From 5b99c1b2f561e4dd034867dffd82254766955c1d Mon Sep 17 00:00:00 2001
From: oterral <oterral@gmail.com>
Date: Thu, 2 Feb 2017 13:29:13 +0100
Subject: [PATCH] Use GroundPrimitive for line

---
 CHANGES.md              |  5 +++++
 Cesium.externs.js       | 20 +++++++++++++++++++-
 src/featureconverter.js | 36 ++++++++++++++++++++++++++----------
 3 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index bda0fda9d..cfd14f042 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,10 @@
 # Changelog
 
+# v 1.24
+
+* Changes
+  * Clamp line to the ground using Corridor geometry (experimental feature).
+
 # v 1.23 - 2016-01-04
 
 * Changes
diff --git a/Cesium.externs.js b/Cesium.externs.js
index d071bbcad..2be1a310b 100644
--- a/Cesium.externs.js
+++ b/Cesium.externs.js
@@ -1273,7 +1273,6 @@ Cesium.CircleOutlineGeometry = function(opt_opts) {};
  */
 Cesium.ColorGeometryInstanceAttribute = function() {};
 
-
 /**
  * @param {!Cesium.Color} color
  * @return {!Cesium.ColorGeometryInstanceAttribute}
@@ -1508,7 +1507,26 @@ Cesium.optionsRectangleGeometry;
  */
 Cesium.RectangleGeometry = function(opt_opts) {};
 
+/**
+ * @constructor
+ * @param {Cesium.optionsCorridorGeometry} opt_opts
+ * @extends {Cesium.Geometry}
+ */
+Cesium.CorridorGeometry = function(opt_opts) {};
 
+/**
+ * @typedef {{
+ * positions: !Array.<Cesium.Cartesian3>,
+ * width: (number|undefined),
+ * ellipsoid: (Cesium.Ellipsoid|undefined),
+ * granularity: (number|undefined),
+ * height: (number|undefined),
+ * extrudedHeight: (number|undefined),
+ * vertexFormat: number,
+ * cornerType: (number|undefined),
+ * }}
+ */
+Cesium.optionsCorridorGeometry;
 
 /**
  * @constructor
diff --git a/src/featureconverter.js b/src/featureconverter.js
index 584ebb900..fd7417f2b 100644
--- a/src/featureconverter.js
+++ b/src/featureconverter.js
@@ -350,21 +350,37 @@ olcs.FeatureConverter.prototype.olLineStringGeometryToCesium = function(layer, f
     material: this.olStyleToCesium(feature, olStyle, true)
   });
 
-  // Handle both color and width
-  var outlineGeometry = new Cesium.PolylineGeometry({
+  var geometryOptions = {
     // always update Cesium externs before adding a property
     positions: positions,
     width: this.extractLineWidthFromOlStyle(olStyle),
     vertexFormat: appearance.vertexFormat
-  });
+  };
+
+  var outlinePrimitive;
+  var heightReference = this.getHeightReference(layer, feature, olGeometry);
+
+  if (heightReference == Cesium.HeightReference.CLAMP_TO_GROUND) {
+    var color = this.extractColorFromOlStyle(olStyle, true);
+    outlinePrimitive = new Cesium.GroundPrimitive({
+      // always update Cesium externs before adding a property
+      geometryInstances: new Cesium.GeometryInstance({
+        geometry: new Cesium.CorridorGeometry(geometryOptions),
+        attributes : {
+          color : Cesium.ColorGeometryInstanceAttribute.fromColor(color)
+        }
+      })
+    });
+  } else {
+    outlinePrimitive = new Cesium.Primitive({
+      // always update Cesium externs before adding a property
+      geometryInstances: new Cesium.GeometryInstance({
+        geometry: new Cesium.PolylineGeometry(geometryOptions)
+      }),
+      appearance: appearance
+    });
+  }
 
-  var outlinePrimitive = new Cesium.Primitive({
-    // always update Cesium externs before adding a property
-    geometryInstances: new Cesium.GeometryInstance({
-      geometry: outlineGeometry
-    }),
-    appearance: appearance
-  });
   this.setReferenceForPicking(layer, feature, outlinePrimitive);
 
   return this.addTextStyle(layer, feature, olGeometry, olStyle,