Got real tracing, seidel calulations working

lib/Petzval/Optics.hs

@@ -11,6 +11,7 @@ module Petzval.Optics
   , ConstMat(..)
     -- * Optical elements
   , Element(..)
+  , isStop, isSurface
   , thickness
   , outsideRadius
   , material
@@ -64,6 +65,15 @@ data Element mat fp =
       }
                     deriving (Show)
 makeLenses ''Element
+
+-- | Determine if an element is a stop
+isStop :: Element mat a -> Bool
+isStop Stop{} = True
+isStop _ = False
+-- | Determine if an element is a refractive surface
+isSurface :: Element mat a -> Bool
+isSurface Surface{} = True
+isSurface _ = False
     {-
 -- | The space after the current element
 thickness :: Lens (Element mat a) (Element mat a) a a
@@ -94,12 +104,14 @@ liftFp inj (s@Surface{_thickness, _outsideRadius, _roc, _material}) = (\t' or' r
 liftFp inj (s@Stop{_thickness, _outsideRadius}) = (\t' or' -> Stop{_thickness=t', _outsideRadius=or'}) <$> inj _thickness <*> inj _outsideRadius
 {-# INLINE liftFp #-}
 
-specialize :: (Material mat) => Double -> [Element mat a] -> [Element Double a]
-specialize wavelength = (each.material) %~ (iorAtWavelength wavelength)
+-- | Specialize a system for a specific wavelength
+specialize :: (Material mat) => Double -> [Element mat a] -> [Element ConstMat a]
+specialize wavelength = (each.material) %~ (ConstMat . iorAtWavelength wavelength)
+-- | Annotate each material with the incoming index of refraction
 bake :: (Material mat) => Double -> [Element mat a] -> [Element BakedIOR a]
 bake wavelength mat =
   snd $
-  mapAccumLOf (each.material) (\n1 n2 -> (n2, BakedIOR n1 n2)) 1 $
+  mapAccumLOf (each.material) (\n1 (ConstMat n2) -> (n2, BakedIOR n1 n2)) 1 $
   specialize wavelength mat