From 9c139ab5be3d9f3cacc4370e27d7f0abfa6c8f30 Mon Sep 17 00:00:00 2001
From: Dan Bagnell <daniel.p.bagnell@gmail.com>
Date: Mon, 3 Apr 2017 19:27:42 -0400
Subject: [PATCH] Update billboard Sandcastle example.

---
 Apps/Sandcastle/gallery/Billboards.html | 39 +++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/Apps/Sandcastle/gallery/Billboards.html b/Apps/Sandcastle/gallery/Billboards.html
index 2a2f623f8704..366e2b7c740b 100644
--- a/Apps/Sandcastle/gallery/Billboards.html
+++ b/Apps/Sandcastle/gallery/Billboards.html
@@ -79,7 +79,7 @@
 
 function sizeBillboardInMeters() {
     Sandcastle.declare(sizeBillboardInMeters);
-    
+
     var entity = viewer.entities.add({
         position : Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883),
         billboard : {
@@ -87,7 +87,7 @@
             sizeInMeters : true
         }
     });
-    
+
     viewer.zoomTo(entity);
 }
 
@@ -221,6 +221,29 @@
     });
 }
 
+var terrainProvider;
+function disableDepthTest() {
+    Sandcastle.declare(disableDepthTest);
+
+    terrainProvider = viewer.terrainProvider;
+    viewer.terrainProvider = new Cesium.CesiumTerrainProvider({
+        url : 'https://assets.agi.com/stk-terrain/world',
+        requestWaterMask : true,
+        requestVertexNormals : true
+    });
+    viewer.scene.globe.depthTestAgainstTerrain = true;
+
+    viewer.entities.add({
+        position : Cesium.Cartesian3.fromDegrees(-122.1958, 46.1915),
+        billboard : {
+            image : '../images/facility.gif',
+            heightReference : Cesium.HeightReference.CLAMP_TO_GROUND,
+            disableDepthTestDistance : Number.POSITIVE_INFINITY
+        }
+    });
+    viewer.zoomTo(viewer.entities);
+}
+
 Sandcastle.addToolbarMenu([{
     text : 'Add billboard',
     onselect : function() {
@@ -275,11 +298,23 @@
         addMarkerBillboards();
         Sandcastle.highlight(addMarkerBillboards);
     }
+}, {
+    text : 'Disable the depth test when clamped to ground',
+    onselect : function() {
+        disableDepthTest();
+        Sandcastle.highlight(disableDepthTest);
+    }
 }]);
 
 Sandcastle.reset = function () {
     viewer.camera.flyHome(0);
     viewer.entities.removeAll();
+
+    if (Cesium.defined(terrainProvider)) {
+        viewer.terrainProvider = terrainProvider;
+        terrainProvider = undefined;
+        viewer.scene.globe.depthTestAgainstTerrain = false;
+    }
 };
 //Sandcastle_End
     Sandcastle.finishedLoading();