run GUI on main thread for Mac OSX/__APPLE__, due to OS limitation

add b3CreateInProcessPhysicsServerAndConnectMainThread to test.c

examples/SharedMemory/SharedMemoryInProcessPhysicsC_API.cpp

@@ -1,9 +1,63 @@
 
 #include "SharedMemoryInProcessPhysicsC_API.h"
+
 #include "PhysicsClientSharedMemory.h"
 #include"../ExampleBrowser/InProcessExampleBrowser.h"
+#include"../ExampleBrowser/InProcessExampleBrowserMainThread.h"
 
 
+
+class InProcessPhysicsClientSharedMemoryMainThread : public PhysicsClientSharedMemory
+{
+    btInProcessExampleBrowserMainThreadInternalData* m_data;
+public:
+    
+    InProcessPhysicsClientSharedMemoryMainThread(int argc, char* argv[])
+    {
+        int newargc = argc+2;
+        char** newargv = (char**)malloc(sizeof(void*)*newargc);
+        for (int i=0;i<argc;i++)
+            newargv[i] = argv[i];
+        
+        char* t0 = (char*)"--logtostderr";
+        char* t1 = (char*)"--start_demo_name=Physics Server";
+        newargv[argc] = t0;
+        newargv[argc+1] = t1;
+        m_data = btCreateInProcessExampleBrowserMainThread(newargc,newargv);
+        SharedMemoryInterface* shMem = btGetSharedMemoryInterfaceMainThread(m_data);
+        
+        setSharedMemoryInterface(shMem);
+    }
+    
+    virtual ~InProcessPhysicsClientSharedMemoryMainThread()
+    {
+        setSharedMemoryInterface(0);
+        btShutDownExampleBrowserMainThread(m_data);
+    }
+    
+    // return non-null if there is a status, nullptr otherwise
+    virtual const struct SharedMemoryStatus* processServerStatus()
+    {
+        btUpdateInProcessExampleBrowserMainThread(m_data);
+        return PhysicsClientSharedMemory::processServerStatus();
+    }
+    
+    virtual bool submitClientCommand(const struct SharedMemoryCommand& command)
+    {
+//        btUpdateInProcessExampleBrowserMainThread(m_data);
+        return PhysicsClientSharedMemory::submitClientCommand(command);
+    }
+    
+};
+
+b3PhysicsClientHandle b3CreateInProcessPhysicsServerAndConnectMainThread(int argc, char* argv[])
+{
+    InProcessPhysicsClientSharedMemoryMainThread* cl = new InProcessPhysicsClientSharedMemoryMainThread(argc, argv);
+    cl->setSharedMemoryKey(SHARED_MEMORY_KEY);
+    cl->connect();
+    return (b3PhysicsClientHandle ) cl;
+}
+
 class InProcessPhysicsClientSharedMemory : public PhysicsClientSharedMemory
 {
 	btInProcessExampleBrowserInternalData* m_data;