Got real tracing, seidel calulations working

lib/Petzval/System.hs

@@ -1,9 +1,8 @@
+-- | General utilities for dealing with full lens systems (i.e., the composition of multiple refracting surfaces)
 module Petzval.System
   ( Pupil(..)
   , entrancePupil
-  , createRay
   , seidel, Seidel(..)
-  , Ray
   ) where
 
 import Petzval.Optics
@@ -15,7 +14,6 @@ import Data.List
 
 import qualified Debug.Trace
 
-data Ray a = Ray (V3 a) (V3 a)
 
 splitSystem :: [ Element mat a ] -> ([Element mat a], Maybe (Element mat a), [Element mat a])
 splitSystem (s@Stop{}:rest) = ([], Just s, rest)
@@ -23,6 +21,7 @@ splitSystem [] = ([], Nothing, [])
 splitSystem (s:rest) = (s:pfx, stop, sfx)
   where (pfx, stop, sfx) = splitSystem rest
 
+-- | A pupil (real or virtual, entrance or exit)
 data Pupil a = Pupil { radius :: a, position :: a }
   deriving (Show)
 
@@ -33,24 +32,13 @@ pupil (stop@Stop{_outsideRadius}) subsystem =
       --msg = intercalate " " ["ptrace: ", show (rtm !* V2 (_outsideRadius / my ) 0)]
   in Pupil { radius = _outsideRadius / my
            , position = -cy / cu }
+
+-- | Compute the entrance pupil of a system viewed from infinity
 entrancePupil :: (RealFloat a, Mode a, Scalar a ~ Double, Epsilon a, Show a) => [Element BakedIOR a] -> Pupil a
 entrancePupil system = pupil stop prefix
   where (prefix, (Just stop), _) = splitSystem system
 
-createRay :: (RealFloat a, Mode a, Scalar a ~ Double, Epsilon a) => Maybe a -> Pupil a -> a -> (a,a) -> Ray a
-createRay (Just objectPlane) Pupil{position=pz,radius=pr} h (px, py) = 
-  Ray source (normalize $ target ^-^ source)
-  where dz = pz - objectPlane 
-        source = V3 0 (dz * tan h) objectPlane
-        target = V3 (px * pr) (py * pr) pz
-createRay Nothing Pupil{position=pz,radius=pr} h (px, py) = Ray source (normalize $ target ^-^ source)
-  where h' = (pi * (-abs h) / 180) -- field angle in rad
-        dy = (V3 0 (cos h') (-sin h')) `project` (V3 0 (py * pr) 0)
-        dz =  V3 0 (pz * tan h') (pz * cos h')
-      
-        source = dy ^+^ dz
-        target = V3 (px * pr) (py * pr) pz
-
+-- | The set of seidel coefficients of a lens system
 data Seidel a = Seidel
                    { sphr, coma, asti, fcur, dist :: a
                    -- , c1, c2 :: a
@@ -114,9 +102,7 @@ seidel' rays (s@Surface{_material=BakedIOR n1 n2,_roc=roc}) = Debug.Trace.trace
         -- cbas = h  (n2 - n1) / n1
         -- c1 = 
         
-        
-  
-
+-- | Compute the seidel coefficients of a system given the pupil and field angle
 seidel :: (RealFloat a, Mode a, Scalar a ~ Double, Epsilon a, Show a) => Pupil a -> Double -> [Element BakedIOR a] -> [Seidel a]
 seidel pupil fieldAngle =
   snd . mapAccumL seidel' rays