Vector4 SteeringBehavior::evade(Handle &p_pursuer_handle){
IHasHandle* tmp;
MovingObject* pursuer;
Vector4 toPursuer;
float look_ahead_time;
tmp = theWorld.get(p_pursuer_handle);
if (pursuer = dynamic_cast<MovingObject*>(tmp)){
toPursuer = pursuer->getPosition() - owner->getPosition();
look_ahead_time = toPursuer.length() / (owner->getMaxSpeed() + pursuer->getSpeed());
return flee(pursuer->getPosition() + pursuer->getVelocity() * look_ahead_time);
}
else {
off(BehaviorType::evade);
}
return Vector4();
}
Vector4 SteeringBehavior::pursuit(Handle &p_evader_handle){
IHasHandle* tmp;
MovingObject* evader;
Vector4 toEvader;
float relativeHeading, look_ahead_time;
tmp = theWorld.get(p_evader_handle);
if (evader = dynamic_cast<MovingObject*>(tmp)){
toEvader = evader->getPosition() - owner->getPosition();
relativeHeading = evader->getHeading().dot(owner->getHeading());
if (toEvader.dot(owner->getHeading()) > 0 && relativeHeading < -0.95){
return this->seek(evader->getPosition());
}
look_ahead_time = toEvader.length() / (owner->getMaxSpeed() + evader->getSpeed());
return seek(evader->getPosition() + evader->getVelocity() * look_ahead_time);
}
else {
off(BehaviorType::pursuit);
}
return Vector4(0, 0, 0);
}
Vector4 SteeringBehavior::offsetPursuit(Handle &p_leader, Vector4 &offset) {
MovingObject* leader = dynamic_cast<MovingObject*>(theWorld.get(p_leader));
if (leader == nullptr) {
// Leader does not exist anymore
off(BehaviorType::offset_pursuit);
return Vector4(0, 0, 0);
}
// calculate the offset's position in world space
Vector4 WorldOffsetPos = leader->getPosition() + offset;
Vector4 ToOffset = WorldOffsetPos - owner->getPosition();
// The lookahead time is propotional to the distance between the leader
// and the pursuer; and is inversely proportional to the sum of both
// agent's velocities
float LookAheadTime = ToOffset.length() / (owner->getMaxSpeed() + leader->getSpeed());
// Arrive at the predicted future position of the offset
return arrive(WorldOffsetPos + leader->getVelocity() * LookAheadTime, fast);
}