feat: first basic enemy patrolling behaviour

modules/wave_survival/SCsub

@@ -2,3 +2,4 @@ Import('env')
 
 env.add_source_files(env.modules_sources, "*.cpp")
 env.add_source_files(env.modules_sources, "weapons/*.cpp")
+env.add_source_files(env.modules_sources, "enemies/*.cpp")

modules/wave_survival/enemies/enemy_wretched.cpp

@@ -0,0 +1,55 @@
+#include "enemy_wretched.h"
+#include "wave_survival/npc_unit.h"
+#include "wave_survival/patrol_path.h"
+#include "wave_survival/player_body.h"
+#include "wave_survival/state_machine.h"
+
+void EnemyWretched::_bind_methods() {
+}
+
+void EnemyWretched::ready() {
+	if (StateMachine * fsm{ cast_to<StateMachine>(get_node(NodePath("%StateMachine"))) }) {
+		fsm->add_state(memnew(WretchedPatrolState));
+	}
+}
+
+void EnemyWretched::_notification(int what) {
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+	switch (what) {
+		default:
+			return;
+		case NOTIFICATION_READY:
+			ready();
+			return;
+	}
+}
+
+void WretchedState::set_target(Node *node) {
+	this->target = cast_to<EnemyWretched>(node);
+}
+
+EnemyWretched *WretchedState::get_target() const {
+	return this->target;
+}
+
+void WretchedPatrolState::enter_state() {
+	this->nav = get_target()->get_nav();
+	this->path = get_target()->get_unit()->get_patrol_path();
+
+	float const max_speed{ get_target()->get_unit()->get_patrol_speed() };
+	get_target()->set_movement_speed(max_speed);
+	this->nav->set_max_speed(max_speed);
+	this->path_point = this->path->get_closest_point(get_target()->get_global_position());
+	this->nav->set_target_position(this->path->point_at(this->path_point));
+}
+
+void WretchedPatrolState::process(double delta) {
+	if (this->nav->is_navigation_finished()) {
+		this->path_point += 1;
+		this->nav->set_target_position(this->path->point_at(this->path_point));
+	}
+	Vector3 const direction{ get_target()->get_global_position().direction_to(this->nav->get_next_path_position()) };
+	get_target()->set_movement_direction(Vector2{ direction.x, direction.z }.normalized());
+}

modules/wave_survival/enemies/enemy_wretched.h

@@ -0,0 +1,45 @@
+#ifndef ENEMY_WRETCHED_H
+#define ENEMY_WRETCHED_H
+
+#include "wave_survival/enemy_body.h"
+#include "wave_survival/state.h"
+class PatrolPath;
+
+class EnemyWretched : public EnemyBody {
+	GDCLASS(EnemyWretched, EnemyBody);
+	static void _bind_methods();
+	void ready();
+
+protected:
+	void _notification(int what);
+};
+
+/* ============================== STATES ============================== */
+
+class WretchedState : public State {
+	GDCLASS(WretchedState, State);
+	static void _bind_methods() {}
+
+public:
+	virtual void set_target(Node *node) override;
+	EnemyWretched *get_target() const;
+
+private:
+	EnemyWretched *target{ nullptr };
+};
+
+class WretchedPatrolState : public WretchedState {
+	GDCLASS(WretchedPatrolState, WretchedState);
+	static void _bind_methods() {}
+
+public:
+	virtual void enter_state() override;
+	virtual void process(double delta) override;
+
+private:
+	NavigationAgent3D *nav{ nullptr };
+	int path_point{ 0 };
+	PatrolPath *path{ nullptr };
+};
+
+#endif // !ENEMY_WRETCHED_H

modules/wave_survival/enemy_body.cpp

@@ -0,0 +1,58 @@
+#include "enemy_body.h"
+#include "macros.h"
+#include "npc_unit.h"
+
+void EnemyBody::_bind_methods() {}
+
+void EnemyBody::ready() {
+	this->fsm = cast_to<StateMachine>(get_node(NodePath("%StateMachine")));
+	this->nav = cast_to<NavigationAgent3D>(get_node(NodePath("%NavigationAgent3D")));
+}
+
+void EnemyBody::physics_process(double delta) {
+	GETSET(velocity, {
+		velocity = Vector3{ this->movement_direction.x, velocity.y, this->movement_direction.y };
+	});
+	move_and_slide();
+}
+
+void EnemyBody::_notification(int what) {
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+	switch (what) {
+		default:
+			return;
+		case NOTIFICATION_READY:
+			set_physics_process(true);
+			ready();
+			return;
+		case NOTIFICATION_PHYSICS_PROCESS:
+			physics_process(get_physics_process_delta_time());
+			return;
+	}
+}
+
+void EnemyBody::set_movement_direction(Vector2 direction) {
+	this->movement_direction = direction;
+}
+
+void EnemyBody::set_unit(NpcUnit *unit) {
+	this->unit = unit;
+}
+
+NpcUnit *EnemyBody::get_unit() const {
+	return this->unit;
+}
+
+NavigationAgent3D *EnemyBody::get_nav() const {
+	return this->nav;
+}
+
+void EnemyBody::set_movement_speed(float value) {
+	this->movement_speed = value;
+}
+
+float EnemyBody::get_movement_speed() const {
+	return this->movement_speed;
+}

modules/wave_survival/enemy_body.h

@@ -0,0 +1,36 @@
+#ifndef ENEMY_BODY_H
+#define ENEMY_BODY_H
+
+#include "scene/3d/navigation/navigation_agent_3d.h"
+#include "scene/3d/physics/character_body_3d.h"
+#include "wave_survival/health_status.h"
+#include "wave_survival/state_machine.h"
+class NpcUnit;
+
+class EnemyBody : public CharacterBody3D {
+	GDCLASS(EnemyBody, CharacterBody3D);
+	static void _bind_methods();
+	void ready();
+	void physics_process(double delta);
+
+public:
+	void _notification(int what);
+
+	void set_movement_direction(Vector2 direction);
+	void set_unit(NpcUnit *unit);
+	NpcUnit *get_unit() const;
+
+	NavigationAgent3D *get_nav() const;
+	void set_movement_speed(float value);
+	float get_movement_speed() const;
+
+private:
+	float movement_speed{ 1.f };
+	Vector2 movement_direction{ 0, 0 };
+
+	StateMachine *fsm{ nullptr };
+	NpcUnit *unit{ nullptr };
+	NavigationAgent3D *nav{ nullptr };
+};
+
+#endif // !ENEMY_BODY_H

modules/wave_survival/macros.h

@@ -17,10 +17,10 @@
 	ADD_PROPERTY(PropertyInfo(m_type, #m_property), "set_" #m_property, \
 			"get_" #m_property)
 
-#define GETSET(m_value, m_block)         \
+#define GETSET(m_value, ...)             \
 	{                                    \
 		auto m_value{ get_##m_value() }; \
-		m_block                          \
+		__VA_ARGS__                      \
 		set_##m_value(m_value);          \
 	}
 

modules/wave_survival/npc_unit.cpp

@@ -0,0 +1,52 @@
+#include "npc_unit.h"
+#include "enemy_body.h"
+#include "macros.h"
+#include "patrol_path.h"
+
+void NpcUnit::_bind_methods() {
+	BIND_HPROPERTY(Variant::OBJECT, patrol_path, PROPERTY_HINT_NODE_TYPE, "PatrolPath");
+}
+
+void NpcUnit::child_added(Node *node) {
+	if (EnemyBody * npc{ cast_to<EnemyBody>(node) }) {
+		this->npcs.push_back(npc);
+		npc->set_unit(this);
+	}
+}
+
+void NpcUnit::enter_tree() {
+	this->connect("child_entered_tree", callable_mp(this, &self_type::child_added));
+}
+
+void NpcUnit::_notification(int what) {
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+	switch (what) {
+		default:
+			return;
+		case NOTIFICATION_ENTER_TREE:
+			enter_tree();
+			return;
+	}
+}
+
+void NpcUnit::set_patrol_path(PatrolPath *path) {
+	this->patrol_path = path;
+}
+
+PatrolPath *NpcUnit::get_patrol_path() const {
+	return this->patrol_path;
+}
+
+bool NpcUnit::is_aware_of_player() const {
+	return false;
+}
+
+void NpcUnit::set_patrol_speed(float speed) {
+	this->patrol_speed = speed;
+}
+
+float NpcUnit::get_patrol_speed() const {
+	return this->patrol_speed;
+}

modules/wave_survival/npc_unit.h

@@ -0,0 +1,31 @@
+#ifndef NPC_UNIT_H
+#define NPC_UNIT_H
+
+#include "scene/main/node.h"
+class StateMachine;
+class EnemyBody;
+class PatrolPath;
+
+class NpcUnit : public Node {
+	GDCLASS(NpcUnit, Node);
+	static void _bind_methods();
+	void child_added(Node *node);
+	void enter_tree();
+
+protected:
+	void _notification(int what);
+
+public:
+	void set_patrol_path(PatrolPath *path);
+	PatrolPath *get_patrol_path() const;
+	bool is_aware_of_player() const; //!< becomes true when any individual in the unit sees the player.
+	void set_patrol_speed(float value);
+	float get_patrol_speed() const;
+
+private:
+	Vector<EnemyBody *> npcs{};
+	PatrolPath *patrol_path{ nullptr };
+	float patrol_speed{ 3.f };
+};
+
+#endif // !NPC_UNIT_H

modules/wave_survival/patrol_path.cpp

@@ -0,0 +1,64 @@
+#include "patrol_path.h"
+
+void PatrolPath::_bind_methods() {}
+
+void PatrolPath::child_added(Node *child) {
+	if (Node3D * child3d{ cast_to<Node3D>(child) }) {
+		this->path.push_back(child3d);
+	}
+}
+
+void PatrolPath::child_removed(Node *child) {
+	if (Node3D * child3d{ cast_to<Node3D>(child) }) {
+		this->path.erase(child3d);
+	}
+}
+
+void PatrolPath::enter_tree() {
+	this->connect("child_entered_tree", callable_mp(this, &self_type::child_added));
+	this->connect("child_exiting_tree", callable_mp(this, &self_type::child_removed));
+}
+
+void PatrolPath::_notification(int what) {
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+	switch (what) {
+		default:
+			return;
+		case NOTIFICATION_ENTER_TREE:
+			enter_tree();
+			return;
+	}
+}
+
+int PatrolPath::point_count() const {
+	return this->path.size();
+}
+
+Vector3 PatrolPath::point_at(int &index) const {
+	index = Math::abs(index) % point_count();
+	return point_at_unchecked(index);
+}
+
+Vector3 PatrolPath::point_at_unchecked(int const index) const {
+	return this->path.get(index)->get_global_position();
+}
+
+int PatrolPath::get_closest_point(Vector3 global_position) {
+	int best_choice_idx{ -1 };
+	float best_choice_distance{ Math::INF };
+	for (int i{ 0 }; i < point_count(); ++i) {
+		int const next_idx{ (i + 1) % point_count() };
+		Vector3 const current{ point_at(i) };
+		Vector3 const next{ point_at_unchecked(next_idx) };
+		Vector3 const path_direction{ (next - current).normalized() };
+		Vector3 const direction{ (global_position - current).normalized() };
+		float const distance{ global_position.distance_squared_to(next) };
+		if (path_direction.dot(direction) > 1.0 && distance < best_choice_distance) {
+			best_choice_idx = next_idx;
+			best_choice_distance = distance;
+		}
+	}
+	return best_choice_idx;
+}

modules/wave_survival/patrol_path.h

@@ -0,0 +1,26 @@
+#ifndef PATROL_PATH_H
+#define PATROL_PATH_H
+
+#include "scene/3d/node_3d.h"
+
+class PatrolPath : public Node3D {
+	GDCLASS(PatrolPath, Node3D);
+	static void _bind_methods();
+	void child_added(Node *child);
+	void child_removed(Node *child);
+	void enter_tree();
+
+protected:
+	void _notification(int what);
+
+public:
+	int point_count() const;
+	Vector3 point_at(int &index) const;
+	Vector3 point_at_unchecked(int const index) const;
+	int get_closest_point(Vector3 global_position);
+
+private:
+	Vector<Node3D *> path{};
+};
+
+#endif // !PATROL_PATH_H

modules/wave_survival/register_types.cpp

@@ -1,8 +1,12 @@
 #include "register_types.h"
 
 #include "core/object/class_db.h"
+#include "wave_survival/enemies/enemy_wretched.h"
+#include "wave_survival/enemy_body.h"
 #include "wave_survival/health_status.h"
 #include "wave_survival/hitscan_muzzle.h"
+#include "wave_survival/npc_unit.h"
+#include "wave_survival/patrol_path.h"
 #include "wave_survival/player_body.h"
 #include "wave_survival/player_camera.h"
 #include "wave_survival/player_input.h"
@@ -26,6 +30,10 @@ void initialize_wave_survival_module(ModuleInitializationLevel p_level) {
 	GDREGISTER_CLASS(HealthStatus);
 	GDREGISTER_CLASS(StateMachine);
 	GDREGISTER_CLASS(State);
+	GDREGISTER_CLASS(EnemyBody);
+	GDREGISTER_CLASS(PatrolPath);
+	GDREGISTER_CLASS(NpcUnit);
+	GDREGISTER_CLASS(EnemyWretched);
 }
 
 void uninitialize_wave_survival_module(ModuleInitializationLevel p_level) {

modules/wave_survival/state_machine.cpp

@@ -3,21 +3,12 @@
 
 void StateMachine::_bind_methods() {}
 
-void StateMachine::add_state(State *state) {
-	state->set_state_machine(this);
-	state->set_target(this->get_parent());
-	this->states.insert(state->get_class(), state);
-	if (this->current_state == nullptr) {
-		this->switch_to_state(state);
-	}
-}
-
 void StateMachine::switch_to_state(State *state) {
-	if (this->current_state) {
+	if (this->current_state != nullptr) {
 		this->current_state->exit_state();
 	}
 	this->current_state = state;
-	if (this->current_state) {
+	if (this->current_state != nullptr) {
 		this->current_state->enter_state();
 	} else {
 		print_error("StateMachine::switch_to_state: New state is nullptr, StateMachine will now stop working");
@@ -53,3 +44,18 @@ void StateMachine::_notification(int what) {
 			return;
 	}
 }
+
+StateMachine::~StateMachine() {
+	for (KeyValue<StringName, State *> kvp : this->states) {
+		memdelete(kvp.value);
+	}
+}
+
+void StateMachine::add_state(State *state) {
+	state->set_state_machine(this);
+	state->set_target(this->get_parent());
+	this->states.insert(state->get_class(), state);
+	if (this->current_state == nullptr) {
+		this->switch_to_state(state);
+	}
+}

modules/wave_survival/state_machine.h

@@ -7,7 +7,6 @@ class State;
 class StateMachine : public Node {
 	GDCLASS(StateMachine, Node);
 	static void _bind_methods();
-	void add_state(State *state);
 	void switch_to_state(State *state);
 	void ready();
 	void process(double delta);
@@ -15,6 +14,10 @@ class StateMachine : public Node {
 protected:
 	void _notification(int what);
 
+public:
+	~StateMachine();
+	void add_state(State *state);
+
 private:
 	State *current_state{ nullptr };
 	HashMap<StringName, State *> states{};

project/objects/enemies/enemy_wretched.tscn

@@ -0,0 +1,21 @@
+[gd_scene load_steps=3 format=3 uid="uid://dqlqgk1veyos8"]
+
+[ext_resource type="PackedScene" uid="uid://7esw31b76x4" path="res://assets/models/base_character.blend" id="1_qot2n"]
+
+[sub_resource type="CapsuleShape3D" id="CapsuleShape3D_ng1ul"]
+
+[node name="EnemyWretched" type="EnemyWretched"]
+
+[node name="base_character" parent="." instance=ExtResource("1_qot2n")]
+
+[node name="CollisionShape3D" type="CollisionShape3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0)
+shape = SubResource("CapsuleShape3D_ng1ul")
+
+[node name="StateMachine" type="StateMachine" parent="."]
+unique_name_in_owner = true
+
+[node name="NavigationAgent3D" type="NavigationAgent3D" parent="."]
+unique_name_in_owner = true
+path_desired_distance = 0.25
+debug_enabled = true