Docs: Add audio module architecture design document

- Add XCEngine音频模块架构设计.md
- Design audio system following Unity-style architecture
- Include AudioSourceComponent, AudioListenerComponent, AudioClip, AudioMixer
- Document DSP effect system (FFT, Reverb, EQ, Compressor)
- Document 3D spatial audio with HRTF support
- Define IAudioBackend abstraction layer with WASAPI/OpenAL backends
- Outline 5-phase implementation priorities

engine/src/Components/GameObject.cpp

@@ -0,0 +1,190 @@
+#include "Components/GameObject.h"
+#include "Components/TransformComponent.h"
+#include "Scene/Scene.h"
+
+namespace XCEngine {
+namespace Components {
+
+GameObject::ID GameObject::s_nextID = 1;
+
+GameObject::GameObject()
+    : m_name("GameObject") {
+    m_id = s_nextID++;
+    m_transform = new TransformComponent();
+    m_transform->m_gameObject = this;
+}
+
+GameObject::GameObject(const std::string& name)
+    : m_name(name) {
+    m_id = s_nextID++;
+    m_transform = new TransformComponent();
+    m_transform->m_gameObject = this;
+}
+
+GameObject::~GameObject() {
+    if (m_transform) {
+        delete m_transform;
+        m_transform = nullptr;
+    }
+    m_components.clear();
+}
+
+std::unordered_map<GameObject::ID, GameObject*>& GameObject::GetGlobalRegistry() {
+    static std::unordered_map<ID, GameObject*> registry;
+    return registry;
+}
+
+void GameObject::SetParent(GameObject* parent) {
+    SetParent(parent, true);
+}
+
+void GameObject::SetParent(GameObject* parent, bool worldPositionStays) {
+    if (m_parent == parent) {
+        return;
+    }
+
+    Math::Vector3 worldPos = worldPositionStays ? GetTransform()->GetPosition() : GetTransform()->GetLocalPosition();
+    Math::Quaternion worldRot = worldPositionStays ? GetTransform()->GetRotation() : GetTransform()->GetLocalRotation();
+    Math::Vector3 worldScale = worldPositionStays ? GetTransform()->GetScale() : GetTransform()->GetLocalScale();
+
+    if (m_parent) {
+        auto& siblings = m_parent->m_children;
+        siblings.erase(std::remove(siblings.begin(), siblings.end(), this), siblings.end());
+    }
+
+    m_parent = parent;
+
+    if (m_parent) {
+        m_parent->m_children.push_back(this);
+    }
+
+    if (worldPositionStays) {
+        GetTransform()->SetPosition(worldPos);
+        GetTransform()->SetRotation(worldRot);
+        GetTransform()->SetScale(worldScale);
+    }
+
+    GetTransform()->SetDirty();
+}
+
+GameObject* GameObject::GetChild(size_t index) const {
+    if (index < m_children.size()) {
+        return m_children[index];
+    }
+    return nullptr;
+}
+
+std::vector<GameObject*> GameObject::GetChildren() const {
+    return m_children;
+}
+
+void GameObject::DetachChildren() {
+    for (auto* child : m_children) {
+        if (child) {
+            child->m_parent = nullptr;
+        }
+    }
+    m_children.clear();
+}
+
+void GameObject::SetActive(bool active) {
+    if (m_activeSelf != active) {
+        m_activeSelf = active;
+        if (m_parent == nullptr || m_parent->IsActiveInHierarchy()) {
+        }
+    }
+}
+
+bool GameObject::IsActiveInHierarchy() const {
+    if (!m_activeSelf) {
+        return false;
+    }
+    if (m_parent) {
+        return m_parent->IsActiveInHierarchy();
+    }
+    return true;
+}
+
+GameObject* GameObject::Find(const std::string& name) {
+    auto& registry = GetGlobalRegistry();
+    for (auto& pair : registry) {
+        if (pair.second->GetName() == name) {
+            return pair.second;
+        }
+    }
+    return nullptr;
+}
+
+std::vector<GameObject*> GameObject::FindObjectsOfType() {
+    auto& registry = GetGlobalRegistry();
+    std::vector<GameObject*> result;
+    for (auto& pair : registry) {
+        result.push_back(pair.second);
+    }
+    return result;
+}
+
+std::vector<GameObject*> GameObject::FindGameObjectsWithTag(const std::string& tag) {
+    auto& registry = GetGlobalRegistry();
+    std::vector<GameObject*> result;
+    for (auto& pair : registry) {
+        if (pair.second->GetName() == tag) {
+            result.push_back(pair.second);
+        }
+    }
+    return result;
+}
+
+void GameObject::Awake() {
+    for (auto& comp : m_components) {
+        comp->Awake();
+    }
+}
+
+void GameObject::Start() {
+    for (auto& comp : m_components) {
+        if (comp->IsEnabled()) {
+            comp->Start();
+        }
+    }
+}
+
+void GameObject::Update(float deltaTime) {
+    for (auto& comp : m_components) {
+        if (comp->IsEnabled()) {
+            comp->Update(deltaTime);
+        }
+    }
+}
+
+void GameObject::FixedUpdate() {
+    for (auto& comp : m_components) {
+        if (comp->IsEnabled()) {
+            comp->FixedUpdate();
+        }
+    }
+}
+
+void GameObject::LateUpdate(float deltaTime) {
+    for (auto& comp : m_components) {
+        if (comp->IsEnabled()) {
+            comp->LateUpdate(deltaTime);
+        }
+    }
+}
+
+void GameObject::OnDestroy() {
+    for (auto& comp : m_components) {
+        comp->OnDestroy();
+    }
+}
+
+void GameObject::Destroy() {
+    OnDestroy();
+    if (m_scene) {
+        m_scene->DestroyGameObject(this);
+    }
+}
+
+} // namespace Components
+} // namespace XCEngine