broken_seals/game/steering_ai_framework/Behaviors/GSAIAvoidCollisions.gd

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2.4 KiB
GDScript

# Steers the agent to avoid obstacles in its path. Approximates obstacles as
# spheres.
class_name GSAIAvoidCollisions
extends GSAIGroupBehavior
var _first_neighbor: GSAISteeringAgent
var _shortest_time: float
var _first_minimum_separation: float
var _first_distance: float
var _first_relative_position: Vector3
var _first_relative_velocity: Vector3
func _init(agent: GSAISteeringAgent, proximity: GSAIProximity).(agent, proximity) -> void:
pass
func _calculate_steering(acceleration: GSAITargetAcceleration) -> void:
_shortest_time = INF
_first_neighbor = null
_first_minimum_separation = 0
_first_distance = 0
var neighbor_count := proximity._find_neighbors(_callback)
if neighbor_count == 0 or not _first_neighbor:
acceleration.set_zero()
else:
if (
_first_minimum_separation <= 0
or _first_distance < agent.bounding_radius + _first_neighbor.bounding_radius
):
acceleration.linear = _first_neighbor.position - agent.position
else:
acceleration.linear = (
_first_relative_position
+ (_first_relative_velocity * _shortest_time)
)
acceleration.linear = (acceleration.linear.normalized() * -agent.linear_acceleration_max)
acceleration.angular = 0
# Callback for the proximity to call when finding neighbors. Keeps track of every `neighbor`
# that was found but only keeps the one the owning agent will most likely collide with.
# tags: virtual
func _report_neighbor(neighbor: GSAISteeringAgent) -> bool:
var relative_position := neighbor.position - agent.position
var relative_velocity := neighbor.linear_velocity - agent.linear_velocity
var relative_speed_squared := relative_velocity.length_squared()
if relative_speed_squared == 0:
return false
else:
var time_to_collision = -relative_position.dot(relative_velocity) / relative_speed_squared
if time_to_collision <= 0 or time_to_collision >= _shortest_time:
return false
else:
var distance = relative_position.length()
var minimum_separation: float = (
distance
- sqrt(relative_speed_squared) * time_to_collision
)
if minimum_separation > agent.bounding_radius + neighbor.bounding_radius:
return false
else:
_shortest_time = time_to_collision
_first_neighbor = neighbor
_first_minimum_separation = minimum_separation
_first_distance = distance
_first_relative_position = relative_position
_first_relative_velocity = relative_velocity
return true