From 482379eb3fefca1d3d28cf8a2cc879f8c6ad0841 Mon Sep 17 00:00:00 2001
From: Omar Shehata <omar@cesium.com>
Date: Thu, 19 Sep 2019 14:38:55 -0400
Subject: [PATCH] Make dynamic polyline create the given arcType

---
 CHANGES.md                                      |  1 +
 Source/DataSources/PolylineGeometryUpdater.js   |  6 +++++-
 .../DataSources/PolylineGeometryUpdaterSpec.js  | 17 +++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/CHANGES.md b/CHANGES.md
index 127a05c942b5..36556f7f973d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -23,6 +23,7 @@ Change Log
 * 3D Tiles geometric error now scales with transform. [#8182](https://github.com/AnalyticalGraphicsInc/cesium/pull/8182)
 * Fixed per-feature post processing from sometimes selecting the wrong feature. [#7929](https://github.com/AnalyticalGraphicsInc/cesium/pull/7929)
 * Fixed labels not showing for individual entities in data sources when clustering is enabled. [#6087](https://github.com/AnalyticalGraphicsInc/cesium/issues/6087)
+* Fixed a bug where dynamic polylines did not use the given arcType. [#8191](https://github.com/AnalyticalGraphicsInc/cesium/issues/8191)
 
 ### 1.61 - 2019-09-03
 
diff --git a/Source/DataSources/PolylineGeometryUpdater.js b/Source/DataSources/PolylineGeometryUpdater.js
index 1ce073bea471..f29323f3dc1c 100644
--- a/Source/DataSources/PolylineGeometryUpdater.js
+++ b/Source/DataSources/PolylineGeometryUpdater.js
@@ -712,7 +712,11 @@ define([
             generateCartesianArcOptions.positions = positions;
             generateCartesianArcOptions.granularity = Property.getValueOrUndefined(polyline._granularity, time);
             generateCartesianArcOptions.height = PolylinePipeline.extractHeights(positions, globe.ellipsoid);
-            positions = PolylinePipeline.generateCartesianArc(generateCartesianArcOptions);
+            if (arcType === ArcType.GEODESIC) {
+                positions = PolylinePipeline.generateCartesianArc(generateCartesianArcOptions);
+            } else {
+                positions = PolylinePipeline.generateCartesianRhumbArc(generateCartesianArcOptions);
+            }
         }
 
         line.show = true;
diff --git a/Specs/DataSources/PolylineGeometryUpdaterSpec.js b/Specs/DataSources/PolylineGeometryUpdaterSpec.js
index 0c4bb0ca6ac0..659307d78c40 100644
--- a/Specs/DataSources/PolylineGeometryUpdaterSpec.js
+++ b/Specs/DataSources/PolylineGeometryUpdaterSpec.js
@@ -831,6 +831,23 @@ describe('DataSources/PolylineGeometryUpdater', function() {
         expect(scene.groundPrimitives.length).toBe(0);
     });
 
+    it('calls generateCartesianRhumbArc for RHUMB arcType', function() {
+        var entity = createBasicPolyline();
+        entity.polyline.width = createDynamicProperty(1);
+        entity.polyline.arcType = ArcType.RHUMB;
+
+        var updater = new PolylineGeometryUpdater(entity, scene);
+        var dynamicUpdater = updater.createDynamicUpdater(scene.primitives, scene.groundPrimitives);
+        spyOn(PolylinePipeline, 'generateCartesianRhumbArc').and.callThrough();
+        dynamicUpdater.update(time);
+        expect(PolylinePipeline.generateCartesianRhumbArc).toHaveBeenCalled();
+        dynamicUpdater.destroy();
+        updater.destroy();
+
+        expect(scene.primitives.length).toBe(0);
+        expect(scene.groundPrimitives.length).toBe(0);
+    });
+
     it('arcType GEODESIC with undefined globe does not call generateCartesianArc', function() {
         if (!Entity.supportsPolylinesOnTerrain(scene)) {
             return;