Random tree structure generation of rooms

src/Dodge/Room/Link.hs

@@ -0,0 +1,57 @@
+module Dodge.Room.Link
+    where
+import Dodge.LevelGen
+import Dodge.LevelGen.Data
+import Dodge.Room.Data
+import Dodge.RandomHelp
+import Geometry
+
+import System.Random
+import Control.Monad.State
+import Control.Lens
+import Data.List (delete)
+
+randLinks :: RandomGen g => Room -> State g Room
+randLinks r = do
+    newLinks <- shuffle $ init $ _rmLinks r
+    return $ r {_rmLinks = newLinks ++ [last $ _rmLinks r]}
+
+filterLinks :: RandomGen g => ((Point2,Float) -> Bool) -> Room -> State g Room
+filterLinks cond r = do
+    newLinks <- shuffle $ filter cond $ init $ _rmLinks r
+    return $ r {_rmLinks = newLinks ++ [last $ _rmLinks r]}
+
+changeLinkTo :: RandomGen g => ((Point2,Float) -> Bool) -> Room -> State g Room
+changeLinkTo cond r = do
+    l <- takeOne $ filter cond $ _rmLinks r
+    let newLinks = delete l (_rmLinks r) ++ [l]
+    return $ r {_rmLinks = newLinks}
+
+{- | Move a room so that the last link in '_rmLinks' lines up to 
+an external point and direction.
+This is intended to work when the external point is an outgoing link from another room.
+-}
+shiftRoomToLink :: (Point2,Float) -> Room -> Room
+shiftRoomToLink l r 
+    = shiftRoomBy l 
+    . shiftRoomBy ((0,0) -.- (rotateV (pi-a) p),0) 
+    $ shiftRoomBy ((0,0),pi-a)  r
+  where 
+    (p,a) = last $ _rmLinks r
+
+shiftRoomBy :: (Point2,Float) -> Room -> Room
+shiftRoomBy shift@(pos,rot) r = 
+   over rmPolys (fmap (map (shiftPointBy shift)))
+   $ over rmLinks (fmap (shiftLinkBy shift))
+   $ over rmPath (map (shiftPathPointBy shift))
+   $ over rmPS (fmap (shiftPSBy shift))
+   $ over rmBound (map (shiftPointBy shift))
+   r
+
+shiftLinkBy (pos,rot) (p,r) = (shiftPointBy (pos,rot) p, r + rot)
+shiftPSBy (pos,rot) ps = case ps of
+    PS {} -> over psPos (shiftPointBy (pos,rot))
+                            $ over psRot (+rot)
+                            ps
+
+shiftPathPointBy s (p1,p2) = (shiftPointBy s p1, shiftPointBy s p2)