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loop/src/Dodge/WallCreatureCollisions.hs
T

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3.8 KiB
Haskell

module Dodge.WallCreatureCollisions where
-- imports {{{
import Dodge.Data
import Dodge.Base
import Geometry
import Data.List
import Data.Maybe
import Data.Function
import Control.Lens
import qualified Data.IntMap.Strict as IM
colCrsWalls :: World -> World
colCrsWalls w = over creatures (fmap (colCrWall w)) w
colCrWall :: World -> Creature -> Creature
colCrWall w c = pushOutFromWall w c
pushOutFromWall :: World -> Creature -> Creature
pushOutFromWall w c
| p1 == p2 = c
| otherwise = over crPos (
collideCorners rad p1 wallPoints
.
collideWalls rad p1 ls
. checkPushThroughs rad p1 ls
)
c
where rad = _crRad c + wallBuffer
p1 = _crOldPos c
p2 = _crPos c
ls = IM.elems $ fmap _wlLine $ wallsNearPoint p2 w
wallPoints = nub $ concat ls
-- colCrPushThrough :: World -> Creature -> Creature
-- colCrPushThrough w cr = set crPos (checkPushThroughs rad p1 p2 ls) cr
-- where rad = _crRad cr + wallBuffer
-- p1 = _crOldPos cr
-- p2 = _crPos cr
-- ls = IM.elems $ fmap _wlLine $ wallsNearPoint p2 w
-- -- probably best to push check pushing through walls before creature springs
-- the amount to push creatures out from walls, extra to their radius
wallBuffer = 3
-- the following tests whether a moving circle crosses a list of walls, and
-- places the circle accordingly.
-- It supposes that the circle will only interact with at most two walls.
-- the reverse prevents the collision from happening again with the first wall,
-- when two walls are collided with
collideWalls :: Float -> Point2 -> [[Point2]] -> Point2 -> Point2
collideWalls rad cp1 walls cp2
= case (listToMaybe.mapMaybe (collideWall rad cp1 cp2)) walls of
Nothing -> cp2
Just cp3 -> case (listToMaybe.reverse.mapMaybe (collideWall rad cp1 cp3)) walls of
Nothing -> cp3
Just cp4 -> cp4
-- assumes that the wall is orientated
-- assumes wall points are different
collideWall :: Float -> Point2 -> Point2 -> [Point2] -> Maybe (Point2)
collideWall rad cp1 cp2 (wp1:wp2:_)
| isOnWall = Just newP -- +.+ (1 *.* norm))
| otherwise = Nothing
where norm = errorNormalizeV 61 $ vNormal (wp1 -.- wp2)
wp1' = (rad *.* norm) +.+ wp1
wp2' = (rad *.* norm) +.+ wp2
newP = errorClosestPointOnLine 5 wp1' wp2' cp2
isOnWall = circOnLine' wp1 wp2 cp2 rad
isJust Nothing = False
isJust _ = True
collideCorners :: Float -> Point2 -> [Point2] -> Point2 -> Point2
collideCorners rad p1 ps p2 = foldr (intersectCirclePoint rad) p2 ps
-- collide circles with points (outer corners)
intersectCirclePoint :: Float -> Point2 -> Point2 -> Point2
intersectCirclePoint rad p cCen | dist cCen p > rad = cCen
| otherwise = p +.+ (rad *.* errorNormalizeV 65 (cCen -.- p))
checkPushThroughs :: Float -> Point2 -> [[Point2]] -> Point2 -> Point2
checkPushThroughs rad cp1 walls cp2
= fromMaybe cp2 $ (listToMaybe.mapMaybe (checkPushThrough rad cp1 cp2)) walls
checkPushThrough :: Float -> Point2 -> Point2 -> [Point2] -> Maybe (Point2)
checkPushThrough rad cp1 cp2 (wp1:wp2:_)
| isPushedThrough = intersectSegSeg' cp1 cp2 wp1 wp2
| otherwise = Nothing
where norm = errorNormalizeV 61 $ vNormal (wp1 -.- wp2)
wp1' = (rad *.* norm) +.+ wp1
wp2' = (rad *.* norm) +.+ wp2
newP = errorClosestPointOnLine 5 wp1' wp2' cp2
isPushedThrough = isRHS wp1 wp2 cp2 && isJust (intersectSegSeg' cp1 cp2 wp1 wp2)
isJust Nothing = False
isJust _ = True