diff options
Diffstat (limited to 'src/Transformable.hs')
-rw-r--r-- | src/Transformable.hs | 40 |
1 files changed, 23 insertions, 17 deletions
diff --git a/src/Transformable.hs b/src/Transformable.hs index 2fd64fe..335b477 100644 --- a/src/Transformable.hs +++ b/src/Transformable.hs @@ -2,11 +2,12 @@ module Transformable ( Coord , Vector3 - , Transform + , TransformMap + , Transform(..) + , ReversibleTransform(..) , Transformable(..) - , translate - , rotate - , scale + , (><) + , (>:<) ) where import Data.LinearMap @@ -14,24 +15,29 @@ import Data.LinearMap type Coord = Double type Vector3 = (Coord, Coord, Coord) -type Transform = Vector3 :-* Vector3 +type TransformMap = Vector3 :-* Vector3 class Transformable a where - (><) :: Transform -> a -> a + transform :: TransformMap -> a -> a -instance Transformable Transform where - t1 >< t2 = t1 *.* t2 +class Transform a where + toMap :: a -> TransformMap + +class Transform a => ReversibleTransform a where + toMap' :: a -> TransformMap instance Transformable Vector3 where - t >< v = t `lapply` v + transform = lapply + +instance Transform TransformMap where + toMap = id + +instance Transformable TransformMap where + transform = (*.*) -translate :: Coord -> Coord -> Transform -translate dx dy = linear $ \(x, y, w) -> (x + w*dx, y + w*dy, w) +(><) :: (Transform t, Transformable a) => t -> a -> a +t >< a = transform (toMap t) a -rotate :: Coord -> Transform -rotate a = linear $ \(x, y, w) -> (c*x - s*y, s*x + c*y, w) where - c = cos a - s = sin a +(>:<) :: (ReversibleTransform t, Transformable a) => t -> a -> a +t >:< a = transform (toMap' t) a -scale :: Coord -> Transform -scale s = linear $ \(x, y, w) -> (s*y, s*y, w) |