diff --git a/src/frontend/InventoryView.cpp b/src/frontend/InventoryView.cpp
index 88181436..35225a06 100644
--- a/src/frontend/InventoryView.cpp
+++ b/src/frontend/InventoryView.cpp
@@ -16,6 +16,7 @@
 #include "../content/Content.h"
 #include "../items/ItemDef.h"
 #include "../items/Inventory.h"
+#include "../items/Inventories.h"
 #include "../maths/voxmaths.h"
 #include "../objects/Player.h"
 #include "../voxels/Block.h"
@@ -47,7 +48,7 @@ InventoryBuilder::InventoryBuilder() {
 /** Add slots grid to inventory view 
  * @param cols grid columns
  * @param count total number of grid slots
- * @param coord position of the first slot of the grid
+ * @param pos position of the first slot of the grid
  * @param padding additional space around the grid
  * @param addpanel automatically create panel behind the grid
  * with size including padding
@@ -55,7 +56,7 @@ InventoryBuilder::InventoryBuilder() {
  */
 void InventoryBuilder::addGrid(
     int cols, int count, 
-    glm::vec2 coord, 
+    glm::vec2 pos, 
     int padding,
     bool addpanel,
     SlotLayout slotLayout) 
@@ -69,18 +70,18 @@ void InventoryBuilder::addGrid(
     uint height = rows * (slotSize + interval) - interval + padding*2;
     
     glm::vec2 vsize = view->getSize();
-    if (coord.x + width > vsize.x) {
-        vsize.x = coord.x + width;
+    if (pos.x + width > vsize.x) {
+        vsize.x = pos.x + width;
     }
-    if (coord.y + height > vsize.y) {
-        vsize.y = coord.y + height;
+    if (pos.y + height > vsize.y) {
+        vsize.y = pos.y + height;
     }
     view->setSize(vsize);
 
     if (addpanel) {
-        auto panel = std::make_shared<gui::Container>(coord, glm::vec2(width, height));
+        auto panel = std::make_shared<gui::Container>(glm::vec2(width, height));
         view->setColor(glm::vec4(0.122f, 0.122f, 0.122f, 0.878f));
-        view->add(panel);
+        view->add(panel, pos);
     }
 
     for (int row = 0; row < rows; row++) {
@@ -109,7 +110,7 @@ std::shared_ptr<InventoryView> InventoryBuilder::build() {
 
 SlotView::SlotView(
     SlotLayout layout
-) : UINode(glm::vec2(), glm::vec2(InventoryView::SLOT_SIZE)),
+) : UINode(glm::vec2(InventoryView::SLOT_SIZE)),
     layout(layout)
 {
     setColor(glm::vec4(0, 0, 0, 0.2f));
@@ -121,7 +122,7 @@ void SlotView::draw(const GfxContext* pctx, Assets* assets) {
 
     ItemStack& stack = *bound;
 
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
 
     int slotSize = InventoryView::SLOT_SIZE;
 
@@ -137,9 +138,9 @@ void SlotView::draw(const GfxContext* pctx, Assets* assets) {
     if (color.a > 0.0) {
         batch->texture(nullptr);
         if (highlighted) {
-            batch->rect(coord.x-4, coord.y-4, slotSize+8, slotSize+8);
+            batch->rect(pos.x-4, pos.y-4, slotSize+8, slotSize+8);
         } else {
-            batch->rect(coord.x, coord.y, slotSize, slotSize);
+            batch->rect(pos.x, pos.y, slotSize, slotSize);
         }
     }
     
@@ -158,7 +159,7 @@ void SlotView::draw(const GfxContext* pctx, Assets* assets) {
 
             UVRegion region = previews->get(cblock.name);
             batch->rect(
-                coord.x, coord.y, slotSize, slotSize, 
+                pos.x, pos.y, slotSize, slotSize, 
                 0, 0, 0, region, false, true, tint);
             break;
         }
@@ -177,7 +178,7 @@ void SlotView::draw(const GfxContext* pctx, Assets* assets) {
                 }
             }
             batch->rect(
-                coord.x, coord.y, slotSize, slotSize, 
+                pos.x, pos.y, slotSize, slotSize, 
                 0, 0, 0, region, false, true, tint);
             break;
         }
@@ -187,8 +188,8 @@ void SlotView::draw(const GfxContext* pctx, Assets* assets) {
         auto font = assets->getFont("normal");
         std::wstring text = std::to_wstring(stack.getCount());
 
-        int x = coord.x+slotSize-text.length()*8;
-        int y = coord.y+slotSize-16;
+        int x = pos.x+slotSize-text.length()*8;
+        int y = pos.y+slotSize-16;
 
         batch->setColor(glm::vec4(0, 0, 0, 1.0f));
         font->draw(batch, text, x+1, y+1);
@@ -259,7 +260,7 @@ void SlotView::clicked(gui::GUI* gui, mousecode button) {
     }
 }
 
-void SlotView::focus(gui::GUI* gui) {
+void SlotView::onFocus(gui::GUI* gui) {
     clicked(gui, mousecode::BUTTON_1);
 }
 
@@ -280,7 +281,7 @@ const SlotLayout& SlotView::getLayout() const {
     return layout;
 }
 
-InventoryView::InventoryView() : Container(glm::vec2(), glm::vec2()) {
+InventoryView::InventoryView() : Container(glm::vec2()) {
     setColor(glm::vec4(0, 0, 0, 0.0f));
 }
 
@@ -291,13 +292,13 @@ std::shared_ptr<SlotView> InventoryView::addSlot(SlotLayout layout) {
     uint width =  InventoryView::SLOT_SIZE + layout.padding;
     uint height = InventoryView::SLOT_SIZE + layout.padding;
 
-    auto coord = layout.position;
+    auto pos = layout.position;
     auto vsize = getSize();
-    if (coord.x + width > vsize.x) {
-        vsize.x = coord.x + width;
+    if (pos.x + width > vsize.x) {
+        vsize.x = pos.x + width;
     }
-    if (coord.y + height > vsize.y) {
-        vsize.y = coord.y + height;
+    if (pos.y + height > vsize.y) {
+        vsize.y = pos.y + height;
     }
     setSize(vsize);
 
@@ -337,6 +338,12 @@ void InventoryView::bind(
     }
 }
 
+void InventoryView::unbind() {
+    if (inventory->isVirtual()) {
+        frontend->getLevel()->inventories->remove(inventory->getId());   
+    }
+}
+
 void InventoryView::setSelected(int index) {
     for (int i = 0; i < int(slots.size()); i++) {
         auto slot = slots[i];
@@ -344,8 +351,8 @@ void InventoryView::setSelected(int index) {
     }
 }
 
-void InventoryView::setCoord(glm::vec2 coord) {
-    Container::setCoord(coord - origin);
+void InventoryView::setPos(glm::vec2 pos) {
+    Container::setPos(pos - origin);
 }
 
 void InventoryView::setOrigin(glm::vec2 origin) {
@@ -378,8 +385,8 @@ static void readSlot(InventoryView* view, gui::UiXmlReader& reader, xml::xmlelem
     int index = element->attr("index", "0").asInt();
     bool itemSource = element->attr("item-source", "false").asBool();
     SlotLayout layout(index, glm::vec2(), true, itemSource, nullptr, nullptr);
-    if (element->has("coord")) {
-        layout.position = element->attr("coord").asVec2();
+    if (element->has("pos")) {
+        layout.position = element->attr("pos").asVec2();
     }
     if (element->has("sharefunc")) {
         layout.shareFunc = readSlotFunc(view, reader, element, "sharefunc");
diff --git a/src/frontend/InventoryView.h b/src/frontend/InventoryView.h
index c33f0823..6124eccf 100644
--- a/src/frontend/InventoryView.h
+++ b/src/frontend/InventoryView.h
@@ -73,7 +73,7 @@ public:
     bool isHighlighted() const;
 
     virtual void clicked(gui::GUI*, mousecode) override;
-    virtual void focus(gui::GUI*) override;
+    virtual void onFocus(gui::GUI*) override;
 
     void bind(
         int64_t inventoryid,
@@ -101,7 +101,7 @@ public:
 
     void setInventory(std::shared_ptr<Inventory> inventory);
 
-    virtual void setCoord(glm::vec2 coord) override;
+    virtual void setPos(glm::vec2 pos) override;
 
     void setOrigin(glm::vec2 origin);
     glm::vec2 getOrigin() const;
@@ -113,6 +113,8 @@ public:
         LevelFrontend* frontend, 
         InventoryInteraction* interaction
     );
+    
+    void unbind();
 
     std::shared_ptr<SlotView> addSlot(SlotLayout layout);
 
@@ -133,7 +135,7 @@ public:
 
     void addGrid(
         int cols, int count, 
-        glm::vec2 coord, 
+        glm::vec2 pos, 
         int padding,
         bool addpanel,
         SlotLayout slotLayout
diff --git a/src/frontend/debug_panel.cpp b/src/frontend/debug_panel.cpp
new file mode 100644
index 00000000..0fb20427
--- /dev/null
+++ b/src/frontend/debug_panel.cpp
@@ -0,0 +1,148 @@
+#include <string>
+#include <memory>
+
+#include "gui/controls.h"
+#include "../graphics/Mesh.h"
+#include "../objects/Player.h"
+#include "../physics/Hitbox.h"
+#include "../world/Level.h"
+#include "../world/World.h"
+#include "../voxels/Chunks.h"
+#include "../voxels/Block.h"
+#include "../util/stringutil.h"
+#include "../delegates.h"
+#include "../engine.h"
+
+#include "WorldRenderer.h"
+
+using namespace gui;
+
+static std::shared_ptr<Label> create_label(wstringsupplier supplier) {
+    auto label = std::make_shared<Label>(L"-");
+    label->textSupplier(supplier);
+    return label;
+}
+
+std::shared_ptr<UINode> create_debug_panel(
+    Engine* engine, 
+    Level* level, 
+    Player* player
+) {
+    auto panel = std::make_shared<Panel>(glm::vec2(250, 200), glm::vec4(5.0f), 2.0f);
+    panel->setPos(glm::vec2(10, 10));
+
+    static int fps = 0;
+    static int fpsMin = fps;
+    static int fpsMax = fps;
+    static std::wstring fpsString = L"";
+
+    panel->listenInterval(0.016f, [engine]() {
+        fps = 1.0f / engine->getDelta();
+        fpsMin = std::min(fps, fpsMin);
+        fpsMax = std::max(fps, fpsMax);
+    });
+
+    panel->listenInterval(0.5f, []() {
+        fpsString = std::to_wstring(fpsMax)+L" / "+std::to_wstring(fpsMin);
+        fpsMin = fps;
+        fpsMax = fps;
+    });
+    panel->add(create_label([](){ return L"fps: "+fpsString;}));
+   
+    panel->add(create_label([](){
+        return L"meshes: " + std::to_wstring(Mesh::meshesCount);
+    }));
+    panel->add(create_label([=](){
+        auto& settings = engine->getSettings();
+        bool culling = settings.graphics.frustumCulling;
+        return L"frustum-culling: "+std::wstring(culling ? L"on" : L"off");
+    }));
+    panel->add(create_label([=]() {
+        return L"chunks: "+std::to_wstring(level->chunks->chunksCount)+
+               L" visible: "+std::to_wstring(level->chunks->visible);
+    }));
+    panel->add(create_label([=](){
+        auto* indices = level->content->getIndices();
+        auto def = indices->getBlockDef(player->selectedVoxel.id);
+        std::wstringstream stream;
+        stream << std::hex << player->selectedVoxel.states;
+        if (def) {
+            stream << L" (" << util::str2wstr_utf8(def->name) << L")";
+        }
+        return L"block: "+std::to_wstring(player->selectedVoxel.id)+
+               L" "+stream.str();
+    }));
+    panel->add(create_label([=](){
+        return L"seed: "+std::to_wstring(level->world->getSeed());
+    }));
+
+    for (int ax = 0; ax < 3; ax++) {
+        auto sub = std::make_shared<Container>(glm::vec2(250, 27));
+
+        std::wstring str = L"x: ";
+        str[0] += ax;
+        auto label = std::make_shared<Label>(str);
+        label->setMargin(glm::vec4(2, 3, 2, 3));
+        label->setSize(glm::vec2(20, 27));
+        sub->add(label);
+        sub->setColor(glm::vec4(0.0f));
+
+        // Coord input
+        auto box = std::make_shared<TextBox>(L"");
+        box->setTextSupplier([=]() {
+            Hitbox* hitbox = player->hitbox.get();
+            return util::to_wstring(hitbox->position[ax], 2);
+        });
+        box->setTextConsumer([=](std::wstring text) {
+            try {
+                glm::vec3 position = player->hitbox->position;
+                position[ax] = std::stoi(text);
+                player->teleport(position);
+            } catch (std::invalid_argument& _){
+            }
+        });
+        box->setOnEditStart([=](){
+            Hitbox* hitbox = player->hitbox.get();
+            box->setText(std::to_wstring(int(hitbox->position[ax])));
+        });
+        box->setSize(glm::vec2(230, 27));
+
+        sub->add(box, glm::vec2(20, 0));
+        panel->add(sub);
+    }
+    panel->add(create_label([=](){
+        int hour, minute, second;
+        timeutil::from_value(level->world->daytime, hour, minute, second);
+
+        std::wstring timeString = 
+                     util::lfill(std::to_wstring(hour), 2, L'0') + L":" +
+                     util::lfill(std::to_wstring(minute), 2, L'0');
+        return L"time: "+timeString;
+    }));
+    {
+        auto bar = std::make_shared<TrackBar>(0.0f, 1.0f, 1.0f, 0.005f, 8);
+        bar->setSupplier([=]() {return level->world->daytime;});
+        bar->setConsumer([=](double val) {level->world->daytime = val;});
+        panel->add(bar);
+    }
+    {
+        auto bar = std::make_shared<TrackBar>(0.0f, 1.0f, 0.0f, 0.005f, 8);
+        bar->setSupplier([=]() {return WorldRenderer::fog;});
+        bar->setConsumer([=](double val) {WorldRenderer::fog = val;});
+        panel->add(bar);
+    }
+    {
+        auto checkbox = std::make_shared<FullCheckBox>(
+            L"Show Chunk Borders", glm::vec2(400, 24)
+        );
+        checkbox->setSupplier([=]() {
+            return engine->getSettings().debug.showChunkBorders;
+        });
+        checkbox->setConsumer([=](bool checked) {
+            engine->getSettings().debug.showChunkBorders = checked;
+        });
+        panel->add(checkbox);
+    }
+    panel->refresh();
+    return panel;
+}
diff --git a/src/frontend/gui/GUI.cpp b/src/frontend/gui/GUI.cpp
index 743e6c35..f3146e49 100644
--- a/src/frontend/gui/GUI.cpp
+++ b/src/frontend/gui/GUI.cpp
@@ -16,7 +16,7 @@
 using namespace gui;
 
 GUI::GUI() {
-    container = std::make_shared<Container>(glm::vec2(0, 0), glm::vec2(1000));
+    container = std::make_shared<Container>(glm::vec2(1000));
     uicamera = std::make_unique<Camera>(glm::vec3(), Window::height);
 	uicamera->perspective = false;
 	uicamera->flipped = true;
@@ -58,7 +58,7 @@ void GUI::actMouse(float delta) {
             }
             if (focus != pressed) {
                 focus = pressed;
-                focus->focus(this);
+                focus->onFocus(this);
                 return;
             }
         }
@@ -126,7 +126,7 @@ void GUI::draw(const GfxContext* pctx, Assets* assets) {
     auto& viewport = pctx->getViewport();
     glm::vec2 wsize = viewport.size();
 
-    menu->setCoord((wsize - menu->getSize()) / 2.0f);
+    menu->setPos((wsize - menu->getSize()) / 2.0f);
     uicamera->setFov(wsize.y);
 
 	Shader* uishader = assets->getShader("ui");
@@ -175,7 +175,7 @@ void GUI::setFocus(std::shared_ptr<UINode> node) {
     }
     focus = node;
     if (focus) {
-        focus->focus(this);
+        focus->onFocus(this);
     }
 }
 
diff --git a/src/frontend/gui/GUI.h b/src/frontend/gui/GUI.h
index 33e57a52..a519d870 100644
--- a/src/frontend/gui/GUI.h
+++ b/src/frontend/gui/GUI.h
@@ -51,7 +51,7 @@ namespace gui {
     class Container;
     class PagesControl;
 
-    /** The main UI controller */
+    /// @brief The main UI controller
     class GUI {
         std::shared_ptr<Container> container;
         std::shared_ptr<UINode> hover = nullptr;
@@ -67,55 +67,58 @@ namespace gui {
         GUI();
         ~GUI();
 
-        /** Get the main menu (PagesControl) node */
+        /// @brief Get the main menu (PagesControl) node
         std::shared_ptr<PagesControl> getMenu();
 
-        /** Get current focused node 
-          * @return focused node or nullptr */
+        /// @brief Get current focused node 
+        /// @return focused node or nullptr
         std::shared_ptr<UINode> getFocused() const;
 
-        /** Check if all user input is caught by some element like TextBox */
+        /// @brief Check if all user input is caught by some element like TextBox
         bool isFocusCaught() const;
 
-        /** Main input handling and logic update method 
-         * @param delta delta time */
+        /// @brief Main input handling and logic update method 
+        /// @param delta delta time
         void act(float delta);
 
-        /** Draw all visible elements on main container 
-         * @param pctx parent graphics context
-         * @param assets active assets storage */
+        /// @brief Draw all visible elements on main container 
+        /// @param pctx parent graphics context
+        /// @param assets active assets storage
         void draw(const GfxContext* pctx, Assets* assets);
 
-        /** Add node to the main container */
+        /// @brief Add element to the main container
+        /// @param node UI element
         void add(std::shared_ptr<UINode> node);
 
-        /** Remove node from the main container */
+        /// @brief Add element to the main container
+        /// @param node UI element
+        /// @param coord element position within the main container
+        void add(std::shared_ptr<UINode> node, glm::vec2 coord);
+
+        /// @brief Remove node from the main container
         void remove(std::shared_ptr<UINode> node) noexcept;
 
-        /** Store node in the GUI nodes dictionary 
-         * (does not add node to the main container)
-         * @param name node key
-         * @param node target node
-         */
+        /// @brief Store node in the GUI nodes dictionary 
+        /// (does not add node to the main container)
+        /// @param name node key
+        /// @param node target node
         void store(std::string name, std::shared_ptr<UINode> node);
 
-        /** Get node from the GUI nodes dictionary 
-         * @param name node key
-         * @return stored node or nullptr
-        */
+        /// @brief Get node from the GUI nodes dictionary 
+        /// @param name node key
+        /// @return stored node or nullptr
         std::shared_ptr<UINode> get(std::string name) noexcept;
 
-        /** Remove node from the GUI nodes dictionary
-         * @param name node key 
-         */
+        /// @brief Remove node from the GUI nodes dictionary
+        /// @param name node key 
         void remove(std::string name) noexcept;
 
-        /** Set node as focused 
-          * @param node new focused node or nullptr to remove focus
-          */
+        /// @brief Set node as focused 
+        /// @param node new focused node or nullptr to remove focus
         void setFocus(std::shared_ptr<UINode> node);
 
-        /** Get the main container */
+        /// @brief Get the main container
+        /// @deprecated
         std::shared_ptr<Container> getContainer() const;
 
         void postRunnable(runnable callback);
diff --git a/src/frontend/gui/UINode.cpp b/src/frontend/gui/UINode.cpp
index 9ca0c150..9d5d60dd 100644
--- a/src/frontend/gui/UINode.cpp
+++ b/src/frontend/gui/UINode.cpp
@@ -5,7 +5,7 @@
 using gui::UINode;
 using gui::Align;
 
-UINode::UINode(glm::vec2 coord, glm::vec2 size) : coord(coord), size(size) {
+UINode::UINode(glm::vec2 size) : size(size) {
 }
 
 UINode::~UINode() {
@@ -63,18 +63,18 @@ bool UINode::isFocused() const {
     return focused;
 }
 
-bool UINode::isInside(glm::vec2 pos) {
-    glm::vec2 coord = calcCoord();
+bool UINode::isInside(glm::vec2 point) {
+    glm::vec2 pos = calcPos();
     glm::vec2 size = getSize();
-    return (pos.x >= coord.x && pos.y >= coord.y && 
-            pos.x < coord.x + size.x && pos.y < coord.y + size.y);
+    return (point.x >= pos.x && point.y >= pos.y && 
+            point.x < pos.x + size.x && point.y < pos.y + size.y);
 }
 
-std::shared_ptr<UINode> UINode::getAt(glm::vec2 pos, std::shared_ptr<UINode> self) {
+std::shared_ptr<UINode> UINode::getAt(glm::vec2 point, std::shared_ptr<UINode> self) {
     if (!interactive) {
         return nullptr;
     }
-    return isInside(pos) ? self : nullptr;
+    return isInside(point) ? self : nullptr;
 }
 
 bool UINode::isInteractive() const {
@@ -93,11 +93,11 @@ bool UINode::isResizing() const {
     return resizing;
 }
 
-glm::vec2 UINode::calcCoord() const {
+glm::vec2 UINode::calcPos() const {
     if (parent) {
-        return coord + parent->calcCoord() + parent->contentOffset();
+        return pos + parent->calcPos() + parent->contentOffset();
     }
-    return coord;
+    return pos;
 }
 
 void UINode::scrolled(int value) {
@@ -106,12 +106,12 @@ void UINode::scrolled(int value) {
     }
 }
 
-void UINode::setCoord(glm::vec2 coord) {
-    this->coord = coord;
+void UINode::setPos(glm::vec2 pos) {
+    this->pos = pos;
 }
 
-glm::vec2 UINode::getCoord() const {
-    return coord;
+glm::vec2 UINode::getPos() const {
+    return pos;
 }
 
 glm::vec2 UINode::getSize() const {
@@ -187,6 +187,53 @@ const std::string& UINode::getId() const {
 
 void UINode::reposition() {
     if (positionfunc) {
-        setCoord(positionfunc());
+        setPos(positionfunc());
+    }
+}
+
+void UINode::setGravity(Gravity gravity) {
+    if (gravity == Gravity::none) {
+        setPositionFunc(nullptr);
+        return;
+    }
+    setPositionFunc([this, gravity](){
+        auto parent = getParent();
+        if (parent == nullptr) {
+            return getPos();
+        }
+        glm::vec4 margin = getMargin();
+        glm::vec2 size = getSize();
+        glm::vec2 parentSize = parent->getSize();
+
+        float x = 0.0f, y = 0.0f;
+        switch (gravity) {
+            case Gravity::top_left:
+            case Gravity::center_left:
+            case Gravity::bottom_left: x = parentSize.x+margin.x; break;
+            case Gravity::top_center:
+            case Gravity::center_center:
+            case Gravity::bottom_center: x = (parentSize.x-size.x)/2.0f; break;
+            case Gravity::top_right:
+            case Gravity::center_right:
+            case Gravity::bottom_right: x = parentSize.x-size.x-margin.z; break;
+            default: break;
+        }
+        switch (gravity) {
+            case Gravity::top_left:
+            case Gravity::top_center:
+            case Gravity::top_right: y = parentSize.y+margin.y; break;
+            case Gravity::center_left:
+            case Gravity::center_center:
+            case Gravity::center_right: y = (parentSize.y-size.y)/2.0f; break;
+            case Gravity::bottom_left:
+            case Gravity::bottom_center:
+            case Gravity::bottom_right: y = parentSize.y-size.y-margin.w; break;
+            default: break;
+        }
+        return glm::vec2(x, y);
+    });
+
+    if (parent) {
+        reposition();
     }
 }
diff --git a/src/frontend/gui/UINode.h b/src/frontend/gui/UINode.h
index bb182993..9389a667 100644
--- a/src/frontend/gui/UINode.h
+++ b/src/frontend/gui/UINode.h
@@ -24,34 +24,66 @@ namespace gui {
         top=left, bottom=right,
     };
 
+    enum class Gravity {
+        none,
+        
+        top_left,
+        top_center,
+        top_right,
+
+        center_left,
+        center_center,
+        center_right,
+
+        bottom_left,
+        bottom_center,
+        bottom_right
+    };
+
+    /// @brief Base abstract class for all UI elements
     class UINode {
-        /** 
-         * element identifier used for direct access in UiDocument
-        */
+        /// @brief element identifier used for direct access in UiDocument
         std::string id = "";
     protected:
-        glm::vec2 coord;
+        /// @brief element position within the parent element
+        glm::vec2 pos {0.0f};
+        /// @brief element size (width, height)
         glm::vec2 size;
+        /// @brief minimal element size
         glm::vec2 minSize {1.0f};
+        /// @brief element primary color (background-color or text-color if label)
         glm::vec4 color {1.0f};
+        /// @brief element color when mouse is over it
         glm::vec4 hoverColor {1.0f};
+        /// @brief element margin (only supported for Panel sub-nodes)
         glm::vec4 margin {1.0f};
+        /// @brief is element visible
         bool visible = true;
+        /// @brief is mouse over the element
         bool hover = false;
+        /// @brief is mouse has been pressed over the element and not released yet
         bool pressed = false;
+        /// @brief is element focused
         bool focused = false;
+        /// @brief is element opaque for cursor interaction
         bool interactive = true;
+        /// @brief does the element support resizing by parent elements
         bool resizing = true;
+        /// @brief z-index property specifies the stack order of an element
         int zindex = 0;
+        /// @brief element content alignment (supported by Label only)
         Align align = Align::left;
+        /// @brief parent element
         UINode* parent = nullptr;
+        /// @brief position supplier for the element (called on parent element size update)
         vec2supplier positionfunc = nullptr;
-        UINode(glm::vec2 coord, glm::vec2 size);
+
+        UINode(glm::vec2 size);
     public:
         virtual ~UINode();
-        /** Called every frame for all visible elements 
-         * @param delta delta time
-        */
+
+        /// @brief Called every frame for all visible elements 
+        /// @param delta delta timУ
         virtual void act(float delta) {};
         virtual void draw(const GfxContext* pctx, Assets* assets) = 0;
 
@@ -67,11 +99,12 @@ namespace gui {
         virtual void setParent(UINode* node);
         UINode* getParent() const;
 
-        /** Set element color (doesn't affect inner elements).
-           Also replaces hover color to avoid adding extra properties. */
+        /// @brief Set element color (doesn't affect inner elements).
+        /// Also replaces hover color to avoid adding extra properties
         virtual void setColor(glm::vec4 newColor);
 
-        /** Get element color (float R,G,B,A in range [0.0, 1.0])*/
+        /// @brief Get element color 
+        /// @return (float R,G,B,A in range [0.0, 1.0])
         glm::vec4 getColor() const;
 
         virtual void setHoverColor(glm::vec4 newColor);
@@ -80,12 +113,14 @@ namespace gui {
         virtual void setMargin(glm::vec4 margin);
         glm::vec4 getMargin() const;
 
-        /** Influences container elements sort order 
-            Doesn't work in Panel */
+        /// @brief Specifies the stack order of an element
+        /// @attention Is not supported by Panel
         virtual void setZIndex(int idx);
+        
+        /// @brief Get element z-index
         int getZIndex() const;
 
-        virtual void focus(GUI*) {focused = true;}
+        virtual void onFocus(GUI*) {focused = true;}
         virtual void click(GUI*, int x, int y);
         virtual void clicked(GUI*, mousecode button) {}
         virtual void mouseMove(GUI*, int x, int y) {};
@@ -123,9 +158,9 @@ namespace gui {
         /* Get inner content offset. Used for scroll */
         virtual glm::vec2 contentOffset() {return glm::vec2(0.0f);};
         /* Calculate screen position of the element */
-        virtual glm::vec2 calcCoord() const;
-        virtual void setCoord(glm::vec2 coord);
-        virtual glm::vec2 getCoord() const;
+        virtual glm::vec2 calcPos() const;
+        virtual void setPos(glm::vec2 pos);
+        virtual glm::vec2 getPos() const;
         virtual glm::vec2 getSize() const;
         virtual void setSize(glm::vec2 size);
         virtual glm::vec2 getMinSize() const;
@@ -140,8 +175,10 @@ namespace gui {
         void setId(const std::string& id);
         const std::string& getId() const;
 
-        /* Fetch coord from positionfunc if assigned */
+        /* Fetch pos from positionfunc if assigned */
         void reposition();
+
+        virtual void setGravity(Gravity gravity);
     };
 }
 
diff --git a/src/frontend/gui/containers.cpp b/src/frontend/gui/containers.cpp
index 7d43db58..f908dc85 100644
--- a/src/frontend/gui/containers.cpp
+++ b/src/frontend/gui/containers.cpp
@@ -10,7 +10,7 @@
 
 using namespace gui;
 
-Container::Container(glm::vec2 coord, glm::vec2 size) : UINode(coord, size) {
+Container::Container(glm::vec2 size) : UINode(size) {
     actualLength = size.y;
     setColor(glm::vec4());
 }
@@ -79,7 +79,7 @@ void Container::setScrollable(bool flag) {
 }
 
 void Container::draw(const GfxContext* pctx, Assets* assets) {
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     glm::vec2 size = getSize();
     drawBackground(pctx, assets);
 
@@ -88,7 +88,7 @@ void Container::draw(const GfxContext* pctx, Assets* assets) {
     batch->flush();
     {
         GfxContext ctx = pctx->sub();
-        ctx.scissors(glm::vec4(coord.x, coord.y, size.x, size.y));
+        ctx.scissors(glm::vec4(pos.x, pos.y, size.x, size.y));
         for (auto node : nodes) {
             if (node->isVisible())
                 node->draw(pctx, assets);
@@ -100,12 +100,12 @@ void Container::draw(const GfxContext* pctx, Assets* assets) {
 void Container::drawBackground(const GfxContext* pctx, Assets* assets) {
     if (color.a <= 0.0f)
         return;
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
 
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
     batch->setColor(color);
-    batch->rect(coord.x, coord.y, size.x, size.y);
+    batch->rect(pos.x, pos.y, size.x, size.y);
 }
 
 void Container::add(std::shared_ptr<UINode> node) {
@@ -115,8 +115,8 @@ void Container::add(std::shared_ptr<UINode> node) {
     refresh();
 }
 
-void Container::add(std::shared_ptr<UINode> node, glm::vec2 coord) {
-    node->setCoord(coord);
+void Container::add(std::shared_ptr<UINode> node, glm::vec2 pos) {
+    node->setPos(pos);
     add(node);
 }
 
@@ -157,9 +157,10 @@ const std::vector<std::shared_ptr<UINode>>& Container::getNodes() const {
 }
 
 Panel::Panel(glm::vec2 size, glm::vec4 padding, float interval)
-    : Container(glm::vec2(), size), 
-      padding(padding), 
-      interval(interval) {
+  : Container(size), 
+    padding(padding), 
+    interval(interval) 
+{
     setColor(glm::vec4(0.0f, 0.0f, 0.0f, 0.75f));
 }
 
@@ -210,7 +211,7 @@ void Panel::refresh() {
             y += margin.y;
             
             float ex = x + margin.x;
-            node->setCoord(glm::vec2(ex, y));
+            node->setPos(glm::vec2(ex, y));
             y += nodesize.y + margin.w + interval;
 
             float width = size.x - padding.x - padding.z - margin.x - margin.z;
@@ -227,7 +228,7 @@ void Panel::refresh() {
             glm::vec2 nodesize = node->getSize();
             const glm::vec4 margin = node->getMargin();
             x += margin.x;
-            node->setCoord(glm::vec2(x, y+margin.y));
+            node->setPos(glm::vec2(x, y+margin.y));
             x += nodesize.x + margin.z + interval;
             
             node->refresh();
@@ -245,7 +246,7 @@ Orientation Panel::getOrientation() const {
     return orientation;
 }
 
-PagesControl::PagesControl() : Container(glm::vec2(), glm::vec2(1)){
+PagesControl::PagesControl() : Container(glm::vec2(1)){
 }
 
 bool PagesControl::has(std::string name) {
diff --git a/src/frontend/gui/containers.h b/src/frontend/gui/containers.h
index b64c0720..3dcf80c8 100644
--- a/src/frontend/gui/containers.h
+++ b/src/frontend/gui/containers.h
@@ -33,14 +33,14 @@ namespace gui {
         int actualLength = 0;
         bool scrollable = true;
     public:
-        Container(glm::vec2 coord, glm::vec2 size);
+        Container(glm::vec2 size);
 
         virtual void act(float delta) override;
         virtual void drawBackground(const GfxContext* pctx, Assets* assets);
         virtual void draw(const GfxContext* pctx, Assets* assets) override;
         virtual std::shared_ptr<UINode> getAt(glm::vec2 pos, std::shared_ptr<UINode> self) override;
         virtual void add(std::shared_ptr<UINode> node);
-        virtual void add(std::shared_ptr<UINode> node, glm::vec2 coord);
+        virtual void add(std::shared_ptr<UINode> node, glm::vec2 pos);
         virtual void remove(std::shared_ptr<UINode> node);
         virtual void scrolled(int value) override;
         virtual void setScrollable(bool flag);
diff --git a/src/frontend/gui/controls.cpp b/src/frontend/gui/controls.cpp
index d0a39af3..d6e2b413 100644
--- a/src/frontend/gui/controls.cpp
+++ b/src/frontend/gui/controls.cpp
@@ -17,17 +17,19 @@
 using namespace gui;
 
 Label::Label(std::string text, std::string fontName) 
-     : UINode(glm::vec2(), glm::vec2(text.length() * 8, 15)), 
-       text(util::str2wstr_utf8(text)), 
-       fontName(fontName) {
+  : UINode(glm::vec2(text.length() * 8, 15)), 
+    text(util::str2wstr_utf8(text)), 
+    fontName(fontName) 
+{
     setInteractive(false);
 }
 
 
 Label::Label(std::wstring text, std::string fontName) 
-     : UINode(glm::vec2(), glm::vec2(text.length() * 8, 15)), 
-       text(text), 
-       fontName(fontName) {
+  : UINode(glm::vec2(text.length() * 8, 15)), 
+    text(text), 
+    fontName(fontName) 
+{
     setInteractive(false);
 }
 
@@ -137,28 +139,28 @@ void Label::draw(const GfxContext* pctx, Assets* assets) {
         (lines == 1 ? lineHeight : lineHeight*lineInterval)*lines + font->getYOffset()
     );
 
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     switch (align) {
         case Align::left:
             break;
         case Align::center:
-            coord.x += (size.x-newsize.x)*0.5f;
+            pos.x += (size.x-newsize.x)*0.5f;
             break;
         case Align::right:
-            coord.x += size.x-newsize.x;
+            pos.x += size.x-newsize.x;
             break;
     }
     switch (valign) {
         case Align::top:
             break;
         case Align::center:
-            coord.y += (size.y-newsize.y)*0.5f;
+            pos.y += (size.y-newsize.y)*0.5f;
             break;
         case Align::bottom:
-            coord.y += size.y-newsize.y;
+            pos.y += size.y-newsize.y;
             break;
     }
-    textYOffset = coord.y-calcCoord().y;
+    textYOffset = pos.y-calcPos().y;
     totalLineHeight = lineHeight * lineInterval;
 
     if (multiline) {
@@ -170,10 +172,10 @@ void Label::draw(const GfxContext* pctx, Assets* assets) {
                 view = std::wstring_view(text.c_str()+offset, end);
                 offset += end + 1;
             }
-            font->draw(batch, view, coord.x, coord.y + i * totalLineHeight, FontStyle::none);
+            font->draw(batch, view, pos.x, pos.y + i * totalLineHeight, FontStyle::none);
         }
     } else {
-        font->draw(batch, text, coord.x, coord.y, FontStyle::none);
+        font->draw(batch, text, pos.x, pos.y, FontStyle::none);
     }
 }
 
@@ -191,12 +193,12 @@ bool Label::isMultiline() const {
 }
 
 // ================================= Image ====================================
-Image::Image(std::string texture, glm::vec2 size) : UINode(glm::vec2(), size), texture(texture) {
+Image::Image(std::string texture, glm::vec2 size) : UINode(size), texture(texture) {
     setInteractive(false);
 }
 
 void Image::draw(const GfxContext* pctx, Assets* assets) {
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     glm::vec4 color = getColor();
     auto batch = pctx->getBatch2D();
     
@@ -206,7 +208,7 @@ void Image::draw(const GfxContext* pctx, Assets* assets) {
     }
     batch->texture(texture);
     batch->setColor(color);
-    batch->rect(coord.x, coord.y, size.x, size.y, 
+    batch->rect(pos.x, pos.y, size.x, size.y, 
                 0, 0, 0, UVRegion(), false, true, color);
 }
 
@@ -294,11 +296,11 @@ void Button::refresh() {
 }
 
 void Button::drawBackground(const GfxContext* pctx, Assets* assets) {
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
     batch->setColor(isPressed() ? pressedColor : (hover ? hoverColor : color));
-    batch->rect(coord.x, coord.y, size.x, size.y);
+    batch->rect(pos.x, pos.y, size.x, size.y);
 }
 
 void Button::mouseRelease(GUI* gui, int x, int y) {
@@ -330,7 +332,7 @@ Align Button::getTextAlign() const {
 }
 
 // ============================== RichButton ==================================
-RichButton::RichButton(glm::vec2 size) : Container(glm::vec2(), size) {
+RichButton::RichButton(glm::vec2 size) : Container(size) {
     setHoverColor(glm::vec4(0.05f, 0.1f, 0.15f, 0.75f));
 }
 
@@ -349,11 +351,11 @@ RichButton* RichButton::listenAction(onaction action) {
 }
 
 void RichButton::drawBackground(const GfxContext* pctx, Assets* assets) {
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
     batch->setColor(isPressed() ? pressedColor : (hover ? hoverColor : color));
-    batch->rect(coord.x, coord.y, size.x, size.y);
+    batch->rect(pos.x, pos.y, size.x, size.y);
 }
 
 // ================================ TextBox ===================================
@@ -366,7 +368,7 @@ TextBox::TextBox(std::wstring placeholder, glm::vec4 padding)
     add(label);
     setHoverColor(glm::vec4(0.05f, 0.1f, 0.2f, 0.75f));
 
-    textInitX = label->getCoord().x;
+    textInitX = label->getPos().x;
 }
 
 void TextBox::draw(const GfxContext* pctx, Assets* assets) {
@@ -377,14 +379,14 @@ void TextBox::draw(const GfxContext* pctx, Assets* assets) {
     if (!isFocused())
         return;
 
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     glm::vec2 size = getSize();
 
     auto subctx = pctx->sub();
-    subctx.scissors(glm::vec4(coord.x, coord.y, size.x, size.y));
+    subctx.scissors(glm::vec4(pos.x, pos.y, size.x, size.y));
 
     const int lineHeight = font->getLineHeight() * label->getLineInterval();
-    glm::vec2 lcoord = label->calcCoord();
+    glm::vec2 lcoord = label->calcPos();
     lcoord.y -= 2;
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
@@ -420,7 +422,7 @@ void TextBox::draw(const GfxContext* pctx, Assets* assets) {
 }
 
 void TextBox::drawBackground(const GfxContext* pctx, Assets* assets) {
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
 
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
@@ -437,14 +439,14 @@ void TextBox::drawBackground(const GfxContext* pctx, Assets* assets) {
         batch->setColor(invalidColor);
     }
 
-    batch->rect(coord.x, coord.y, size.x, size.y);
+    batch->rect(pos.x, pos.y, size.x, size.y);
     if (!isFocused() && supplier) {
         input = supplier();
     }
 
     if (isFocused() && multiline) {
         batch->setColor(glm::vec4(1, 1, 1, 0.1f));
-        glm::vec2 lcoord = label->calcCoord();
+        glm::vec2 lcoord = label->calcPos();
         lcoord.y -= 2;
         uint line = label->getLineByTextIndex(caret);
         int lineY = label->getLineYOffset(line);
@@ -536,7 +538,7 @@ size_t TextBox::getSelectionLength() const {
 /// @brief Set scroll offset
 /// @param x scroll offset
 void TextBox::setTextOffset(uint x) {
-    label->setCoord(glm::vec2(textInitX - int(x), label->getCoord().y));
+    label->setPos(glm::vec2(textInitX - int(x), label->getPos().y));
     textOffset = x;
 }
 
@@ -583,8 +585,8 @@ void TextBox::setOnEditStart(runnable oneditstart) {
     onEditStart = oneditstart;
 }
 
-void TextBox::focus(GUI* gui) {
-    Panel::focus(gui);
+void TextBox::onFocus(GUI* gui) {
+    Panel::onFocus(gui);
     if (onEditStart){
         setCaret(input.size());
         onEditStart();
@@ -611,7 +613,7 @@ size_t TextBox::normalizeIndex(int index) {
 int TextBox::calcIndexAt(int x, int y) const {
     if (font == nullptr)
         return 0;
-    glm::vec2 lcoord = label->calcCoord();
+    glm::vec2 lcoord = label->calcPos();
     uint line = label->getLineByYOffset(y-lcoord.y);
     line = std::min(line, label->getLinesNumber()-1);
     size_t lineLength = getLineLength(line);
@@ -883,11 +885,11 @@ InputBindBox::InputBindBox(Binding& binding, glm::vec4 padding)
 }
 
 void InputBindBox::drawBackground(const GfxContext* pctx, Assets* assets) {
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
     batch->setColor(isFocused() ? focusedColor : (hover ? hoverColor : color));
-    batch->rect(coord.x, coord.y, size.x, size.y);
+    batch->rect(pos.x, pos.y, size.x, size.y);
     label->setText(util::str2wstr_utf8(binding.text()));
 }
 
@@ -904,17 +906,19 @@ void InputBindBox::keyPressed(keycode key) {
 }
 
 // ================================ TrackBar ==================================
-TrackBar::TrackBar(double min, 
-                   double max, 
-                   double value, 
-                   double step, 
-                   int trackWidth)
-    : UINode(glm::vec2(), glm::vec2(26)), 
-      min(min), 
-      max(max), 
-      value(value), 
-      step(step), 
-      trackWidth(trackWidth) {
+TrackBar::TrackBar(
+    double min, 
+    double max, 
+    double value, 
+    double step, 
+    int trackWidth
+) : UINode(glm::vec2(26)), 
+    min(min), 
+    max(max), 
+    value(value), 
+    step(step), 
+    trackWidth(trackWidth) 
+{
     setColor(glm::vec4(0.f, 0.f, 0.f, 0.4f));
     setHoverColor(glm::vec4(0.01f, 0.02f, 0.03f, 0.5f));
 }
@@ -923,18 +927,18 @@ void TrackBar::draw(const GfxContext* pctx, Assets* assets) {
     if (supplier) {
         value = supplier();
     }
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
     batch->setColor(hover ? hoverColor : color);
-    batch->rect(coord.x, coord.y, size.x, size.y);
+    batch->rect(pos.x, pos.y, size.x, size.y);
 
     float width = size.x;
     float t = (value - min) / (max-min+trackWidth*step);
 
     batch->setColor(trackColor);
     int actualWidth = size.x * (trackWidth / (max-min+trackWidth*step) * step);
-    batch->rect(coord.x + width * t, coord.y, actualWidth, size.y);
+    batch->rect(pos.x + width * t, pos.y, actualWidth, size.y);
 }
 
 void TrackBar::setSupplier(doublesupplier supplier) {
@@ -946,9 +950,9 @@ void TrackBar::setConsumer(doubleconsumer consumer) {
 }
 
 void TrackBar::mouseMove(GUI*, int x, int y) {
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     value = x;
-    value -= coord.x;
+    value -= pos.x;
     value = (value)/size.x * (max-min+trackWidth*step);
     value += min;
     value = (value > max) ? max : value;
@@ -1009,7 +1013,7 @@ void TrackBar::setTrackColor(glm::vec4 color) {
 }
 
 // ================================ CheckBox ==================================
-CheckBox::CheckBox(bool checked) : UINode(glm::vec2(), glm::vec2(32.0f)), checked(checked) {
+CheckBox::CheckBox(bool checked) : UINode(glm::vec2(32.0f)), checked(checked) {
     setColor(glm::vec4(0.0f, 0.0f, 0.0f, 0.5f));
 }
 
@@ -1017,11 +1021,11 @@ void CheckBox::draw(const GfxContext* pctx, Assets* assets) {
     if (supplier) {
         checked = supplier();
     }
-    glm::vec2 coord = calcCoord();
+    glm::vec2 pos = calcPos();
     auto batch = pctx->getBatch2D();
     batch->texture(nullptr);
     batch->setColor(checked ? checkColor : (hover ? hoverColor : color));
-    batch->rect(coord.x, coord.y, size.x, size.y);
+    batch->rect(pos.x, pos.y, size.x, size.y);
 }
 
 void CheckBox::mouseRelease(GUI*, int x, int y) {
diff --git a/src/frontend/gui/controls.h b/src/frontend/gui/controls.h
index 539e46a9..79cacf38 100644
--- a/src/frontend/gui/controls.h
+++ b/src/frontend/gui/controls.h
@@ -272,7 +272,7 @@ namespace gui {
         /// @brief Set runnable called on textbox focus
         virtual void setOnEditStart(runnable oneditstart);
 
-        virtual void focus(GUI*) override;
+        virtual void onFocus(GUI*) override;
         virtual void refresh() override;
         virtual void click(GUI*, int, int) override;
         virtual void mouseMove(GUI*, int x, int y) override;
diff --git a/src/frontend/gui/gui_xml.cpp b/src/frontend/gui/gui_xml.cpp
index 18d2b125..b2c02e0c 100644
--- a/src/frontend/gui/gui_xml.cpp
+++ b/src/frontend/gui/gui_xml.cpp
@@ -22,13 +22,32 @@ static Align align_from_string(const std::string& str, Align def) {
     return def;
 }
 
+static Gravity gravity_from_string(const std::string& str) {
+    static const std::unordered_map<std::string, Gravity> gravity_names {
+        {"top-left", Gravity::top_left},
+        {"top-center", Gravity::top_center},
+        {"top-right", Gravity::top_right},
+        {"center-left", Gravity::center_left},
+        {"center-center", Gravity::center_center},
+        {"center-right", Gravity::center_right},
+        {"bottom-left", Gravity::bottom_left},
+        {"bottom-center", Gravity::bottom_center},
+        {"bottom-right", Gravity::bottom_right},
+    };
+    auto found = gravity_names.find(str);
+    if (found == gravity_names.end()) {
+        return found->second;
+    }
+    return Gravity::none;
+}
+
 /* Read basic UINode properties */
 static void _readUINode(UiXmlReader& reader, xml::xmlelement element, UINode& node) {
     if (element->has("id")) {
         node.setId(element->attr("id").getText());
     }
     if (element->has("pos")) {
-        node.setCoord(element->attr("pos").asVec2());
+        node.setPos(element->attr("pos").asVec2());
     }
     if (element->has("size")) {
         node.setSize(element->attr("size").asVec2());
@@ -67,6 +86,12 @@ static void _readUINode(UiXmlReader& reader, xml::xmlelement element, UINode& no
     }
     std::string alignName = element->attr("align", "").getText();
     node.setAlign(align_from_string(alignName, node.getAlign()));
+
+    if (element->has("gravity")) {
+        node.setGravity(gravity_from_string(
+            element->attr("gravity").getText()
+        ));
+    }
 }
 
 
@@ -149,7 +174,7 @@ static std::shared_ptr<UINode> readLabel(UiXmlReader& reader, xml::xmlelement el
 }
 
 static std::shared_ptr<UINode> readContainer(UiXmlReader& reader, xml::xmlelement element) {
-    auto container = std::make_shared<Container>(glm::vec2(), glm::vec2());
+    auto container = std::make_shared<Container>(glm::vec2());
     _readContainer(reader, element, *container);
     return container;
 }
diff --git a/src/frontend/hud.cpp b/src/frontend/hud.cpp
index 1e14501a..d7cf2d7a 100644
--- a/src/frontend/hud.cpp
+++ b/src/frontend/hud.cpp
@@ -1,15 +1,11 @@
 #include "hud.h"
 
-// TODO: refactor this garbage
-
 #include <iostream>
 #include <sstream>
 #include <memory>
 #include <string>
 #include <assert.h>
 #include <stdexcept>
-#include <GL/glew.h>
-#include <GLFW/glfw3.h>
 
 #include "../typedefs.h"
 #include "../content/Content.h"
@@ -55,13 +51,50 @@
 #include "../items/Inventories.h"
 #include "../logic/scripting/scripting.h"
 
-using namespace gui;
 
-static std::shared_ptr<Label> create_label(wstringsupplier supplier) {
-    auto label = std::make_shared<Label>(L"-");
-    label->textSupplier(supplier);
-    return label;
-}
+// implemented in debug_panel.cpp
+extern std::shared_ptr<gui::UINode> create_debug_panel(
+    Engine* engine, 
+    Level* level, 
+    Player* player
+);
+
+class DeltaGrapher : public gui::UINode {
+    std::unique_ptr<int[]> points;
+    float multiplier;
+    int index = 0;
+    int dmwidth;
+    int dmheight;
+public:
+    DeltaGrapher(uint width, uint height, float multiplier) 
+      : gui::UINode(glm::vec2(width, height)), 
+        multiplier(multiplier),
+        dmwidth(width),
+        dmheight(height)
+    {
+        points = std::make_unique<int[]>(width);
+    }
+
+    void act(float delta) override {
+        index = index + 1 % dmwidth;
+        int value = static_cast<int>(delta * multiplier);
+        points[index % dmwidth] = std::min(value, dmheight);
+    }
+
+    void draw(const GfxContext* pctx, Assets* assets) override {
+        glm::vec2 pos = calcPos();
+        auto batch = pctx->getBatch2D();
+        batch->texture(nullptr);
+        batch->lineWidth(1);
+        for (int i = index+1; i < index+dmwidth; i++) {
+            int j = i % dmwidth;
+            batch->line(
+                pos.x + i - index, pos.y + size.y - points[j], 
+                pos.x + i - index, pos.y + size.y, 1.0f, 1.0f, 1.0f, 0.2f
+            );
+        }
+    }
+};
 
 HudElement::HudElement(
     hud_element_mode mode, 
@@ -74,6 +107,7 @@ HudElement::HudElement(
 void HudElement::update(bool pause, bool inventoryOpen, bool debugMode) {
     if (debug && !debugMode) {
         node->setVisible(false);
+        return;
     }
     switch (mode) {
         case hud_element_mode::permanent:
@@ -99,115 +133,6 @@ std::shared_ptr<gui::UINode> HudElement::getNode() const {
     return node;
 }
 
-std::shared_ptr<UINode> Hud::createDebugPanel(Engine* engine) {
-    auto level = frontend->getLevel();
-
-    auto panel = std::make_shared<Panel>(glm::vec2(250, 200), glm::vec4(5.0f), 2.0f);
-    panel->listenInterval(0.5f, [this]() {
-        fpsString = std::to_wstring(fpsMax)+L" / "+std::to_wstring(fpsMin);
-        fpsMin = fps;
-        fpsMax = fps;
-    });
-    panel->setCoord(glm::vec2(10, 10));
-    panel->add(create_label([this](){ return L"fps: "+this->fpsString;}));
-    panel->add(create_label([](){
-        return L"meshes: " + std::to_wstring(Mesh::meshesCount);
-    }));
-    panel->add(create_label([=](){
-        auto& settings = engine->getSettings();
-        bool culling = settings.graphics.frustumCulling;
-        return L"frustum-culling: "+std::wstring(culling ? L"on" : L"off");
-    }));
-    panel->add(create_label([=]() {
-        return L"chunks: "+std::to_wstring(level->chunks->chunksCount)+
-               L" visible: "+std::to_wstring(level->chunks->visible);
-    }));
-    panel->add(create_label([=](){
-        auto* indices = level->content->getIndices();
-        auto def = indices->getBlockDef(player->selectedVoxel.id);
-        std::wstringstream stream;
-        stream << std::hex << player->selectedVoxel.states;
-        if (def) {
-            stream << L" (" << util::str2wstr_utf8(def->name) << L")";
-        }
-        return L"block: "+std::to_wstring(player->selectedVoxel.id)+
-               L" "+stream.str();
-    }));
-    panel->add(create_label([=](){
-        return L"seed: "+std::to_wstring(level->world->getSeed());
-    }));
-
-    for (int ax = 0; ax < 3; ax++) {
-        auto sub = std::make_shared<Container>(glm::vec2(), glm::vec2(250, 27));
-
-        std::wstring str = L"x: ";
-        str[0] += ax;
-        auto label = std::make_shared<Label>(str);
-        label->setMargin(glm::vec4(2, 3, 2, 3));
-        label->setSize(glm::vec2(20, 27));
-        sub->add(label);
-        sub->setColor(glm::vec4(0.0f));
-
-        // Coord input
-        auto box = std::make_shared<TextBox>(L"");
-        box->setTextSupplier([=]() {
-            Hitbox* hitbox = player->hitbox.get();
-            return util::to_wstring(hitbox->position[ax], 2);
-        });
-        box->setTextConsumer([=](std::wstring text) {
-            try {
-                glm::vec3 position = player->hitbox->position;
-                position[ax] = std::stoi(text);
-                player->teleport(position);
-            } catch (std::invalid_argument& _){
-            }
-        });
-        box->setOnEditStart([=](){
-            Hitbox* hitbox = player->hitbox.get();
-            box->setText(std::to_wstring(int(hitbox->position[ax])));
-        });
-        box->setSize(glm::vec2(230, 27));
-
-        sub->add(box, glm::vec2(20, 0));
-        panel->add(sub);
-    }
-    panel->add(create_label([=](){
-        int hour, minute, second;
-        timeutil::from_value(level->world->daytime, hour, minute, second);
-
-        std::wstring timeString = 
-                     util::lfill(std::to_wstring(hour), 2, L'0') + L":" +
-                     util::lfill(std::to_wstring(minute), 2, L'0');
-        return L"time: "+timeString;
-    }));
-    {
-        auto bar = std::make_shared<TrackBar>(0.0f, 1.0f, 1.0f, 0.005f, 8);
-        bar->setSupplier([=]() {return level->world->daytime;});
-        bar->setConsumer([=](double val) {level->world->daytime = val;});
-        panel->add(bar);
-    }
-    {
-        auto bar = std::make_shared<TrackBar>(0.0f, 1.0f, 0.0f, 0.005f, 8);
-        bar->setSupplier([=]() {return WorldRenderer::fog;});
-        bar->setConsumer([=](double val) {WorldRenderer::fog = val;});
-        panel->add(bar);
-    }
-    {
-        auto checkbox = std::make_shared<FullCheckBox>(
-            L"Show Chunk Borders", glm::vec2(400, 24)
-        );
-        checkbox->setSupplier([=]() {
-            return engine->getSettings().debug.showChunkBorders;
-        });
-        checkbox->setConsumer([=](bool checked) {
-            engine->getSettings().debug.showChunkBorders = checked;
-        });
-        panel->add(checkbox);
-    }
-    panel->refresh();
-    return panel;
-}
-
 std::shared_ptr<InventoryView> Hud::createContentAccess() {
     auto level = frontend->getLevel();
     auto content = level->content;
@@ -252,14 +177,12 @@ std::shared_ptr<InventoryView> Hud::createHotbar() {
 }
 
 Hud::Hud(Engine* engine, LevelFrontend* frontend, Player* player) 
-    : engine(engine),
-      assets(engine->getAssets()), 
-      gui(engine->getGUI()),
-      frontend(frontend),
-      player(player)
+  : engine(engine),
+    assets(engine->getAssets()), 
+    gui(engine->getGUI()),
+    frontend(frontend),
+    player(player)
 {
-    auto menu = gui->getMenu();
-
     interaction = std::make_unique<InventoryInteraction>();
     grabbedItemView = std::make_shared<SlotView>(
         SlotLayout(-1, glm::vec2(), false, false, nullptr, nullptr)
@@ -275,7 +198,7 @@ Hud::Hud(Engine* engine, LevelFrontend* frontend, Player* player)
     grabbedItemView->setZIndex(1);
 
     contentAccess = createContentAccess();
-    contentAccessPanel = std::make_shared<Panel>(
+    contentAccessPanel = std::make_shared<gui::Panel>(
         contentAccess->getSize(), glm::vec4(0.0f), 0.0f
     );
     contentAccessPanel->setColor(glm::vec4());
@@ -283,7 +206,7 @@ Hud::Hud(Engine* engine, LevelFrontend* frontend, Player* player)
     contentAccessPanel->setScrollable(true);
 
     hotbarView = createHotbar();
-    darkOverlay = std::make_unique<Panel>(glm::vec2(4000.0f));
+    darkOverlay = std::make_unique<gui::Panel>(glm::vec2(4000.0f));
     darkOverlay->setColor(glm::vec4(0, 0, 0, 0.5f));
     darkOverlay->setZIndex(-1);
     darkOverlay->setVisible(false);
@@ -292,9 +215,7 @@ Hud::Hud(Engine* engine, LevelFrontend* frontend, Player* player)
     uicamera->perspective = false;
     uicamera->flipped = true;
 
-    debugPanel = createDebugPanel(engine);
-    menu->reset();
-
+    debugPanel = create_debug_panel(engine, frontend->getLevel(), player);
     debugPanel->setZIndex(2);
     
     gui->add(darkOverlay);
@@ -302,13 +223,17 @@ Hud::Hud(Engine* engine, LevelFrontend* frontend, Player* player)
     gui->add(debugPanel);
     gui->add(contentAccessPanel);
     gui->add(grabbedItemView);
+
+    auto dgrapher = std::make_shared<DeltaGrapher>(350, 250, 2000);
+    dgrapher->setGravity(gui::Gravity::bottom_right);
+    add(HudElement(hud_element_mode::permanent, nullptr, dgrapher, true));
 }
 
 Hud::~Hud() {
     // removing all controlled ui
     gui->remove(grabbedItemView);
     for (auto& element : elements) {
-        remove(element);
+        onRemove(element);
     }
     gui->remove(hotbarView);
     gui->remove(darkOverlay);
@@ -316,21 +241,55 @@ Hud::~Hud() {
     gui->remove(debugPanel);
 }
 
-void Hud::drawDebug(int fps){
-    this->fps = fps;
-    fpsMin = min(fps, fpsMin);
-    fpsMax = max(fps, fpsMax);
-}
-
-/**
- * Remove all elements marked as removed
- */
+/// @brief Remove all elements marked as removed
 void Hud::cleanup() {
     auto it = std::remove_if(elements.begin(), elements.end(), [](const HudElement& e) {
         return e.isRemoved();
     });
     elements.erase(it, elements.end());
-} 
+}
+
+void Hud::processInput(bool visible) {
+    if (Events::jpressed(keycode::ESCAPE)) {
+        if (pause) {
+            setPause(false);
+        } else if (inventoryOpen) {
+            closeInventory();
+        } else {
+            setPause(true);
+        }
+    }
+
+    if (visible && Events::jactive(BIND_HUD_INVENTORY)) {
+        if (inventoryOpen) {
+            closeInventory();
+        } else {
+            openInventory();
+        }
+    }
+    if (!pause) {
+        if (!inventoryOpen && Events::scroll) {
+            int slot = player->getChosenSlot();
+            slot = (slot - Events::scroll) % 10;
+            if (slot < 0) {
+                slot += 10;
+            }
+            player->setChosenSlot(slot);
+        }
+        for (
+            int i = static_cast<int>(keycode::NUM_1); 
+            i <= static_cast<int>(keycode::NUM_9); 
+            i++
+        ) {
+            if (Events::jpressed(i)) {
+                player->setChosenSlot(i - static_cast<int>(keycode::NUM_1));
+            }
+        }
+        if (Events::jpressed(keycode::NUM_0)) {
+            player->setChosenSlot(9);
+        }
+    }
+}
 
 void Hud::update(bool visible) {
     auto level = frontend->getLevel();
@@ -344,31 +303,16 @@ void Hud::update(bool visible) {
     if (pause && menu->getCurrent().panel == nullptr) {
         setPause(false);
     }
-    if (Events::jpressed(keycode::ESCAPE) && !gui->isFocusCaught()) {
-        if (pause) {
-            setPause(false);
-        } else if (inventoryOpen) {
-            closeInventory();
-        } else {
-            setPause(true);
-        }
-    }
 
-    if (visible && !gui->isFocusCaught() && !pause) {
-        if (Events::jactive(BIND_HUD_INVENTORY)) {
-            if (inventoryOpen) {
-                closeInventory();
-            } else {
-                openInventory();
-            }
-        }
+    if (!gui->isFocusCaught()) {
+        processInput(visible);
     }
     if ((pause || inventoryOpen) == Events::_cursor_locked) {
         Events::toggleCursor();
     }
 
     if (blockUI) {
-        voxel* vox = level->chunks->get(currentblock.x, currentblock.y, currentblock.z);
+        voxel* vox = level->chunks->get(blockPos.x, blockPos.y, blockPos.z);
         if (vox == nullptr || vox->id != currentblockid) {
             closeInventory();
         }
@@ -384,58 +328,33 @@ void Hud::update(bool visible) {
     contentAccess->setMinSize(glm::vec2(1, Window::height));
     hotbarView->setVisible(visible);
 
-    if (!gui->isFocusCaught() && !pause) {
-        for (int i = static_cast<int>(keycode::NUM_1); i <= static_cast<int>(keycode::NUM_9); i++) {
-            if (Events::jpressed(i)) {
-                player->setChosenSlot(i - static_cast<int>(keycode::NUM_1));
-            }
-        }
-        if (Events::jpressed(keycode::NUM_0)) {
-            player->setChosenSlot(9);
-        }
-    }
-    if (!pause && !inventoryOpen && Events::scroll) {
-        int slot = player->getChosenSlot();
-        slot = (slot - Events::scroll) % 10;
-        if (slot < 0) {
-            slot += 10;
-        }
-        player->setChosenSlot(slot);
-    }
-
     if (visible) {
         for (auto& element : elements) {
             element.update(pause, inventoryOpen, player->debug);
             if (element.isRemoved()) {
-                remove(element);
+                onRemove(element);
             }
         }
     }
     cleanup();
 }
 
-/** 
- * Show inventory on the screen and turn on inventory mode blocking movement
- */
+/// @brief Show inventory on the screen and turn on inventory mode blocking movement
 void Hud::openInventory() {
-    auto inventory = player->getInventory();
-
     inventoryOpen = true;
-
+    auto inventory = player->getInventory();
     auto inventoryDocument = assets->getLayout("core:inventory");
     inventoryView = std::dynamic_pointer_cast<InventoryView>(inventoryDocument->getRoot());
     inventoryView->bind(inventory, frontend, interaction.get());
     add(HudElement(hud_element_mode::inventory_bound, inventoryDocument, inventoryView, false));
 }
 
-/**
- * Show player inventory + block UI
- * @param block world position of the open block
- * @param doc block UI document (root element must be an InventoryView)
- * @param blockinv block inventory. 
- * In case of nullptr a new virtual inventory will be created
- */
-void Hud::openInventory(glm::ivec3 block, UiDocument* doc, std::shared_ptr<Inventory> blockinv, bool playerInventory) {
+void Hud::openInventory(
+    glm::ivec3 block, 
+    UiDocument* doc, 
+    std::shared_ptr<Inventory> blockinv, 
+    bool playerInventory
+) {
     if (isInventoryOpen()) {
         closeInventory();
     }
@@ -444,6 +363,7 @@ void Hud::openInventory(glm::ivec3 block, UiDocument* doc, std::shared_ptr<Inven
     if (blockUI == nullptr) {
         throw std::runtime_error("block UI root element must be 'inventory'");
     }
+    secondUI = blockUI;
     if (playerInventory) {
         openInventory();
     } else {
@@ -454,15 +374,24 @@ void Hud::openInventory(glm::ivec3 block, UiDocument* doc, std::shared_ptr<Inven
     }
     level->chunks->getChunkByVoxel(block.x, block.y, block.z)->setUnsaved(true);
     blockUI->bind(blockinv, frontend, interaction.get());
-    currentblock = block;
+    blockPos = block;
     currentblockid = level->chunks->get(block.x, block.y, block.z)->id;
     add(HudElement(hud_element_mode::inventory_bound, doc, blockUI, false));
 }
 
-/** 
- * Add element as permanent overlay
- * @param doc element layout document
- */
+void Hud::showOverlay(UiDocument* doc, bool playerInventory) {
+    if (isInventoryOpen()) {
+        closeInventory();
+    }
+    secondUI = doc->getRoot();
+    if (playerInventory) {
+        openInventory();
+    } else {
+        inventoryOpen = true;
+    }
+    add(HudElement(hud_element_mode::inventory_bound, doc, secondUI, false));
+}
+
 void Hud::openPermanent(UiDocument* doc) {
     auto root = doc->getRoot();
     remove(root);
@@ -475,24 +404,13 @@ void Hud::openPermanent(UiDocument* doc) {
     add(HudElement(hud_element_mode::permanent, doc, doc->getRoot(), false));
 }
 
-/**
- * Hide inventory and turn off inventory mode
- */
 void Hud::closeInventory() {
-    auto level = frontend->getLevel();
-
     inventoryOpen = false;
     ItemStack& grabbed = interaction->getGrabbedItem();
     grabbed.clear();
     inventoryView = nullptr;
-    if (blockUI) {
-        auto blockinv = blockUI->getInventory();
-        // todo: do it automatically
-        if (blockinv->isVirtual()) {
-            level->inventories->remove(blockinv->getId());   
-        }
-        blockUI = nullptr;
-    }
+    blockUI = nullptr;
+    secondUI = nullptr;
 }
 
 void Hud::add(HudElement element) {
@@ -505,20 +423,20 @@ void Hud::add(HudElement element) {
             scripting::on_ui_open(
                 element.getDocument(), 
                 inventory.get(), 
-                currentblock
+                blockPos
             );
         } else {
             scripting::on_ui_open(
                 element.getDocument(), 
                 nullptr, 
-                currentblock
+                blockPos
             );
         }
     }
     elements.push_back(element);
 }
 
-void Hud::remove(HudElement& element) {
+void Hud::onRemove(HudElement& element) {
     auto document = element.getDocument();
     if (document) {
         Inventory* inventory = nullptr;
@@ -527,16 +445,18 @@ void Hud::remove(HudElement& element) {
             inventory = invview->getInventory().get();
         }
         scripting::on_ui_close(document, inventory);
+        if (invview) {
+            invview->unbind();
+        }
     }
     gui->remove(element.getNode());
 }
 
-// todo: refactor this garbage
-void Hud::remove(std::shared_ptr<UINode> node) {
+void Hud::remove(std::shared_ptr<gui::UINode> node) {
     for (auto& element : elements) {
         if (element.getNode() == node) {
             element.setRemoved();
-            remove(element);
+            onRemove(element);
         }
     }
     cleanup();
@@ -547,6 +467,8 @@ void Hud::draw(const GfxContext& ctx){
     const uint width = viewport.getWidth();
     const uint height = viewport.getHeight();
 
+    updateElementsPosition(viewport);
+
     uicamera->setFov(height);
 
     auto batch = ctx.getBatch2D();
@@ -555,12 +477,9 @@ void Hud::draw(const GfxContext& ctx){
     Shader* uishader = assets->getShader("ui");
     uishader->use();
     uishader->uniformMatrix("u_projview", uicamera->getProjView());
-    
-    hotbarView->setCoord(glm::vec2(width/2, height-65));
-    hotbarView->setSelected(player->getChosenSlot());
 
     // Crosshair
-    if (!pause && Events::_cursor_locked && !player->debug) {
+    if (!pause && !inventoryOpen && !player->debug) {
         GfxContext chctx = ctx.sub();
         chctx.blendMode(blendmode::inversion);
         auto texture = assets->getTexture("gui/crosshair");
@@ -573,55 +492,45 @@ void Hud::draw(const GfxContext& ctx){
         );
         batch->flush();
     }
+    batch->flush();
+}
 
-    // Delta-time visualizer
-    if (player->debug) {
-        batch->texture(nullptr);
-        const int dmwidth = 256;
-        const float dmscale = 4000.0f;
-        static float deltameter[dmwidth]{};
-        static int index=0;
-        index = index + 1 % dmwidth;
-        deltameter[index%dmwidth] = glm::min(0.2f, 1.f/fps)*dmscale;
-        batch->lineWidth(1);
-        for (int i = index+1; i < index+dmwidth; i++) {
-            int j = i % dmwidth;
-            batch->line(width-dmwidth+i-index, height-deltameter[j], 
-                        width-dmwidth+i-index, height, 1.0f, 1.0f, 1.0f, 0.2f);
-        }
-    }
-
+void Hud::updateElementsPosition(const Viewport& viewport) {
+    const uint width = viewport.getWidth();
+    const uint height = viewport.getHeight();
+    
     if (inventoryOpen) {
         float caWidth = inventoryView ? contentAccess->getSize().x : 0.0f;
-        contentAccessPanel->setCoord(glm::vec2(width-caWidth, 0));
+        contentAccessPanel->setPos(glm::vec2(width-caWidth, 0));
 
         glm::vec2 invSize = inventoryView ? inventoryView->getSize() : glm::vec2();
-        if (blockUI == nullptr) {
+        if (secondUI == nullptr) {
             if (inventoryView) {
-                inventoryView->setCoord(glm::vec2(
+                inventoryView->setPos(glm::vec2(
                     glm::min(width/2-invSize.x/2, width-caWidth-10-invSize.x),
                     height/2-invSize.y/2
                 ));
             }
         } else {
-            glm::vec2 blockInvSize = blockUI->getSize();
-            float invwidth = glm::max(invSize.x, blockInvSize.x);
+            glm::vec2 secondUISize = secondUI->getSize();
+            float invwidth = glm::max(invSize.x, secondUISize.x);
             int interval = invSize.y > 0.0 ? 5 : 0;
-            float totalHeight = invSize.y + blockInvSize.y + interval;
+            float totalHeight = invSize.y + secondUISize.y + interval;
             if (inventoryView) {
-                inventoryView->setCoord(glm::vec2(
+                inventoryView->setPos(glm::vec2(
                     glm::min(width/2-invwidth/2, width-caWidth-10-invwidth),
                     height/2+totalHeight/2-invSize.y
                 ));
             }
-            blockUI->setCoord(glm::vec2(
+            secondUI->setPos(glm::vec2(
                 glm::min(width/2-invwidth/2, width-caWidth-10-invwidth),
                 height/2-totalHeight/2
             ));
         }
     }
-    grabbedItemView->setCoord(glm::vec2(Events::cursor));
-    batch->flush();
+    grabbedItemView->setPos(glm::vec2(Events::cursor));
+    hotbarView->setPos(glm::vec2(width/2, height-65));
+    hotbarView->setSelected(player->getChosenSlot());
 }
 
 bool Hud::isInventoryOpen() const {
diff --git a/src/frontend/hud.h b/src/frontend/hud.h
index e9171eeb..c2a3ee03 100644
--- a/src/frontend/hud.h
+++ b/src/frontend/hud.h
@@ -9,11 +9,9 @@
 #include "../graphics/GfxContext.h"
 
 class Camera;
-class Level;
 class Block;
 class Assets;
 class Player;
-class Level;
 class Engine;
 class SlotView;
 class Inventory;
@@ -23,104 +21,138 @@ class UiDocument;
 class InventoryInteraction;
 
 namespace gui {
-	class GUI;
-	class UINode;
+    class GUI;
+    class UINode;
     class Panel;
-	class Container;
+    class Container;
 }
 
 enum class hud_element_mode {
-	// element is hidden if menu or inventory open
-	ingame,
-	// element is visible if hud is visible
-	permanent,
-	// element is visible in inventory mode
-	inventory_any,
-	// element will be removed on inventory close
-	inventory_bound
+    // element is hidden if menu or inventory open
+    ingame,
+    // element is visible if hud is visible
+    permanent,
+    // element is visible in inventory mode
+    inventory_any,
+    // element will be removed on inventory close
+    inventory_bound
 };
 
 class HudElement {
-	hud_element_mode mode;
-	UiDocument* document;
-	std::shared_ptr<gui::UINode> node;
+    hud_element_mode mode;
+    UiDocument* document;
+    std::shared_ptr<gui::UINode> node;
 
-	bool debug;
-	bool removed = false;
+    bool debug;
+    bool removed = false;
 public:
-	HudElement(hud_element_mode mode, UiDocument* document, std::shared_ptr<gui::UINode> node, bool debug);
+    HudElement(hud_element_mode mode, UiDocument* document, std::shared_ptr<gui::UINode> node, bool debug);
 
-	void update(bool pause, bool inventoryOpen, bool debug);
+    void update(bool pause, bool inventoryOpen, bool debug);
 
-	UiDocument* getDocument() const;
-	std::shared_ptr<gui::UINode> getNode() const;
+    UiDocument* getDocument() const;
+    std::shared_ptr<gui::UINode> getNode() const;
 
     void setRemoved() {
         removed = true;
     }
 
-	bool isRemoved() const {
-		return removed;
-	}
+    bool isRemoved() const {
+        return removed;
+    }
 };
 
 class Hud {
     Engine* engine;
     Assets* assets;
-	std::unique_ptr<Camera> uicamera;
-
-	int fps = 60;
-	int fpsMin = 60;
-	int fpsMax = 60;
-	std::wstring fpsString;
-	bool inventoryOpen = false;
-	bool pause = false;
-
-    std::shared_ptr<gui::Container> contentAccessPanel;
-    std::shared_ptr<InventoryView> contentAccess;
-    std::shared_ptr<InventoryView> hotbarView;
-	std::shared_ptr<gui::UINode> debugPanel;
-    std::shared_ptr<gui::Panel> darkOverlay;
-    std::unique_ptr<InventoryInteraction> interaction;
-    std::shared_ptr<SlotView> grabbedItemView;
-	gui::GUI* gui;
-	LevelFrontend* frontend;
+    std::unique_ptr<Camera> uicamera;
+    gui::GUI* gui;
+    LevelFrontend* frontend;
     Player* player;
 
-	std::vector<HudElement> elements;
+    /// @brief Is any overlay/inventory open
+    bool inventoryOpen = false;
+    /// @brief Is pause mode on
+    bool pause = false;
 
+    /// @brief Content access panel scroll container
+    std::shared_ptr<gui::Container> contentAccessPanel;
+    /// @brief Content access panel itself
+    std::shared_ptr<InventoryView> contentAccess;
+    /// @brief Player inventory hotbar
+    std::shared_ptr<InventoryView> hotbarView;
+    /// @brief Debug info and control panel (F3 key)
+    std::shared_ptr<gui::UINode> debugPanel;
+    /// @brief Overlay used in pause mode
+    std::shared_ptr<gui::Panel> darkOverlay;
+    /// @brief Inventories interaction agent (grabbed item and other info)
+    std::unique_ptr<InventoryInteraction> interaction;
+    /// @brief Grabbed item visual element
+    std::shared_ptr<SlotView> grabbedItemView;
+    /// @brief List of all controlled hud elements
+    std::vector<HudElement> elements;
+
+    /// @brief Player inventory view
     std::shared_ptr<InventoryView> inventoryView = nullptr;
-	std::shared_ptr<InventoryView> blockUI = nullptr;
-	glm::ivec3 currentblock {};
+    /// @brief Block inventory view
+    std::shared_ptr<InventoryView> blockUI = nullptr;
+    /// @brief Position of the block open
+    glm::ivec3 blockPos {};
+    /// @brief Id of the block open (used to detect block destruction or replacement)
     blockid_t currentblockid = 0;
 
-    std::shared_ptr<gui::UINode> createDebugPanel(Engine* engine);
+    /// @brief UI element will be dynamicly positioned near to inventory or in screen center
+    std::shared_ptr<gui::UINode> secondUI = nullptr;
+    
     std::shared_ptr<InventoryView> createContentAccess();
     std::shared_ptr<InventoryView> createHotbar();
 
+    void processInput(bool visible);
+    void updateElementsPosition(const Viewport& viewport);
     void cleanup();
 public:
-	Hud(Engine* engine, LevelFrontend* frontend, Player* player);
-	~Hud();
+    Hud(Engine* engine, LevelFrontend* frontend, Player* player);
+    ~Hud();
 
-	void update(bool hudVisible);
-	void draw(const GfxContext& context);
-	void drawDebug(int fps);
+    void update(bool hudVisible);
+    void draw(const GfxContext& context);
 
-	bool isInventoryOpen() const;
-	bool isPause() const;
+    /// @brief Check if inventory mode on
+    bool isInventoryOpen() const;
+
+    /// @brief Check if pause mode on
+    bool isPause() const;
+
+    /// @brief Enable/disable pause mode
     void setPause(bool pause);
 
+    /// @brief Show player inventory in inventory-mode
     void openInventory();
-	void openInventory(glm::ivec3 block, UiDocument* doc, std::shared_ptr<Inventory> blockInv, bool playerInventory);
+    
+    /// @brief Show block inventory in inventory-mode
+    /// @param block block position
+    /// @param doc block ui layout
+    /// @param blockInv block inventory
+    /// @param playerInventory show player inventory too
+    void openInventory(glm::ivec3 block, UiDocument* doc, std::shared_ptr<Inventory> blockInv, bool playerInventory);
+
+    /// @brief Show element in inventory-mode
+    /// @param doc element layout
+    /// @param playerInventory show player inventory too
+    void showOverlay(UiDocument* doc, bool playerInventory);
+
+    /// @brief Close all open inventories and overlay
     void closeInventory();
+
+    /// @brief Add element will be visible until removed
+    /// @param doc element layout
     void openPermanent(UiDocument* doc);
 
-	void add(HudElement element);
-	void remove(HudElement& element);
+    void add(HudElement element);
+    void onRemove(HudElement& element);
     void remove(std::shared_ptr<gui::UINode> node);
 
     Player* getPlayer() const;
 };
 
-#endif /* SRC_HUD_H_ */
+#endif // SRC_HUD_H_
diff --git a/src/frontend/screens.cpp b/src/frontend/screens.cpp
index be3535b8..8c12074e 100644
--- a/src/frontend/screens.cpp
+++ b/src/frontend/screens.cpp
@@ -92,6 +92,8 @@ static bool backlight;
 LevelScreen::LevelScreen(Engine* engine, Level* level) : Screen(engine) {
     auto& settings = engine->getSettings();
     auto assets = engine->getAssets();
+    auto menu = engine->getGUI()->getMenu();
+    menu->reset();
 
     controller = std::make_unique<LevelController>(settings, level);
     frontend = std::make_unique<LevelFrontend>(level, assets);
@@ -186,8 +188,5 @@ void LevelScreen::draw(float delta) {
 
     if (hudVisible) {
         hud->draw(ctx);
-        if (controller->getPlayer()->debug) {
-            hud->drawDebug(1 / delta);
-        }
     }
 }
diff --git a/src/graphics/Batch2D.cpp b/src/graphics/Batch2D.cpp
index ce9fe3ac..d576a387 100644
--- a/src/graphics/Batch2D.cpp
+++ b/src/graphics/Batch2D.cpp
@@ -19,12 +19,11 @@ Batch2D::Batch2D(size_t capacity) : capacity(capacity), color(1.0f){
     ubyte pixels[] = {
         0xFF, 0xFF, 0xFF, 0xFF
     };
-    blank = new Texture(pixels, 1, 1, GL_RGBA);
+    blank = std::make_unique<Texture>(pixels, 1, 1, GL_RGBA);
     _texture = nullptr;
 }
 
 Batch2D::~Batch2D(){
-    delete blank;
     delete[] buffer;
 }
 
diff --git a/src/graphics/Batch2D.h b/src/graphics/Batch2D.h
index 2c6e0e2a..7f83e258 100644
--- a/src/graphics/Batch2D.h
+++ b/src/graphics/Batch2D.h
@@ -15,10 +15,9 @@ class Batch2D {
     float* buffer;
     size_t capacity;
     std::unique_ptr<Mesh> mesh;
+    std::unique_ptr<Texture> blank;
     size_t index;
     glm::vec4 color;
-
-    Texture* blank;
     Texture* _texture;
 
     void vertex(
diff --git a/src/logic/scripting/lua/libgui.cpp b/src/logic/scripting/lua/libgui.cpp
index 11d563af..e25e6af8 100644
--- a/src/logic/scripting/lua/libgui.cpp
+++ b/src/logic/scripting/lua/libgui.cpp
@@ -171,7 +171,7 @@ static int l_gui_getattr(lua_State* L) {
     if (attr == "color") {
         return lua::pushcolor_arr(L, node->getColor());
     } else if (attr == "pos") {
-        return lua::pushvec2_arr(L, node->getCoord());
+        return lua::pushvec2_arr(L, node->getPos());
     } else if (attr == "size") {
         return lua::pushvec2_arr(L, node->getSize());
     } else if (attr == "hoverColor") {
@@ -210,7 +210,7 @@ static int l_gui_setattr(lua_State* L) {
 
     auto node = getDocumentNode(L, docname, element);
     if (attr == "pos") {
-        node->setCoord(lua::tovec2(L, 4));
+        node->setPos(lua::tovec2(L, 4));
     } else if (attr == "size") {
         node->setSize(lua::tovec2(L, 4));
     } else if (attr == "color") {
diff --git a/src/logic/scripting/lua/libhud.cpp b/src/logic/scripting/lua/libhud.cpp
index 85567d75..971b4931 100644
--- a/src/logic/scripting/lua/libhud.cpp
+++ b/src/logic/scripting/lua/libhud.cpp
@@ -65,6 +65,19 @@ static int l_hud_open_block(lua_State* L) {
     return 2;
 }
 
+static int l_hud_show_overlay(lua_State* L) {
+    const char* name = lua_tostring(L, 1);
+    bool playerInventory = lua_toboolean(L, 2);
+
+    auto assets = scripting::engine->getAssets();
+    auto layout = assets->getLayout(name);
+    if (layout == nullptr) {
+        luaL_error(L, "there is no ui layout '%s'", name);
+    }
+    scripting::hud->showOverlay(layout, playerInventory);
+    return 0;
+}
+
 static UiDocument* require_layout(lua_State* L, const char* name) {
     auto assets = scripting::engine->getAssets();
     auto layout = assets->getLayout(name);
@@ -91,6 +104,7 @@ const luaL_Reg hudlib [] = {
     {"close_inventory", lua_wrap_errors<l_hud_close_inventory>},
     {"open_block", lua_wrap_errors<l_hud_open_block>},
     {"open_permanent", lua_wrap_errors<l_hud_open_permanent>},
+    {"show_overlay", lua_wrap_errors<l_hud_show_overlay>},
     {"close", lua_wrap_errors<l_hud_close>},
     {NULL, NULL}
 };