fix type

2 files changed, 4 insertions, 4 deletions

diff --git a/src/global.rs b/src/global.rs
index b322746..9357920 100644
--- a/src/global.rs
+++ b/src/global.rs
@@ -8,9 +8,9 @@ pub const IMG_WIDTH: usize = 400;
 const IMG_HEIGHT_TMP: usize = (IMG_WIDTH as f32 / ASPECT_RATIO) as usize;
 pub const IMG_HEIGHT: usize = if (IMG_HEIGHT_TMP < 1) { 1 } else { IMG_HEIGHT_TMP };
 
-pub const VIEWPORT_HEIGHT: usize = 2;
-pub const VIEWPORT_WIDTH: usize = VIEWPORT_HEIGHT * (IMG_WIDTH / IMG_HEIGHT);
-pub const FOCAL_LENGTH: f32 = 2.0;
+pub const VIEWPORT_HEIGHT: f32 = 2.0;
+pub const VIEWPORT_WIDTH: f32 = VIEWPORT_HEIGHT * (IMG_WIDTH as f32 / IMG_HEIGHT as f32);
+pub const FOCAL_LENGTH: f32 = 1.0;
 pub const CAMERA_CENTER: Point3 = Point3 { x: 0f32, y: 0f32, z: 0f32 };
 
 #[derive(Debug, Copy, Clone)]
diff --git a/src/renderer.rs b/src/renderer.rs
index 7e46834..3f94437 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -16,7 +16,7 @@ fn hit_sphere(center: &Point3, radius: f32, ray: &Ray) -> bool {
     let oc = center.sub(&ray.origin);
     let a = ray.direction.dot_prod(&ray.direction);
     let b = -2.0 * ray.direction.dot_prod(&oc);
-    let mut c  = oc.dot_prod(&oc) - radius * radius;
+    let c  = oc.dot_prod(&oc) - radius * radius;
     let discriminant = b * b - 4.0 * a * c;
     discriminant >= 0.0
 }