From a3ebdcdbc38226daf2adb049bd4eb214397a0215 Mon Sep 17 00:00:00 2001
From: Jesse Mazzella <jesse.d.mazzella@nasa.gov>
Date: Thu, 3 Oct 2024 13:29:21 -0700
Subject: [PATCH 1/2] feat: add function to generate a seeded random value

---
 src/utils/random.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 src/utils/random.js

diff --git a/src/utils/random.js b/src/utils/random.js
new file mode 100644
index 00000000000..f8d82a9a056
--- /dev/null
+++ b/src/utils/random.js
@@ -0,0 +1,12 @@
+/**
+ * Generates a pseudo-random number based on a seed.
+ *
+ * @param {number} seed - The seed value to generate the random number.
+ * @returns {number} A pseudo-random number between 0 (inclusive) and 1 (exclusive).
+ */
+function seededRandom(seed = Date.now()) {
+  const x = Math.sin(seed) * 10000;
+  return x - Math.floor(x);
+}
+
+export { seededRandom };

From 51b0526955f9465ff49b118f18aac434a969ed6e Mon Sep 17 00:00:00 2001
From: Jesse Mazzella <jesse.d.mazzella@nasa.gov>
Date: Thu, 3 Oct 2024 13:30:08 -0700
Subject: [PATCH 2/2] fix: produce the same compass orientation per timestamp -
 helps for consistent visual tests

---
 example/imagery/plugin.js | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/example/imagery/plugin.js b/example/imagery/plugin.js
index 9d37bbc925a..7194e4724e6 100644
--- a/example/imagery/plugin.js
+++ b/example/imagery/plugin.js
@@ -20,6 +20,8 @@
  * at runtime from the About dialog for additional information.
  *****************************************************************************/
 
+import { seededRandom } from 'utils/random.js';
+
 const DEFAULT_IMAGE_SAMPLES = [
   'https://www.nasa.gov/wp-content/uploads/static/history/alsj/a16/AS16-117-18731.jpg',
   'https://www.nasa.gov/wp-content/uploads/static/history/alsj/a16/AS16-117-18732.jpg',
@@ -162,8 +164,8 @@ export default function () {
   };
 }
 
-function getCompassValues(min, max) {
-  return min + Math.random() * (max - min);
+function getCompassValues(min, max, timestamp) {
+  return min + seededRandom(timestamp) * (max - min);
 }
 
 function getImageSamples(configuration) {
@@ -283,9 +285,9 @@ function pointForTimestamp(timestamp, name, imageSamples, delay) {
     utc: Math.floor(timestamp / delay) * delay,
     local: Math.floor(timestamp / delay) * delay,
     url,
-    sunOrientation: getCompassValues(0, 360),
-    cameraAzimuth: getCompassValues(0, 360),
-    heading: getCompassValues(0, 360),
+    sunOrientation: getCompassValues(0, 360, timestamp),
+    cameraAzimuth: getCompassValues(0, 360, timestamp),
+    heading: getCompassValues(0, 360, timestamp),
     transformations: navCamTransformations,
     imageDownloadName
   };