feat(ContextServrice): Added 'createGeoEntity’

src/context.d.ts

@@ -1,5 +1,5 @@
 /// <reference types="cesium" />
-import { Entity, EntityCollection, Cartographic, Cartesian3, Quaternion, JulianDate, ReferenceFrame } from './cesium/cesium-imports';
+import { Entity, EntityCollection, Cartographic, Cartesian3, Quaternion, Transforms, JulianDate, ReferenceFrame } from './cesium/cesium-imports';
 import { SerializedEntityState, SerializedEntityStateMap, ContextFrameState, GeolocationOptions } from './common';
 import { SessionService, SessionPort } from './session';
 import { Event } from './utils';
@@ -233,6 +233,28 @@ export declare class ContextService {
      * Get the cartographic position of an Entity
      */
     getEntityCartographic(entity?: Entity, cartographic?: Cartographic): Cartographic | undefined;
+    private _scratchMatrix3;
+    private _scratchMatrix4;
+    /**
+    * Create an entity that is positioned at the given cartographic location,
+    * with an orientation computed according to the given local to fixed frame converter.
+    *
+    * For the localFrameToFixedFrame parameter, Cesium provides the following:
+    *
+    * Cesium.Transforms.eastNorthUpToFixedFrame
+    * Cesium.Transforms.northEastDownToFixedFrame
+    * Cesium.Transforms.northUpEastToFixedFrame
+    * Cesium.Transforms.northWestUpToFixedFrame
+    *
+    * Additionally, argon.js provides:
+    *
+    * Argon.eastUpSouthToFixedFrame
+    *
+    * Alternative transform functions can be created with:
+    *
+    * Cesium.Transforms.localFrameToFixedFrameGenerator
+    */
+    createGeoEntity(cartographic: Cartographic, localFrameToFixedFrame: typeof Transforms.northUpEastToFixedFrame): Entity;
     /**
      * Create a new EntityPose instance to represent the pose of an entity
      * relative to a given reference frame. If no reference frame is specified,

src/context.ts

@@ -9,7 +9,9 @@ import {
     Cartesian3,
     Quaternion,
     Matrix4,
+    Matrix3,
     CesiumMath,
+    Transforms,
     JulianDate,
     ReferenceFrame,
     PerspectiveFrustum,
@@ -18,7 +20,7 @@ import {
 import {
     DEFAULT_NEAR_PLANE,
     DEFAULT_FAR_PLANE,
-    SerializedEntityState, 
+    SerializedEntityState,
     SerializedEntityStateMap,
     SubviewType,
     ContextFrameState,
@@ -521,6 +523,45 @@ export class ContextService {
         return undefined;
     }
 
+    private _scratchMatrix3 = new Matrix3;
+    private _scratchMatrix4 = new Matrix4;
+
+     /**
+     * Create an entity that is positioned at the given cartographic location,
+     * with an orientation computed according to the given local to fixed frame converter.
+     * 
+     * For the localFrameToFixedFrame parameter, Cesium provides the following:
+     * 
+     * Cesium.Transforms.eastNorthUpToFixedFrame
+     * Cesium.Transforms.northEastDownToFixedFrame
+     * Cesium.Transforms.northUpEastToFixedFrame
+     * Cesium.Transforms.northWestUpToFixedFrame
+     *  
+     * Additionally, argon.js provides:
+     * 
+     * Argon.eastUpSouthToFixedFrame
+     * 
+     * Alternative transform functions can be created with:
+     * 
+     * Cesium.Transforms.localFrameToFixedFrameGenerator
+     */
+    public createGeoEntity(cartographic: Cartographic, localFrameToFixedFrame: typeof Transforms.northUpEastToFixedFrame) : Entity {
+        // Convert the cartographic location to an ECEF position
+        var position = Cartesian3.fromDegrees(cartographic.longitude, cartographic.latitude, cartographic.height, undefined, this._scratchCartesian);
+
+        // compute an appropriate orientation on the surface of the earth
+        var transformMatrix = localFrameToFixedFrame(position, undefined, this._scratchMatrix4);
+        var rotationMatrix = Matrix4.getRotation(transformMatrix,this._scratchMatrix3)
+        var orientation = Quaternion.fromRotationMatrix(rotationMatrix, this._scratchQuaternion);
+
+        // create the entity
+        var entity = new Entity({
+            position,
+            orientation
+        });
+        return entity;
+    }
+
     /**
      * Create a new EntityPose instance to represent the pose of an entity
      * relative to a given reference frame. If no reference frame is specified,

src/utils.d.ts

@@ -1,11 +1,18 @@
 /// <reference types="cesium" />
 import { SerializedEntityState } from './common';
-import { Entity, JulianDate, PerspectiveFrustum, PerspectiveOffCenterFrustum, Quaternion, Cartesian3, ReferenceFrame, Matrix4 } from './cesium/cesium-imports';
+import { Entity, JulianDate, PerspectiveFrustum, PerspectiveOffCenterFrustum, Quaternion, Cartesian3, ReferenceFrame, Matrix4, Transforms } from './cesium/cesium-imports';
 export * from './utils/command-queue';
 export * from './utils/event';
 export * from './utils/message-channel';
 export { default as getEventSynthesizier } from './utils/ui-event-synthesizer';
 export { default as createEventForwarder } from './utils/ui-event-forwarder';
+/**
+ * Computes a 4x4 transformation matrix from a reference frame with an east-up-south axes centered at the provided origin to the provided ellipsoid's fixed reference frame. The local axes are defined as:
+ * The x axis points in the local east direction.
+ * The y axis points in the points in the direction of the ellipsoid surface normal which passes through the position..
+ * The z axis points in the local south direction.
+ */
+export declare const eastUpSouthToFixedFrame: Transforms.ConversionFunction;
 /**
  * Get array of ancestor reference frames of a Cesium Entity, ordered from
  * farthest ancestor to the passed frame, excluding the passed frame.

src/utils.ts

@@ -12,7 +12,8 @@ import {
     Quaternion,
     Cartesian3,
     ReferenceFrame,
-    Matrix4
+    Matrix4,
+    Transforms
 } from './cesium/cesium-imports'
 
 export * from './utils/command-queue';
@@ -21,6 +22,16 @@ export * from './utils/message-channel';
 export {default as getEventSynthesizier} from './utils/ui-event-synthesizer';
 export {default as createEventForwarder} from './utils/ui-event-forwarder';
 
+
+
+/**
+ * Computes a 4x4 transformation matrix from a reference frame with an east-up-south axes centered at the provided origin to the provided ellipsoid's fixed reference frame. The local axes are defined as:
+ * The x axis points in the local east direction.
+ * The y axis points in the points in the direction of the ellipsoid surface normal which passes through the position..
+ * The z axis points in the local south direction.
+ */
+export const eastUpSouthToFixedFrame = Transforms.localFrameToFixedFrameGenerator('east','up');
+
 /**
  * Get array of ancestor reference frames of a Cesium Entity, ordered from 
  * farthest ancestor to the passed frame, excluding the passed frame.

types/cesium/index.d.ts

@@ -4732,6 +4732,8 @@ declare module 'cesium' {
     }
 
     module Transforms {
+        type ConversionFunction = (origin: Cartesian3, ellipsoid?: Ellipsoid, result?: Matrix4) => Matrix4;
+        function localFrameToFixedFrameGenerator(firstAxis: string, secondAxis: string): ConversionFunction;
         function eastNorthUpToFixedFrame(origin: Cartesian3, ellipsoid?: Ellipsoid, result?: Matrix4): Matrix4;
         function northEastDownToFixedFrame(origin: Cartesian3, ellipsoid?: Ellipsoid, result?: Matrix4): Matrix4;
         function northUpEastToFixedFrame(origin: Cartesian3, ellipsoid?: Ellipsoid, result?: Matrix4): Matrix4;