Tokuda at 21:10, 15 July 2008

2008-07-15T21:10:28Z

Tokuda at 21:10, 15 July 2008

2008-07-15T21:10:01Z

Tokuda: New page: =Serializing Open IGT Link message for linear transform data= To generate a transform message using the igtlutil library, first we include following header files: #include "igtl_util.h...

2008-07-15T21:09:06Z

New page: =Serializing Open IGT Link message for linear transform data= To generate a transform message using the igtlutil library, first we include following header files: #include "igtl_util.h...

New page

=Serializing Open IGT Link message for linear transform data=

To generate a transform message using the igtlutil library, first we include following header files:

#include "igtl_util.h"
#include "igtl_header.h"
#include "igtl_transform.h"

Then, prepare a transform:
/********** pack data body **********/
igtl_float32 transform[12];

transform[0] = tx;
transform[1] = ty;
transform[2] = tz;
transform[3] = sx;
transform[4] = sy;
transform[5] = sz;
transform[6] = nx;
transform[7] = ny;
transform[8] = nz;
transform[9] = px;
transform[10] = py;
transform[11] = pz;

igtl_transform_convert_byte_order(transform); /* convert endian if necessary */

Once the transform data has been prepared, we create a general header:

/********** general header **********/
igtl_header header;
igtl_uint64 crc = crc64(0, 0, 0LL); /* initial crc */
header.version = IGTL_HEADER_VERSION;
header.timestamp = 0;
header.body_size = IGTL_TRANSFORM_SIZE;
header.crc = crc64((unsigned char*)transform, IGTL_TRANSFORM_SIZE, crc);

strncpy(header.name, "TRANSFORM", 12); /* Device Type: should be "TRANSFORM" */
strncpy(header.device_name, "Tracker", 20); /* Device name */

igtl_header_convert_byte_order(&header); /* convert endian if necessary */

Now it's time to send the serialized data. Since igtlutil library doesn't have a socket implementation, we need to some socket libraries or API, available in the environment we are working on. In case of BSD socket, call:

send(sock, (void*) &header, IGTL_HEADER_SIZE, 0);
send(sock, (void*) transform, IGTL_TRANSFORM_SIZE, 0);

after establishing the connection.

=Deserializing Open IGT Link message for linear transform data=
<br>

First of all, we receive the header data from the sender. It may look like the following code,
in case of using BSD socket API:

igtl_header header;
int n;

n = recv(sock, header, IGTL_HEADER_SIZE);
if (n != IGTL_HEADER_SIZE)
{
/*** do something for error handling ***/
}

Then convert byte order of each element:

igtl_header_convert_byte_order(&header);

Now the header is ready to be read. Header fields e.g. header version, size, CRC etc. can be access as members of igtl_header structure.

The following code shows how to detect which type of message is in the body part.

char deviceType[13];
deviceType[12] = 0;
memcpy((void*)deviceType, header.name, 12);

if (strcmp(deviceType, "TRANSFORM") == 0)
{
/*** code to read TRANSFORM data ***/
}
else if (strcmp(deviceType, "IMAGE") == 0)
{
/*** code to read IMAGE data ***/
}

/*** .... other types ... ***/

else
{
/*** Unknown type: read the rest of the message and discard it. ***/
}

← Older revision		Revision as of 21:10, 15 July 2008
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−	[[OpenIGTLink/Tutorial \| << OpenIGTLink Tutorial Home]]	+	[[OpenIGTLink/Library/Tutorial \| << OpenIGTLink Tutorial Home]]
	<div class="floatright">__TOC__</div>		<div class="floatright">__TOC__</div>

← Older revision		Revision as of 21:10, 15 July 2008
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		+	[[OpenIGTLink/Tutorial \| << OpenIGTLink Tutorial Home]]
		+	<div class="floatright">__TOC__</div>
		+
		+
	=Serializing Open IGT Link message for linear transform data=		=Serializing Open IGT Link message for linear transform data=

OpenIGTLink/Tutorial/igtlutil - Revision history

Tokuda at 21:10, 15 July 2008

Tokuda at 21:10, 15 July 2008

Tokuda: New page: =Serializing Open IGT Link message for linear transform data= To generate a transform message using the igtlutil library, first we include following header files: #include "igtl_util.h...