Add airlocks

src/Geometry.hs

@@ -461,6 +461,29 @@ divideCircle x cen rad = map (cen +.+) $ nRaysRad n rad
   where 
     n = ceiling $ rad * 2 * pi / x
 
+arcStepwise
+    :: Float    -- ^ Maximum distance between points
+    -> Float    -- ^ Angle to travel
+    -> Point2   -- ^ Center
+    -> Point2   -- ^ Start vector from center
+    -> [Point2]
+arcStepwise ssize a c v
+    | a < 0 = reverse $ arcStepwisePositive ssize (negate a) c (rotateV a v)
+    | otherwise = arcStepwisePositive ssize a c v
+
+arcStepwisePositive
+    :: Float    -- ^ Maximum distance between points
+    -> Float    -- ^ Angle to travel, assumed to be positive
+    -> Point2   -- ^ Center
+    -> Point2   -- ^ Start vector from center
+    -> [Point2]
+arcStepwisePositive ssize a cen v = ((cen +.+) . (\rot -> rotateV rot v) ) <$> rots
+  where
+    rots :: [Float]
+    rots = map ((a*) . (/ fromIntegral n ) . fromIntegral) [0 .. n]
+    n :: Int
+    n = ceiling (a * magV v / ssize)
+
 --nPointsOnCirc :: Int -> Float -> [Point2]
 --nPointsOnCirc n rad = take n $ iterate (rotateV (2*pi/fromIntegral n)) (rad,0)