Nice tank-border collision detection

htanks.cabal

@@ -14,6 +14,7 @@ data-files:          tex/*.png
 executable:          HTanks
 hs-source-dirs:      src
 main-is:             HTanks.hs
-other-modules:       CPUPlayer, DefaultPlayer, Game, GLDriver, GLX, Level, MainLoop, Paths_htanks, Player, Render, Simulation, Texture, Bindings.GLX, Bindings.GLPng
-ghc-options:         -threaded
+other-modules:       Collision, CPUPlayer, DefaultPlayer, Game, GLDriver, GLX, Level, MainLoop, Paths_htanks, Player, Render, Simulation, Texture,
+                     Bindings.GLX, Bindings.GLPng
+ghc-options:         -threaded -O2
 extra-libraries:     glpng

src/CPUPlayer.hs

@@ -16,4 +16,4 @@ data CPUPlayer = CPUPlayer Micro
                  deriving (Typeable, Show)
 
 instance Player CPUPlayer where
-    playerUpdate (CPUPlayer angle) _ = (CPUPlayer (if (angle+0.1) > 180 then angle-359.9 else angle+0.1), Just angle, True, Just (-angle), False)
+    playerUpdate (CPUPlayer angle) _ = (CPUPlayer (if (angle+0.1) > 180 then angle-359.08 else angle+0.02), Just angle, True, Just (-angle), False)

src/Collision.hs

@@ -0,0 +1,41 @@
+module Collision ( collisionTankBorder
+                 ) where
+
+import Game
+
+import Data.Fixed
+import Data.Ratio
+
+tankWidth :: Micro
+tankWidth = 0.95
+
+tankLength :: Micro
+tankLength = 0.95
+
+collisionTankBorder :: Micro -> Micro -> Tank -> Tank
+collisionTankBorder lw lh tank = tank {tankX = newx, tankY = newy}
+    where
+      dir = (fromRational . toRational . tankDir $ tank)*pi/180
+      cosd = fromRational (round ((cos dir)*1000000)%1000000)
+      sind = fromRational (round ((sin dir)*1000000)%1000000)
+      
+      points = [ (tankLength/2, tankWidth/2)
+               , (-tankLength/2, tankWidth/2)
+               , (-tankLength/2, -tankWidth/2)
+               , (tankLength/2, -tankWidth/2)
+               ]
+      
+      rotp (x, y) = (cosd*x - sind*y, sind*x + cosd*y)
+      transp (x, y) = (x + tankX tank, y + tankY tank)
+      
+      pointst = map (transp . rotp) points
+      minx = minimum $ map fst pointst
+      maxx = maximum $ map fst pointst
+      miny = minimum $ map snd pointst
+      maxy = maximum $ map snd pointst
+      
+      dx = if minx < 0 then (-minx) else if maxx > lw then (-maxx+lw) else 0
+      dy = if miny < 0 then (-miny) else if maxy > lh then (-maxy+lh) else 0
+      
+      newx = (tankX tank) + dx
+      newy = (tankY tank) + dy

src/Simulation.hs

@@ -1,6 +1,7 @@
 module Simulation ( simulationStep
                   ) where
 
+import Collision
 import Game
 import Level
 import MainLoop
@@ -47,8 +48,8 @@ updateAngle angle = do
   modify $ \tank -> tank {tankDir = newangle180}
 
 
-updateTank :: Maybe Micro -> Bool -> Maybe Micro -> State Tank ()
-updateTank angle move aangle = do
+updateTank :: GameState -> Maybe Micro -> Bool -> Maybe Micro -> State Tank ()
+updateTank game angle move aangle = do
   when (isJust angle) $
        updateAngle $ fromJust angle
   
@@ -56,19 +57,24 @@ updateTank angle move aangle = do
        modify $ \tank -> tank {tankAim = fromJust aangle}
   
   when move $ do
-    tdir <- gets tankDir
-    tspeed <- gets tankSpeed
-    moved <- gets tankMoving
+    tank <- get
+    let tdir = tankDir tank
+        tspeed = tankSpeed tank
+        moved = tankMoving tank
     
     when (isNothing angle || (isJust angle && (tdir == fromJust angle)) || moved) $ do
                    let anglej = (fromRational . toRational $ tdir)*pi/180
-                       x = tspeed * fromRational (round ((cos anglej)*1000)%1000000)
-                       y = tspeed * fromRational (round ((sin anglej)*1000)%1000000)
+                       dx = tspeed * fromRational (round ((cos anglej)*1000)%1000000)
+                       dy = tspeed * fromRational (round ((sin anglej)*1000)%1000000)
                    
-                   modify $ \tank -> tank {tankX = x + tankX tank, tankY = y + tankY tank, tankMoving = True}
+                   put tank {tankX = dx + tankX tank, tankY = dy + tankY tank, tankMoving = True}
   
   when (not move) $ do
                    modify $ \tank -> tank {tankMoving = False}
+  
+  let lw = fromIntegral . levelWidth . level $ game
+      lh = fromIntegral . levelHeight . level $ game
+  modify $ collisionTankBorder lw lh
 
 
 updateBullet :: GameState -> State Bullet Bool
@@ -96,9 +102,10 @@ updateBullet game = do
 simulationStep :: Main ()
 simulationStep = do
   oldplayers <- gets players
-  oldtanks <- lift $ gets tanks
+  game <- lift get
+  let oldtanks = tanks game
   
-  let (p, t, s) = unzip3 $ map updateTank' $ zip oldplayers oldtanks
+  let (p, t, s) = unzip3 $ map (updateTank' game) $ zip oldplayers oldtanks
       ts = zip3 t s [0..]
       shootingtanks = map (\(tank, _, n) -> (tank, n)) $ filter (\(tank, shoot, _) -> shoot && (tankBulletsLeft tank) > 0) $ ts
       newtanks = map (\(tank, shoot, _) -> if (shoot && (tankBulletsLeft tank) > 0) then tank {tankBulletsLeft = (tankBulletsLeft tank) - 1} else tank) $ ts
@@ -117,8 +124,8 @@ simulationStep = do
           thetanks = map (\(tank, n) -> tank {tankBulletsLeft = (tankBulletsLeft tank) + (countLostTankBullets n thebullets)}) $ zip newtanks [0..]
       in state {tanks = thetanks, bullets = map snd . filter fst $ thebullets}
     where
-      updateTank' (player, tank) = let (p, angle, move, aangle, bullet) = playerUpdate player tank
-                                       t = execState (updateTank angle move aangle) tank
-                                   in (p, t, bullet)
+      updateTank' game (player, tank) = let (p, angle, move, aangle, bullet) = playerUpdate player tank
+                                            t = execState (updateTank game angle move aangle) tank
+                                        in (p, t, bullet)
       countLostTankBullets n (x:xs) = (if ((not . fst $ x) && (n == (bulletTank . snd $ x))) then 1 else 0) + (countLostTankBullets n xs)
       countLostTankBullets n []     = 0