godot-steering-ai-framework/godot/addons/com.gdquest.godot-steering-ai-framework/Behaviors/GSAIFollowPath.gd

54 lines
1.8 KiB
GDScript

# Produces a linear acceleration that moves the agent along the specified path.
# @category - Individual behaviors
class_name GSAIFollowPath
extends GSAIArrive
# The path to follow and travel along.
var path : GSAIPath
# The distance along the path to generate the next target position.
var path_offset : float = 0.0
# Whether to use `GSAIArrive` behavior on an open path.
var is_arrive_enabled : bool = true
# The amount of time in the future to predict the owning agent's position along
# the path. Setting it to 0.0 will force non-predictive path following.
var prediction_time : float = 0.0
func _init(agent: GSAISteeringAgent, _path: GSAIPath, _path_offset := 0.0, _prediction_time := 0.0).(agent, null) -> void:
self.path = _path
self.path_offset = _path_offset
self.prediction_time = _prediction_time
func _calculate_steering(acceleration: GSAITargetAcceleration) -> void:
var location : Vector3
if prediction_time == 0:
location = agent.position
else:
location = agent.position + (agent.linear_velocity * prediction_time)
var distance : float = path.calculate_distance(location)
var target_distance : float = distance + path_offset
if prediction_time > 0 and path.is_open:
if target_distance < path.calculate_distance(agent.position):
target_distance = path.length
var target_position : Vector3 = path.calculate_target_position(target_distance)
if is_arrive_enabled and path.is_open:
if path_offset >= 0:
if target_distance > path.length - deceleration_radius:
_arrive(acceleration, target_position)
return
else:
if target_distance < deceleration_radius:
_arrive(acceleration, target_position)
return
acceleration.linear = (target_position - agent.position).normalized()
acceleration.linear *= agent.linear_acceleration_max
acceleration.angular = 0