// per frame simulation update
void LowSpeedTurn::update(const float currentTime, const float elapsedTime){
// apply force to vehicle
applySteeringForce(steering(), elapsedTime);
// update Irrlicht node
setPosition(position().vector3df());
irr::scene::ISceneNode::setRotation(forward().vector3df().getHorizontalAngle());
// update motion trail
recordTrailVertex(currentTime, position());
}
//-----------------------------------------------------------------------------
// per frame simulation update
void PhysicsVehicle::update( const float currentTime, const float elapsedTime )
{
// prevent any updates with zero or negative delta time
// prevent any updates where the elapsed time is > 5 sec
// this might be a result of debugging
// or is plainly very very bad
if( ( elapsedTime <= 0.0f ) || ( elapsedTime > 5.0f ) ) {
return;
}
bool ticked(false);
// just update the tick structure
_physicsUpdateTick.setAnimationInterval(getPhysicsUpdateFrameTime());
SLSize ticks(_physicsUpdateTick.update(elapsedTime, ticked));
if(ticked == false) {
// just do nothing
// a feature is missing here ...
// state interpolation
return;
}
// now read the internal motion state in case needed
if(_dirtyLocalSpaceData) {
_internalMotionState.readLocalSpaceData(*this);
_dirtyLocalSpaceData = false;
}
// set the updateTick counter to the right value
// this is a very interesting value for networking
// assuming the physics frame rate does not change
_updateTicks = ticks;
// following code should be stable enough to change the physics frame rate during runtime
const float deltaTime(static_cast<float>(_physicsUpdateTick.getAnimationInterval()));
SLSize deltaTicks(ticks - _physicsUpdateTick.getLastAnimationTick());
float tickDeltaTime(static_cast<float>(deltaTicks) * deltaTime);
float accumTime(static_cast<float>(_physicsUpdateTick.getTickedAccumTime()));
accumTime -= tickDeltaTime;
for(SLSize i(0); i < deltaTicks; ++i) {
updateTick(accumTime, deltaTime);
accumTime += deltaTime;
}
// pass over the internal 'fixed frame time' motion state to the 'render state'
_motionState = _internalMotionState;
SLTimeInterval missedDeltaTime(_physicsUpdateTick.getAccumTime() - _physicsUpdateTick.getTickedAccumTime());
if(missedDeltaTime != 0.0) {
#if 0
printf("Missed dt(%f)\n", missedDeltaTime);
#endif
// integrate with given linear and angular velocity
_motionState.integrateMotionState(static_cast<float>(missedDeltaTime));
}
// and finally write the motion state back to the local space
_motionState.writeLocalSpaceData(*this);
if( _proximityToken != NULL ) {
// notify proximity database that our position has changed
_proximityToken->updateForNewPosition( position() );
}
// annotation
annotationVelocityAcceleration (5, 0);
recordTrailVertex(static_cast<float>(_physicsUpdateTick.getAccumTime()), position());
}
