Move to double to avoid rounding error

This rounding errors seems to happen when adding floats very close to 1
to a relatively large number.

325.0 + 0.99999034 = 326.0

This is a problem as this sample should be counted at the 325 pixel.
However this will be a lesser problem when filtering is implemented.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/sample/mod.rs b/src/sample/mod.rs
index 84ac755..5095501 100644
--- a/src/sample/mod.rs
+++ b/src/sample/mod.rs
@@ -1,6 +1,5 @@
-use crate::Float;
+use crate::{M_PI, Float};
 use crate::core::{Vector3f, Vector2f};
-use std::f32::consts::PI;
 
 mod uniform;
 
@@ -20,7 +19,7 @@ pub trait Sampler {
     fn get_unit_vector(&mut self) -> Vector3f {
         let s2d = self.get_sample_2d();
 
-        let lambda = distribute_between(s2d.x, -PI, PI);
+        let lambda = distribute_between(s2d.x, -M_PI, M_PI);
         let costheta = 2.0 * s2d.y - 1.0;
         let sintheta = costheta.acos().sin();