{-# LANGUAGE DeriveGeneric #-}
module Game.LambdaHack.Common.Vector
( Vector(..), isUnit, isDiagonal, neg, chessDistVector, euclidDistSqVector
, moves, movesCardinal, movesDiagonal, compassText
, vicinity, vicinityUnsafe, vicinityCardinal, vicinityCardinalUnsafe
, squareUnsafeSet
, shift, shiftBounded, trajectoryToPath, trajectoryToPathBounded
, vectorToFrom, pathToTrajectory
, RadianAngle, rotate, towards
#ifdef EXPOSE_INTERNAL
, maxVectorDim, _moveTexts, longMoveTexts, normalize, normalizeVector
#endif
) where
import Prelude ()
import Game.LambdaHack.Common.Prelude
import Control.DeepSeq
import Data.Binary
import qualified Data.EnumMap.Strict as EM
import qualified Data.EnumSet as ES
import Data.Int (Int32)
import GHC.Generics (Generic)
import Game.LambdaHack.Common.Point
data Vector = Vector
{ vx :: X
, vy :: Y
}
deriving (Show, Read, Eq, Ord, Generic)
instance Binary Vector where
put = put . (fromIntegral :: Int -> Int32) . fromEnum
get = fmap (toEnum . (fromIntegral :: Int32 -> Int)) get
instance Enum Vector where
fromEnum (Vector vx vy) = vx + vy * (2 ^ maxLevelDimExponent)
toEnum n =
let (y, x) = n `quotRem` (2 ^ maxLevelDimExponent)
(vx, vy) | x > maxVectorDim = (x - 2 ^ maxLevelDimExponent, y + 1)
| x < - maxVectorDim = (x + 2 ^ maxLevelDimExponent, y - 1)
| otherwise = (x, y)
in Vector{..}
instance NFData Vector
maxVectorDim :: Int
{-# INLINE maxVectorDim #-}
maxVectorDim = 2 ^ (maxLevelDimExponent - 1) - 1
isUnit :: Vector -> Bool
{-# INLINE isUnit #-}
isUnit v = chessDistVector v == 1
isDiagonal :: Vector -> Bool
{-# INLINE isDiagonal #-}
isDiagonal (Vector x y) = x * y /= 0
neg :: Vector -> Vector
{-# INLINE neg #-}
neg (Vector vx vy) = Vector (-vx) (-vy)
chessDistVector :: Vector -> Int
{-# INLINE chessDistVector #-}
chessDistVector (Vector x y) = max (abs x) (abs y)
euclidDistSqVector :: Vector -> Vector -> Int
euclidDistSqVector (Vector x0 y0) (Vector x1 y1) =
(x1 - x0) ^ (2 :: Int) + (y1 - y0) ^ (2 :: Int)
moves :: [Vector]
moves =
map (uncurry Vector)
[(-1, -1), (0, -1), (1, -1), (1, 0), (1, 1), (0, 1), (-1, 1), (-1, 0)]
movesCardinal :: [Vector]
movesCardinal = map (uncurry Vector) [(0, -1), (1, 0), (0, 1), (-1, 0)]
movesDiagonal :: [Vector]
movesDiagonal = map (uncurry Vector) [(-1, -1), (1, -1), (1, 1), (-1, 1)]
_moveTexts :: [Text]
_moveTexts = ["NW", "N", "NE", "E", "SE", "S", "SW", "W"]
longMoveTexts :: [Text]
longMoveTexts = [ "northwest", "north", "northeast", "east"
, "southeast", "south", "southwest", "west" ]
compassText :: Vector -> Text
compassText v = let m = EM.fromList $ zip moves longMoveTexts
assFail = error $ "not a unit vector" `showFailure` v
in EM.findWithDefault assFail v m
vicinity :: X -> Y
-> Point
-> [Point]
vicinity lxsize lysize p =
if inside p (1, 1, lxsize - 2, lysize - 2)
then vicinityUnsafe p
else [ res | dxy <- moves
, let res = shift p dxy
, inside res (0, 0, lxsize - 1, lysize - 1) ]
vicinityUnsafe :: Point -> [Point]
vicinityUnsafe p = [ shift p dxy | dxy <- moves ]
vicinityCardinal :: X -> Y
-> Point
-> [Point]
vicinityCardinal lxsize lysize p =
[ res | dxy <- movesCardinal
, let res = shift p dxy
, inside res (0, 0, lxsize - 1, lysize - 1) ]
vicinityCardinalUnsafe :: Point -> [Point]
vicinityCardinalUnsafe p = [ shift p dxy | dxy <- movesCardinal ]
squareUnsafeSet :: Point -> ES.EnumSet Point
squareUnsafeSet (Point x y) =
ES.fromDistinctAscList $ map (uncurry Point)
[ (x - 1, y - 1)
, (x, y - 1)
, (x + 1, y - 1)
, (x - 1, y)
, (x, y)
, (x + 1, y)
, (x - 1, y + 1)
, (x, y + 1)
, (x + 1, y + 1) ]
shift :: Point -> Vector -> Point
{-# INLINE shift #-}
shift (Point x0 y0) (Vector x1 y1) = Point (x0 + x1) (y0 + y1)
shiftBounded :: X -> Y -> Point -> Vector -> Point
shiftBounded lxsize lysize pos v@(Vector xv yv) =
if inside pos (-xv, -yv, lxsize - xv - 1, lysize - yv - 1)
then shift pos v
else pos
trajectoryToPath :: Point -> [Vector] -> [Point]
trajectoryToPath _ [] = []
trajectoryToPath start (v : vs) = let next = shift start v
in next : trajectoryToPath next vs
trajectoryToPathBounded :: X -> Y -> Point -> [Vector] -> [Point]
trajectoryToPathBounded _ _ _ [] = []
trajectoryToPathBounded lxsize lysize start (v : vs) =
let next = shiftBounded lxsize lysize start v
in next : trajectoryToPathBounded lxsize lysize next vs
vectorToFrom :: Point -> Point -> Vector
{-# INLINE vectorToFrom #-}
vectorToFrom (Point x0 y0) (Point x1 y1) = Vector (x0 - x1) (y0 - y1)
pathToTrajectory :: [Point] -> [Vector]
pathToTrajectory [] = []
pathToTrajectory lp1@(_ : lp2) = zipWith vectorToFrom lp2 lp1
type RadianAngle = Double
rotate :: RadianAngle -> Vector -> Vector
rotate angle (Vector x' y') =
let x = fromIntegral x'
y = fromIntegral y'
dx = x * cos (-angle) - y * sin (-angle)
dy = x * sin (-angle) + y * cos (-angle)
in normalize dx dy
normalize :: Double -> Double -> Vector
normalize dx dy =
assert (dx /= 0 || dy /= 0 `blame` "can't normalize zero" `swith` (dx, dy)) $
let angle :: Double
angle = atan (dy / dx) / (pi / 2)
dxy | angle <= -0.75 && angle >= -1.25 = (0, -1)
| angle <= -0.25 = (1, -1)
| angle <= 0.25 = (1, 0)
| angle <= 0.75 = (1, 1)
| angle <= 1.25 = (0, 1)
| otherwise = error $ "impossible angle" `showFailure` (dx, dy, angle)
in if dx >= 0
then uncurry Vector dxy
else neg $ uncurry Vector dxy
normalizeVector :: Vector -> Vector
normalizeVector v@(Vector vx vy) =
let res = normalize (fromIntegral vx) (fromIntegral vy)
in assert (not (isUnit v) || v == res
`blame` "unit vector gets untrivially normalized"
`swith` (v, res))
res
towards :: Point -> Point -> Vector
towards pos0 pos1 =
assert (pos0 /= pos1 `blame` "towards self" `swith` (pos0, pos1))
$ normalizeVector $ pos1 `vectorToFrom` pos0