diff --git a/rtiow/src/renderer.rs b/rtiow/src/renderer.rs
index 5355e9d..ce4583a 100644
--- a/rtiow/src/renderer.rs
+++ b/rtiow/src/renderer.rs
@@ -294,16 +294,8 @@ enum Request {
 }
 
 enum Response {
-    Pixel {
-        x: usize,
-        y: usize,
-        pixel: Vec3,
-    },
-    Line {
-        width: usize,
-        y: usize,
-        pixels: Vec<Vec3>,
-    },
+    Pixel { x: usize, y: usize, pixel: Vec3 },
+    Line { y: usize, pixels: Vec<Vec3> },
 }
 
 static PIXEL_COUNT: AtomicUsize = AtomicUsize::new(0);
@@ -341,12 +333,16 @@ fn render_worker(
                 Request::Line { width, y } => {
                     trace!("tid {} width {} y {}", tid, width, y);
                     let pixels = (0..width).map(|x| render_pixel(scene, x, y)).collect();
-                    output_chan.send(Response::Line { width, y, pixels });
+                    output_chan
+                        .send(Response::Line { y, pixels })
+                        .expect("failed to send pixel response");
                 }
                 Request::Pixel { x, y } => {
                     trace!("tid {} x {} y {}", tid, x, y);
                     let pixel = render_pixel(scene, x, y);
-                    output_chan.send(Response::Pixel { x, y, pixel });
+                    output_chan
+                        .send(Response::Pixel { x, y, pixel })
+                        .expect("failed to send line response");
                 }
             },
         }
@@ -378,12 +374,16 @@ pub fn render(scene: Scene, output_dir: &Path) -> std::result::Result<(), std::i
         let batch_line_requests = true;
         if batch_line_requests {
             for y in 0..h {
-                pixel_req_tx.send(Request::Line { width: w, y });
+                pixel_req_tx
+                    .send(Request::Line { width: w, y })
+                    .expect("failed to send line request");
             }
         } else {
             for y in 0..h {
                 for x in 0..w {
-                    pixel_req_tx.send(Request::Pixel { x, y });
+                    pixel_req_tx
+                        .send(Request::Pixel { x, y })
+                        .expect("failed to send pixel request");
                 }
             }
         }
@@ -435,11 +435,7 @@ pub fn render(scene: Scene, output_dir: &Path) -> std::result::Result<(), std::i
                     ]),
                 );
             }
-            Response::Line {
-                width: _,
-                y,
-                pixels,
-            } => {
+            Response::Line { y, pixels } => {
                 for (x, pixel) in pixels.iter().enumerate() {
                     let y_inv = scene.height - y - 1;
                     img.put_pixel(