Move towards removal of ssaTri, which was buggy

src/Geometry/Intersect.hs

@@ -8,8 +8,7 @@ import Geometry.LHS
 import Control.Applicative
 
 import Data.List
-
-import Data.Maybe (isNothing)
+import Data.Maybe
 -- | If two lines intersect, return 'Just' that point.
 intersectLineLine' :: Point2 -> Point2 -> Point2 -> Point2 -> Maybe Point2
 {-# INLINE intersectLineLine' #-}
@@ -267,3 +266,6 @@ intersectCircSeg c r a b
     y = r ** 2 - x ** 2
     z = sqrt y
     v = z *.* normalizeV (b -.- a)
+
+intersectCircSegFirst :: Point2 -> Float -> Point2 -> Point2 -> Maybe Point2
+intersectCircSegFirst c r a = listToMaybe . intersectCircSeg c r a