From 58f2190199ae7de34d3850bc0924c93d213246b0 Mon Sep 17 00:00:00 2001
From: Isuru Samarathunga <isuru.00.aravinda@gmail.com>
Date: Tue, 14 Oct 2025 01:50:56 +0530
Subject: [PATCH] Fixes

---
 .../Imp/CPP/Components/CameraComponent.cpp    |   9 +-
 Engine/Src/Imp/CPP/Engine.cpp                 |  27 ++--
 Engine/Src/Imp/CPP/Renderer/Renderer.cpp      |  21 +--
 Engine/Src/Imp/CPP/Scene.cpp                  | 133 +++++++++++++++++-
 Engine/Src/Imp/CPP/UI.cpp                     |  15 +-
 Engine/Src/Imp/CPP/Utils.cpp                  |  38 ++++-
 Engine/Src/Imp/CPP/WorldManager.cpp           |   1 +
 Engine/Src/Inc/IAEngine/Base.hpp              |   9 +-
 .../IAEngine/Components/CameraComponent.hpp   |   7 +-
 Engine/Src/Inc/IAEngine/Engine.hpp            |   2 +-
 Engine/Src/Inc/IAEngine/Scene.hpp             |  39 ++++-
 Engine/Src/Inc/IAEngine/UI.hpp                |   2 +-
 Engine/Src/Inc/IAEngine/Utils.hpp             |   3 +
 13 files changed, 261 insertions(+), 45 deletions(-)

diff --git a/Engine/Src/Imp/CPP/Components/CameraComponent.cpp b/Engine/Src/Imp/CPP/Components/CameraComponent.cpp
index 5d15d69..7249d18 100644
--- a/Engine/Src/Imp/CPP/Components/CameraComponent.cpp
+++ b/Engine/Src/Imp/CPP/Components/CameraComponent.cpp
@@ -36,6 +36,13 @@ namespace ia::iae
             glm::orthoLH(0.0f, (FLOAT32) width, (FLOAT32) height, 0.0f, Renderer::MIN_DEPTH, Renderer::MAX_DEPTH);
     }
 
+    CONST Mat4 *CameraComponent::GetViewMatrix()
+    {
+        const auto pos = m_node->GetPosition() + m_positionOffset;
+        m_viewMatrix = glm::lookAtLH(glm::vec3{pos, -2.0f}, {pos, 0.0f}, {0.0f, 1.0f, 0.0f});
+        return &m_viewMatrix;
+    }
+
     VOID CameraComponent::Draw()
     {
     }
@@ -46,8 +53,6 @@ namespace ia::iae
 
     VOID CameraComponent::Update()
     {
-        const auto pos = m_node->GetPosition() + m_positionOffset;
-        m_viewMatrix = glm::lookAtLH(glm::vec3{pos, -2.0f}, {pos, 0.0f}, {0.0f, 1.0f, 0.0f});
     }
 
     VOID CameraComponent::FixedUpdate()
diff --git a/Engine/Src/Imp/CPP/Engine.cpp b/Engine/Src/Imp/CPP/Engine.cpp
index a508d64..fbbf86b 100644
--- a/Engine/Src/Imp/CPP/Engine.cpp
+++ b/Engine/Src/Imp/CPP/Engine.cpp
@@ -38,11 +38,26 @@ namespace ia::iae
 #endif
     }
 
+    String Engine::ReadTextAsset(IN CONST String &path)
+    {
+        SDL_IOStream *f = SDL_IOFromFile(path.c_str(), "r");
+        if (!f)
+            THROW_FILE_OPEN_READ(path);
+        Vector<CHAR> result;
+        SDL_SeekIO(f, 0, SDL_IO_SEEK_END);
+        result.resize(SDL_TellIO(f) + 1);
+        SDL_SeekIO(f, 0, SDL_IO_SEEK_SET);
+        SDL_ReadIO(f, result.data(), result.size());
+        result.back() = '\0';
+        SDL_CloseIO(f);
+        return result.data();
+    }
+
     Vector<UINT8> Engine::ReadBinaryAsset(IN CONST String &path)
     {
-        SDL_IOStream* f = SDL_IOFromFile(path.c_str(), "rb");
-        if(!f)
-        THROW_FILE_OPEN_READ(path);
+        SDL_IOStream *f = SDL_IOFromFile(path.c_str(), "rb");
+        if (!f)
+            THROW_FILE_OPEN_READ(path);
         Vector<UINT8> result;
         SDL_SeekIO(f, 0, SDL_IO_SEEK_END);
         result.resize(SDL_TellIO(f));
@@ -90,12 +105,6 @@ namespace ia::iae
         return CreateSound(name, data.data(), data.size());
     }
 
-    RefPtr<Scene> Engine::CreateSceneFromFile(IN CONST String &path)
-    {
-        const auto data = File::ReadToString(path.c_str());
-        return Scene::Create(data);
-    }
-
     Handle Engine::ResizeImage(IN CONST String &name, IN INT32 newWidth, IN INT32 newHeight)
     {
         return ResizeImage(GetImage(name), newWidth, newHeight);
diff --git a/Engine/Src/Imp/CPP/Renderer/Renderer.cpp b/Engine/Src/Imp/CPP/Renderer/Renderer.cpp
index 9869cff..e417390 100644
--- a/Engine/Src/Imp/CPP/Renderer/Renderer.cpp
+++ b/Engine/Src/Imp/CPP/Renderer/Renderer.cpp
@@ -27,6 +27,8 @@
 
 namespace ia::iae
 {
+    STATIC Mat4 IdentityMatrix(1.0f);
+
     EXTERN SDL_Window *g_windowHandle;
 
     INT32 Renderer::s_screenWidth{};
@@ -136,8 +138,6 @@ namespace ia::iae
 
     VOID Renderer::BeginFrame()
     {
-        STATIC Mat4 IdentityMatrix(1.0f);
-
         if (!(s_state.ActiveCommandBuffer = SDL_AcquireGPUCommandBuffer(s_gpuDevice)))
             THROW_UNKNOWN("Failed to acquire SDL GPU command buffer: ", SDL_GetError());
 
@@ -152,10 +152,6 @@ namespace ia::iae
         SDL_PushGPUVertexUniformData(
             s_state.ActiveCommandBuffer, 0,
             s_state.ActiveCamera ? s_state.ActiveCamera->GetProjectionMatrix() : &IdentityMatrix, sizeof(Mat4));
-        SDL_PushGPUVertexUniformData(
-            s_state.ActiveCommandBuffer, 1,
-            (s_state.ActiveCamera && s_state.CameraRelative) ? s_state.ActiveCamera->GetViewMatrix() : &IdentityMatrix,
-            sizeof(Mat4));
     }
 
     VOID Renderer::EndFrame()
@@ -236,9 +232,9 @@ namespace ia::iae
         const auto activeScene = WorldManager::GetActiveScene();
         if (activeScene)
         {
-            const auto sceneExtent = activeScene->Extent();
-            s_state.SceneScaleFactor = {(FLOAT32) newWidth / (FLOAT32) sceneExtent.x,
-                                        (FLOAT32) newHeight / (FLOAT32) sceneExtent.y};
+            const auto sceneViewport = activeScene->Viewport();
+            s_state.SceneScaleFactor = {(FLOAT32) newWidth / (FLOAT32) sceneViewport.x,
+                                        (FLOAT32) newHeight / (FLOAT32) sceneViewport.y};
             IAE_LOG_INFO("Updated Scene Scale Factor: (", s_state.SceneScaleFactor.x, ", ", s_state.SceneScaleFactor.y,
                          ")");
         }
@@ -282,6 +278,11 @@ namespace ia::iae
 
 #pragma pack(pop)
 
+        SDL_PushGPUVertexUniformData(
+            s_state.ActiveCommandBuffer, 1,
+            (s_state.ActiveCamera && s_state.CameraRelative) ? s_state.ActiveCamera->GetViewMatrix() : &IdentityMatrix,
+            sizeof(Mat4));
+
         s_fragmentUniform.ColorOverlay = s_state.ColorOverlay.GetAsFloatVec();
         s_fragmentUniform.FlippedH = s_state.FlippedH;
         s_fragmentUniform.FlippedV = s_state.FlippedV;
@@ -385,7 +386,7 @@ namespace ia::iae
             sortIndex += static_cast<INT16>(position.y);
 
         position *= Renderer::s_state.SceneScaleFactor;
-        // scale *= Renderer::s_state.SceneScaleFactor;
+        scale *= Renderer::s_state.SceneScaleFactor;
 
         Renderer::s_state.ModelMatrix =
             glm::translate(glm::mat4(1.0f), glm::vec3{position.x, position.y,
diff --git a/Engine/Src/Imp/CPP/Scene.cpp b/Engine/Src/Imp/CPP/Scene.cpp
index 9a50723..ad5b2b6 100644
--- a/Engine/Src/Imp/CPP/Scene.cpp
+++ b/Engine/Src/Imp/CPP/Scene.cpp
@@ -17,20 +17,138 @@
 #include <IAEngine/Engine.hpp>
 #include <IAEngine/Scene.hpp>
 
+#include <IAEngine/pugixml/pugixml.hpp>
+
 namespace ia::iae
 {
+     // -----------------------------------------------
+    // getInnerXML and xml_string_writer were taken from https://stackoverflow.com/a/60337372
+    struct xml_string_writer : pugi::xml_writer
+    {
+        std::string result;
+
+        virtual void write(const void *data, size_t size)
+        {
+            result.append(static_cast<const char *>(data), size);
+        }
+    };
+
+    const auto getInnerXML = [](pugi::xml_node target) {
+        xml_string_writer writer;
+        for (pugi::xml_node child = target.first_child(); child; child = child.next_sibling())
+            child.print(writer, "");
+        return writer.result;
+    };
+
+    // -----------------------------------------------
+
     RefPtr<Scene> Scene::Create()
     {
         const auto scene = MakeRefPtr<Scene>();
         scene->Extent() = Engine::GetDisplayExtent();
+        const auto cameraNode = MakeRefPtr<CameraNode>("MainCamera");
+        scene->AddNode(cameraNode);
+        scene->m_camera = cameraNode->GetCameraComponent();
         return scene;
     }
 
-    RefPtr<Scene> Scene::Create(IN CONST String &sceneXML)
+    RefPtr<Scene> Scene::Create(IN CONST String &sceneXML,
+                                IN std::function<RefPtr<Node2D>(IN CONST String &, IN Handle)> getCustomNode,
+                                IN std::function<Handle(IN ResourceType type, IN CONST String &, IN INT64)> getResource)
     {
-        const auto scene = MakeRefPtr<Scene>();
-        scene->Extent() = Engine::GetDisplayExtent();
-        
+        const auto scene = Create();
+
+        pugi::xml_document doc;
+        doc.load_string(sceneXML.c_str());
+        const auto sceneRoot = doc.child("Scene");
+
+        Map<String, Handle> resources;
+
+        // Process Resources
+        const auto resRoot = sceneRoot.child("Resources");
+        if (!resRoot)
+            THROW_INVALID_DATA("Scene file is missing 'Resources' tag");
+        {
+            for (const auto &t : resRoot.children())
+            {
+                if (!strcmp(t.name(), "Image"))
+                {
+                    resources[t.attribute("name").as_string()] = getResource(
+                        ResourceType::IMAGE, t.attribute("path").as_string(), t.attribute("index").as_llong());
+                }
+                else if (!strcmp(t.name(), "Audio"))
+                {
+                    resources[t.attribute("name").as_string()] =
+                        getResource(ResourceType::SOUND, t.attribute("path").as_string(), 0);
+                }
+            }
+        }
+
+        // Process Properties
+        const auto propRoot = sceneRoot.child("Properties");
+        if (!propRoot)
+            THROW_INVALID_DATA("Scene file is missing 'Properties' tag");
+        {
+            auto t = propRoot.child("Extent");
+            scene->Extent() = Vec2{t.attribute("width").as_float(), t.attribute("height").as_float()};
+
+            t = propRoot.child("Viewport");
+            scene->Viewport() = Vec2{t.attribute("width").as_float(), t.attribute("height").as_float()};
+        }
+
+        // Process Nodes
+        const auto nodeRoot = sceneRoot.child("Nodes");
+        if (!nodeRoot)
+            THROW_INVALID_DATA("Scene file is missing 'Nodes' tag");
+        {
+            for (const auto &t : nodeRoot)
+            {
+                Node2D* n{}; 
+                if (!strcmp(t.name(), "TextureNode"))
+                {
+                    const auto node = MakeRefPtr<TextureNode>(Engine::GetUniqueResourceName());
+                    node->GetTextureComponent()->SetTexture(resources[t.attribute("texture").as_string()]);
+                    scene->AddNode(node);
+                    n = node.get();
+                }
+                else
+                {
+                    Handle id{INVALID_HANDLE};
+                    const auto attrID = t.attribute("id");
+                    if(attrID)
+                        id = (Handle)attrID.as_ullong();
+                    const auto node = getCustomNode(t.name(), id);
+                    scene->AddNode(node);
+                    n = node.get();
+                }
+                
+                if(!n) continue;
+                if(t.attribute("X") && t.attribute("Y"))
+                {
+                    n->SetLocalPosition({
+                        t.attribute("X").as_float(),
+                        t.attribute("Y").as_float()
+                    });   
+                }
+            }
+        }
+
+        // Process UI
+        const auto uiRoot = sceneRoot.child("UI");
+        if (!uiRoot)
+            THROW_INVALID_DATA("Scene file is missing 'UI' tag");
+        {
+            scene->UIMarkupStyles() = getInnerXML(uiRoot.child("CSS")).c_str();
+            auto html = String(getInnerXML(uiRoot.child("HTML")).c_str());
+            html =
+                Utils::RegexReplaceGroups(html, "<img(.*?)src=\"(.*?)\"", [&](IN INT32 index, IN CONST String &match) {
+                    if(index == 1)
+                        return BuildString("$H$", resources[match]);
+                    return match;
+                });
+            scene->UIMarkup() = html;
+        }
+
         return scene;
     }
 
@@ -72,4 +190,11 @@ namespace ia::iae
     {
         m_nodes[name] = nullptr;
     }
+
+    VOID Scene::OnActivate()
+    {
+        UI::SetMarkup(UIMarkup(), UIMarkupStyles());
+        if(m_camera)
+            Engine::SetActiveCamera(m_camera);
+    }
 } // namespace ia::iae
diff --git a/Engine/Src/Imp/CPP/UI.cpp b/Engine/Src/Imp/CPP/UI.cpp
index 30e03af..93889e7 100644
--- a/Engine/Src/Imp/CPP/UI.cpp
+++ b/Engine/Src/Imp/CPP/UI.cpp
@@ -452,10 +452,11 @@ namespace ia::iae
         Rml::LoadFontFace(path.c_str());
     }
 
-    VOID UI::SetHTML(IN CONST String &source)
+    VOID UI::SetMarkup(IN CONST String &markup, IN CONST String &styles)
     {
+        g_document->SetStyleSheetContainer(Rml::Factory::InstanceStyleSheetString(styles.c_str()));
         g_document->SetInnerRML(
-            BuildString("<body style=\"display: block; width: 100%; height: 100%;\">", source, "</body>").c_str());
+            BuildString("<body style=\"display: block; width: 100%; height: 100%;\">", markup, "</body>").c_str());
     }
 
     VOID UI::AddClickEvent(IN PCCHAR elementId, IN std::function<VOID()> callback)
@@ -502,8 +503,14 @@ namespace ia::iae
 
     Rml::TextureHandle RmlUIRenderInterface::LoadTexture(Rml::Vector2i &texture_dimensions, const Rml::String &source)
     {
-        return Engine::CreateImageFromFile(Engine::GetUniqueResourceName(), source.c_str(), texture_dimensions.x,
-                                           texture_dimensions.y);
+        Handle result;
+        if (source.starts_with("$H$"))
+            result = (Handle) std::stoi(source.substr(3));
+        else
+            result = Engine::CreateImageFromFile(Engine::GetUniqueResourceName(), source.c_str());
+        const auto extent = Engine::GetImageExtent(result);
+        texture_dimensions = {extent.x, extent.y};
+        return result;
     }
 
     Rml::TextureHandle RmlUIRenderInterface::GenerateTexture(Rml::Span<const Rml::byte> source,
diff --git a/Engine/Src/Imp/CPP/Utils.cpp b/Engine/Src/Imp/CPP/Utils.cpp
index d0dad3b..21bc40d 100644
--- a/Engine/Src/Imp/CPP/Utils.cpp
+++ b/Engine/Src/Imp/CPP/Utils.cpp
@@ -18,13 +18,15 @@
 
 #include <zlib.h>
 
+#include <regex>
+
 namespace ia::iae
 {
     Vector<UINT8> Utils::Inflate(IN PCUINT8 data, IN SIZE_T dataSize)
     {
         STATIC UINT8 TMP_BUFFER[16384];
         Vector<UINT8> result;
-        result.reserve(ia_min((SIZE_T)(dataSize * 3), sizeof(TMP_BUFFER)));
+        result.reserve(ia_min((SIZE_T) (dataSize * 3), sizeof(TMP_BUFFER)));
         z_stream stream;
         stream.zalloc = Z_NULL;
         stream.zfree = Z_NULL;
@@ -35,7 +37,8 @@ namespace ia::iae
             THROW_UNKNOWN("Inflate failed: init zlib inflate");
         stream.avail_in = dataSize;
         stream.next_in = (Bytef *) data;
-        while (true) {
+        while (true)
+        {
             stream.avail_out = sizeof(TMP_BUFFER);
             stream.next_out = TMP_BUFFER;
             const auto r = inflate(&stream, Z_SYNC_FLUSH);
@@ -58,4 +61,35 @@ namespace ia::iae
         result.resize(deflateBound);
         return result;
     }
+
+    String Utils::RegexReplaceString(IN CONST String &input, IN CONST String &from, IN CONST String &to)
+    {
+        return std::regex_replace(input.c_str(), std::regex(from.c_str()), to.c_str()).c_str();
+    }
+
+    String Utils::RegexReplaceGroups(IN CONST String &input, IN CONST String &pattern,
+                                     IN std::function<String(IN INT32, IN CONST String &)> groupTransformer)
+    {
+        std::string text = input.c_str();
+
+        std::smatch match;
+        std::string result;
+        std::string::const_iterator search_start(text.cbegin());
+
+        SIZE_T t1 = 0, t2 = 0;
+        while (std::regex_search(search_start, text.cend(), match, std::regex(pattern.c_str())))
+        {
+            for(SIZE_T i = 1; i < match.size(); i++)
+            {
+                result += text.substr(t1, match.position(i) - t1);
+                result += std::string(groupTransformer(i - 1, match.str(i).c_str()).c_str());
+                t1 = match.position(i);
+                t2 = match.str(i).length();
+            }
+            result += text.substr(match.suffix().first - text.begin() - 1);
+            search_start = match.suffix().first;
+        }
+
+        return result.c_str();
+    }
 } // namespace ia::iae
\ No newline at end of file
diff --git a/Engine/Src/Imp/CPP/WorldManager.cpp b/Engine/Src/Imp/CPP/WorldManager.cpp
index 253f1fd..bbd6726 100644
--- a/Engine/Src/Imp/CPP/WorldManager.cpp
+++ b/Engine/Src/Imp/CPP/WorldManager.cpp
@@ -54,6 +54,7 @@ namespace ia::iae
     VOID WorldManager::ChangeActiveScene(IN RefPtr<Scene> scene)
     {
         s_activeScene = scene;
+        scene->OnActivate();
     }
 
     VOID WorldManager::AddNodeToActiveScene(IN RefPtr<INode> node)
diff --git a/Engine/Src/Inc/IAEngine/Base.hpp b/Engine/Src/Inc/IAEngine/Base.hpp
index edc9052..7c8de88 100644
--- a/Engine/Src/Inc/IAEngine/Base.hpp
+++ b/Engine/Src/Inc/IAEngine/Base.hpp
@@ -102,7 +102,8 @@ namespace ia::iae
         Vec4 Color{};
     };
 
-    enum class Direction : UINT8 {
+    enum class Direction : UINT8
+    {
         NONE = 255,
         DOWN = 0,
         DOWN_LEFT,
@@ -114,6 +115,12 @@ namespace ia::iae
         DOWN_RIGHT
     };
 
+    enum class ResourceType
+    {
+        IMAGE,
+        SOUND,
+    };
+
     struct Color
     {
         UINT8 R{0xFF};
diff --git a/Engine/Src/Inc/IAEngine/Components/CameraComponent.hpp b/Engine/Src/Inc/IAEngine/Components/CameraComponent.hpp
index fe9c044..bf63f80 100644
--- a/Engine/Src/Inc/IAEngine/Components/CameraComponent.hpp
+++ b/Engine/Src/Inc/IAEngine/Components/CameraComponent.hpp
@@ -45,10 +45,7 @@ namespace ia::iae
             return m_viewport;
         }
 
-        CONST Mat4 *GetViewMatrix() CONST
-        {
-            return &m_viewMatrix;
-        }
+        CONST Mat4 *GetViewMatrix();
 
         CONST Mat4 *GetProjectionMatrix() CONST
         {
@@ -57,8 +54,8 @@ namespace ia::iae
 
       private:
         Vec4 m_viewport{};
-        Mat4 m_viewMatrix{1.0f};
         Vec2 m_positionOffset{};
+        Mat4 m_viewMatrix{1.0f};
         Mat4 m_projectionMatrix{1.0f};
     };
 } // namespace ia::iae
diff --git a/Engine/Src/Inc/IAEngine/Engine.hpp b/Engine/Src/Inc/IAEngine/Engine.hpp
index a6e6543..ef664e7 100644
--- a/Engine/Src/Inc/IAEngine/Engine.hpp
+++ b/Engine/Src/Inc/IAEngine/Engine.hpp
@@ -93,7 +93,6 @@ namespace ia::iae
         STATIC CameraComponent *GetActiveCamera();
 
         // Scene Functions
-        STATIC RefPtr<Scene> CreateSceneFromFile(IN CONST String &path);
         STATIC Scene *GetActiveScene();
         STATIC VOID ChangeActiveScene(IN RefPtr<Scene> scene);
         STATIC VOID AddNodeToActiveScene(IN RefPtr<INode> node);
@@ -118,6 +117,7 @@ namespace ia::iae
         STATIC VOID BindInputAxis(IN InputKey upKey, IN InputKey downKey, IN InputKey leftKey, IN InputKey rightKey);
 
         // Utility Functions
+        STATIC String ReadTextAsset(IN CONST String& path);
         STATIC Direction GetVectorPointingDirection(IN Vec2 v);
         STATIC Vector<UINT8> ReadBinaryAsset(IN CONST String& path);
 
diff --git a/Engine/Src/Inc/IAEngine/Scene.hpp b/Engine/Src/Inc/IAEngine/Scene.hpp
index d05950f..68c13a6 100644
--- a/Engine/Src/Inc/IAEngine/Scene.hpp
+++ b/Engine/Src/Inc/IAEngine/Scene.hpp
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include <IAEngine/Components/CameraComponent.hpp>
 #include <IAEngine/Nodes/INode.hpp>
 
 namespace ia::iae
@@ -23,27 +24,48 @@ namespace ia::iae
     class Scene
     {
       public:
-        STATIC  RefPtr<Scene> Create();
-        STATIC  RefPtr<Scene> Create(IN CONST String &sceneXML);
+        STATIC RefPtr<Scene> Create();
+        STATIC RefPtr<Scene> Create(
+            IN CONST String &sceneXML, IN std::function<RefPtr<Node2D>(IN CONST String &, IN Handle)> getCustomNode,
+            IN std::function<Handle(IN ResourceType type, IN CONST String &, IN INT64)> getResource);
 
       public:
-         VOID AddNode(IN RefPtr<INode> node);
-         INode *GetNode(IN CONST String &name);
-         VOID RemoveNode(IN CONST String &name);
+        VOID AddNode(IN RefPtr<INode> node);
+        INode *GetNode(IN CONST String &name);
+        VOID RemoveNode(IN CONST String &name);
 
       public:
-        IVec2& Extent()
+        String &UIMarkup()
+        {
+            return m_uiMarkup;
+        }
+
+        String &UIMarkupStyles()
+        {
+            return m_uiMarkupStyles;
+        }
+
+        IVec2 &Extent()
         {
             return m_extent;
         }
 
+        IVec2 &Viewport()
+        {
+            return m_viewport;
+        }
+
         Color &BackgroundColor()
         {
             return m_backgroundColor;
         }
 
       private:
+        String m_uiMarkup{};
+        String m_uiMarkupStyles{};
         IVec2 m_extent{100, 100};
+        IVec2 m_viewport{100, 100};
+        CameraComponent *m_camera{};
         Color m_backgroundColor{0, 0, 0, 255};
         Map<String, RefPtr<INode>> m_nodes;
 
@@ -53,5 +75,10 @@ namespace ia::iae
 
         VOID FixedUpdate();
         VOID Update();
+
+      private:
+        VOID OnActivate();
+
+        friend class WorldManager;
     };
 } // namespace ia::iae
\ No newline at end of file
diff --git a/Engine/Src/Inc/IAEngine/UI.hpp b/Engine/Src/Inc/IAEngine/UI.hpp
index e84e864..16a07cb 100644
--- a/Engine/Src/Inc/IAEngine/UI.hpp
+++ b/Engine/Src/Inc/IAEngine/UI.hpp
@@ -25,7 +25,7 @@ namespace ia::iae
       public:
         STATIC VOID AddFontFromFile(IN CONST String &path);
 
-        STATIC VOID SetHTML(IN CONST String &source);
+        STATIC VOID SetMarkup(IN CONST String &markup, IN CONST String &styles);
 
         STATIC VOID AddClickEvent(IN PCCHAR elementId, IN std::function<VOID()> callback);
 
diff --git a/Engine/Src/Inc/IAEngine/Utils.hpp b/Engine/Src/Inc/IAEngine/Utils.hpp
index 61033d9..11f0882 100644
--- a/Engine/Src/Inc/IAEngine/Utils.hpp
+++ b/Engine/Src/Inc/IAEngine/Utils.hpp
@@ -25,5 +25,8 @@ namespace ia::iae
     public:
         STATIC Vector<UINT8> Inflate(IN PCUINT8 data, IN SIZE_T dataSize);
         STATIC Vector<UINT8> Deflate(IN PCUINT8 data, IN SIZE_T dataSize);
+
+        STATIC String RegexReplaceString(IN CONST String& input, IN CONST String& from, IN CONST String& to);
+        STATIC String RegexReplaceGroups(IN CONST String& input, IN CONST String& pattern, IN std::function<String(IN INT32, IN CONST String&)> groupTransformer);
     };
 }
\ No newline at end of file