3 ChunkType, ChunkData, chunkType,
4 initSimSpace, testSim, physStep, updateWaterChunk, validDirects, simToString
8 import Data.Vector ((!), (//))
9 import qualified Data.Vector as V
11 data Simulation = Simulation
12 { simSpace :: V.Vector ChunkData
19 | Wall deriving (Show, Enum)
21 data ChunkData = ChunkData
22 { chunkType :: ChunkType
26 simGet Simulation{simSpace=s,simW=w} x y = s ! (y*w+x)
27 simSet sim@Simulation{simSpace=s,simW=w,simH=h} c x y = sim { simSpace = (s // [(y*w+x,c)]) }
28 simGetChunkType sim x y = chunkType $ simGet sim x y
30 initSimSpace x y = Simulation
31 { simSpace = V.replicate (y*x) ChunkData { chunkType=Air }
36 testSim = simSet (initSimSpace 3 3) (ChunkData Water) 1 1
38 physStep sim@Simulation{simW=w,simH=h} = _physStep [(x, y) | x <- [0..w-1], y <- [0..h-1]] sim sim
39 -- _physStep grid acc sim@Simulation{simSpace=s,simW=w,simH=h} | trace ("" ++ show acc) False = undefined
40 _physStep grid acc sim@Simulation{simSpace=s,simW=w,simH=h} =
42 else _physStep (tail grid) next sim
43 where x = fst $ head grid
45 valid = validDirects x y w h
46 next = case simGetChunkType sim x y of
47 Water -> updateWaterChunk x y valid acc
50 -- takes in list of valid chunks, as well as the sim to modify
51 updateWaterChunk x y valid sim =
52 -- if the chunk below is free, fall straight down
53 if elem (0,-1) valid && fromEnum (simGetChunkType sim x (y-1)) == fromEnum Air
55 let moved = simSet sim ChunkData { chunkType=Air } x y
56 in simSet moved ChunkData { chunkType=Water } x (y-1)
57 else if elem (-1,-1) valid && fromEnum (simGetChunkType sim (x-1) (y-1)) == fromEnum Air
59 let moved = simSet sim ChunkData { chunkType=Air } x y
60 in simSet moved ChunkData { chunkType=Water } (x-1) (y-1)
61 else if elem (1,-1) valid && fromEnum (simGetChunkType sim (x+1) (y-1)) == fromEnum Air
63 let moved = simSet sim ChunkData { chunkType=Air } x y
64 in simSet moved ChunkData { chunkType=Water } (x+1) (y-1)
68 -- gets chunks around a given chunk that are inside grid
69 validDirects x y w h = filter
70 (\q -> 0 <= (fst q) && (fst q) < w && (snd q) <= 0 && (snd q) < h)
71 [(a-x,b-y) | a <- [x-1..x+1], b <- [y-1..y+1], not (a==x && b==y)]
73 simToString :: Simulation -> [Char]
74 simToString sim@Simulation{simW=w} =
75 let simStr = V.toList $ V.map chunkToChar $ simSpace sim
76 in insert w '\n' simStr
78 -- from https://stackoverflow.com/questions/12659562/insert-specific-element-y-after-every-n-elements-in-a-list
79 insert :: Int -> a -> [a] -> [a]
80 insert n y xs = countdown n xs where
81 countdown 0 xs = y:countdown n xs
83 countdown m (x:xs) = x:countdown (m-1) xs
85 chunkToChar :: ChunkData -> Char