hello_xr: Use trigger/value for grabAction on vive_controller

Squeeze is a physical button on this controller.
If possible, grabAction should be a float.

Author: ChristophHaag

src/tests/hello_xr/openxr_program.cpp

@@ -414,6 +414,7 @@ struct OpenXrProgram : IOpenXrProgram {
         std::array<XrPath, Side::COUNT> hapticPath;
         std::array<XrPath, Side::COUNT> menuClickPath;
         std::array<XrPath, Side::COUNT> bClickPath;
+        std::array<XrPath, Side::COUNT> triggerValuePath;
         CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/left/input/select/click", &selectPath[Side::LEFT]));
         CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/right/input/select/click", &selectPath[Side::RIGHT]));
         CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/left/input/squeeze/value", &squeezeValuePath[Side::LEFT]));
@@ -428,6 +429,8 @@ struct OpenXrProgram : IOpenXrProgram {
         CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/right/input/menu/click", &menuClickPath[Side::RIGHT]));
         CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/left/input/b/click", &bClickPath[Side::LEFT]));
         CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/right/input/b/click", &bClickPath[Side::RIGHT]));
+        CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/left/input/trigger/value", &triggerValuePath[Side::LEFT]));
+        CHECK_XRCMD(xrStringToPath(m_instance, "/user/hand/right/input/trigger/value", &triggerValuePath[Side::RIGHT]));
         // Suggest bindings for KHR Simple.
         {
             XrPath khrSimpleInteractionProfilePath;
@@ -471,8 +474,8 @@ struct OpenXrProgram : IOpenXrProgram {
             XrPath viveControllerInteractionProfilePath;
             CHECK_XRCMD(
                 xrStringToPath(m_instance, "/interaction_profiles/htc/vive_controller", &viveControllerInteractionProfilePath));
-            std::vector<XrActionSuggestedBinding> bindings{{{m_input.grabAction, squeezeClickPath[Side::LEFT]},
-                                                            {m_input.grabAction, squeezeClickPath[Side::RIGHT]},
+            std::vector<XrActionSuggestedBinding> bindings{{{m_input.grabAction, triggerValuePath[Side::LEFT]},
+                                                            {m_input.grabAction, triggerValuePath[Side::RIGHT]},
                                                             {m_input.poseAction, posePath[Side::LEFT]},
                                                             {m_input.poseAction, posePath[Side::RIGHT]},
                                                             {m_input.quitAction, menuClickPath[Side::LEFT]},