fix crash on mac when sixense DLL can't be loaded

plugins/hifiSixense/src/SixenseManager.cpp

@@ -13,6 +13,9 @@
 
 #ifdef HAVE_SIXENSE
 #include <sixense.h>
+#else
+#define SIXENSE_FAILURE -1
+#define SIXENSE_SUCCESS 0
 #endif
 
 #include <QCoreApplication>
@@ -43,6 +46,14 @@ static const unsigned int BUTTON_TRIGGER = 1U << 8;
 
 const glm::vec3 SixenseManager::DEFAULT_AVATAR_POSITION { -0.25f, -0.35f, -0.3f }; // in hydra frame
 const float SixenseManager::CONTROLLER_THRESHOLD { 0.35f };
+bool SixenseManager::_sixenseLoaded = false;
+
+#define BAIL_IF_NOT_LOADED \
+    if (!_sixenseLoaded) { \
+        return; \
+    }
+
+
 
 const QString SixenseManager::NAME = "Sixense";
 const QString SixenseManager::HYDRA_ID_STRING = "Razer Hydra";
@@ -89,11 +100,12 @@ void SixenseManager::activate() {
     userInputMapper->registerDevice(_inputDevice);
 
     loadSettings();
-    sixenseInit();
+    _sixenseLoaded = (sixenseInit() == SIXENSE_SUCCESS);
 #endif
 }
 
 void SixenseManager::deactivate() {
+    BAIL_IF_NOT_LOADED
     InputPlugin::deactivate();
 
 #ifdef HAVE_SIXENSE
@@ -114,12 +126,14 @@ void SixenseManager::deactivate() {
 }
 
 void SixenseManager::setSixenseFilter(bool filter) {
+    BAIL_IF_NOT_LOADED
 #ifdef HAVE_SIXENSE
     sixenseSetFilterEnabled(filter ? 1 : 0);
 #endif
 }
 
 void SixenseManager::pluginUpdate(float deltaTime, bool jointsCaptured) {
+    BAIL_IF_NOT_LOADED
     _inputDevice->update(deltaTime, jointsCaptured);
     if (_inputDevice->_requestReset) {
         _container->requestReset();
@@ -128,6 +142,7 @@ void SixenseManager::pluginUpdate(float deltaTime, bool jointsCaptured) {
 }
 
 void SixenseManager::InputDevice::update(float deltaTime, bool jointsCaptured) {
+    BAIL_IF_NOT_LOADED
 #ifdef HAVE_SIXENSE
     _buttonPressedMap.clear();
 
@@ -246,6 +261,7 @@ void SixenseManager::InputDevice::update(float deltaTime, bool jointsCaptured) {
 }
 
 void SixenseManager::InputDevice::setDebugDrawRaw(bool flag) {
+    BAIL_IF_NOT_LOADED
     _debugDrawRaw = flag;
     if (!flag) {
         DebugDraw::getInstance().removeMyAvatarMarker("SIXENSE_RAW_LEFT");
@@ -254,6 +270,7 @@ void SixenseManager::InputDevice::setDebugDrawRaw(bool flag) {
 }
 
 void SixenseManager::InputDevice::setDebugDrawCalibrated(bool flag) {
+    BAIL_IF_NOT_LOADED
     _debugDrawCalibrated = flag;
     if (!flag) {
         DebugDraw::getInstance().removeMyAvatarMarker("SIXENSE_CALIBRATED_LEFT");
@@ -281,6 +298,7 @@ static bool calibrationRequested(SixenseControllerData* controllers) {
 }
 
 void SixenseManager::InputDevice::updateCalibration(SixenseControllerData* controllers) {
+    BAIL_IF_NOT_LOADED
     const SixenseControllerData* dataLeft = controllers;
     const SixenseControllerData* dataRight = controllers + 1;
 
@@ -365,11 +383,13 @@ void SixenseManager::InputDevice::updateCalibration(SixenseControllerData* contr
 #endif  // HAVE_SIXENSE
 
 void SixenseManager::InputDevice::focusOutEvent() {
+    BAIL_IF_NOT_LOADED
     _axisStateMap.clear();
     _buttonPressedMap.clear();
 };
 
 void SixenseManager::InputDevice::handleButtonEvent(unsigned int buttons, bool left) {
+    BAIL_IF_NOT_LOADED
     using namespace controller;
     if (buttons & BUTTON_0) {
         _buttonPressedMap.insert(left ? BACK : START);
@@ -395,6 +415,7 @@ void SixenseManager::InputDevice::handleButtonEvent(unsigned int buttons, bool l
 }
 
 void SixenseManager::InputDevice::handlePoseEvent(float deltaTime, glm::vec3 position, glm::quat rotation, bool left) {
+    BAIL_IF_NOT_LOADED
 #ifdef HAVE_SIXENSE
     auto hand = left ? controller::StandardPoseChannel::LEFT_HAND : controller::StandardPoseChannel::RIGHT_HAND;
 

plugins/hifiSixense/src/SixenseManager.h

@@ -98,6 +98,8 @@ private:
 
     static const QString NAME;
     static const QString HYDRA_ID_STRING;
+    
+    static bool _sixenseLoaded;
 };
 
 #endif // hifi_SixenseManager_h

plugins/hifiSixense/src/SixenseSupportOSX.cpp

@@ -63,6 +63,9 @@ void unloadSixense() {
 // sixense.h wrapper for OSX dynamic linking
 int sixenseInit() {
     loadSixense();
+    if (!SIXENSE || !SIXENSE->isLoaded()) {
+        return SIXENSE_FAILURE;
+    }
     return FORWARD();
 }
 int sixenseExit() {