import Vector from '../../math/Vector';
import RayConfiguration from '../utils/RayConfiguration';
import RaycastCollisionDetector from '../../utils/RaycastCollisionDetector';
import Limiter from '../Limiter';
import Steerable from '../Steerable';
import SteeringAcceleration from '../SteeringAcceleration';
import SteeringBehavior from '../SteeringBehavior';
/**
* With the {@code RaycastObstacleAvoidance} the moving agent (the owner) casts one or more rays out in the direction of its
* motion. If these rays collide with an obstacle, then a target is created that will avoid the collision, and the owner does a
* basic seek on this target. Typically, the rays extend a short distance ahead of the character (usually a distance corresponding
* to a few seconds of movement).
*
* This behavior is especially suitable for large-scale obstacles like walls.
*
* You should use the {@link RayConfiguration} more suitable for your game environment. Some basic ray configurations are provided
* by the framework: {@link SingleRayConfiguration}, {@link ParallelSideRayConfiguration} and
* {@link CentralRayWithWhiskersConfiguration}. There are no hard and fast rules as to which configuration is better. Each has its
* own particular idiosyncrasies. A single ray with short whiskers is often the best initial configuration to try but can make it
* impossible for the character to move down tight passages. The single ray configuration is useful in concave environments but
* grazes convex obstacles. The parallel configuration works well in areas where corners are highly obtuse but is very susceptible
* to the corner trap.
*
*
* The corner trap
All the basic configurations for multi-ray obstacle avoidance can suffer from a crippling problem
* with acute angled corners (any convex corner, in fact, but it is more prevalent with acute angles). Consider a character with
* two parallel rays that is going towards a corner. As soon as its left ray is colliding with the wall near the corner, the
* steering behavior will turn it to the left to avoid the collision. Immediately, the right ray will then be colliding the other
* side of the corner, and the steering behavior will turn the character to the right. The character will repeatedly collide both
* sides of the corner in rapid succession. It will appear to home into the corner directly, until it slams into the wall. It will
* be unable to free itself from the trap.
*
* The fan structure, with a wide enough fan angle, alleviates this problem. Often, there is a trade-off, however, between
* avoiding the corner trap with a large fan angle and keeping the angle small to allow the character to access small passages. At
* worst, with a fan angle near PI radians, the character will not be able to respond quickly enough to collisions detected on its
* side rays and will still graze against walls. There are two approaches that work well and represent the most practical
* solutions to the problem:
*
* - Adaptive fan angles: If the character is moving successfully without a collision, then the fan angle is narrowed. If
* a collision is detected, then the fan angle is widened. If the character detects many collisions on successive frames, then the
* fan angle will continue to widen, reducing the chance that the character is trapped in a corner.
* - Winner ray: If a corner trap is detected, then one of the rays is considered to have won, and the collisions
* detected by other rays are ignored for a while.
*
* It seems that the most practical solution is to use adaptive fan angles, with one long ray cast and two shorter whiskers.
*
* @param Type of vector, either 2D or 3D, implementing the {@link Vector} interface
*
* @author davebaol
*/
declare class RaycastObstacleAvoidance> extends SteeringBehavior {
/** The inputRay configuration */
protected rayConfiguration: RayConfiguration;
/** The collision detector */
protected raycastCollisionDetector: RaycastCollisionDetector;
/** The minimum distance to a wall, i.e. how far to avoid collision. */
protected distanceFromBoundary: number;
private outputCollision;
private minOutputCollision;
/**
* Creates a {@code RaycastObstacleAvoidance} behavior.
* @param owner the owner of this behavior
* @param rayConfiguration the ray configuration
* @param raycastCollisionDetector the collision detector
* @param distanceFromBoundary the minimum distance to a wall (i.e., how far to avoid collision).
*/
constructor(owner: Steerable, rayConfiguration?: RayConfiguration, raycastCollisionDetector?: RaycastCollisionDetector, distanceFromBoundary?: number);
/** Returns the ray configuration of this behavior. */
getRayConfiguration(): RayConfiguration;
/**
* Sets the ray configuration of this behavior.
* @param rayConfiguration the ray configuration to set
* @return this behavior for chaining.
*/
setRayConfiguration(rayConfiguration: RayConfiguration): RaycastObstacleAvoidance;
/** Returns the raycast collision detector of this behavior. */
getRaycastCollisionDetector(): RaycastCollisionDetector;
/**
* Sets the raycast collision detector of this behavior.
* @param raycastCollisionDetector the raycast collision detector to set
* @return this behavior for chaining.
*/
setRaycastCollisionDetector(raycastCollisionDetector: RaycastCollisionDetector): RaycastObstacleAvoidance;
/** Returns the distance from boundary, i.e. the minimum distance to an obstacle. */
getDistanceFromBoundary(): number;
/**
* Sets the distance from boundary, i.e. the minimum distance to an obstacle.
* @param distanceFromBoundary the distanceFromBoundary to set
* @return this behavior for chaining.
*/
setDistanceFromBoundary(distanceFromBoundary: number): RaycastObstacleAvoidance;
setOwner(owner: Steerable): RaycastObstacleAvoidance;
setEnabled(enabled: boolean): RaycastObstacleAvoidance;
/**
* Sets the limiter of this steering behavior. The given limiter must at least take care of the maximum linear acceleration.
* @return this behavior for chaining.
*/
setLimiter(limiter: Limiter): RaycastObstacleAvoidance;
protected calculateRealSteering(steering: SteeringAcceleration): SteeringAcceleration;
}
export default RaycastObstacleAvoidance;