// ----------------------------------------------------------------------------
// Path Following behaviors
public Vector3 steerToStayOnPath(float predictionTime, Pathway path)
{
// predict our future position
Vector3 futurePosition = predictFuturePosition(predictionTime);
// find the point on the path nearest the predicted future position
//Vector3 tangent;
//float outside;
mapReturnStruct tStruct = new mapReturnStruct();
Vector3 onPath = path.mapPointToPath(futurePosition, tStruct);
if (tStruct.outside < 0)
{
// our predicted future position was in the path,
// return zero steering.
return(Vector3.Zero);
}
else
{
// our predicted future position was outside the path, need to
// steer towards it. Use onPath projection of futurePosition
// as seek target
annotatePathFollowing(futurePosition, onPath, onPath, tStruct.outside);
return(steerForSeek(onPath));
}
}
public Vector3 steerToFollowPath(int direction, float predictionTime, Pathway path)
{
// our goal will be offset from our path distance by this amount
float pathDistanceOffset = direction * predictionTime * speed();
// predict our future position
Vector3 futurePosition = predictFuturePosition(predictionTime);
// measure distance along path of our current and predicted positions
float nowPathDistance =
path.mapPointToPathDistance(Position);
float futurePathDistance =
path.mapPointToPathDistance(futurePosition);
// are we facing in the correction direction?
bool rightway = ((pathDistanceOffset > 0) ?
(nowPathDistance < futurePathDistance) :
(nowPathDistance > futurePathDistance));
// find the point on the path nearest the predicted future position
// XXX need to improve calling sequence, maybe change to return a
// XXX special path-defined object which includes two Vector3s and a
// XXX bool (onPath,tangent (ignored), withinPath)
// Vector3 tangent;
//float outside;
mapReturnStruct tStruct = new mapReturnStruct();
Vector3 onPath = path.mapPointToPath(futurePosition, tStruct);
// no steering is required if (a) our future position is inside
// the path tube and (b) we are facing in the correct direction
if ((tStruct.outside < 0) && rightway)
{
// all is well, return zero steering
return(Vector3.Zero);
}
else
{
// otherwise we need to steer towards a target point obtained
// by adding pathDistanceOffset to our current path position
float targetPathDistance = nowPathDistance + pathDistanceOffset;
Vector3 target = path.mapPathDistanceToPoint(targetPathDistance);
annotatePathFollowing(futurePosition, onPath, target, tStruct.outside);
// return steering to seek target on path
return(steerForSeek(target));
}
}
// ----------------------------------------------------------------------------
// Path Following behaviors
public Vector3 steerToStayOnPath(float predictionTime, Pathway path)
{
// predict our future position
Vector3 futurePosition = predictFuturePosition (predictionTime);
// find the point on the path nearest the predicted future position
//Vector3 tangent;
//float outside;
mapReturnStruct tStruct = new mapReturnStruct();
Vector3 onPath = path.mapPointToPath(futurePosition, tStruct);
if (tStruct.outside < 0)
{
// our predicted future position was in the path,
// return zero steering.
return Vector3.ZERO;
}
else
{
// our predicted future position was outside the path, need to
// steer towards it. Use onPath projection of futurePosition
// as seek target
annotatePathFollowing (futurePosition, onPath, onPath,tStruct.outside);
return steerForSeek (onPath);
}
}
public Vector3 steerToFollowPath(int direction, float predictionTime, Pathway path)
{
// our goal will be offset from our path distance by this amount
float pathDistanceOffset = direction * predictionTime * speed();
// predict our future position
Vector3 futurePosition = predictFuturePosition (predictionTime);
// measure distance along path of our current and predicted positions
float nowPathDistance =
path.mapPointToPathDistance (Position);
float futurePathDistance =
path.mapPointToPathDistance (futurePosition);
// are we facing in the correction direction?
bool rightway = ((pathDistanceOffset > 0) ?
(nowPathDistance < futurePathDistance) :
(nowPathDistance > futurePathDistance));
// find the point on the path nearest the predicted future position
// XXX need to improve calling sequence, maybe change to return a
// XXX special path-defined object which includes two Vector3s and a
// XXX bool (onPath,tangent (ignored), withinPath)
// Vector3 tangent;
//float outside;
mapReturnStruct tStruct = new mapReturnStruct();
Vector3 onPath = path.mapPointToPath(futurePosition, tStruct);
// no steering is required if (a) our future position is inside
// the path tube and (b) we are facing in the correct direction
if ((tStruct.outside < 0) && rightway)
{
// all is well, return zero steering
return Vector3.ZERO;
}
else
{
// otherwise we need to steer towards a target point obtained
// by adding pathDistanceOffset to our current path position
float targetPathDistance = nowPathDistance + pathDistanceOffset;
Vector3 target = path.mapPathDistanceToPoint (targetPathDistance);
annotatePathFollowing(futurePosition, onPath, target, tStruct.outside);
// return steering to seek target on path
return steerForSeek (target);
}
}
