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starting rewrite of collision detection to force based model

physics3
nek0 2 months ago
parent
commit
01c152c1a5
  1. 196
      src/Physics/Classes/Collidible.hs

196
src/Physics/Classes/Collidible.hs

@ -28,6 +28,30 @@ data CollisionResult time direction
-- | Typeclass for implementing collision results on objects.
class (Show c, Mass c) => Collidible c where
-- | Final position of the object in the previous timestep
prevPosition :: c -> V2 Double
-- | Aggregated impact forces in a simulation step
impactForces :: c -> V2 Double
-- | Overwrite the impact forces of the mass object
impactForcesUpdater :: c -> (V2 Double -> c)
-- | reset impact forces vector at the beginning of a simulation step
resetImpactForces :: c -> c
resetImpactForces c = impactForcesUpdater c (V2 0 0)
-- | Add a impact force to the impact forces acting on the mass object
addImpactForce
:: c
-> V2 Double
-> c
addImpactForce c force =
impactForcesUpdater c (impactForces c + force)
-- | Flag indicating a collision during the current time step
collisionOccured :: c -> Bool
-- | returns the bottom left and top right corners relative to the objects
-- positional vector of the axis aligned bounding box (AABB) serving here
-- as collision boundaries.
@ -39,177 +63,11 @@ class (Show c, Mass c) => Collidible c where
collisionCheck
:: (Collidible other)
=> Double -- ^ Time step length
-> c -- ^ First object
=> c -- ^ First object
-> other -- ^ second object
-> CollisionResult Double (V2 Int) -- ^ Do the objects collide?
collisionCheck dt m1 m2 =
let d1@(V2 d1x d1y) = velocity m1
d2@(V2 d2x d2y) = velocity m2
p1@(V2 p1x p1y) = position m1
p2@(V2 p2x p2y) = position m2
(m1b1@(V2 m1b1x m1b1y), m1b2@(V2 m1b2x m1b2y)) = boundary m1
(m2b1@(V2 m2b1x m2b1y), m2b2@(V2 m2b2x m2b2y)) = boundary m2
(V2 pm1b1x pm1b1y, V2 pm1b2x pm1b2y) = (p1 +) <$> boundary m1
(V2 pm2b1x pm2b1y, V2 pm2b2x pm2b2y) = (p2 +) <$> boundary m2
m1p1@(V2 m1p1x m1p1y) = p1 + m1b1
m1p2 = p1 + V2 m1b1x m1b2y
m1p3@(V2 m1p3x m1p3y) = p1 + m1b2
m1p4@(V2 m1p4x _) = p1 + V2 m1b2x m1b1y
m2p1@(V2 m2p1x m2p1y) = p2 + m2b1
m2p2 = p2 + V2 m2b1x m2b2y
m2p3@(V2 m2p3x m2p3y) = p2 + m2b2
m2p4 = p2 + V2 m2b2x m2b1y
(V2 b1minx b1miny, V2 b1maxx b1maxy) =
( V2
((\(V2 x _) -> x) (if d1x < 0 then m1p1 + ((dt *) <$> d1) else m1p1))
((\(V2 _ y) -> y) (if d1y < 0 then m1p1 + ((dt *) <$> d1) else m1p1))
, V2
((\(V2 x _) -> x) (if d1x < 0 then m1p3 else m1p3 + ((dt *) <$> d1)))
((\(V2 _ y) -> y) (if d1y < 0 then m1p3 else m1p3 + ((dt *) <$> d1)))
)
(V2 b2minx b2miny, V2 b2maxx b2maxy) =
( V2
((\(V2 x _) -> x) (if d2x < 0 then m2p1 + ((dt *) <$> d2) else m2p1))
((\(V2 _ y) -> y) (if d2y < 0 then m2p1 + ((dt *) <$> d2) else m2p1))
, V2
((\(V2 x _) -> x) (if d2x < 0 then m2p3 else m2p3 + ((dt *) <$> d2)))
((\(V2 _ y) -> y) (if d2y < 0 then m2p3 else m2p3 + ((dt *) <$> d2)))
)
broadphaseOverlap =
let in2 =
(b1minx > b2minx && b1minx < b2maxx &&
b1miny > b2miny && b1miny < b2maxy) ||
(b1maxx > b2minx && b1maxx < b2maxx &&
b1miny > b2miny && b1miny < b2maxy) ||
(b1minx > b2minx && b1minx < b2maxx &&
b1maxy > b2miny && b1maxy < b2maxy) ||
(b1maxx > b2minx && b1maxx < b2maxx &&
b1maxy > b2miny && b1maxy < b2maxy)
in1 =
(b2minx > b1minx && b2minx < b1maxx &&
b2miny > b1miny && b2miny < b1maxy) ||
(b2maxx > b1minx && b2maxx < b1maxx &&
b2miny > b1miny && b2miny < b1maxy) ||
(b2minx > b1minx && b2minx < b1maxx &&
b2maxy > b1miny && b2maxy < b1maxy) ||
(b2maxx > b1minx && b2maxx < b1maxx &&
b2maxy > b1miny && b2maxy < b1maxy)
in
in2 || in1
overlap =
let in1 =
(pm1b1x > pm2b1x && pm1b1x < pm2b2x &&
pm1b1y > pm2b1y && pm1b1y < pm2b2y) ||
(pm1b2x > pm2b1x && pm1b2x < pm2b2x &&
pm1b1y > pm2b1y && pm1b1y < pm2b2y) ||
(pm1b1x > pm2b1x && pm1b2x < pm2b2x &&
pm1b2y > pm2b1y && pm1b2y < pm2b2y) ||
(pm1b2x > pm2b1x && pm1b2x < pm2b2x &&
pm1b2y > pm2b1y && pm1b2y < pm2b2y)
in2 =
(pm2b1x > pm1b1x && pm2b1x < pm1b2x &&
pm2b1y > pm1b1y && pm2b1y < pm1b2y) ||
(pm2b2x > pm1b1x && pm2b2x < pm1b2x &&
pm2b1y > pm1b1y && pm2b1y < pm1b2y) ||
(pm2b1x > pm1b1x && pm2b2x < pm1b2x &&
pm2b2y > pm1b1y && pm2b2y < pm1b2y) ||
(pm2b2x > pm1b1x && pm2b2x < pm1b2x &&
pm2b2y > pm1b1y && pm2b2y < pm1b2y)
in
in2 || in1
tx =
let p1x = (\(V2 x _) -> x) (if d1x < 0 then m1p1 else m1p4)
p2x = (\(V2 x _) -> x) (if d1x < 0 then m2p4 else m2p1)
in
if d2x - d1x == 0 then dt else (p1x - p2x) / (d2x - d1x)
ty =
let p1y = (\(V2 _ y) -> y) (if d1y < 0 then m1p1 else m1p2)
p2y = (\(V2 _ y) -> y) (if d1y < 0 then m2p2 else m2p1)
in
if d2y - d1y == 0 then dt else (p1y - p2y) / (d2y - d1y)
in
if broadphaseOverlap
then
let coll xdir =
let (p11, p12, p21, p22)
| xdir =
if d1x < 0
then
(m1p1, m1p2, m2p4, m2p3)
else
(m1p4, m1p3, m2p1, m2p2)
| otherwise =
if d1y < 0
then
(m1p1, m1p4, m2p2, m2p3)
else
(m1p2, m1p3, m2p1, m2p4)
vselector (V2 x y) = if xdir then y else x
tick = if xdir then tx else ty
g1s = vselector $ p11 + ((tick *) <$> d1)
g1e = vselector $ p12 + ((tick *) <$> d1)
g2s = vselector $ p21 + ((tick *) <$> d2)
g2e = vselector $ p22 + ((tick *) <$> d2)
s11 = (g1s - g2s) / (g2e - g2s)
s12 = (g1e - g2s) / (g2e - g2s)
s21 = (g2s - g1s) / (g1e - g1s)
s22 = (g2e - g1s) / (g1e - g1s)
in
any (\x -> x > 0 && x < 1) [s11, s12, s21 ,s22]
res = case (tx < dt, ty < dt, tx < ty, coll True, coll False) of
(True, _, True, True, _) ->
CollisionImminent tx (V2 (floor $ signum d1x) 0)
(_, True, False, _, True) ->
CollisionImminent ty (V2 0 (floor $ signum d1y))
(True, _, False, True, False) ->
CollisionImminent tx (V2 (floor $ signum d1x) 0)
(_, True, True, False, True) ->
CollisionImminent ty (V2 0 (floor $ signum d1y))
(_, _, _, False, False) ->
NoCollision
(_, _, True, _, _) ->
A.log A.Debug "CORNER CASE!" NoCollision
(False, False, _, _, _) ->
NoCollision
x -> error $
"Unhandled combination of collision check results: "
<> fromString (show x)
in
case res of
CollisionImminent _ _ ->
res
NoCollision ->
if overlap
then
let xoverlap = floor (maximum (filter (0 >)
[ pm2b2x - pm2b1x
, pm2b1x - pm1b2x
]))
yoverlap = floor (maximum (filter (0 >)
[ pm2b1y - pm1b2y
, pm2b2y - pm1b1y
]))
in
if xoverlap < yoverlap
then
if xoverlap < 0
then OverlapCollision
(V2 xoverlap 0)
else
NoCollision
else
if yoverlap < 0
then OverlapCollision
(V2 0 yoverlap)
else NoCollision
else NoCollision
_ -> A.log
A.Error
"Premature overlap collision detection"
NoCollision
else
NoCollision
collisionCheck m1 m2 =
error "collisionCheck: not yet implemented!"
-- | This Function is called for every collision on both colliding objects.
collide

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