Rename xbus to xswiftbus

Summary:
I wanted to rename xbus because its relation to //swift// is not immediately clear from the name.

xswiftbus seems reasonable.

Reviewers: #swift_pilot_client, kbasan

Reviewed By: kbasan

Subscribers: kbasan, jenkins

Tags: #swift_pilot_client

Differential Revision: https://dev.swift-project.org/D14

src/xswiftbus/terrainprobe.cpp

@@ -0,0 +1,36 @@
+/* Copyright (C) 2017
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#include "terrainprobe.h"
+#include <XPLM/XPLMGraphics.h>
+#include <limits>
+
+namespace XSwiftBus
+{
+    CTerrainProbe::CTerrainProbe() : m_ref(XPLMCreateProbe(xplm_ProbeY)) {}
+
+    CTerrainProbe::~CTerrainProbe() { XPLMDestroyProbe(m_ref); }
+
+    double CTerrainProbe::getElevation(double degreesLatitude, double degreesLongitude, double metersAltitude) const
+    {
+        double x, y, z;
+        XPLMWorldToLocal(degreesLatitude, degreesLongitude, metersAltitude, &x, &y, &z);
+
+        XPLMProbeInfo_t probe;
+        probe.structSize = sizeof(probe);
+        auto result = XPLMProbeTerrainXYZ(m_ref, static_cast<float>(x), static_cast<float>(y), static_cast<float>(z), &probe);
+        if (result != xplm_ProbeHitTerrain)
+        {
+            return std::numeric_limits<double>::quiet_NaN();
+        }
+
+        XPLMLocalToWorld(probe.locationX, probe.locationY, probe.locationZ, &degreesLatitude, &degreesLongitude, &metersAltitude);
+        return metersAltitude;
+    }
+}