From 336754d5595d62a1de3261d7117c9c6ac2cff18c Mon Sep 17 00:00:00 2001
From: Sara <sara@saragerretsen.nl>
Date: Wed, 20 Mar 2024 09:50:10 +0100
Subject: [PATCH] feat: implemented a zero-volume pellet projectile

---
 src/pellet_projectile.cpp | 43 +++++++++++++++++++++++++++++++++++++++
 src/pellet_projectile.hpp | 22 ++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 src/pellet_projectile.cpp
 create mode 100644 src/pellet_projectile.hpp

diff --git a/src/pellet_projectile.cpp b/src/pellet_projectile.cpp
new file mode 100644
index 0000000..b9a537c
--- /dev/null
+++ b/src/pellet_projectile.cpp
@@ -0,0 +1,43 @@
+#include "pellet_projectile.hpp"
+#include "health.hpp"
+#include "utils/godot_macros.h"
+#include <godot_cpp/classes/physics_direct_space_state3d.hpp>
+#include <godot_cpp/classes/physics_ray_query_parameters3d.hpp>
+#include <godot_cpp/classes/physics_server3d.hpp>
+#include <godot_cpp/classes/world3d.hpp>
+
+namespace godot {
+void PelletProjectile::_bind_methods() {
+#define CLASSNAME PelletProjectile
+}
+
+void PelletProjectile::_enter_tree() {
+    this->distance_traveled = 0;
+}
+
+void PelletProjectile::_physics_process(double delta_time) { GDGAMEONLY();
+    float const speed = this->data->get_projectile_speed()->sample(distance_traveled / this->data->get_range());
+    this->distance_traveled += speed;
+    Vector3 const next_position{this->get_global_position() + this->get_global_transform().basis.get_column(2) * speed};
+    if(this->check_hit(next_position) || this->distance_traveled > this->data->get_range()) {
+        this->return_to_pool();
+    } else {
+        this->set_global_position(next_position);
+    }
+}
+
+bool PelletProjectile::check_hit(Vector3 next_position) {
+    Ref<PhysicsRayQueryParameters3D> query{PhysicsRayQueryParameters3D::create(this->get_global_position(), next_position, 0x4)};
+    Dictionary hit = this->get_world_3d()->get_direct_space_state()->intersect_ray(query);
+    if(hit.is_empty())
+        return false;
+    Node *collider = Object::cast_to<Node>(hit.get("collider", nullptr));
+    if(collider == nullptr)
+        return false;
+    IHealthEntity *health_entity = dynamic_cast<IHealthEntity*>(collider);
+    if(health_entity == nullptr)
+        return false;
+    health_entity->get_health()->damage(this->data->get_damage());
+    return true;
+}
+}
diff --git a/src/pellet_projectile.hpp b/src/pellet_projectile.hpp
new file mode 100644
index 0000000..b86b532
--- /dev/null
+++ b/src/pellet_projectile.hpp
@@ -0,0 +1,22 @@
+#ifndef PELLET_PROJECTILE_HPP
+#define PELLET_PROJECTILE_HPP
+
+#include "weapon_data.hpp"
+#include "projectile.hpp"
+#include <godot_cpp/classes/node3d.hpp>
+
+namespace godot {
+class PelletProjectile : public Projectile {
+    GDCLASS(PelletProjectile, Projectile);
+    static void _bind_methods();
+public:
+    virtual void _enter_tree() override;
+    virtual void _physics_process(double delta_time) override;
+
+    bool check_hit(Vector3 next_position);
+private:
+    float distance_traveled{0.f};
+};
+}
+
+#endif // !PELLET_PROJECTILE_HPP