feat: add interaction primitives

build/typescript/Camera.d.ts

@@ -11,14 +11,13 @@ export default class Camera {
     private context;
     private camera;
     private cameraControls;
-    private followMesh?;
+    private followTarget?;
     /**
      * @param {Object} context The simulation context
      */
     constructor(context: SimulationContext);
     /**
-     * Move the camera to follow a SpaceObject as it moves. Currently only works
-     * for non-particlesystems.
+     * Move the camera to follow a SpaceObject as it moves.
      * @param {SpaceObject} obj SpaceObject to follow.
      * @param {Array.<Number>} position Position of the camera with respect to
      * the object.

build/typescript/Camera.js

@@ -37,8 +37,8 @@ var Camera = /** @class */ (function () {
     function Camera(context) {
         // TODO(ian): Accept either context or container
         this.context = context;
-        // Optional mesh that we are following.
-        this.followMesh = undefined;
+        // Optional object that we are following.
+        this.followTarget = undefined;
         var containerWidth = this.context.container.width;
         var containerHeight = this.context.container.height;
         var camera = new THREE.PerspectiveCamera(50, containerWidth / containerHeight, (0, Scale_1.rescaleNumber)(0.00001), (0, Scale_1.rescaleNumber)(2000));
@@ -67,35 +67,32 @@ var Camera = /** @class */ (function () {
         this.cameraControls = controls;
     }
     /**
-     * Move the camera to follow a SpaceObject as it moves. Currently only works
-     * for non-particlesystems.
+     * Move the camera to follow a SpaceObject as it moves.
      * @param {SpaceObject} obj SpaceObject to follow.
      * @param {Array.<Number>} position Position of the camera with respect to
      * the object.
      */
     Camera.prototype.followObject = function (obj, position) {
-        var followMesh = obj.get3jsObjects()[0];
         this.cameraControls.enablePan = false;
         var rescaled = (0, Scale_1.rescaleArray)(position);
         this.camera.position.add(new THREE.Vector3(rescaled[0], rescaled[1], rescaled[2]));
         this.cameraControls.update();
-        this.followMesh = followMesh;
+        this.followTarget = obj;
     };
     /**
      * Stop the camera from following the object.
      */
     Camera.prototype.stopFollowingObject = function () {
-        if (this.followMesh) {
-            this.followMesh.remove(this.camera);
-            this.followMesh = undefined;
+        if (this.followTarget) {
+            this.followTarget = undefined;
             this.cameraControls.enablePan = true;
         }
     };
     /**
      * @returns {boolean} True if camera is following object.
      */
     Camera.prototype.isFollowingObject = function () {
-        return !!this.followMesh;
+        return !!this.followTarget;
     };
     /**
      * @returns {THREE.PerspectiveCamera} The THREE.js camera object.
@@ -114,7 +111,8 @@ var Camera = /** @class */ (function () {
      */
     Camera.prototype.update = function () {
         if (this.isFollowingObject()) {
-            var newpos = this.followMesh.position.clone();
+            var _a = this.followTarget.getPosition(this.context.simulation.getJd()), x = _a[0], y = _a[1], z = _a[2];
+            var newpos = new THREE.Vector3(x, y, z);
             var offset = newpos.clone().sub(this.cameraControls.target);
             this.camera.position.add(offset);
             this.cameraControls.target.set(newpos.x, newpos.y, newpos.z);

build/typescript/Coordinates.js

@@ -42,7 +42,7 @@ var Coordinates = /** @class */ (function () {
     Coordinates.getNutationAndObliquity = function (jd) {
         if (jd === void 0) { jd = J2000; }
         var t = (jd - J2000) / 36525;
-        var omega = Units_1["default"].rad(125.04452 - 1934.136261 * t + 0.0020708 * t * t + (t * t + t) / 450000);
+        var omega = Units_1["default"].rad(125.04452 - 1934.136261 * t + 0.0020708 * t * t + (t * t * t) / 450000);
         var Lsun = Units_1["default"].rad(280.4665 + 36000.7698 * t);
         var Lmoon = Units_1["default"].rad(218.3165 + 481267.8813 * t);
         var nutation = (-17.2 / 3600) * Math.sin(omega) -

build/typescript/Ephem.js

@@ -217,16 +217,16 @@ var Ephem = /** @class */ (function () {
         var n = this.getUnsafe('n');
         var GM = this.getUnsafe('GM');
         var period = this.getUnsafe('period');
-        if (!isDef(period) && isDef(a)) {
-            if (!isDef(GM)) {
-                throw new Error('Expected ephemeris attribute GM to be set');
-            }
-            period =
-                (2 * Math.PI * Math.sqrt((aMeters * aMeters * aMeters) / GM)) /
-                    SECONDS_IN_DAY;
-            this.set('period', period);
-        }
         if (e < 1.0) {
+            if (!isDef(period) && isDef(a)) {
+                if (!isDef(GM)) {
+                    throw new Error('Expected ephemeris attribute GM to be set');
+                }
+                period =
+                    (2 * Math.PI * Math.sqrt((aMeters * aMeters * aMeters) / GM)) /
+                        SECONDS_IN_DAY;
+                this.set('period', period);
+            }
             // Only work with mean motion for elliptical orbits.
             if (isDef(period) && !isDef(n)) {
                 // Set radians

build/typescript/EphemPresets.js

@@ -59,7 +59,7 @@ exports.EphemPresets = {
     }, 'deg', true /* locked */),
     MOON: new Ephem_1.Ephem({
         // https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html
-        GM: 0.3986e15,
+        GM: Ephem_1.GM.EARTH_MOON,
         // Geocentric
         // https://ssd.jpl.nasa.gov/horizons.cgi#results
         epoch: 2458621.5,

build/typescript/EphemerisTable.js

@@ -206,8 +206,11 @@ var EphemerisTable = /** @class */ (function () {
         var stopIndex = startIndex + Number(this.interpolationOrder);
         if (stopIndex >= this.data.length) {
             stopIndex = this.data.length - 1;
-            if (this.data.length > halfSampleSize) {
-                startIndex = stopIndex - halfSampleSize;
+            if (this.data.length > this.interpolationOrder) {
+                startIndex = stopIndex - this.interpolationOrder;
+            }
+            else {
+                startIndex = 0;
             }
         }
         return { startIndex: startIndex, stopIndex: stopIndex };

build/typescript/Interaction.d.ts

@@ -0,0 +1,23 @@
+import type { Coordinate3d } from './Coordinates';
+import type { SpaceObject } from './SpaceObject';
+export interface ScreenPosition {
+    x: number;
+    y: number;
+}
+export interface PickCandidate {
+    object: SpaceObject;
+    point?: Coordinate3d;
+    radiusPx: number;
+    screen: ScreenPosition;
+}
+interface Object3dLike {
+    parent?: Object3dLike | null;
+    uuid: string;
+}
+export declare function getNormalizedPointer(screen: ScreenPosition, width: number, height: number): ScreenPosition;
+export declare function findParentPickMatch(target: Object3dLike | null | undefined, objectsByUuid: Map<string, SpaceObject>): SpaceObject | undefined;
+export declare function findClosestPickCandidate(screen: ScreenPosition, candidates: PickCandidate[]): {
+    candidate: PickCandidate;
+    distancePx: number;
+} | undefined;
+export {};

build/typescript/Interaction.js

@@ -0,0 +1,42 @@
+"use strict";
+exports.__esModule = true;
+exports.findClosestPickCandidate = exports.findParentPickMatch = exports.getNormalizedPointer = void 0;
+function getNormalizedPointer(screen, width, height) {
+    return {
+        x: (screen.x / width) * 2 - 1,
+        y: -(screen.y / height) * 2 + 1
+    };
+}
+exports.getNormalizedPointer = getNormalizedPointer;
+function findParentPickMatch(target, objectsByUuid) {
+    var _a;
+    var current = target;
+    while (current) {
+        var matched = objectsByUuid.get(current.uuid);
+        if (matched) {
+            return matched;
+        }
+        current = (_a = current.parent) !== null && _a !== void 0 ? _a : undefined;
+    }
+    return undefined;
+}
+exports.findParentPickMatch = findParentPickMatch;
+function findClosestPickCandidate(screen, candidates) {
+    var bestMatch;
+    candidates.forEach(function (candidate) {
+        var dx = candidate.screen.x - screen.x;
+        var dy = candidate.screen.y - screen.y;
+        var distancePx = Math.hypot(dx, dy);
+        if (distancePx > candidate.radiusPx) {
+            return;
+        }
+        if (!bestMatch || distancePx < bestMatch.distancePx) {
+            bestMatch = {
+                candidate: candidate,
+                distancePx: distancePx
+            };
+        }
+    });
+    return bestMatch;
+}
+exports.findClosestPickCandidate = findClosestPickCandidate;

build/typescript/RotatingObject.d.ts

@@ -24,6 +24,7 @@ export declare class RotatingObject extends SpaceObject {
      * @return {Array.<THREE.Object>} A list of THREE.js objects
      */
     get3jsObjects(): THREE.Object3D[];
+    getPrimaryObject3js(): THREE.Object3D | undefined;
     /**
      * Begin rotating this object.
      */

build/typescript/RotatingObject.js

@@ -191,6 +191,9 @@ var RotatingObject = /** @class */ (function (_super) {
         ret.unshift(this._obj);
         return ret;
     };
+    RotatingObject.prototype.getPrimaryObject3js = function () {
+        return this._obj;
+    };
     /**
      * Begin rotating this object.
      */

build/typescript/Simulation.d.ts

@@ -25,6 +25,25 @@ interface DebugOptions {
     showGrid?: boolean;
     showStats?: boolean;
 }
+export interface InteractionOptions {
+    enableClick?: boolean;
+    enableHover?: boolean;
+    pickRadiusPx?: number;
+    particlePickRadiusPx?: number;
+}
+export declare type PickSource = 'raycast' | 'screen-proximity';
+export declare type PickKind = 'object';
+export interface PickResult {
+    object: SpaceObject;
+    source: PickSource;
+    kind: PickKind;
+    point?: Coordinate3d;
+    screen: {
+        x: number;
+        y: number;
+    };
+    distancePx: number;
+}
 interface SpacekitOptions {
     basePath: string;
     startDate?: Date;
@@ -97,6 +116,7 @@ export declare class Simulation {
     private useLightSources;
     private lightPosition?;
     private subscribedObjects;
+    private objectRegistry;
     private particles;
     private stats?;
     private fps;
@@ -108,6 +128,14 @@ export declare class Simulation {
     private scene;
     private renderer;
     private composer?;
+    onObjectClick?: (result: PickResult, ev: MouseEvent) => void;
+    onObjectHover?: (result: PickResult | undefined, ev: PointerEvent) => void;
+    private interactionOptions;
+    private hoveredObject?;
+    private selectedObject?;
+    private interactionListenersInstalled;
+    private raycaster;
+    private pointerNdc;
     /**
      * @param {HTMLCanvasElement} simulationElt The container for this simulation.
      * @param {Object} options for simulation
@@ -163,6 +191,31 @@ export declare class Simulation {
      * @private
      */
     private initPasses;
+    /**
+     * @private
+     * Installs DOM event handlers for object interaction.
+     */
+    private installInteractionListeners;
+    /**
+     * @private
+     * Gets the pointer position relative to the renderer's canvas.
+     */
+    private getCanvasRelativePosition;
+    /**
+     * @private
+     * Handles click selection on the renderer canvas.
+     */
+    private handleCanvasClick;
+    /**
+     * @private
+     * Handles hover interactions on the renderer canvas.
+     */
+    private handleCanvasPointerMove;
+    /**
+     * @private
+     * Clears hover state when the pointer leaves the renderer canvas.
+     */
+    private handleCanvasPointerLeave;
     /**
      * @private
      */
@@ -261,6 +314,39 @@ export declare class Simulation {
      * @see {NaturalSatellites}
      */
     loadNaturalSatellites(): Promise<NaturalSatellites>;
+    /**
+     * Configures interaction handlers for the simulation canvas.
+     * @param {Object} options Interaction options
+     */
+    configureInteraction(options?: InteractionOptions): void;
+    /**
+     * Gets the current list of registered space objects in the visualization.
+     * @return {SpaceObject[]} Space objects currently managed by the simulation
+     */
+    getObjects(): SpaceObject[];
+    /**
+     * Gets a registered space object by id.
+     * @param {String} id Space object id
+     * @return {SpaceObject | undefined} Matching object, if any
+     */
+    getObjectById(id: string): SpaceObject | undefined;
+    /**
+     * Attempts to pick a space object at the given screen coordinates.
+     * @param {Number} clientX Pointer x position in client coordinates
+     * @param {Number} clientY Pointer y position in client coordinates
+     * @return {PickResult | undefined} Picked object details
+     */
+    pick(clientX: number, clientY: number): PickResult | undefined;
+    /**
+     * Sets the selected space object, or clears selection if target is omitted.
+     * @param {SpaceObject | String | undefined} target SpaceObject or id
+     */
+    selectObject(target?: SpaceObject | string): void;
+    /**
+     * Gets the currently selected space object.
+     * @return {SpaceObject | undefined} Selected object, if any
+     */
+    getSelectedObject(): SpaceObject | undefined;
     /**
      * Installs a scroll handler that only renders the visualization while it is
      * in the user's viewport.