module Camera where

import Basics
import Vectors
import Objects
import Data.Array 
import Trace
import World

cameraLooks vertical from to = Camera from n u v
    where n = normalized (to-from)
	  u = normalized vertical * n
	  v = u * n


render :: World -> Camera -> Scal -> Scal -> Int -> Int -> Frame

render world (Camera from n u v)
       fovx fovy
       width height =
       bitmap
    where bitmap = array ((0,0), (height-1, width-1)) $ 
		   do y <- [0..height-1]
		      x <- [0..width-1]
		      let fx = fromIntegral x
			  fy = fromIntegral y
		      let psi = fovx * (fx / floatWidth - 0.5) 
			  phi = fovy * (fy / floatHeight - 0.5)
			  h = rotateMatrix psi v `mulVec` n
			  direction = cos phi `scale` h + sin phi `scale` v
		      return ((y, x), traceRay 0 world from (normalized direction) [] 1)
	  floatWidth = fromIntegral width 
	  floatHeight = fromIntegral height