module Trace where
import Scene
import Data.List
import Control.Concurrent.MVar
import System.IO.Unsafe
--import Packet
{-
We put lighting code in this file because it needs to be
mutually recursive with the trace function, for refraction
and reflection.
-}
data PacketColor = PacketColor !Color !Color !Color !Color
{-
simple_shade :: Rayint -> [Light] -> Solid -> Color -> Color
simple_shade ri lights s bg =
case ri of
(RayHit d p n t) ->
let (Material clr refl refr ior kd shine) = t ri
in cscale clr (vdot n (Vec 0.0 1.0 0.0))
(RayMiss) -> bg
-}
-- set rgb to normal's xyz coordinates
-- as a debugging aid
debug_norm_shade :: Rayint -> Ray -> Scene -> Int -> Int -> Color
debug_norm_shade ri (Ray o indir) scn recurs debug =
case ri of
RayHit d p (Vec nx ny nz) t -> (Color (fabs $ nx/2) (fabs $ ny/2) (fabs $ nz/2))
RayMiss -> bground scn
-- no shadows, reflection, or lighting
flat_shade :: Rayint -> Ray -> Scene -> Int -> Int -> Color
flat_shade ri (Ray o indir) scn recurs debug =
case ri of
RayMiss -> bground scn
RayHit d p n t ->
let (Material clr refl refr ior kd shine) = t ri
in clr
-- handles diffuse light, shadows, specular highlights and reflection
-- todo: refraction
shade :: Rayint -> Ray -> Scene -> Int -> Int -> Color
shade ri (Ray o indir) scn recurs !debug =
case ri of
(RayHit d p n t) ->
let (Material clr refl_ refr ior kd shine) = t ri
s = sld scn
lights = lits scn
direct = foldl' cadd c_black
(map (\ (Light lp lc) ->
let eyedir = vinvert indir
lvec = vsub lp p
llen = vlen lvec
ldir = vscale lvec (1.0/llen)
halfangle = bisect ldir eyedir
ldotn = fmax 0 $ vdot ldir n
-- blinn = fmax 0 ((vdot halfangle n)**(shine*3))
blinn = fmax 0 $ ((vdot halfangle n) ** shine) * ldotn
blinn_correct = if isNaN blinn then 0 else blinn
-- indotn = fmax 0 $ vdot eyedir n
intensity = 5.0 / (llen*llen)
--intensity = 0.2
in
if vdot n lvec < 0
then c_black
else
if not $ shadow s (Ray (vscaleadd p n delta) ldir) (llen-(2*delta))
then
cadd
-- diffuse
--c_black
(cmul clr $ cscale lc $ ldotn * intensity)
-- blinn/torrance-sparrow highlight (pbrt p 440)
(cscale lc $ blinn_correct * intensity)
-- c_black
else
c_black) lights)
reflect_ =
if (refl_ > delta) && (recurs > 0)
then let outdir = reflect indir n
in cscale (trace scn
(Ray (vscaleadd p outdir delta) outdir)
infinity (recurs-1) ) refl_
else c_black
refract =
if (refr > delta) && (recurs > 0)
then c_black
else c_black
in
cadd direct $ cadd reflect_ refract
(RayMiss) -> bground scn
trace :: Scene -> Ray -> Flt -> Int -> Color
trace scn ray depth recurs =
let (Scene sld lights cam dtex bgcolor) = scn
in shade (rayint sld ray depth dtex) ray scn recurs 0
-- return depth as well as color, for post-processing effects
trace_depth :: Scene -> Ray -> Flt -> Int -> (Color,Flt)
trace_depth scn ray depth recurs =
let (Scene sld lights cam dtex bgcolor) = scn
ri = rayint sld ray depth dtex
d = case ri of
RayHit d_ _ _ _ -> d_
RayMiss -> infinity
clr = shade ri ray scn recurs 0
in (clr,d)
-- return hit position as well as color
trace_pos :: Scene -> Ray -> Flt -> Int -> (Color,Vec)
trace_pos scn ray depth recurs =
let (Scene sld lights cam dtex bgcolor) = scn
ri = rayint sld ray depth dtex
p = case ri of
RayHit _ p _ _ -> p
RayMiss -> (Vec 0 0 0) -- fixme
clr = shade ri ray scn recurs 0
in (clr,p)
trace_packet :: Scene -> Ray -> Ray -> Ray -> Ray -> Flt -> Int -> PacketColor
trace_packet scn ray1 ray2 ray3 ray4 depth recurs =
let (Scene sld lights cam dtex bgcolor) = scn
PacketResult ri1 ri2 ri3 ri4 = packetint sld ray1 ray2 ray3 ray4 depth dtex
in PacketColor (shade ri1 ray1 scn recurs 0)
(shade ri2 ray2 scn recurs 0)
(shade ri3 ray3 scn recurs 0)
(shade ri4 ray4 scn recurs 0)