Added some docs

src/setup/label.ts

@@ -11,12 +11,18 @@ export interface PointOfInterest {
 
 export class Label {
   parent: THREE.Object3D;
-  parentRadius: number;
+  radius: number;
   elements: CSS2DObject[];
 
-  constructor(parent: THREE.Object3D, parentRadius: number) {
+  /**
+   * Represents a collection of labels for a celestial body.
+   * @constructor
+   * @param parent - Parent object for the labels.
+   * @param radius - Distance between parent centre and label positions.
+   */
+  constructor(parent: THREE.Object3D, radius: number) {
     this.parent = parent;
-    this.parentRadius = parentRadius;
+    this.radius = radius;
     this.elements = [];
   }
 
@@ -46,18 +52,28 @@ export class Label {
     this.elements.push(label);
   };
 
+  /**
+   * Show all point-of-interest labels.
+   */
   showPOI = () => {
     this.elements.forEach((label) => {
       label.layers.enable(LAYERS.POILabel);
     });
   };
 
+  /**
+   * Hides all point-of-interest labels.
+   */
   hidePOI = () => {
     this.elements.forEach((label) => {
       label.layers.disable(LAYERS.POILabel);
     });
   };
 
+  /**
+   * Update label opacities depending on camera position and direction.
+   * @param camera - Camera used to calculate distance and direction to labels.
+   */
   update = (camera: THREE.Camera) => {
     this.elements.forEach((label) => {
       const rotationOpacity = this.getRotationOpacity(camera, label);
@@ -67,16 +83,21 @@ export class Label {
     });
   };
 
-  rotateLabel = (y: number, z: number) => {
-    const vector = new THREE.Vector3(this.parentRadius, 0, 0);
+  private rotateLabel = (y: number, z: number) => {
+    const vector = new THREE.Vector3(this.radius, 0, 0);
     vector.applyAxisAngle(new THREE.Vector3(0, 1, 0), y);
     vector.applyAxisAngle(new THREE.Vector3(0, 0, 1), z);
     return vector;
   };
 
-  getRotationOpacity = (camera: THREE.Camera, label: CSS2DObject): number => {
+  private getRotationOpacity = (
+    camera: THREE.Camera,
+    label: CSS2DObject
+  ): number => {
     const hideThreshold = 1;
     const fadeThreshold = 0.75;
+
+    // Calculates the great-circle distance between the camera and label with normalised vectors.
     const cameraVector = camera.position.clone().normalize();
     const labelVector = label.position.clone().normalize();
     const delta = Math.acos(cameraVector.dot(labelVector));
@@ -90,9 +111,9 @@ export class Label {
     }
   };
 
-  getDistanceOpacity = (camera: THREE.Camera): number => {
-    const hideThreshold = this.parentRadius * 12;
-    const fadeThreshold = this.parentRadius * 8;
+  private getDistanceOpacity = (camera: THREE.Camera): number => {
+    const hideThreshold = this.radius * 12;
+    const fadeThreshold = this.radius * 8;
     const distance = camera.position.length();
 
     if (distance > hideThreshold) {

src/setup/loading.ts

@@ -1,3 +1,4 @@
+// List of prompts to display whilst loading textures.
 const loadingPrompts = [
   "Detecting neutrinos",
   "Forming event horizons",
@@ -10,14 +11,18 @@ const loadingPrompts = [
   "Increasing entropy",
 ];
 
-const loadingTextInterval = setInterval(() => {
+// Switch loading screen text every 2 seconds.
+const switchLoadText = setInterval(() => {
   const index = Math.floor(Math.random() * loadingPrompts.length);
   const loadText = document.getElementById("loader-text") as HTMLDivElement;
   loadText.textContent = `${loadingPrompts[index]}...`;
 }, 2000);
 
+/**
+ * Updates the loading screen once textures are loaded.
+ */
 export const onLoaded = () => {
-  clearInterval(loadingTextInterval);
+  clearInterval(switchLoadText);
   const loadText = document.getElementById("loader-text") as HTMLDivElement;
   loadText.textContent = "Click to continue...";
 

src/setup/planetary-object.ts

@@ -88,20 +88,28 @@ export class PlanetaryObject {
       this.mesh.add(this.createAtmosphereMesh());
     }
 
-    this.initLabels(body);
+    this.initLabels(body.labels);
   }
 
-  initLabels = (body: Body) => {
+  /**
+   * Creates label objects for each point-of-interest.
+   * @param labels - List of labels to display.
+   */
+  private initLabels = (labels?: PointOfInterest[]) => {
     this.labels = new Label(this.mesh, this.radius);
 
-    if (body.labels) {
-      body.labels.forEach((poi) => {
+    if (labels) {
+      labels.forEach((poi) => {
         this.labels.createPOILabel(poi);
       });
     }
   };
 
-  loadTextures(textures: TexturePaths) {
+  /**
+   * Prepare and load textures.
+   * @param textures - Object of texture paths to load.
+   */
+  private loadTextures(textures: TexturePaths) {
     this.map = loadTexture(textures.map);
     if (textures.bump) {
       this.bumpMap = loadTexture(textures.bump);
@@ -117,7 +125,11 @@ export class PlanetaryObject {
     }
   }
 
-  createMesh = () => {
+  /**
+   * Creates the main mesh object with textures.
+   * @returns celestial body mesh.
+   */
+  private createMesh = () => {
     if (this.type === "ring") {
       return createRingMesh(this.map);
     }
@@ -156,7 +168,11 @@ export class PlanetaryObject {
     return sphere;
   };
 
-  createAtmosphereMesh = () => {
+  /**
+   * Creates the atmosphere mesh object with textures.
+   * @returns atmosphere mesh.
+   */
+  private createAtmosphereMesh = () => {
     const geometry = new THREE.SphereGeometry(this.radius + 0.0005, 64, 64);
 
     const material = new THREE.MeshPhongMaterial({
@@ -174,14 +190,18 @@ export class PlanetaryObject {
     return sphere;
   };
 
-  getRotation = (elapsedTime: number) => {
+  private getRotation = (elapsedTime: number) => {
     return this.daylength ? (elapsedTime * timeFactor) / this.daylength : 0;
   };
 
-  getOrbitRotation = (elapsedTime: number) => {
+  private getOrbitRotation = (elapsedTime: number) => {
     return this.daylength ? (elapsedTime * timeFactor) / (this.period * 24) : 0;
   };
 
+  /**
+   * Updates orbital position and rotation.
+   * @param elapsedTime - number of seconds elapsed.
+   */
   tick = (elapsedTime: number) => {
     // Convert real-time seconds to rotation.
     const rotation = this.getRotation(elapsedTime);
@@ -199,6 +219,9 @@ export class PlanetaryObject {
     }
   };
 
+  /**
+   * @returns the minimum orbital control camera distance allowed.
+   */
   getMinDistance = (): number => {
     return this.radius * 3.5;
   };