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authorJakob L. Kreuze <zerodaysfordays@sdf.org>2020-07-20 15:23:45 -0400
committerJakob L. Kreuze <zerodaysfordays@sdf.org>2020-07-20 15:23:45 -0400
commitc747738b7b9de8f7218156893e82429a25a822a9 (patch)
tree2c68693e0469f4ea82fb0d04a1538931d8339dfe /cl-raytracer.lisp
parent79fb23ef37d3e98bad18f5211720393ce8cd9a52 (diff)
Fix `degrees->radians'.
Diffstat (limited to 'cl-raytracer.lisp')
-rw-r--r--cl-raytracer.lisp4
1 files changed, 2 insertions, 2 deletions
diff --git a/cl-raytracer.lisp b/cl-raytracer.lisp
index 23b5232..f30099a 100644
--- a/cl-raytracer.lisp
+++ b/cl-raytracer.lisp
@@ -121,7 +121,7 @@ format (PPM), writing the result to `(current-output-port)'."
(defun to-radians (d)
"Convert D, a value in degrees, to radians."
- (* d (/ PI 360)))
+ (* d (/ PI 180)))
;;;
@@ -285,7 +285,7 @@ format (PPM), writing the result to `(current-output-port)'."
(defun coord-to-ray (x y)
"Return the ray corresponding to the point X, Y on the viewport plane."
(let* ((dist 1.0)
- (top (* dist (tan (to-radians camera-fov))))
+ (top (* dist (tan (/ (to-radians camera-fov) 2))))
(right (* top image-aspect-ratio))
(bottom (- top))
(left (- right))