Implement Separation behavior and add Proximity

project/project.godot

@@ -39,6 +39,11 @@ _global_script_classes=[ {
 "language": "GDScript",
 "path": "res://src/behaviors/GSTFlee.gd"
 }, {
+"base": "GSTProximity",
+"class": "GSTInfiniteProximity",
+"language": "GDScript",
+"path": "res://src/proximities/GSTInfiniteProximity.gd"
+}, {
 "base": "GSTMatchOrientation",
 "class": "GSTLookWhereYouGo",
 "language": "GDScript",
@@ -54,16 +59,31 @@ _global_script_classes=[ {
 "language": "GDScript",
 "path": "res://src/behaviors/GSTPriority.gd"
 }, {
+"base": "Reference",
+"class": "GSTProximity",
+"language": "GDScript",
+"path": "res://src/proximities/GSTProximity.gd"
+}, {
 "base": "GSTSteeringBehavior",
 "class": "GSTPursue",
 "language": "GDScript",
 "path": "res://src/behaviors/GSTPursue.gd"
 }, {
+"base": "GSTProximity",
+"class": "GSTRadiusProximity",
+"language": "GDScript",
+"path": "res://src/proximities/GSTRadiusProximity.gd"
+}, {
 "base": "GSTSteeringBehavior",
 "class": "GSTSeek",
 "language": "GDScript",
 "path": "res://src/behaviors/GSTSeek.gd"
 }, {
+"base": "GSTSteeringBehavior",
+"class": "GSTSeparation",
+"language": "GDScript",
+"path": "res://src/behaviors/GSTSeparation.gd"
+}, {
 "base": "GSTAgentLocation",
 "class": "GSTSteeringAgent",
 "language": "GDScript",
@@ -91,11 +111,15 @@ _global_script_class_icons={
 "GSTEvade": "",
 "GSTFace": "",
 "GSTFlee": "",
+"GSTInfiniteProximity": "",
 "GSTLookWhereYouGo": "",
 "GSTMatchOrientation": "",
 "GSTPriority": "",
+"GSTProximity": "",
 "GSTPursue": "",
+"GSTRadiusProximity": "",
 "GSTSeek": "",
+"GSTSeparation": "",
 "GSTSteeringAgent": "",
 "GSTSteeringBehavior": "",
 "GSTTargetAcceleration": "",

project/src/behaviors/GSTSeparation.gd

@@ -0,0 +1,40 @@
+extends GSTSteeringBehavior
+class_name GSTSeparation
+# Group behavior that produces acceleration repelling from the other neighbors that are in the
+# immediate area defined by the given `GSTProximity`.
+
+# # The produced acceleration is an average of all agents under consideration, multiplied by a
+# # strength decreasing by the inverse square law in relation to distance, and accumulated.
+# # In effect, all neighbors produce a single repelling force.
+
+
+var decay_coefficient: = 1.0
+
+var acceleration: GSTTargetAcceleration
+var proximity: GSTProximity
+
+
+func _init(agent: GSTSteeringAgent, proximity: GSTProximity).(agent) -> void:
+	self.proximity = proximity
+
+
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+	acceleration.set_zero()
+	self.acceleration = acceleration
+	proximity.find_neighbors(funcref(self, "_report_neighbor"))
+	return acceleration
+
+
+func _report_neighbor(neighbor: GSTSteeringAgent) -> bool:
+	var to_agent: = agent.position - neighbor.position
+
+	var distance_squared: = to_agent.length_squared()
+	var max_acceleration: = agent.max_linear_acceleration
+
+	var strength: = decay_coefficient / distance_squared
+	if strength > max_acceleration:
+		strength = max_acceleration
+	
+	acceleration.linear += to_agent * (strength / sqrt(distance_squared))
+
+	return true

project/src/proximities/GSTInfiniteProximity.gd

@@ -0,0 +1,20 @@
+extends GSTProximity
+class_name GSTInfiniteProximity
+# Specifies any agent that is in the specified list as being neighbors with the owner agent.
+
+
+func _init(agent: GSTSteeringAgent, agents: Array).(agent, agents) -> void:
+	pass
+
+
+func find_neighbors(callback: FuncRef) -> int:
+	var neighbor_count: = 0
+	var agent_count: = agents.size()
+	for i in range(agent_count):
+		var current_agent: = agents[i] as GSTSteeringAgent
+
+		if current_agent != agent:
+			if callback.call_func(current_agent):
+				neighbor_count += 1
+	
+	return neighbor_count

project/src/proximities/GSTProximity.gd

@@ -0,0 +1,16 @@
+extends Reference
+class_name GSTProximity
+# Defines an area that is used by group behaviors to find and process the owner's neighbors.
+
+
+var agent: GSTSteeringAgent
+var agents: = []
+
+
+func _init(agent: GSTSteeringAgent, agents: Array) -> void:
+    self.agent = agent
+    self.agents = agents
+
+
+func find_neighbors(callback: FuncRef) -> int:
+    return 0

project/src/proximities/GSTRadiusProximity.gd

@@ -0,0 +1,33 @@
+extends GSTProximity
+class_name GSTRadiusProximity
+# Specifies any agent that is in the specified list as being neighbors with the owner agent if they
+# lie within the specified radius.
+
+
+var radius: = 0.0
+
+
+func _init(agent: GSTSteeringAgent, agents: Array, radius: float).(agent, agents) -> void:
+	self.radius = radius
+
+
+func find_neighbors(callback: FuncRef) -> int:
+	var agent_count: = agents.size()
+	var neighbor_count: = 0
+
+	var owner_position: = agent.position
+	
+	for i in range(agent_count):
+		var current_agent: = agents[i] as GSTSteeringAgent
+
+		if current_agent != agent:
+			var distance_squared: = owner_position.distance_squared_to(current_agent.position)
+
+			var range_to: = radius + current_agent.bounding_radius
+
+			if distance_squared < range_to * range_to:
+				if callback.call_func(current_agent) == true:
+					neighbor_count += 1
+					continue
+	
+	return neighbor_count