[IGSTK-Developers] SerialCommunicationSimulator data file format

[David Gobbi]

Hi Hee-Su,

I've taken a look at the simulator data file and it the 
SerialCommunicationSimulator and it misses one of the requirements: it 
isn't able to handle binary data streams.

The difference between an ASCII data stream and a binary data stream is 
that the bytes in an ASCII stream only contains ASCII characters, that 
is, the byte values are always in the range [1,127].

The bytes in a binary stream can have any value in the range [0,255].  A 
binary stream can contain zeros, but an ASCII stream cannot.
A chunk of binary data cannot be stored in a C++ string, because a C++ 
string cannot contain a zero byte, except at the very end.

The reason that this is important is that virtually all tracking systems 
do at least some communication using binary data, for example we cannot 
support the Aurora's BX "binary transform" command unless we can 
communicate with binary data, and tracking systems like the Flock of 
Birds always communicate transforms with binary data.

In summary:

The Communication classes cannot store their input or data in C++ 
strings.  The data must either be stored in a char array e.g. char 
data[1024], or in a C++ vector.  Or perhaps, going along with Luis' 
philosophy on these things, we should define our own data container type 
for this purpose.

The file format for the CommunicationSimulator data file will also have 
to be adjusted, because it doesn't support binary data either.  On my 
wiki design page for SerialCommunicationSimulator I specified a file 
format that stored the number of bytes used by every sent and received 
data record, but the file format used by the simulator doesn't appear to 
follow that design.

 - David