Add options page scrolling

src/Geometry/Zone.hs

@@ -4,6 +4,7 @@ module Geometry.Zone
     , ddaExt'
     , ddaSq
     , ddaSqStream
+    , ddaStream
     ) where
 import Geometry.Data
 
@@ -127,6 +128,10 @@ ddaExt' s sp@(V2 sx sy) ep@(V2 ex ey)
                          [y1 .. y2] 
         | otherwise = zip (map (divTo s) [y2x,y2x+xdy..])
                          [y2-1 .. y1-1] 
+ddaStream :: Float -> Point2 -> Point2 -> Stream (Of (V2 Int)) Identity ()
+ddaStream s sp _ -- @(V2 sx sy) ep@(V2 ex ey) 
+    = S.yield $ sizeZoneOfPoint' s sp
+
 -- | Determines which horizontal and vertical lines on a grid are crossed by a
 -- line. For each adds the x-y index of the square to the right or above the
 -- crossed grid line. Also adds the index of the square containing the start