Files
loop/src/Geometry/Zone.hs
T
2021-08-16 14:44:52 +02:00

150 lines
4.2 KiB
Haskell

{-# LANGUAGE TupleSections #-}
module Geometry.Zone
( ddaExt
)
where
import Geometry.Data
import Data.Foldable
import qualified Data.IntMap.Strict as IM
import qualified Data.IntSet as IS
foldl2'
:: (b -> a -> a -> b)
-> b
-> [a]
-> b
foldl2' f s (t:ts) = fst $ foldl' g (s, t) ts
where
g (r,x) y = (f r x y,y)
foldl2' _ s _ = s
sortArguments
:: Ord a
=> (a -> a -> b)
-> a -> a -> b
sortArguments f x y
| x < y = f x y
| otherwise = f y x
sortArgumentsReverse
:: Ord a
=> (a -> a -> [b])
-> a -> a -> [b]
sortArgumentsReverse f x y
| x < y = f x y
| otherwise = reverse $ f y x
intervalBounds
:: Float -- ^ interval threshold
-> Float -- ^ First endpoint
-> Float -- ^ Second endpoint
-> [Float]
intervalBounds = sortArgumentsReverse . f
where
f r a b
| x > b = [a]
| otherwise = (a : [x,x+r..b])
where
x = floorTo r a + r
floorTo :: Float -> Float -> Float
floorTo r x = r * (fromIntegral ((floor $ x / r) :: Int))
ceilingTo :: Float -> Float -> Float
ceilingTo r x = r * (fromIntegral ((ceiling $ x / r) :: Int))
divTo :: Float -> Float -> Int
{-# INLINE divTo #-}
divTo s = floor . (/s)
flipV :: Point2 -> Point2
{-# INLINE flipV #-}
flipV (V2 a b) = V2 b a
applyInverted
:: (Point2 -> Point2 -> [Point2])
-> Point2 -> Point2 -> [Point2]
applyInverted f sp@(V2 sx sy) ep@(V2 ex ey)
| abs (sx-ex) > abs (sy-ey) = f sp ep
| otherwise = map flipV $ f (flipV sp) (flipV ep)
sizeZoneOfPoint' :: Float -> Point2 -> V2 Int
sizeZoneOfPoint' s = fmap (divTo s)
increasingInterval :: Int -> Int -> [Int]
increasingInterval x y
| y > x = [x .. y]
| otherwise = [y .. x]
-- | Determines which horizontal and vertical lines on a grid are crossed by a
-- line. For each adds the x-y index of the square to the right or above the
-- crossed grid line. Also adds the index of the square containing the start
-- point.
ddaExt :: Float -> V2 Float -> V2 Float -> IM.IntMap IS.IntSet
ddaExt s sp@(V2 sx sy) ep@(V2 ex ey)
| x1 <= x2 = addys . IM.fromDistinctAscList $ zip [x1 .. x2]
$ map (IS.singleton . divTo s) [x1y,x1y+ydx..]
| otherwise = addys . IM.fromDistinctAscList $ zip [x2-1 .. x1-1]
$ map (IS.singleton . divTo s) [x2y,x2y+ydx..]
where
x1 = divTo s sx
x2 = divTo s ex
x1y = fx' sp ep $ s * (fromIntegral x1)
x2y = fx' sp ep $ s * (fromIntegral x2)
ydx = s * ydx' sp ep
addys m = add2s m ypairs
y1 = divTo s sy
y2 = divTo s ey
y1x = fy' sp ep $ s * (fromIntegral y1)
y2x = fy' sp ep $ s * (fromIntegral y2)
xdy = s * xdy' sp ep
ypairs
| y1 <= y2 = zip (map (divTo s) [y1x,y1x+xdy..])
[y1 .. y2]
| otherwise = zip (map (divTo s) [y2x,y2x+xdy..])
[y2-1 .. y1-1]
ydx' :: Point2 -> Point2 -> Float
{-# INLINE ydx' #-}
ydx' (V2 sx sy) (V2 ex ey)
| sx == ex = 0
| otherwise = (ey - sy) / (ex - sx)
xInt' :: Float -> Point2 -> Point2 -> Float
xInt' s (V2 sx _) (V2 ex _)
| ex > sx = ceilingTo s sx
| otherwise = floorTo s sx
fx' :: Point2 -> Point2 -> Float -> Float
fx' sp@(V2 sx sy) ep@(V2 _ ey) x
| sy == ey = sy
| otherwise = sy + ydx' sp ep * (x - sx)
xdy' :: Point2 -> Point2 -> Float
xdy' (V2 sx sy) (V2 ex ey)
| sy == ey = 0
| otherwise = (ex - sx) / (ey - sy)
yInt' :: Float -> Point2 -> Point2 -> Float
yInt' s (V2 _ sy) (V2 _ ey)
| ey > sy = ceilingTo s sy
| otherwise = floorTo s sy
fy' :: Point2 -> Point2 -> Float -> Float
fy' sp@(V2 sx sy) ep@(V2 ex _) y
| sx == ex = sx
| otherwise = sx + xdy' sp ep * (y - sy)
add2s :: IM.IntMap IS.IntSet -> [(Int,Int)] -> IM.IntMap IS.IntSet
{-# INLINE add2s #-}
add2s imis = foldl'
(\m (k,x) -> IM.insertWith (\_ old -> IS.insert x old) k (IS.singleton x) m)
imis
addV2s :: IM.IntMap IS.IntSet -> [V2 Int] -> IM.IntMap IS.IntSet
{-# INLINE addV2s #-}
addV2s imis = foldl'
(\m (V2 k x) -> IM.insertWith (\_ old -> IS.insert x old) k (IS.singleton x) m)
imis
pairsToIntMapSet :: [V2 Int] -> IM.IntMap IS.IntSet
pairsToIntMapSet = foldl'
(\m (V2 k x) -> IM.insertWith (\_ old -> IS.insert x old) k (IS.singleton x) m)
IM.empty