parabox/app/Model.hs
Eric Mertens a67bbea3cb big ?
2022-12-07 17:31:07 -08:00

229 lines
7.0 KiB
Haskell

module Model where
import Data.Array
import Data.Map (Map)
import Data.Map qualified as Map
import Graphics.Vty
import Control.Monad
import Data.Maybe
import Data.Set qualified as Set
import Data.Set (Set)
type Coord = (Int, Int)
data Box = Box {
boxLocation :: Maybe Location,
boxType :: BoxType,
boxColor :: Attr,
boxBoring :: Bool
}
deriving (Show, Read, Eq)
boxWalls :: World -> Box -> Array Coord Bool
boxWalls world box =
case boxType box of
Original walls -> walls
Link c -> boxWalls world (boxIx world c)
Infinity c -> boxWalls world (boxIx world c)
Epsilon _ walls -> walls
data BoxType
= Original (Array Coord Bool)
| Link Char
| Infinity Char
| Epsilon Char (Array Coord Bool)
deriving (Show, Read, Eq)
data Location = Location { locName :: Char, locY :: Int, locX :: Int }
deriving (Read, Show, Ord, Eq)
data World = World {
worldBoxes :: Map Char Box,
worldMe :: Char,
worldButtons :: Set Location,
worldHome :: Location,
worldHeight :: Int,
worldWidth :: Int
}
deriving (Show, Read, Eq)
winCondition :: World -> Bool
winCondition world =
Set.isSubsetOf (worldButtons world) coverage &&
Just (worldHome world) == boxLocation (boxIx world (worldMe world))
where
coverage = Set.fromList (mapMaybe boxLocation (Map.elems (worldBoxes world)))
boxSize :: World -> Box -> Int
boxSize world box = yhi-ylo+1
where
((ylo,_),(yhi,_)) = bounds (boxWalls world box)
move :: World -> (Int,Int) -> World
move world dir =
case myLocation world of
Nothing -> world
Just loc ->
case moveBlock world Map.empty loc dir 0 of
Nothing -> world
Just changes ->
let f box change = box { boxLocation = change } in
world { worldBoxes = Map.mergeWithKey (\_ a b -> Just (f a b)) id (const Map.empty) (worldBoxes world) changes}
myLocation :: World -> Maybe Location
myLocation world = boxLocation (boxIx world (worldMe world))
isWall :: World -> Location -> Bool
isWall world (Location n y x) =
case Map.lookup n (worldBoxes world) of
Nothing -> True
Just box -> boxWalls world box ! (y,x)
type Movement = (Int, Int)
moveBlock ::
World ->
Map Location (Int, Char, Maybe Location) ->
Location ->
Movement ->
Rational {- ^ offset -} ->
Maybe (Map Char (Maybe Location))
-- moving into a wall, not possible
moveBlock world _ loc _ _
| isWall world loc = Nothing
-- move introduced a loop, trim off the tail and report success
moveBlock _ visited loc _ _
| Just (n,_,_) <- Map.lookup loc visited
= Just (Map.fromList [(c,l) | (a,c,l) <- Map.elems visited, a >= n])
moveBlock world visited loc dir offset =
case [(n,box) | (n,box) <- Map.assocs (worldBoxes world), boxLocation box == Just loc] of
-- moving an empty space, so we're done
[] -> Just (Map.fromList [(c,l) | (_,c,l) <- Map.elems visited])
-- moving a box
(name,box):_ ->
case nextLoc world dir loc offset of
Nothing -> Just (Map.fromList ((name, Nothing) : [(c,l) | (_,c,l) <- Map.elems visited]))
Just (loc', offset') ->
do guard (not (isWall world loc'))
moveBlock' world visited loc loc' dir name box Set.empty offset'
moveBlock' ::
World ->
Map Location (Int, Char, Maybe Location) ->
Location ->
Location ->
Movement ->
Char ->
Box ->
Set Location ->
Rational {- ^ offset -} ->
Maybe (Map Char (Maybe Location))
moveBlock' world visited loc loc' dir name box enters offset =
msum [moveTo, moveInto, moveToEat]
where
moveTo =
do moveBlock world (addVisited name loc (Just loc') visited) loc' dir 0
moveInto =
do (n,b) <- boxAt world loc'
(locI, offset') <- enterLoc world n b dir offset
if Set.member locI enters then
moveEpsilon
else
moveBlock' world visited loc locI dir name box (Set.insert locI enters) offset'
moveEpsilon =
do epsilon <- findEpsilon world (locName loc')
let eBox = boxIx world epsilon
(locI, offset') <- enterLoc world epsilon eBox dir offset
moveBlock' world visited loc locI dir name box (Set.insert locI enters) offset'
moveToEat =
do let dir' = invert dir
(locE, _) <- enterLoc world name box dir' 0
(name', box') <- boxAt world loc'
moveBlock' world (addVisited name loc (Just loc') visited) loc' locE dir' name' box' Set.empty 0
enterLoc :: World -> Char -> Box -> Movement -> Rational -> Maybe (Location, Rational)
enterLoc world name box dir@(dy,dx) offset =
do name' <-
case boxType box of
Link c -> Just c
Original{} -> Just name
Infinity{} -> Nothing
Epsilon {} -> Just name
let go y x = Just
(Location name' y x,
fromIntegral(boxSize world box) * offset
- fromIntegral ((abs dy *x + abs dx*y)))
((ylo,xlo),(yhi,xhi)) = bounds (boxWalls world box)
case dir of
(-1, 0) -> go yhi (midpoint xlo xhi offset)
( 1, 0) -> go ylo (midpoint xlo xhi offset)
( 0,-1) -> go (midpoint ylo yhi offset) xhi
( 0, 1) -> go (midpoint ylo yhi offset) xlo
_ -> error "enterLoc: bad direction"
boxAt :: World -> Location -> Maybe (Char, Box)
boxAt world loc =
listToMaybe [(n,b) | (n,b) <- Map.assocs (worldBoxes world), boxLocation b == Just loc]
boxIx :: World -> Char -> Box
boxIx world name = worldBoxes world Map.! name
invert :: Movement -> Movement
invert (dy,dx) = (-dy, -dx)
midpoint :: Int -> Int -> Rational -> Int
midpoint lo hi offset = round (offset * fromIntegral (hi-lo+1))
addVisited ::
Char {- ^ name -} ->
Location {- ^ start -} ->
Maybe Location {- ^ end -} ->
Map Location (Int, Char, Maybe Location) ->
Map Location (Int, Char, Maybe Location)
addVisited name k v m = Map.insert k (Map.size m, name, v) m
nextLoc :: World -> Movement -> Location -> Rational -> Maybe (Location, Rational)
nextLoc world (dy, dx) = go Set.empty
where
go _ (Location b y x) offset
| Just box <- Map.lookup b (worldBoxes world)
, inRange (bounds (boxWalls world box)) (y+dy, x+dx)
= Just (Location b (y+dy) (x+dx), offset)
go visited (Location b y x) offset
| Just box <- Map.lookup b (worldBoxes world)
, Set.notMember b visited
, Just boxLoc <- boxLocation box
= go (Set.insert b visited) boxLoc
$ (offset + fromIntegral (abs dy*x+abs dx*y))
/ fromIntegral (boxSize world box)
go visited (Location b y x) offset
| Set.member b visited
, Just b' <- findInfinity world b
= go visited (Location b' y x) offset
go _ _ _ = Nothing
findInfinity :: World -> Char -> Maybe Char
findInfinity world b =
listToMaybe [b' | (b', box) <- Map.assocs (worldBoxes world)
, Infinity i <- [boxType box], i == b]
findEpsilon :: World -> Char -> Maybe Char
findEpsilon world b =
listToMaybe [b' | (b', box) <- Map.assocs (worldBoxes world)
, Epsilon i _ <- [boxType box], i == b]