feat: added simple enemy with chase behaviour

src/enemy.cpp

@@ -0,0 +1,69 @@
+#include "enemy.hpp"
+#include "godot_cpp/classes/time.hpp"
+#include "godot_cpp/variant/utility_functions.hpp"
+#include "health.hpp"
+#include "player_character.hpp"
+#include "utils/godot_macros.h"
+#include <godot_cpp/classes/navigation_agent3d.hpp>
+
+namespace godot {
+void Enemy::_bind_methods() {
+#define CLASSNAME Enemy
+    GDFUNCTION_ARGS(body_entered_vision_area, "body");
+}
+
+void Enemy::_ready() { GDGAMEONLY();
+    this->health = this->get_node<Health>("Health");
+    this->nav_agent = this->get_node<NavigationAgent3D>("NavigationAgent3D");
+    this->vision_area = this->get_node<Area3D>("VisionArea");
+    this->vision_area->connect("body_entered", Callable(this, "body_entered_vision_area"));
+    this->update_navigation_target();
+}
+
+void Enemy::_process(double delta_time) { GDGAMEONLY();
+    if(this->renav_time > Time::get_singleton()->get_ticks_msec() / 1000.f) {
+        this->update_navigation_target();
+    }
+    this->process_navigation(delta_time);
+    this->move_and_slide();
+}
+
+void Enemy::process_navigation(double delta_time) {
+    if(this->nav_agent->is_navigation_finished()) {
+        return;
+    }
+    Vector3 const desired_direction = (this->nav_agent->get_next_path_position() - this->get_global_position()).normalized();
+    this->set_velocity(desired_direction);
+    Transform3D trans = this->get_global_transform();
+    Vector3 const forward = desired_direction;
+    trans.set_basis(Basis{desired_direction.cross(Vector3{0.f, 1.f, 0.f}), Vector3{0.f, 1.f, 0.f}, forward});
+    this->set_global_transform(trans);
+}
+
+void Enemy::body_entered_vision_area(Node3D *body) {
+    PlayerCharacter *player = Object::cast_to<PlayerCharacter>(body);
+    if(player == nullptr)
+        return;
+    // TODO: replace this with some condition deciding wether to attack the new character or the current target
+    this->target_player = player;
+    this->update_navigation_target();
+}
+
+void Enemy::update_navigation_target() {
+    this->renav_time = float(Time::get_singleton()->get_ticks_msec()) / 1000.f + Enemy::RENAV_INTERVAL;
+    if(this->target_player == nullptr)
+        this->nav_agent->set_target_position(this->get_global_position());
+    else
+        this->nav_agent->set_target_position(this->target_player->get_global_position());
+}
+
+Health *Enemy::get_health() {
+    return this->health;
+}
+
+Health const *Enemy::get_health() const {
+    return this->health;
+}
+
+float const Enemy::RENAV_INTERVAL{0.25f};
+}

src/enemy.hpp

@@ -0,0 +1,40 @@
+#ifndef ENEMY_HPP
+#define ENEMY_HPP
+
+#include "godot_cpp/classes/area3d.hpp"
+#include "health.hpp"
+#include <godot_cpp/classes/character_body3d.hpp>
+
+namespace godot {
+class PlayerCharacter;
+class NavigationAgent3D;
+
+class Enemy : public CharacterBody3D,
+              public IHealthEntity {
+    GDCLASS(Enemy, CharacterBody3D);
+    static void _bind_methods();
+public:
+    virtual void _ready() override;
+    virtual void _process(double delta_time) override;
+    void process_navigation(double delta_time);
+
+    void body_entered_vision_area(Node3D *body);
+
+    void update_navigation_target();
+
+    virtual Health *get_health() override;
+    virtual Health const *get_health() const override;
+
+private:
+    float renav_time{0.f};
+
+    PlayerCharacter *target_player{nullptr};
+    Health *health{nullptr};
+    NavigationAgent3D *nav_agent{nullptr};
+    Area3D *vision_area{nullptr};
+
+    static float const RENAV_INTERVAL;
+};
+}
+
+#endif // !ENEMY_HPP

src/register_types.cpp

@@ -9,6 +9,7 @@
 #include "utils/level.hpp"
 #include "utils/player_input.hpp"
 #include "utils/spawn_point.hpp"
+#include "enemy.hpp"
 #include "health.hpp"
 #include "player_character.hpp"
 #include "tunnels_game_mode.hpp"
@@ -22,16 +23,18 @@ void initialize_gdextension_types(ModuleInitializationLevel p_level)
         return;
     }
     ClassDB::register_abstract_class<GameRoot>();
-    ClassDB::register_class<GameRoot3D>();
-    ClassDB::register_class<SpawnPoint3D>();
-    ClassDB::register_class<PlayerInput>();
     ClassDB::register_class<GameMode>();
+    ClassDB::register_class<GameRoot3D>();
     ClassDB::register_class<GameState>();
     ClassDB::register_class<Level3D>();
+    ClassDB::register_class<PlayerInput>();
+    ClassDB::register_class<SpawnPoint3D>();
+
+    ClassDB::register_class<Enemy>();
+    ClassDB::register_class<Health>();
+    ClassDB::register_class<PlayerCharacter>();
     ClassDB::register_class<TunnelsGameMode>();
     ClassDB::register_class<TunnelsPlayer>();
-    ClassDB::register_class<PlayerCharacter>();
-    ClassDB::register_class<Health>();
 }
 
 extern "C"

src/tunnels_player.cpp

@@ -68,7 +68,7 @@ void TunnelsPlayer::process_mouse_location(double delta_time) {
 
 void TunnelsPlayer::process_camera_rotation(double delta_time) {
     Vector3 rotation = this->get_global_rotation();
-    float const y_multiplier = std::max(0.4f, this->mouse_location.y); // the influence of the mouse's y position on the rotation speed
+    float const y_multiplier = std::max(TunnelsPlayer::ROTATION_Y_MIN_INFLUENCE, this->mouse_location.y); // the influence of the mouse's y position on the rotation speed
     // rotate the camera when the mouse is close to the edge of the screen
     if(this->mouse_location.x < TunnelsPlayer::ROTATION_MARGIN) {
         // normalized measurement of how far into the rotation margin the mouse is
@@ -156,6 +156,7 @@ Ref<Curve> TunnelsPlayer::get_camera_rotation_ramp() const {
     return this->camera_rotation_ramp;
 }
 
-float const TunnelsPlayer::ROTATION_SPEED{4.f};
-float const TunnelsPlayer::ROTATION_MARGIN{0.35f};
+float const TunnelsPlayer::ROTATION_SPEED{6.f};
+float const TunnelsPlayer::ROTATION_Y_MIN_INFLUENCE{7.f};
+float const TunnelsPlayer::ROTATION_MARGIN{0.4f};
 }

src/tunnels_player.hpp

@@ -53,7 +53,9 @@ private:
     Camera3D *camera{nullptr};
 
     Ref<Curve> camera_rotation_ramp{};
+
     static float const ROTATION_SPEED;
+    static float const ROTATION_Y_MIN_INFLUENCE;
     static float const ROTATION_MARGIN;
 };
 }