godot-steering-ai-framework/godot/addons/com.gdquest.godot-steering-ai-framework/Behaviors/GSAIPursue.gd
2020-08-23 12:25:09 -04:00

39 lines
1.3 KiB
GDScript

# Calculates an acceleration to make an agent intercept another based on the
# target agent's movement.
# @category - Individual behaviors
class_name GSAIPursue
extends GSAISteeringBehavior
# The target agent that the behavior is trying to intercept.
var target: GSAISteeringAgent
# The maximum amount of time in the future the behavior predicts the target's
# location.
var predict_time_max: float
func _init(agent: GSAISteeringAgent, _target: GSAISteeringAgent, _predict_time_max := 1.0).(agent) -> void:
self.target = _target
self.predict_time_max = _predict_time_max
func _calculate_steering(acceleration: GSAITargetAcceleration) -> void:
var target_position := target.position
var distance_squared := (target_position - agent.position).length_squared()
var speed_squared := agent.linear_velocity.length_squared()
var predict_time := predict_time_max
if speed_squared > 0:
var predict_time_squared := distance_squared / speed_squared
if predict_time_squared < predict_time_max * predict_time_max:
predict_time = sqrt(predict_time_squared)
acceleration.linear = ((target_position + (target.linear_velocity * predict_time)) - agent.position).normalized()
acceleration.linear *= _get_modified_acceleration()
acceleration.angular = 0
func _get_modified_acceleration() -> float:
return agent.linear_acceleration_max