ (\qd -> simSet sim ChunkData { chunkType=Air } ((+) x $ fst qd) ((+) y $ snd qd))
+
+-- gets chunks around a given chunk that are inside grid
+-- validDirects x y w h | trace ("w:"++ show w ++ "h:" ++ show h) False = undefined
+validDirects x y w h = filter
+ (\q -> 0 <= (fst q)+x && (fst q)+x < w && 0 <= (snd q)+y && (snd q)+y < h)
+ [(a,b) | a <- [-1..1], b <- [-1..1], not (a==0 && b==0)]
+
+simToString :: Simulation -> [Char]
+simToString sim@Simulation{simW=w} =
+ let simStr = V.toList $ V.map chunkToChar $ simSpace sim
+ in Sim.insert w '\n' simStr
+
+-- from https://stackoverflow.com/questions/12659562/insert-specific-element-y-after-every-n-elements-in-a-list
+insert :: Int -> a -> [a] -> [a]
+insert n y xs = countdown n xs where
+ countdown 0 xs = y:countdown n xs
+ countdown _ [] = []
+ countdown m (x:xs) = x:countdown (m-1) xs
+
+-- stringToSim :: [String] -> Simulation
+stringToSim strings =
+ _stringToSim st grid (initSimSpace w h)
+ where stripped = strings
+ w = maximum $ [(length s) | s <- stripped]
+ h = length stripped
+ grid = [(a,b) | a <- [0..(length stripped)-1], b <- [0..(length $ stripped !! a)-1]]
+ st = concat stripped
+
+_stringToSim st grid acc =
+ if null grid || null st then acc
+ else _stringToSim (tail st) (tail grid) next
+ where y = fst $ head grid -- not exactly sure why y and x got switched here
+ x = snd $ head grid
+ next = simSet acc (charToChunk $ head st) x y
+
+-- maps each chunktype to an ascii character
+chunkToChar :: ChunkData -> Char
+chunkToChar c =
+ case chunkType c of
+ Water -> '~'
+ Air -> ' '
+ Wall -> '#'
+ Pump -> '@'
+ Drain -> 'O'
+ _ -> '?'
+
+-- this is redundant, fix this somehow
+charToChunk :: Char -> ChunkData
+charToChunk c =
+ ChunkData { chunkType=ctype }
+ where ctype = if c=='~' then Water
+ else if c=='#' then Wall
+ else if c=='@' then Pump
+ else if c=='O' then Drain
+ else Air
--- gaussSeidel