diff --git a/src/gui.rs b/src/gui.rs
index 09d54de..dc8e1fa 100644
--- a/src/gui.rs
+++ b/src/gui.rs
@@ -7,7 +7,7 @@ const BUFFER_PROPORTION_MAX: f32 = 0.9;
 
 const RAYS_INIT: i32 = 100;
 const RAYS_MIN: i32 = 100;
-const RAYS_MAX: i32 = 1000;
+const RAYS_MAX: i32 = 10000;
 
 /// Manages all state required for rendering Dear ImGui over `Pixels`.
 pub(crate) struct Gui {
diff --git a/src/main.rs b/src/main.rs
index d09abc3..41e0030 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -163,7 +163,7 @@ impl State {
             let mut pixels = self.pixels.lock().unwrap();
             let frame = pixels.frame_mut();
             frame[i * 4..(i + 1) * 4].copy_from_slice(&rgba);
-            self.index = self.index + 1;
+            self.index = (self.index + 1) % (frame.len() / 4);
         }
     }