Vector3 SteeringBehaviour :: escort (const WorldInterface& world,
const PhysicsObjectId& id_target,
const Vector3& offset)
{
assert(id_target != PhysicsObjectId::ID_NOTHING);
// no initialization needed
m_steering_behaviour = ESCORT;
//
// This is a variation on the arrive steering behaviour.
// First we work out the desired position from the
// offset. Then we arrive at that position. Finally we
// add on the velocity of the target and truncate to our
// maximum speed.
//
// A more sophisticated implementation would use a form of
// arrive based on pursue instead of seek. Or maybe this
// already happens; I'm not sure. In either case,
// slowing down for arrival messes up time predictions.
//
if(!world.isAlive(m_id_agent) ||
!world.isAlive( id_target))
{
assert(invariant());
return Vector3::ZERO;
}
assert(world.isAlive(m_id_agent ));
assert(world.isAlive( id_target));
Vector3 agent_position = world.getPosition(m_id_agent);
Vector3 target_velocity = world.getVelocity( id_target);
Vector3 escort_position = calculateEscortPosition(world, id_target, offset);
if(agent_position == escort_position)
{
// we are in the correct position, so just match speeds
assert(invariant());
return target_velocity;
}
double agent_speed_max = world.getShipSpeedMax(m_id_agent);
assert(agent_speed_max >= 0.0);
double agent_acceleration = world.getShipSpeedMax(m_id_agent);
assert(agent_acceleration >= 0.0);
double current_distance = agent_position.getDistance(escort_position);
double desired_relative_speed = calculateMaxSafeSpeed(current_distance, agent_acceleration);
Vector3 desired_relative_velocity = (escort_position - agent_position).getCopyWithNorm(desired_relative_speed);
Vector3 desired_agent_velocity = desired_relative_velocity + target_velocity;
// limit desired velocity to maximum speed
assert(invariant());
return desired_agent_velocity.getTruncated(agent_speed_max);
}
Vector3 SteeringBehaviour :: evade (const WorldInterface& world,
const PhysicsObjectId& id_target)
{
assert(id_target != PhysicsObjectId::ID_NOTHING);
// no initialization needed
m_steering_behaviour = EVADE;
if(!world.isAlive(m_id_agent) ||
!world.isAlive( id_target))
{
assert(invariant());
return Vector3::ZERO;
}
Vector3 agent_position = world.getPosition(m_id_agent);
Vector3 target_position = world.getPosition( id_target);
if(agent_position == target_position)
{
assert(invariant());
return Vector3::ZERO;
}
assert(world.isAlive(m_id_agent ));
assert(world.isAlive( id_target));
Vector3 target_velocity = world.getVelocity(id_target);
double agent_speed_max = world.getShipSpeedMax(m_id_agent);
assert(agent_speed_max >= 0.0);
Vector3 aim_direction = getAimDirection(agent_position,
agent_speed_max,
target_position,
target_velocity);
if(aim_direction.isZero())
{
assert(invariant());
return (agent_position - target_position).getCopyWithNorm(agent_speed_max);
}
else
{
assert(invariant());
return aim_direction * -agent_speed_max;
}
}
void UnitAiMoonGuard::steerToTargetAndShoot(const WorldInterface& world)
{
assert(m_id_target != PhysicsObjectId::ID_NOTHING);
assert(world.isAlive(m_id_target));
Vector3 agent = getShip().getPosition();
Vector3 agent_velocity = world.getVelocity(getShip().getId());
Vector3 target = world.getPosition(m_id_target);
Vector3 target_velocity = world.getVelocity(m_id_target);
Vector3 desired_velocity;
double agent_max_speed = world.getShipSpeedMax(getShip().getId());
double fromAgentToTarget = agent.getAngle(target);
double fromAgentToTargetFront = agent.getAngle(target + target_velocity);
if (fromAgentToTargetFront < fromAgentToTarget) {
desired_velocity = m_steering_behaviour.seek(world, m_id_target);
}
else {
desired_velocity = m_steering_behaviour.getAimDirection(agent, Bullet::SPEED,
target, target_velocity);
if (desired_velocity == Vector3::ZERO) {
desired_velocity = m_steering_behaviour.pursue(world, m_id_target);
}
else {
desired_velocity.setNorm(agent_max_speed);
}
}
Vector3 avoid_velocity = avoidPlanets(world, desired_velocity);
avoid_velocity = avoidParticles(world, avoid_velocity);
avoid_velocity = avoidShips(world, avoid_velocity);
getShipAi().setDesiredVelocity(avoid_velocity);
double angle = agent_velocity.getAngle(desired_velocity);
double distance = target.getDistanceSquared(agent);
if (angle <= SHOOT_ANGLE_RADIANS_MAX && distance < FIRE_RANGE)
{
getShipAi().markFireBulletDesired();
}
}
Vector3 SteeringBehaviour :: explore (const WorldInterface& world,
double distance_new_position_min,
double distance_new_position_max)
{
assert(distance_new_position_min >= 0.0);
assert(distance_new_position_min <= distance_new_position_max);
assert(distance_new_position_min > EXPLORE_DISTANCE_NEW_POSITION);
double position_distance = (distance_new_position_max + distance_new_position_min) * 0.5;
double position_distance_tolerance = (distance_new_position_max - distance_new_position_min) * 0.5;
bool is_new_position_needed = false;
if(m_steering_behaviour != EXPLORE ||
m_desired_distance != position_distance ||
m_desired_distance_tolerance != position_distance_tolerance)
{
m_steering_behaviour = EXPLORE;
m_desired_distance = position_distance;
m_desired_distance_tolerance = position_distance_tolerance;
is_new_position_needed = true;
}
if(!world.isAlive(m_id_agent))
{
// the explore position doesn't matter at this point
assert(invariant());
return Vector3::ZERO;
}
Vector3 agent_position = world.getPosition(m_id_agent);
double agent_speed_max = world.getShipSpeedMax(m_id_agent);
assert(agent_speed_max >= 0.0);
if(agent_position.isDistanceLessThan(m_explore_position, EXPLORE_DISTANCE_NEW_POSITION) ||
is_new_position_needed)
{
m_explore_position = calculateExplorePosition(agent_position);
}
return (m_explore_position - agent_position).getCopyWithNorm(agent_speed_max);
}
Vector3 SteeringBehaviour :: arrive (const WorldInterface& world,
const Vector3& target_position)
{
// no initialization needed
m_steering_behaviour = ARRIVE;
PhysicsObjectId id_agent = m_id_agent;
if(!world.isAlive(id_agent))
{
assert(invariant());
return Vector3::ZERO;
}
Vector3 agent_position = world.getPosition(id_agent);
if(agent_position == target_position)
{
assert(invariant());
return Vector3::ZERO;
}
double agent_speed = world.getShipSpeedMax(id_agent);
assert(agent_speed >= 0.0);
double agent_acceleration = world.getShipAcceleration(id_agent);
assert(agent_acceleration >= 0.0);
double distance = agent_position.getDistance(target_position);
double max_safe_speed = calculateMaxSafeSpeed(distance, agent_acceleration);
if(max_safe_speed < agent_speed)
agent_speed = max_safe_speed;
assert(agent_speed >= 0.0);
assert(agent_speed <= max_safe_speed);
assert(invariant());
return (target_position - agent_position).getCopyWithNorm(agent_speed);
}
Vector3 SteeringBehaviour :: aim (const WorldInterface& world,
const PhysicsObjectId& id_target,
double shot_speed)
{
assert(id_target != PhysicsObjectId::ID_NOTHING);
assert(shot_speed >= 0.0);
// no initialization needed
m_steering_behaviour = AIM;
if(!world.isAlive(m_id_agent) ||
!world.isAlive( id_target))
{
assert(invariant());
return Vector3::ZERO;
}
Vector3 agent_position = world.getPosition(m_id_agent);
Vector3 target_position = world.getPosition( id_target);
if(agent_position == target_position)
{
assert(invariant());
return Vector3::ZERO;
}
assert(world.isAlive(m_id_agent ));
assert(world.isAlive( id_target));
double agent_speed_max = world.getShipSpeedMax(m_id_agent);
assert(agent_speed_max >= 0.0);
Vector3 target_velocity = world.getVelocity(id_target);
Vector3 aim_direction = getAimDirection(agent_position, shot_speed, target_position, target_velocity);
assert(invariant());
return aim_direction * agent_speed_max;
}
Vector3 SteeringBehaviour :: flee (const WorldInterface& world,
const Vector3& target_position)
{
// no initialization needed
m_steering_behaviour = FLEE;
if(!world.isAlive(m_id_agent))
{
assert(invariant());
return Vector3::ZERO;
}
Vector3 agent_position = world.getPosition(m_id_agent);
if(agent_position == target_position)
{
assert(invariant());
return Vector3::ZERO;
}
double agent_speed_max = world.getShipSpeedMax(m_id_agent);
assert(agent_speed_max >= 0.0);
return (agent_position - target_position).getCopyWithNorm(agent_speed_max);
}
// avoid only when going to collide
Vector3 SteeringBehaviour :: avoid (const WorldInterface& world,
const Vector3& original_velocity,
const Vector3& sphere_center,
double sphere_radius,
double clearance,
double avoid_distance) const
{
assert(sphere_radius >= 0.0);
assert(clearance > 0.0);
assert(clearance <= avoid_distance);
if(!world.isAlive(m_id_agent) ||
original_velocity.isZero())
{
assert(invariant());
return Vector3::ZERO;
}
Vector3 agent_position = world.getPosition(m_id_agent);
double agent_radius = world.getRadius(m_id_agent);
double desired_speed = world.getShipSpeedMax(m_id_agent);
Vector3 relative_position = sphere_center - agent_position;
double radius_sum = sphere_radius + agent_radius;
if(relative_position.isNormGreaterThan(radius_sum + avoid_distance))
{
if(DEBUGGING_AVOID)
cout << "Avoid: Outside avoid distance" << endl;
assert(invariant());
return original_velocity.getTruncated(desired_speed); // too far away to worry about
}
Vector3 agent_forward = world.getForward(m_id_agent);
if(relative_position.dotProduct(agent_forward) < 0.0)
{
// past center of object; no cylinder
if(DEBUGGING_AVOID)
cout << "Avoid: Departing from object" << endl;
if(relative_position.isNormLessThan(radius_sum + clearance))
{
// we are too close, so flee and slow down
double distance_fraction = (relative_position.getNorm() - radius_sum) / clearance;
if(DEBUGGING_AVOID)
cout << "\tInside panic distance: fraction = " << distance_fraction << endl;
if(distance_fraction < 0.0)
distance_fraction = 0.0;
Vector3 interpolated = original_velocity.getNormalized() * distance_fraction +
-relative_position.getNormalized() * (1.0 - distance_fraction);
if(distance_fraction > AVOID_SPEED_FACTOR_MIN)
desired_speed *= distance_fraction;
else
desired_speed *= AVOID_SPEED_FACTOR_MIN;
if(original_velocity.isNormLessThan(desired_speed))
desired_speed = original_velocity.getNorm();
assert(invariant());
return interpolated.getCopyWithNorm(desired_speed);
}
else
{
if(DEBUGGING_AVOID)
cout << "\tPast object" << endl;
assert(invariant());
return original_velocity.getTruncated(desired_speed); // far enough past object
}
}
else
{
// have not reached center of object; check against cylinder
if(DEBUGGING_AVOID)
cout << "Avoid: Approaching object" << endl;
double distance_from_cylinder_center = relative_position.getAntiProjection(agent_forward).getNorm();
double clearance_fraction = (distance_from_cylinder_center - radius_sum) / clearance;
if(DEBUGGING_AVOID)
{
cout << "\tTo sphere: " << relative_position << endl;
cout << "\tDistance_from_cylinder_center: " << distance_from_cylinder_center << endl;
cout << "\tRadius_sum: " << radius_sum << endl;
cout << "\tClearance: " << clearance << endl;
cout << "\tFraction: " << clearance_fraction << endl;
}
if(clearance_fraction < 0.0)
{
clearance_fraction = 0.0;
if(DEBUGGING_AVOID)
cout << "\tLined up at sphere" << endl;
}
if(clearance_fraction > 1.0)
{
if(DEBUGGING_AVOID)
cout << "\tOutside cylinder" << endl;
assert(invariant());
return original_velocity; // outside of danger cylinder
}
if(DEBUGGING_AVOID)
cout << "\tModified fraction: " << clearance_fraction << endl;
assert(!original_velocity.isZero());
assert(!agent_forward.isZero());
Vector3 sideways_vector = -relative_position.getAntiProjection(agent_forward);
while(sideways_vector.isNormLessThan(AVOID_SIDEWAYS_NORM_MIN))
{
// we have almost no sideways, so use a random value
sideways_vector = Vector3::getRandomUnitVector().getAntiProjection(agent_forward);
// keep trying until we get a good one
}
assert(!original_velocity.isZero());
assert(!sideways_vector.isZero());
assert(sideways_vector.isOrthogonal(agent_forward));
if(DEBUGGING_AVOID)
cout << "\tSideways: " << sideways_vector << endl;
Vector3 interpolated = original_velocity.getNormalized() * clearance_fraction +
sideways_vector .getNormalized() * (1.0 - clearance_fraction);
if(original_velocity.isNormLessThan(desired_speed))
desired_speed = original_velocity.getNorm();
if(DEBUGGING_AVOID)
cout << "\tDodging out of cylinder: " << interpolated.getCopyWithNorm(desired_speed) << endl;
assert(invariant());
return interpolated.getCopyWithNorm(desired_speed);
}
}
Vector3 SteeringBehaviour :: patrolSphere (const WorldInterface& world,
const Vector3& sphere_center,
double patrol_radius,
double patrol_radius_tolerance)
{
assert(patrol_radius >= 0.0);
assert(patrol_radius_tolerance >= 0.0);
bool is_new_position_needed = false;
if(m_steering_behaviour != PATROL_SPHERE ||
m_sphere_center != sphere_center ||
m_desired_distance != patrol_radius ||
m_desired_distance_tolerance != patrol_radius_tolerance)
{
m_steering_behaviour = PATROL_SPHERE;
m_sphere_center = sphere_center;
m_desired_distance = patrol_radius;
m_desired_distance_tolerance = patrol_radius_tolerance;
is_new_position_needed = true;
}
if(!world.isAlive(m_id_agent))
{
// the explore position doesn't matter at this point
assert(invariant());
return Vector3::ZERO;
}
Vector3 agent_position = world.getPosition(m_id_agent);
if(isNearEnoughPatrolSpherePoint(agent_position) ||
is_new_position_needed)
{
m_explore_position = calculatePatrolSpherePosition(agent_position);
}
double agent_speed_max = world.getShipSpeedMax(m_id_agent);
assert(agent_speed_max >= 0.0);
if(DEBUGGING_PATROL_SPHERE)
{
cout << "Explore:" << endl;
cout << "\tAgent position: " << agent_position << endl;
cout << "\tSphere position: " << m_sphere_center << endl;
cout << "\tExplore position: " << m_explore_position << endl;
}
double distance_from_sphere = agent_position.getDistance(m_sphere_center);
double weight_parallel = 1.0;
if(m_desired_distance_tolerance > 0.0)
{
double distance_outside_optimum = distance_from_sphere - m_desired_distance;
weight_parallel = distance_outside_optimum / m_desired_distance_tolerance;
if(weight_parallel > 1.0)
weight_parallel = 1.0;
if(weight_parallel < -1.0)
weight_parallel = -1.0;
if(DEBUGGING_PATROL_SPHERE)
{
cout << "\tSphere distance: " << distance_from_sphere << endl;
cout << "\tDesired distance: " << m_desired_distance << endl;
cout << "\tTolerance: " << m_desired_distance_tolerance << endl;
cout << "\tweight_parallel: " << weight_parallel << endl;
}
if(weight_parallel >= 0.0)
weight_parallel = weight_parallel * weight_parallel;
else
weight_parallel = -(weight_parallel * weight_parallel);
if(DEBUGGING_PATROL_SPHERE)
cout << "\t => " << weight_parallel << endl;
assert(weight_parallel <= 1.0);
assert(weight_parallel >= -1.0);
}
assert(weight_parallel <= 1.0);
assert(weight_parallel >= -1.0);
double weight_perpendicular = 1.0 - fabs(weight_parallel);
assert(weight_perpendicular <= 1.0);
assert(weight_perpendicular >= -1.0);
if(DEBUGGING_PATROL_SPHERE)
cout << "\tweight_perpendicular: " << weight_perpendicular << endl;
Vector3 to_sphere = m_sphere_center - agent_position;
Vector3 to_destination = m_explore_position - agent_position;
Vector3 parallel_to_normal = to_destination.getProjection(to_sphere);
Vector3 perpendicular_to_normal = to_destination - parallel_to_normal;
Vector3 desired_vector = parallel_to_normal * weight_parallel +
perpendicular_to_normal * weight_perpendicular;
assert(invariant());
return desired_vector.getCopyWithNormSafe(agent_speed_max);
}