add experimental vrSyncPlugin, that syncs the position/orientation of a vr controller to a gripper (through a constraint)

This is in C++ and the sync runs at the simulation speed (240 Hz), so there is less lag than in Python.
Modify the pybullet/examples/vr_kuka_setup.py at the end to do this:

plugin = p.loadPlugin("e:/develop/bullet3/bin/pybullet_vrSyncPlugin_vs2010_x64_release.dll")
controllerId = 3
p.executePluginCommand(plugin ,"bla", [controllerId,pr2_cid],[50])

examples/SharedMemory/plugins/vrSyncPlugin/premake4.lua

@@ -0,0 +1,42 @@
+		
+
+project ("pybullet_vrSyncPlugin")
+		language "C++"
+		kind "SharedLib"
+		
+		includedirs {".","../../../../src", "../../../../examples",
+		"../../../ThirdPartyLibs"}
+		defines {"PHYSICS_IN_PROCESS_EXAMPLE_BROWSER"}
+	hasCL = findOpenCL("clew")
+
+	links{"BulletFileLoader", "Bullet3Common", "LinearMath"}
+
+
+	if os.is("MacOSX") then
+--		targetextension {"so"}
+		links{"Cocoa.framework","Python"}
+	end
+
+
+		files {
+			"vrSyncPlugin.cpp",
+			"../../PhysicsClient.cpp",
+			"../../PhysicsClient.h",
+			"../../PhysicsClientSharedMemory.cpp",
+			"../../PhysicsClientSharedMemory.h",
+			"../../PhysicsClientSharedMemory_C_API.cpp",
+			"../../PhysicsClientSharedMemory_C_API.h",
+			"../../PhysicsClientC_API.cpp",
+			"../../PhysicsClientC_API.h",
+			"../../Win32SharedMemory.cpp",
+			"../../Win32SharedMemory.h",
+			"../../PosixSharedMemory.cpp",
+			"../../PosixSharedMemory.h",
+			"../../../Utils/b3Clock.cpp",
+			"../../../Utils/b3Clock.h",
+			"../../../Utils/b3ResourcePath.cpp",
+			"../../../Utils/b3ResourcePath.h",
+				}
+	
+	
+	

examples/SharedMemory/plugins/vrSyncPlugin/vrSyncPlugin.cpp

@@ -0,0 +1,116 @@
+
+//vrSyncPlugin plugin, will query the vr controller events
+//and set change the user constraint to match the pose
+
+//in Python you can load and configure the plugin like this:
+//plugin = p.loadPlugin("e:/develop/bullet3/bin/pybullet_vrSyncPlugin_vs2010_x64_release.dll")
+//could also be plugin = p.loadPlugin("vrSyncPlugin.so") on Mac/Linux
+//controllerId = 3
+//p.executePluginCommand(plugin ,"bla", [controllerId,pr2_cid],[50])
+
+#include "vrSyncPlugin.h"
+#include "../../SharedMemoryPublic.h"
+#include "../b3PluginContext.h"
+#include <stdio.h>
+
+struct MyClass
+{
+	int m_testData;
+
+	int m_controllerId;
+	int m_constraintId;
+	float m_maxForce;
+	MyClass()
+		:m_testData(42),
+		m_controllerId(-1),
+		m_constraintId(-1),
+		m_maxForce(0)
+	{
+	}
+	virtual ~MyClass()
+	{
+	}
+};
+
+B3_SHARED_API int initPlugin(struct b3PluginContext* context)
+{
+	MyClass* obj = new MyClass();
+	context->m_userPointer = obj;
+
+	printf("hi vrSyncPlugin!\n");
+	return SHARED_MEMORY_MAGIC_NUMBER;
+}
+
+
+B3_SHARED_API int preTickPluginCallback(struct b3PluginContext* context)
+{
+	MyClass* obj = (MyClass* )context->m_userPointer;
+	if (obj->m_controllerId>=0)
+	{
+		b3SharedMemoryCommandHandle commandHandle = b3RequestVREventsCommandInit(context->m_physClient);
+		int deviceTypeFilter = VR_DEVICE_CONTROLLER;
+		b3VREventsSetDeviceTypeFilter(commandHandle, deviceTypeFilter);
+
+		b3SharedMemoryStatusHandle statusHandle = b3SubmitClientCommandAndWaitStatus(context->m_physClient, commandHandle);
+		int statusType = b3GetStatusType(statusHandle);
+		if (statusType == CMD_REQUEST_VR_EVENTS_DATA_COMPLETED)
+		{
+			struct b3VREventsData vrEvents;
+		
+			int i = 0;
+			b3GetVREventsData(context->m_physClient, &vrEvents);
+			if (vrEvents.m_numControllerEvents)
+			{
+				for (int n=0;n<vrEvents.m_numControllerEvents;n++)
+				{
+					b3VRControllerEvent& event = vrEvents.m_controllerEvents[n];
+					if (event.m_controllerId ==obj->m_controllerId)
+					{
+						b3SharedMemoryCommandHandle commandHandle;
+						int userConstraintUniqueId = obj->m_constraintId;
+						commandHandle = b3InitChangeUserConstraintCommand(context->m_physClient, userConstraintUniqueId);
+						double pos[4] = {event.m_pos[0],event.m_pos[1],event.m_pos[2],1};
+						b3InitChangeUserConstraintSetPivotInB(commandHandle, pos);
+						double orn[4] = {event.m_orn[0],event.m_orn[1],event.m_orn[2],event.m_orn[3]};
+						b3InitChangeUserConstraintSetFrameInB(commandHandle, orn);
+						b3InitChangeUserConstraintSetMaxForce(commandHandle, obj->m_maxForce);
+						
+						b3SharedMemoryStatusHandle statusHandle = b3SubmitClientCommandAndWaitStatus(context->m_physClient, commandHandle);
+						//this is basically equivalent to doing this in Python/pybullet:
+						//p.changeConstraint(pr2_cid, e[POSITION], e[ORIENTATION], maxForce=500)
+					}
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+
+
+B3_SHARED_API int executePluginCommand(struct b3PluginContext* context, const struct b3PluginArguments* arguments)
+{
+	MyClass* obj = (MyClass*) context->m_userPointer;
+	if (arguments->m_numInts>=2 && arguments->m_numFloats >= 0)
+	{
+		obj->m_constraintId = arguments->m_ints[1];
+		printf("obj->m_constraintId=%d\n", obj->m_constraintId);
+		obj->m_maxForce = arguments->m_floats[0];
+		printf("obj->m_maxForce = %f\n", obj->m_maxForce);
+		obj->m_controllerId = arguments->m_ints[0];
+		printf("obj->m_controllerId=%d\n", obj->m_controllerId);
+
+	}
+	return 0;
+}
+
+
+B3_SHARED_API void exitPlugin(struct b3PluginContext* context)
+{
+	MyClass* obj = (MyClass*) context->m_userPointer;
+	delete obj;
+	context->m_userPointer = 0;
+
+	printf("bye vrSyncPlugin!\n");
+}

examples/SharedMemory/plugins/vrSyncPlugin/vrSyncPlugin.h

@@ -0,0 +1,25 @@
+#ifndef TEST_PLUGIN_H
+#define TEST_PLUGIN_H
+
+#include "../b3PluginAPI.h"
+
+#ifdef __cplusplus
+extern "C" 
+{
+#endif
+
+//initPlugin, exitPlugin and executePluginCommand are required, otherwise plugin won't load
+B3_SHARED_API int initPlugin(struct b3PluginContext* context);
+B3_SHARED_API void exitPlugin(struct b3PluginContext* context);
+B3_SHARED_API int executePluginCommand(struct b3PluginContext* context, const struct b3PluginArguments* arguments);
+
+//preTickPluginCallback and postTickPluginCallback are optional.
+B3_SHARED_API int preTickPluginCallback(struct b3PluginContext* context);
+
+
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif//#define TEST_PLUGIN_H