wave :: Exp Angle -> Exp R2 -> Exp R
wave th pt = (cos (cth*x + sth*y) + 1) / 2
  where
    (x,y)       = A.unlift pt
    cth         = cos th
    sth         = sin th

-- | Convert an image point to a point on our wave plane.
wave :: Exp Angle -> Exp R2 -> Exp R
wave th pt = (cos (cth*x + sth*y) + 1) / 2
  where
    (x,y)       = A.unlift pt
    cth         = cos th
    sth         = sin th

-- | Convert an image point to a point on our wave plane.
wave th pt = (cos (cth*x + sth*y) + 1) / 2
  where
    (x,y)       = A.unlift pt
    cth         = cos th
    sth         = sin th

-- | Convert an image point to a point on our wave plane.