From 581af5c50f8c91752e44ff8cdb49663e2059f35e Mon Sep 17 00:00:00 2001
From: Rostyslav Hnatyshyn <rostyslav.hnatyshyn@gmail.com>
Date: Sat, 24 Sep 2022 19:16:07 -0700
Subject: [PATCH] Added randomRange, improve AA

---
 src/Maths.hs | 4 ++++
 src/Ray.hs   | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/Maths.hs b/src/Maths.hs
index c295df5..941a032 100644
--- a/src/Maths.hs
+++ b/src/Maths.hs
@@ -4,6 +4,7 @@ module Maths
     unitVector,
     randV3,
     rand,
+    randRange,
     reflect,
     refract,
     reflectance,
@@ -19,6 +20,9 @@ import System.Random
 rand :: (RandomGen g) => Rand g Double
 rand = getRandomR (-1.0, 1.0 :: Double)
 
+randRange :: (RandomGen g) => Double -> Double -> Rand g Double
+randRange a b = getRandomR (a, b :: Double)
+
 randV3 :: (RandomGen g) => Rand g (V3 Double)
 randV3 = do
   x <- rand
diff --git a/src/Ray.hs b/src/Ray.hs
index 28ed401..b38bfc0 100644
--- a/src/Ray.hs
+++ b/src/Ray.hs
@@ -25,8 +25,8 @@ calculateRayNormal r t = unitVector (rayAt r t ^-^ V3 0.0 0.0 1.0)
 
 buildRayAA :: (RandomGen g) => Double -> Double -> Double -> Double -> Camera -> Rand g Ray
 buildRayAA u v w h camera = do
-  ur <- rand
-  vr <- rand
+  ur <- randRange 0 1
+  vr <- randRange 0 1
   return $ buildRay ((u + ur) / w) ((v + vr) / h) camera
 
 buildRay :: Double -> Double -> Camera -> Ray