-module Sim ( ChunkData, initSimSpace, defaultChunkData ) where
+module Sim ( initSimSpace, testSim, physStep, validDirects ) where
+import Data.Vector ((!), (//))
import qualified Data.Vector as V
-data ChunkData = ChunkData
- { velocity :: (Float, Float)
- , density :: Float
- } deriving (Show)
+-- Simulation simSpace simW simH
+data Simulation = Simulation (V.Vector ChunkData) Int Int deriving (Show)
-defaultChunkData = ChunkData
- { velocity = (0,0)
- , density = 0
- }
+data ChunkType = Empty
+ | Water
+ | Wall deriving (Show)
-initSimSpace :: Int -> Int -> V.Vector ChunkData
-initSimSpace x y = V.replicate (y*x) defaultChunkData
+data ChunkData = ChunkData ChunkType deriving (Show)
+
+-- vec accessors
+simGet (Simulation s w _) x y = s ! (y*w+x)
+simSet (Simulation s w h) c x y = Simulation (s // [(y*w+x,c)]) w h
+
+initSimSpace x y = Simulation (V.replicate (y*x) (ChunkData Empty)) x y
+
+testSim = simSet (initSimSpace 10 10) (ChunkData Water) 5 0
+
+physStep sim@(Simulation _ w h) = _physStep [(x, y) | x <- [0..w-1], y <- [0..h-1]] (initSimSpace w h) sim
+_physStep grid acc sim@(Simulation s w h) =
+ if null grid then acc
+ else _physStep (tail grid) next sim
+ where x = fst $ head grid
+ y = snd $ head grid
+ next = sim
+
+-- gets chunks around a given chunk that are inside grid
+validDirects x y w h = filter
+ (\q -> 0 <= (fst q) && (fst q) < w && (snd q) <= 0 && (snd q) < h)
+ [(a,b) | a <- [x-1..x+1], b <- [y-1..y+1], not (a==x && b==y)]
--- gaussSeidel
