Added the gallery

crates/resolved-cli/tests/cli.rs

@@ -120,6 +120,34 @@ fn example_scene_on_gpu_and_cpu() {
     );
 }
 
+#[test]
+fn pretty_previews_lift_the_darks_and_leave_space_black() {
+    let preview = |pretty: bool| {
+        let path = out_dir().join(format!("preview-pretty-{pretty}.png"));
+        let path_str = path.to_str().unwrap();
+        let mut args = vec![
+            "render",
+            "--scene",
+            "examples/scenes/boxwing.toml",
+            "--preview",
+            path_str,
+        ];
+        if pretty {
+            args.push("--pretty");
+        }
+        let result = resolved(&args);
+        assert!(result.status.success(), "{result:?}");
+        image::open(&path).unwrap().into_rgb8()
+    };
+    let (raw, pretty) = (preview(false), preview(true));
+    // Space is the bias, black either way.
+    assert_eq!(raw.get_pixel(0, 0).0, [0; 3]);
+    assert_eq!(pretty.get_pixel(0, 0).0, [0; 3]);
+    // Earth's dayside below the limb, well short of saturation: brighter when pretty.
+    let (r, p) = (raw.get_pixel(0, 1079).0, pretty.get_pixel(0, 1079).0);
+    assert!((0..3).all(|k| p[k] > r[k]), "raw {r:?}, pretty {p:?}");
+}
+
 #[cfg(feature = "astrokit")]
 #[test]
 fn lunar_eclipse_darkens_the_moon() {