DLLCLBK void opcPreStep(double simt, double simdt, double mjd)
{
OrbiterPluginMessage * opm; // holds our msg and msg data
char * msg;
int len;
// nextMessage() returns MESSAGE_OK if a message is succesfully polled
while(OICOM::nextMessage(pid, &opm)==MESSAGE_OK)
{
msg=opm->strMsg;
len=strlen(msg);
// we don't care about any text only events for this module
if ( opm->data == 0 )
{
// remove this message from the message stack
OICOM::removeLastMessage(pid);
continue;
}
// perma-link! hook up this module's state variables with any module providing input
// this is powerful
if ( !_strnicmp(msg, "link_state", len) )
active=(bool*)opm->data;
else if (!_strnicmp(msg, "link_setpoint", len) )
setpoint=(double*)opm->data;
OICOM::removeLastMessage(pid); // this is important otherwise we'll end up with an infinite loop!
// I am thinking about automating it.. calling this at nextMessage
}
// if not linked to any module for input, no need to proceed
if ( active == 0 || setpoint == 0 ) return;
if ( !*active ) return;
// crappy "autopilot" code follows, IGNORE IT xD
VESSEL * vessel = oapiGetFocusInterface();
DWORD inx = vessel->GetGroupThrusterCount(THGROUP_MAIN);
VECTOR3 dv;
vessel->GetDragVector(dv);
THRUSTER_HANDLE th;
double e = *setpoint-vessel->GetAirspeed();
double lvl = 0;
for (DWORD i = 0; i < inx; i++)
{
th = vessel->GetGroupThruster(THGROUP_MAIN, i);
lvl = (-dv.z+e*vessel->GetMass()*70)/vessel->GetThrusterMax0(th);
if (lvl<0)
lvl=0;
else if (lvl>1)
lvl=1;
vessel->SetThrusterLevel(th, lvl);
}
}
