Work on chasm rooms

src/Geometry/Polygon.hs

@@ -2,6 +2,7 @@
 
 module Geometry.Polygon where
 
+import Geometry.Intersect
 import qualified Control.Foldl as L
 import Data.Maybe
 import Geometry.Data
@@ -46,6 +47,23 @@ rectVV (V2 x y) (V2 a b) = rectNSWE n s w e
 square :: Float -> [Point2]
 square n = rectWH n n
 
+polyOrthDist :: Int -> Float -> [Point2]
+polyOrthDist n x = mapMaybe
+            (\(ra, rb) -> intersectLineLine (rotateV ra bl) (rotateV ra br) (rotateV rb bl) (rotateV rb br))
+            $ loopPairs rots
+  where
+    rot = 2 * pi / fromIntegral n
+    rots = map ((rot *) . fromIntegral) [0 .. n -1]
+    bl = V2 x x
+    br = V2 (- x) x
+
+polyCornerDist :: Int -> Float -> [Point2]
+polyCornerDist n x = map f rots
+  where
+    rot = 2 * pi / fromIntegral n
+    rots = map ((rot *) . fromIntegral) [0 .. n -1]
+    f a = rotateV a (V2 x 0)
+
 mirrorXAxis :: [Point2] -> [Point2]
 mirrorXAxis ps = orderPolygon $ ps ++ mapMaybe f ps
   where