Plugin Initialization

I'm having trouble initializing a native plugin I'm writing and wondering if there is anything special you need to do when initializing plugins? I'm really new to this and don't really know C++ so it's quite possible I'm overlooking something obvious. I'm modifying C++ code that was originally written as an executable and was initialized with the function _tmain which read arguments from the command line. I commented out this function and created a new function called InitializePluginInternal and hard coded the arguments into the function. When I compile an executable and run it everything works fine, however when I compile a DLL and run InitializePlugin in Unity the app hangs and I have to kill it.

Below is
1. MotiveToUnityPlugin.cpp: excerpts showing the two initialization functions and the EXPORT_API functions for Unity.
2. InitializeMotiveToUnityPlugin.cs: showing how I am calling the DLL functions.

Here is a ZIP of the Visual Studio Community 2013 project and the Unity project if anyone wants to checkout the full source: https://drive.google.com/file/d/0B_5Y8udovIdbQVNLRlhGSTBPTFU/view?usp=sharing

Thanks,
Brad

MotiveToUnityPlugin.cpp

Code (CSharp):

1.  
2. //ORIGINAL INITIALIZATION CODE/////////////////////////////
3. int _tmain(int argc, _TCHAR* argv[])
4.  
5. {
6.  
7.     tmainExcuted = true;
8.     int iResult;
9.     int iConnectionType = ConnectionType_Multicast;
10.     //int iConnectionType = ConnectionType_Unicast;
11.  
12.     // parse command line args
13.     if (argc > 1)
14.     {
15.         strcpy(szServerIPAddress, argv[1]);    // specified on command line
16.         printf("Connecting to server at %s...\n", szServerIPAddress);
17.     }
18.     else
19.     {
20.         strcpy(szServerIPAddress, "");        // not specified - assume server is local machine
21.         printf("Connecting to server at LocalMachine\n");
22.     }
23.     if (argc > 2)
24.     {
25.         strcpy(szMyIPAddress, argv[2]);        // specified on command line
26.         printf("Connecting from %s...\n", szMyIPAddress);
27.     }
28.     else
29.     {
30.         strcpy(szMyIPAddress, "");          // not specified - assume server is local machine
31.         printf("Connecting from LocalMachine...\n");
32.     }
33.  
34.     // Create NatNet Client
35.     iResult = CreateClient(iConnectionType);
36.     if (iResult != ErrorCode_OK)
37.     {
38.         printf("Error initializing client.  See log for details.  Exiting");
39.         return 1;
40.     }
41.     else
42.     {
43.         printf("Client initialized and ready.\n");
44.     }
45.  
46.  
47.     // send/receive test request
48.     printf("[SampleClient] Sending Test Request\n");
49.     void* response;
50.     int nBytes;
51.     iResult = theClient->SendMessageAndWait("TestRequest", &response, &nBytes);
52.     if (iResult == ErrorCode_OK)
53.     {
54.         printf("[SampleClient] Received: %s", (char*)response);
55.     }
56.  
57.     // Retrieve Data Descriptions from server
58.     printf("\n\n[SampleClient] Requesting Data Descriptions...");
59.     sDataDescriptions* pDataDefs = NULL;
60.     int nBodies = theClient->GetDataDescriptions(&pDataDefs);
61.     if (!pDataDefs)
62.     {
63.         printf("[SampleClient] Unable to retrieve Data Descriptions.");
64.     }
65.     else
66.     {
67.         printf("[SampleClient] Received %d Data Descriptions:\n", pDataDefs->nDataDescriptions);
68.         for (int i = 0; i < pDataDefs->nDataDescriptions; i++)
69.         {
70.             printf("Data Description # %d (type=%d)\n", i, pDataDefs->arrDataDescriptions[i].type);
71.             if (pDataDefs->arrDataDescriptions[i].type == Descriptor_MarkerSet)
72.             {
73.                 // MarkerSet
74.                 sMarkerSetDescription* pMS = pDataDefs->arrDataDescriptions[i].Data.MarkerSetDescription;
75.                 printf("MarkerSet Name : %s\n", pMS->szName);
76.                 for (int i = 0; i < pMS->nMarkers; i++)
77.                     printf("%s\n", pMS->szMarkerNames[i]);
78.             }
79.             else if (pDataDefs->arrDataDescriptions[i].type == Descriptor_RigidBody)
80.             {
81.                 //ORIGINAL CODE START
82.  
83.                 // RigidBody
84.                 sRigidBodyDescription* pRB = pDataDefs->arrDataDescriptions[i].Data.RigidBodyDescription;
85.                 printf("RigidBody Name : %s\n", pRB->szName);
86.                 printf("RigidBody ID : %d\n", pRB->ID);
87.                 printf("RigidBody Parent ID : %d\n", pRB->parentID);
88.                 printf("Parent Offset : %3.2f,%3.2f,%3.2f\n", pRB->offsetx, pRB->offsety, pRB->offsetz);
89.                 //ORIGINAL CODE END
90.             }
91.             else if (pDataDefs->arrDataDescriptions[i].type == Descriptor_Skeleton)
92.             {
93.                 // Skeleton
94.                 sSkeletonDescription* pSK = pDataDefs->arrDataDescriptions[i].Data.SkeletonDescription;
95.                 printf("Skeleton Name : %s\n", pSK->szName);
96.                 printf("Skeleton ID : %d\n", pSK->skeletonID);
97.                 printf("RigidBody (Bone) Count : %d\n", pSK->nRigidBodies);
98.                 for (int j = 0; j < pSK->nRigidBodies; j++)
99.                 {
100.                     sRigidBodyDescription* pRB = &pSK->RigidBodies[j];
101.                     printf("  Skeleton RigidBody Name : %s\n", pRB->szName);
102.                     printf("  Skeleton RigidBody ID : %d\n", pRB->ID);
103.                     printf("  Skeleton RigidBody Parent ID : %d\n", pRB->parentID);
104.                     printf("  Parent Offset : %3.2f,%3.2f,%3.2f\n", pRB->offsetx, pRB->offsety, pRB->offsetz);
105.  
106.                     // populate bone name dictionary for use in xml ==--
107.                     gBoneNames[pRB->ID] = pRB->szName;
108.                 }
109.             }
110.             else
111.             {
112.                 printf("Unknown data type.");
113.                 // Unknown
114.             }
115.         }
116.     }
117.  
118.     // Ready to receive marker stream!
119.     printf("\nClient is connected to server and listening for data...\n");
120.     int c;
121.     bool bExit = false;
122.     while (c = _getch())
123.     {
124.         switch (c)
125.         {
126.         case 'q':
127.             bExit = true;
128.             break;
129.         case 'r':
130.             resetClient();
131.             break;
132.         case 'p':
133.             sServerDescription ServerDescription;
134.             memset(&ServerDescription, 0, sizeof(ServerDescription));
135.             theClient->GetServerDescription(&ServerDescription);
136.             if (!ServerDescription.HostPresent)
137.             {
138.                 printf("Unable to connect to server. Host not present. Exiting.");
139.                 return 1;
140.             }
141.             break;
142.         case 'f':
143.         {
144.             sFrameOfMocapData* pData = theClient->GetLastFrameOfData();
145.             printf("Most Recent Frame: %d", pData->iFrame);
146.         }
147.         break;
148.         case 'm':                            // change to multicast
149.             iResult = CreateClient(ConnectionType_Multicast);
150.             if (iResult == ErrorCode_OK)
151.                 printf("Client connection type changed to Multicast.\n\n");
152.             else
153.                 printf("Error changing client connection type to Multicast.\n\n");
154.             break;
155.         case 'u':                            // change to unicast
156.             iResult = CreateClient(ConnectionType_Unicast);
157.             if (iResult == ErrorCode_OK)
158.                 printf("Client connection type changed to Unicast.\n\n");
159.             else
160.                 printf("Error changing client connection type to Unicast.\n\n");
161.             break;
162.  
163.  
164.         default:
165.             break;
166.         }
167.         if (bExit)
168.             break;
169.     }
170.  
171.     // Done - clean up.
172.     theClient->Uninitialize();
173.  
174.     return ErrorCode_OK;
175. }
176. */
177.  
178. //NEW INITIALIZATION CODE/////////////////////////////////
179. int InitializePluginInternal()
180. {
181.     printf("InitializePluginInternal.\n");
182.    
183.     int iResult;
184.     int iConnectionType = ConnectionType_Multicast;
185.     //int iConnectionType = ConnectionType_Unicast;
186.  
187.     strcpy(szServerIPAddress, "127.0.0.1");
188.     strcpy(szMyIPAddress, "127.0.0.1");
189.  
190.     // Create NatNet Client
191.     iResult = CreateClient(iConnectionType);
192.     if (iResult != ErrorCode_OK)
193.     {
194.         printf("Error initializing client.  See log for details.  Exiting");
195.         return 1;
196.     }
197.     else
198.     {
199.         printf("Client initialized and ready.\n");
200.     }
201.  
202.     // send/receive test request
203.     printf("[SampleClient] Sending Test Request\n");
204.     void* response;
205.     int nBytes;
206.     iResult = theClient->SendMessageAndWait("TestRequest", &response, &nBytes);
207.     if (iResult == ErrorCode_OK)
208.     {
209.         printf("[SampleClient] Received: %s", (char*)response);
210.     }
211.  
212.     // Retrieve Data Descriptions from server
213.     printf("\n\n[SampleClient] Requesting Data Descriptions...");
214.     sDataDescriptions* pDataDefs = NULL;
215.     int nBodies = theClient->GetDataDescriptions(&pDataDefs);
216.     if (!pDataDefs)
217.     {
218.         printf("[SampleClient] Unable to retrieve Data Descriptions.");
219.     }
220.     else
221.     {
222.         printf("[SampleClient] Received %d Data Descriptions:\n", pDataDefs->nDataDescriptions);
223.         for (int i = 0; i < pDataDefs->nDataDescriptions; i++)
224.         {
225.             printf("Data Description # %d (type=%d)\n", i, pDataDefs->arrDataDescriptions[i].type);
226.             if (pDataDefs->arrDataDescriptions[i].type == Descriptor_MarkerSet)
227.             {
228.                 // MarkerSet
229.                 sMarkerSetDescription* pMS = pDataDefs->arrDataDescriptions[i].Data.MarkerSetDescription;
230.                 printf("MarkerSet Name : %s\n", pMS->szName);
231.                 for (int i = 0; i < pMS->nMarkers; i++)
232.                     printf("%s\n", pMS->szMarkerNames[i]);
233.             }
234.             else if (pDataDefs->arrDataDescriptions[i].type == Descriptor_RigidBody)
235.             {
236.                 //ORIGINAL CODE START
237.  
238.                 // RigidBody
239.                 sRigidBodyDescription* pRB = pDataDefs->arrDataDescriptions[i].Data.RigidBodyDescription;
240.                 printf("RigidBody Name : %s\n", pRB->szName);
241.                 printf("RigidBody ID : %d\n", pRB->ID);
242.                 printf("RigidBody Parent ID : %d\n", pRB->parentID);
243.                 printf("Parent Offset : %3.2f,%3.2f,%3.2f\n", pRB->offsetx, pRB->offsety, pRB->offsetz);
244.                 //ORIGINAL CODE END
245.             }
246.             else if (pDataDefs->arrDataDescriptions[i].type == Descriptor_Skeleton)
247.             {
248.                 // Skeleton
249.                 sSkeletonDescription* pSK = pDataDefs->arrDataDescriptions[i].Data.SkeletonDescription;
250.                 printf("Skeleton Name : %s\n", pSK->szName);
251.                 printf("Skeleton ID : %d\n", pSK->skeletonID);
252.                 printf("RigidBody (Bone) Count : %d\n", pSK->nRigidBodies);
253.                 for (int j = 0; j < pSK->nRigidBodies; j++)
254.                 {
255.                     sRigidBodyDescription* pRB = &pSK->RigidBodies[j];
256.                     printf("  Skeleton RigidBody Name : %s\n", pRB->szName);
257.                     printf("  Skeleton RigidBody ID : %d\n", pRB->ID);
258.                     printf("  Skeleton RigidBody Parent ID : %d\n", pRB->parentID);
259.                     printf("  Parent Offset : %3.2f,%3.2f,%3.2f\n", pRB->offsetx, pRB->offsety, pRB->offsetz);
260.  
261.                     // populate bone name dictionary for use in xml ==--
262.                     gBoneNames[pRB->ID] = pRB->szName;
263.                 }
264.             }
265.             else
266.             {
267.                 printf("Unknown data type.");
268.                 // Unknown
269.             }
270.         }
271.     }
272.  
273.     // Ready to receive marker stream!
274.     printf("\nClient is connected to server and listening for data...\n");
275.     int c;
276.     bool bExit = false;
277.     while (c = _getch())
278.     {
279.         switch (c)
280.         {
281.         case 'q':
282.             bExit = true;
283.             break;
284.         case 'r':
285.             resetClient();
286.             break;
287.         case 'p':
288.             sServerDescription ServerDescription;
289.             memset(&ServerDescription, 0, sizeof(ServerDescription));
290.             theClient->GetServerDescription(&ServerDescription);
291.             if (!ServerDescription.HostPresent)
292.             {
293.                 printf("Unable to connect to server. Host not present. Exiting.");
294.                 return 1;
295.             }
296.             break;
297.         case 'f':
298.         {
299.             sFrameOfMocapData* pData = theClient->GetLastFrameOfData();
300.             printf("Most Recent Frame: %d", pData->iFrame);
301.         }
302.         break;
303.         case 'm':                            // change to multicast
304.             iResult = CreateClient(ConnectionType_Multicast);
305.             if (iResult == ErrorCode_OK)
306.                 printf("Client connection type changed to Multicast.\n\n");
307.             else
308.                 printf("Error changing client connection type to Multicast.\n\n");
309.             break;
310.         case 'u':                            // change to unicast
311.             iResult = CreateClient(ConnectionType_Unicast);
312.             if (iResult == ErrorCode_OK)
313.                 printf("Client connection type changed to Unicast.\n\n");
314.             else
315.                 printf("Error changing client connection type to Unicast.\n\n");
316.             break;
317.  
318.  
319.         default:
320.             break;
321.         }
322.         if (bExit)
323.             break;
324.     }
325.  
326.     // Done - clean up.
327.     theClient->Uninitialize();
328.  
329.     return ErrorCode_OK;
330. }
331.  
332. //UNITY FUNCTIONS///////////////////////////////
333. extern "C"
334. {
335.     int EXPORT_API InitializePlugin() {
336.         int iResult;
337.         iResult = InitializePluginInternal();
338.         return iResult;
339.     }
340.  
341.     float EXPORT_API GetRigidBodyX(int ID) {
342.         for (int i = 0; i < rigidBodyArraySize; i++) {
343.             if (rigidBodyIDs[i] == ID) {
344.                 return rigidBodyX[i];
345.             }
346.             else {
347.                 return 666.0;
348.             }
349.         }
350.     }
351.  
352.     int EXPORT_API GetRigidBodyID(int i) {
353.         return rigidBodyIDs[i];
354.     }
355. }
356.  

InitializeMotiveToUnityPlugin.cs

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System;
4. using System.Runtime.InteropServices;
5.  
6. public class InitializeMotiveToUnityPlugin : MonoBehaviour {
7.  
8.     [DllImport ("MotiveToUnityPlugin")]
9.     private static extern int InitializePlugin();
10.  
11.     void Awake() {
12.         Debug.Log("Initializing Plugin...");
13.         int iResult = InitializePlugin();
14.         if(iResult == 1) {
15.             Debug.Log("Error initializing client.");
16.         }
17.         if(iResult == 0) {
18.             Debug.Log("ErrorCode_OK.");
19.         }
20.     }
21. }