X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=Sim.hs;h=c48dbe4d2194456d72af2cce1db1f8ae925c9df9;hb=c68579ccc2b03996eec6ac5c1526d6e5d20c3c78;hp=bb96fe387c6a89a8099afb7beb79e4a8c7977b3f;hpb=19625d0c9e1d31e1966815bfefba8af794b3dba2;p=ekitaihs.git

diff --git a/Sim.hs b/Sim.hs
index bb96fe3..c48dbe4 100644
--- a/Sim.hs
+++ b/Sim.hs
@@ -1,18 +1,68 @@
-module Sim ( ChunkData, initSimSpace, defaultChunkData ) where
+module Sim ( initSimSpace, testSim, physStep, updateWaterChunk, validDirects ) where
 
+import Debug.Trace
+import           Data.Vector ((!), (//))
 import qualified Data.Vector as V
 
-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 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 = simSet (initSimSpace 3 3) (ChunkData Water) 1 1
+
+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 acc) 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
+              _ -> acc
+
+-- takes in list of valid chunks, as well as the sim to modify
+updateWaterChunk x y valid sim =
+    -- if the chunk below is free, fall straight down
+    if elem (0,-1) valid && fromEnum (simGetChunkType sim x (y-1)) == fromEnum Air
+        then
+            let moved = simSet sim ChunkData { chunkType=Air } x y
+            in simSet moved ChunkData { chunkType=Water } x (y-1)
+    else if elem (-1,-1) valid && fromEnum (simGetChunkType sim (x-1) (y-1)) == fromEnum Air
+        then
+            let moved = simSet sim ChunkData { chunkType=Air } x y
+            in simSet moved ChunkData { chunkType=Water } (x-1) (y-1)
+    else if elem (1,-1) valid && fromEnum (simGetChunkType sim (x+1) (y-1)) == fromEnum Air
+        then
+            let moved = simSet sim ChunkData { chunkType=Air } x y
+            in simSet moved ChunkData { chunkType=Water } (x+1) (y-1)
+    -- stay put
+    else 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-x,b-y) | a <- [x-1..x+1], b <- [y-1..y+1], not (a==x && b==y)]
 
--- gaussSeidel