diff --git a/src/renderer.rs b/src/renderer.rs
index 26c3889..3d03950 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -19,7 +19,7 @@ use crate::{
     ray::Ray,
     scene::{Scene, SceneLightSample},
     scramble::owen4,
-    space_fill::{hilbert, morton},
+    space_fill::{hilbert_spiral, morton},
     timer::Timer,
     tracer::Tracer,
 };
@@ -128,16 +128,15 @@ impl<'a> Renderer<'a> {
                 let pow2 = upper_power_of_two(larger);
                 let buffer = hilbert_count; // For hilbert spiral.
                 (
-                    (bucket_count_x / 2, bucket_count_y / 2),
+                    (bucket_count_x as i32 / 2 - 1, bucket_count_y as i32 / 2 - 1),
                     (pow2 + buffer) * (pow2 + buffer),
                 )
             };
             for hilbert_spiral_i in 0..bucket_n {
-                let (bx, by) =
-                    crate::space_fill::hilbert_spiral::decode(hilbert_spiral_i, hilbert_count);
+                let (bx, by) = hilbert_spiral::decode(hilbert_spiral_i, hilbert_count);
 
-                let bx = middle_bucket.0 as i32 + bx;
-                let by = middle_bucket.1 as i32 + by;
+                let bx = middle_bucket.0 + bx;
+                let by = middle_bucket.1 + by;
                 if bx < 0 || by < 0 {
                     continue;
                 }
diff --git a/src/space_fill.rs b/src/space_fill.rs
index 8e06ea6..67a7de9 100644
--- a/src/space_fill.rs
+++ b/src/space_fill.rs
@@ -148,10 +148,10 @@ pub mod hilbert_spiral {
             let (hx, hy) = super::hilbert::decode(hilbert_i, hilbert_size);
             let a = hilbert_size - 1;
             match section {
-                0 => (hx, a - hy),
-                1 => (a - hy, hx),
-                2 => (a - hx, hy),
-                3 => (hy, a - hx),
+                0 => (hy, hx),
+                1 => (a - hx, a - hy),
+                2 => (a - hy, a - hx),
+                3 => (hx, hy),
                 _ => unreachable!(),
             }
         };
@@ -179,10 +179,10 @@ pub mod hilbert_spiral {
         let d = -(size as i32 / 2) + 1 + arm_n as i32;
 
         match arm {
-            0 => (d, -radius, 0),
-            1 => (radius, d, if arm_n == (size - 2) { 2 } else { 1 }),
-            2 => (-d, radius, 2),
-            3 => (-radius, -d, 3),
+            0 => (radius, d, 0),
+            1 => (-d, radius, if arm_n == (size - 2) { 2 } else { 1 }),
+            2 => (-radius, -d, 2),
+            3 => (d, -radius, 3),
             _ => unreachable!(),
         }
     }