$msg =
chr(0x20) // Size = 32 (4+1*28)
. chr(0x1) // Type = 1
. chr(0x0) // ReqI=0
. chr(0x1) // NumC=1
. chr(0x1) . chr(0x0) // node=1
. chr(0x2) . chr(0x0) // lap=2
. chr(0x3) // puid=3
. chr(0x5) // pos=5
. chr(0x10) // info=16
. chr(0x0) //sp3=0
. chr(0x0) . chr(0x0) . chr(0x1) . chr(0x0) // x=65536
. chr(0x0) . chr(0x0) . chr(0x2) . chr(0x0) // y=65536*2
. chr(0x0) . chr(0x0) . chr(0x3) . chr(0x0) // z=65536*3
. chr(0x0) . chr(0x20) // speed=8192
. chr(0x0) . chr(0x10) // dir=4096
. chr(0x0) . chr(0x8) // heading=2048
. chr(0x0) . chr(0x4) // AngVel=1024
;
$IS_MCI = unpack('CSize', $msg);
if ( strlen($msg) < $IS_MCI['Size'] ) {
die("not enough data");
}
$IS_MCI += unpack('CType/CReqI/CNumC', substr($msg, 1));
$IS_MCI['Info'] = array();
for($i=0; $i<$IS_MCI['NumC']; $i++) {
$data = substr($msg, 4+($i*28), 28);
$IS_MCI['Info'][] = unpack('vNode/vLap/CPLID/CPosition/CInfo/CSp3/lX/lY/lZ/vSpeed/vDirection/vHeading/sAngVel', $data);
}
print_r($IS_MCI);
prints
Array
(
[Size] => 32
[Type] => 1
[ReqI] => 0
[NumC] => 1
[Info] => Array
(
[0] => Array
(
[Node] => 1
[Lap] => 2
[PLID] => 3
[Position] => 5
[Info] => 16
[Sp3] => 0
[X] => 65536
[Y] => 131072
[Z] => 196608
[Speed] => 8192
[Direction] => 4096
[Heading] => 2048
[AngVel] => 1024
)
)
)
Now, that code makes some assumptions that you might not want to take for granted (i.e. add a lot more error/read-data handling).
- It assumes the packet ($msg) has been completely read before the code runs. You might want to read only the parts you currently need (no need for substr() then). Or least be prepared that the message can arrive in several chunks.
- It also takes the size/num parameters for granted, i.e. it doesn't check if the values are feasible and enough data is available. That's definitely something you have to change.
Size
must be between 0...228, NumC must be between 0...8 and both values must fit together and so on.
- Also take a closer look at the format identifiers I've used in unpack(). For
word
I've used v
which stands for "unsigned short (always 16 bit, little endian byte order). But for int
I've used l
: "signed long (always 32 bit, machine byte order)". That's ok on my machine. But search the documentation of the protocol for the endianness of the data.
The testdata in $msg has been taken from the result of
__declspec(align(1)) struct CompCar // Car info in 28 bytes - there is an array of these in the MCI (below)
{
word Node; // current path node
word Lap; // current lap
byte PLID; // player's unique id
byte Position; // current race position : 0 = unknown, 1 = leader, etc...
byte Info; // flags and other info - see below
byte Sp3;
int X; // X map (65536 = 1 metre)
int Y; // Y map (65536 = 1 metre)
int Z; // Z alt (65536 = 1 metre)
word Speed; // speed (32768 = 100 m/s)
word Direction; // direction of car's motion : 0 = world y direction, 32768 = 180 deg
word Heading; // direction of forward axis : 0 = world y direction, 32768 = 180 deg
short AngVel; // signed, rate of change of heading : (16384 = 360 deg/s)
};
__declspec(align(1)) struct IS_MCI // Multi Car Info - if more than 8 in race then more than one of these is sent
{
byte Size; // 4 + NumC * 28
byte Type; // ISP_MCI
byte ReqI; // 0 unless this is a reply to an TINY_MCI request
byte NumC; // number of valid CompCar structs in this packet
CompCar Info[1]; // example: one element, fixed
};
int _tmain(int argc, _TCHAR* argv[])
{
struct IS_MCI mci = {
32, 1, 0, 1,
{ 1, 2, 3, 5, 16, 0, 65536, 65536*2, 65536*3, 8192, 4096, 2048, 1024 }
};
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD( 2, 2 );
int err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
/* Tell the user that we could not find a usable */
/* WinSock DLL. */
return 1;
}
SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = inet_addr( "127.0.0.1" );
addr.sin_port = htons( 8081 );
if ( 0!=connect( s, (SOCKADDR*) &addr, sizeof(addr) ) ) {
printf("%X ", WSAGetLastError());
return 0;
}
send(s, (const char*)&mci, sizeof(mci), 0);
shutdown(s, SD_BOTH);
closesocket(s);
return 0;
}