simuv2 bug fix

Ok, it's a kludge, not really a fix for some cars being
positioned wrong on the track. You can reproduce this problem with the xml
file i provided in my previous post. The problem is in wheel.cpp in 
SimWheelUpdateRide().
The problem manifests itself when

new_susp_x=prexwheel - wheel->rel_vel * SimDeltaTime;

generates a wrong value for new_susp_x. I would like to have a real 
solution to this
problem. The code changes are just a work around for the problem. I am 
not familiar
enough with the torcs code to even know where to begin looking for the 
root of this problem.

Here is the code:

void SimWheelUpdateRide(tCar *car, int index)
{
    tWheel *wheel = &(car->wheel[index]);
    tdble Zroad;

    // compute suspension travel
    RtTrackGlobal2Local(car->trkPos.seg, wheel->pos.x, wheel->pos.y, 
&(wheel->trkPos), TR_LPOS_SEGMENT);
    wheel->zRoad = Zroad = RtTrackHeightL(&(wheel->trkPos));


    // Wheel susp.x is not the wheel movement, look at SimSuspCheckIn, 
it becomes there scaled with
    // susp->spring.bellcrank, so we invert this here.
    tdble prexwheel = wheel->susp.x / wheel->susp.spring.bellcrank;

    tdble new_susp_x= prexwheel - wheel->rel_vel * SimDeltaTime;


        tdble max_extend =  wheel->pos.z - Zroad;
    wheel->rideHeight = max_extend;

//////////////////////test///////////////////
    tdble prex = wheel->susp.x;
//////////////////////////////////////////////////


    if (max_extend < wheel->susp.x) {
        wheel->susp.x = max_extend;
        wheel->rel_vel = 0.0f;
    } else if (wheel->susp.x < wheel->susp.spring.packers) {
        //////////////test (fixes elevated car at race start for most 
cars)///
        //wheel->susp.x = wheel->susp.spring.packers;
        /////////////////////////////////////////////////////
        wheel->rel_vel = 0.0f;
    ///////////////test fixes all mispositioned car problems/////       
        wheel->susp.x = wheel->pos.z - Zroad;
    }else if (wheel->rel_vel != 0.0f){
        wheel->susp.x = new_susp_x;
    }else{
        wheel->susp.x = wheel->pos.z - Zroad;
    }
    //////////////////////////////////////////////////////////////
 
//    tdble prex = wheel->susp.x;


//    wheel->susp.x = new_susp_x;


    // verify the suspension travel, beware, wheel->susp.x will be 
scaled by SimSuspCheckIn
    SimSuspCheckIn(&(wheel->susp));
    wheel->susp.v = (prex - wheel->susp.x) / SimDeltaTime;
   
    // update wheel brake
    SimBrakeUpdate(car, wheel, &(wheel->brake));

}

Thank you.

brian


------------------------------------------------------------------------------