From f09e998d526a3c2804e24bdb17b13adbbc740fc4 Mon Sep 17 00:00:00 2001
From: Riyyi <riyyi3@gmail.com>
Date: Mon, 18 Jan 2021 17:20:50 +0100
Subject: [PATCH] Add script system

---
 inferno/src/inferno/scene/scene.cpp    | 19 +++++---
 inferno/src/inferno/systems/script.cpp | 65 ++++++++++++++++++++++++++
 inferno/src/inferno/systems/script.h   | 30 ++++++++++++
 3 files changed, 107 insertions(+), 7 deletions(-)
 create mode 100644 inferno/src/inferno/systems/script.cpp
 create mode 100644 inferno/src/inferno/systems/script.h

diff --git a/inferno/src/inferno/scene/scene.cpp b/inferno/src/inferno/scene/scene.cpp
index 1aaa584..fd222ea 100644
--- a/inferno/src/inferno/scene/scene.cpp
+++ b/inferno/src/inferno/scene/scene.cpp
@@ -5,6 +5,7 @@
 #include "inferno/script/nativescript.h"
 #include "inferno/systems/camera.h"
 #include "inferno/systems/render.h"
+#include "inferno/systems/script.h"
 #include "inferno/systems/transform.h"
 
 namespace Inferno {
@@ -34,6 +35,10 @@ namespace Inferno {
 		renderSystem->initialize();
 		RenderSystem::the().setRegistry(m_registry);
 
+		ScriptSystem* scriptSystem = new ScriptSystem();
+		scriptSystem->initialize();
+		ScriptSystem::the().setScene(this);
+
 		// Load assets
 		// ---------------------------------
 
@@ -61,7 +66,7 @@ namespace Inferno {
 
 	void Scene::update(float deltaTime)
 	{
-		(void)deltaTime;
+		ScriptSystem::the().update(deltaTime);
 
 		TransformSystem::the().update();
 		CameraSystem::the().update();
@@ -74,6 +79,7 @@ namespace Inferno {
 
 	void Scene::destroy()
 	{
+		ScriptSystem::the().destroy();
 		RenderSystem::the().destroy();
 		CameraSystem::the().destroy();
 		TransformSystem::the().destroy();
@@ -88,14 +94,13 @@ namespace Inferno {
 		return entity;
 	}
 
-	Entity Scene::createEntity(entt::entity handle)
+	void Scene::destroyEntity(uint32_t entity)
 	{
-		return Entity(m_registry, handle);
-	}
+		if (hasComponent<NativeScript>(entity)) {
+			ScriptSystem::the().cleanup(entity);
+		}
 
-	Entity Scene::createEntity(uint32_t handle)
-	{
-		return Entity(m_registry, handle);
+		m_registry->destroy(entt::entity { entity });
 	}
 
 	glm::mat4 Scene::cameraProjectionView()
diff --git a/inferno/src/inferno/systems/script.cpp b/inferno/src/inferno/systems/script.cpp
new file mode 100644
index 0000000..cdc948e
--- /dev/null
+++ b/inferno/src/inferno/systems/script.cpp
@@ -0,0 +1,65 @@
+#include "entt/entity/registry.hpp" // entt::entity, entt::registry
+
+#include "inferno/assertions.h"
+#include "inferno/scene/components.h"
+#include "inferno/script/nativescript.h"
+#include "inferno/systems/script.h"
+#include <bits/stdint-uintn.h>
+
+namespace Inferno {
+
+	ScriptSystem* ScriptSystem::s_instance = nullptr;
+
+	void ScriptSystem::initialize()
+	{
+		ASSERT(!s_instance, "ScriptSystem already exists!");
+		s_instance = this;
+
+		dbg(Log::Info) << "ScriptSystem initialized";
+	}
+
+	void ScriptSystem::destroy()
+	{
+		auto view = m_scene->registry()->view<NativeScriptComponent>();
+
+		// @Todo change the getComponent() call to retrieve from the view for more performance
+		for (auto entity : view) {
+			cleanup(static_cast<uint32_t>(entity));
+		}
+
+		delete s_instance;
+		s_instance = nullptr;
+	}
+
+	void ScriptSystem::update(float deltaTime)
+	{
+		// @Todo figure out why group doesn't work here
+		auto view = m_scene->registry()->view<TransformComponent, NativeScriptComponent>();
+
+		for (auto [entity, transform, nativeScript] : view.each()) {
+
+			// Create script if not initialized
+			if (!nativeScript.instance) {
+				nativeScript.initialize();
+				nativeScript.instance->transform = &transform;
+				nativeScript.instance->m_scene = m_scene;
+				nativeScript.instance->m_entity = static_cast<uint32_t>(entity);
+				nativeScript.instance->initialize();
+			}
+
+			nativeScript.instance->transform = &transform;
+			nativeScript.instance->update(deltaTime);
+		}
+	}
+
+	void ScriptSystem::cleanup(uint32_t entity)
+	{
+		auto& nativeScript = m_scene->getComponent<NativeScriptComponent>(entity);
+
+		if (!nativeScript.instance) {
+			nativeScript.instance->destroy();
+			nativeScript.destroy();
+		}
+	}
+
+}
diff --git a/inferno/src/inferno/systems/script.h b/inferno/src/inferno/systems/script.h
new file mode 100644
index 0000000..c61a5c7
--- /dev/null
+++ b/inferno/src/inferno/systems/script.h
@@ -0,0 +1,30 @@
+#ifndef SCRIPT_SYSTEM_H
+#define SCRIPT_SYSTEM_H
+
+#include <memory> //std::shared_ptr
+
+namespace Inferno {
+
+	class Scene;
+
+	class ScriptSystem {
+	public:
+		void initialize();
+		void destroy();
+		void update(float deltaTime);
+
+		void cleanup(uint32_t entity);
+
+		void setScene(Scene* scene) { m_scene = scene; }
+
+		static inline ScriptSystem& the() { return *s_instance; }
+
+	private:
+		Scene* m_scene;
+
+		static ScriptSystem* s_instance;
+	};
+
+}
+
+#endif // SCRIPT_SYSTEM_H