feat: implementations of initial weapon inventory interface

modules/wave_survival/weapon_inventory.cpp

@@ -1,10 +1,99 @@
 #include "weapon_inventory.h"
+#include "macros.h"
+#include "weapon_base.h"
 
-void WeaponInventory::_bind_methods() {}
+void WeaponInventory::_bind_methods() {
+	BIND_HPROPERTY(Variant::OBJECT, fallback_weapon, PROPERTY_HINT_RESOURCE_TYPE, "PackedScene");
+}
 
 void WeaponInventory::on_switch_input() {
 	this->current = (this->current + 1) % 1;
 	this->select_weapon(this->weapons[this->current]);
 }
 
+void WeaponInventory::ready() {
+	// initialize the fallback weapon
+	this->weapon_parent = cast_to<Node3D>(get_node(NodePath("%PlayerCamera")));
+	if (this->fallback_weapon_scene.is_valid()) {
+		Node *fallback_as_node{ this->fallback_weapon_scene->instantiate() };
+		this->weapon_parent->add_child(fallback_as_node);
+		if ((this->fallback_weapon = cast_to<WeaponBase>(fallback_as_node))) {
+			this->select_weapon(this->fallback_weapon);
+		} else if(fallback_as_node != nullptr) {
+			fallback_as_node->queue_free();
+		}
+	}
+	if (this->fallback_weapon == nullptr) {
+		print_error("WeaponInventory::ready(): fallback weapon is invalid, expect unintended behaviour.");
+	}
+}
 
+void WeaponInventory::_notification(int what) {
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+	switch (what) {
+		default:
+			return;
+		case NOTIFICATION_READY:
+			ready();
+			return;
+	}
+}
+
+void WeaponInventory::set_fallback_weapon(Ref<PackedScene> scene) {
+	this->fallback_weapon_scene = scene;
+}
+
+Ref<PackedScene> WeaponInventory::get_fallback_weapon() const {
+	return this->fallback_weapon_scene;
+}
+
+void WeaponInventory::select_weapon(WeaponBase *new_weapon) {
+	if (new_weapon == nullptr) {
+		new_weapon = this->fallback_weapon;
+	}
+	if (this->current_weapon != nullptr) {
+		this->current_weapon->set_process_mode(PROCESS_MODE_DISABLED);
+		this->current_weapon->set_visible(false);
+	}
+	this->current_weapon = new_weapon;
+	if (new_weapon != nullptr) {
+		this->current_weapon->set_process_mode(PROCESS_MODE_PAUSABLE);
+		this->current_weapon->set_visible(true);
+		this->current_weapon->notify_selected();
+		if (new_weapon == this->weapons[0]) {
+			this->current = 0;
+		} else if (new_weapon == this->weapons[1]) {
+			this->current = 1;
+		} else {
+			print_error("WeaponInventory::select_weapon: Attempt to select weapon that is not in inventory");
+		}
+	}
+}
+
+WeaponBase *WeaponInventory::get_current_weapon() const {
+	return this->current_weapon;
+}
+
+void WeaponInventory::pickup_weapon(Ref<PackedScene> weapon_scene) {
+	Node *weapon_as_node{ weapon_scene->instantiate() };
+	if (WeaponBase *weapon{ cast_to<WeaponBase>(weapon_as_node) }) {
+		if (this->weapons[0] == nullptr) {
+			this->weapons[0] = weapon;
+			select_weapon(weapon);
+			return;
+		} else if (this->weapons[1] == nullptr) {
+			this->weapons[1] = weapon;
+			select_weapon(weapon);
+			return;
+		} else {
+			this->current_weapon->queue_free();
+			this->weapons[this->current] = weapon;
+			this->current_weapon = nullptr;
+			select_weapon(weapon);
+		}
+	} else if (weapon_as_node != nullptr) {
+		weapon_as_node->queue_free();
+	}
+}