diff --git a/Player.cpp b/Player.cpp
index 0088517..82735c0 100755
--- a/Player.cpp
+++ b/Player.cpp
@@ -90,7 +90,7 @@ void Player::nextWeapon() {
         _removeWeaponCallBack(_weapons[_selectedWeapon]);
         _selectedWeapon = (_selectedWeapon + 1) % _weapons.size();
         _addWeaponCallBack(_weapons[_selectedWeapon]);
-        Log::log("selected _selectedWeapon " + std::to_string(_selectedWeapon));
+        Log::log("_selected _selectedWeapon " + std::to_string(_selectedWeapon));
         _changeWeaponSound.play();
     }
 }
@@ -104,7 +104,7 @@ void Player::previousWeapon() {
         else
             _selectedWeapon = _weapons.size() - 1;
         _addWeaponCallBack(_weapons[_selectedWeapon]);
-        Log::log("selected _selectedWeapon " + std::to_string(_selectedWeapon));
+        Log::log("_selected _selectedWeapon " + std::to_string(_selectedWeapon));
         _changeWeaponSound.play();
     }
 }
diff --git a/engine/Camera.cpp b/engine/Camera.cpp
index b26bdf1..d9265ab 100755
--- a/engine/Camera.cpp
+++ b/engine/Camera.cpp
@@ -101,7 +101,7 @@ void Camera::init(int width, int height, double fov, double ZNear, double ZFar)
 
 std::vector<Triangle> &Camera::sorted() {
 
-    // Sort _tris from back to front
+    // Sort _tris from _back to front
     // This is some replacement for Z-buffer
     std::sort(_triangles.begin(), _triangles.end(), [](Triangle &t1, Triangle &t2)
     {
diff --git a/engine/Engine.cpp b/engine/Engine.cpp
index 86f1064..a822cf9 100755
--- a/engine/Engine.cpp
+++ b/engine/Engine.cpp
@@ -24,7 +24,7 @@ void Engine::create(int screenWidth, int screenHeight, const std::string &name,
     screen->open(screenWidth, screenHeight, name, verticalSync, background, style);
     screen->attachMouse(mouse);
 
-    Log::log("Engine::create(): started engine (" + std::to_string(screenWidth) + " x " + std::to_string(screenHeight) + ") with title '" + name + "'.");
+    Log::log("Engine::create(): started engine (" + std::to_string(screenWidth) + " _x " + std::to_string(screenHeight) + ") with title '" + name + "'.");
     Time::update();
 
     start();
@@ -74,7 +74,7 @@ void Engine::exit() {
         screen->close();
     }
     ResourceManager::unloadAllResources();
-    Log::log("Engine::exit(): exit engine (" + std::to_string(screen->width()) + " x " + std::to_string(screen->height()) + ") with title '" +
+    Log::log("Engine::exit(): exit engine (" + std::to_string(screen->width()) + " _x " + std::to_string(screen->height()) + ") with title '" +
                      screen->title() + "'.");
 }
 
@@ -84,7 +84,7 @@ void Engine::printDebugText() const {
                           std::to_string((camera->position().x())) + "\n Y: " +
                           std::to_string((camera->position().y())) + "\n Z: " +
                           std::to_string((camera->position().z())) + "\n\n" +
-                          std::to_string(screen->width()) + "x" +
+                          std::to_string(screen->width()) + "_x" +
                           std::to_string(screen->height()) + "\n" +
                           std::to_string(Time::fps()) +
                           " fps \n" + std::to_string((int) _triPerSec) + " _tris/s");
diff --git a/engine/Keyboard.h b/engine/Keyboard.h
index 897b4ab..b5b96ef 100644
--- a/engine/Keyboard.h
+++ b/engine/Keyboard.h
@@ -13,8 +13,8 @@ private:
 public:
     Keyboard() = default;
 
-    static bool isKeyPressed(sf::Keyboard::Key key); // returns true if this key is pressed
-    bool isKeyTapped(sf::Keyboard::Key key); // returns true if this key is tapped and 1/5 sec passed (button bouncing problem solved)
+    static bool isKeyPressed(sf::Keyboard::Key key); // returns true if this key is _pressed
+    bool isKeyTapped(sf::Keyboard::Key key); // returns true if this key is tapped and 1/5 sec passed (_button bouncing problem solved)
 };
 
 
diff --git a/engine/Mesh.h b/engine/Mesh.h
index 006f121..4d29e8c 100755
--- a/engine/Mesh.h
+++ b/engine/Mesh.h
@@ -36,7 +36,7 @@ public:
     void rotate(const Point4D& r) override;
     // Rotate body around normalised vector 'v' by 'r' radians
     void rotate(const Point4D& v, double r) override;
-    // Rotate body around XYZ by (r.x, r.y, r.z) radians relative val 'point4D'
+    // Rotate body around XYZ by (r._x, r._y, r.z) radians relative val 'point4D'
     void rotateRelativePoint(const Point4D& point4D, const Point4D& r) override;
     // Rotate body around normalised vector 'v' by 'r' radians relative val 'point4D'
     void rotateRelativePoint(const Point4D& point4D, const Point4D& v, double r) override;
diff --git a/engine/Mouse.h b/engine/Mouse.h
index 2b43053..81d7cea 100644
--- a/engine/Mouse.h
+++ b/engine/Mouse.h
@@ -18,8 +18,8 @@ public:
 
     void setWindow(std::shared_ptr<sf::RenderWindow> window);
 
-    static bool isButtonPressed(sf::Mouse::Button button); // returns true if this button is pressed
-    bool isButtonTapped(sf::Mouse::Button button); // returns true if this button is tapped and 1/5 sec passed (button bouncing problem solved)
+    static bool isButtonPressed(sf::Mouse::Button button); // returns true if this _button is _pressed
+    bool isButtonTapped(sf::Mouse::Button button); // returns true if this _button is tapped and 1/5 sec passed (_button bouncing problem solved)
 
     [[nodiscard]] Point4D getMousePosition() const;
     [[nodiscard]] Point4D getMouseDisplacement() const;
diff --git a/engine/gui/Button.cpp b/engine/gui/Button.cpp
index 3548669..b9de7b8 100755
--- a/engine/gui/Button.cpp
+++ b/engine/gui/Button.cpp
@@ -3,56 +3,66 @@
 //
 
 #include "Button.h"
+
+#include <utility>
 #include "../ResourceManager.h"
 
 void Button::select()
 {
-    if (!selected && !pressed)
+    if (!_selected && !_pressed)
     {
-        button.setTextureRect(sf::IntRect(selectedState.tx, selectedState.ty, w, h));
-        selected = true;
+        _button.setTextureRect(sf::IntRect(_selectedState.tx, _selectedState.ty, _w, _h));
+        _selected = true;
     }
 }
 
 void Button::unSelect()
 {
-    if (selected && !pressed)
+    if (_selected && !_pressed)
     {
-        button.setTextureRect(sf::IntRect(usualState.tx, usualState.ty, w, h));
-        selected = false;
+        _button.setTextureRect(sf::IntRect(_usualState.tx, _usualState.ty, _w, _h));
+        _selected = false;
     }
 }
 
 void Button::press()
 {
-    if (!pressed)
+    if (!_pressed)
     {
-        button.setTextureRect(sf::IntRect(pressedState.tx, pressedState.ty, w, h));
-        if(checkBox)
-            pressed = true;
-        clickSound.play();
-        click();
+        _button.setTextureRect(sf::IntRect(_pressedState.tx, _pressedState.ty, _w, _h));
+        if(_checkBox)
+            _pressed = true;
+        _clickSound.play();
+        _click();
     }
     else
     {
-        button.setTextureRect(sf::IntRect(usualState.tx, usualState.ty, w, h));
-        if(checkBox)
-            pressed = false;
+        _button.setTextureRect(sf::IntRect(_usualState.tx, _usualState.ty, _w, _h));
+        if(_checkBox)
+            _pressed = false;
     }
 }
 
 void Button::init() {
-    button.setTexture(*ResourceManager::loadTexture(s_texture));
-    button.setTextureRect(sf::IntRect(usualState.tx, usualState.ty, w, h));
-    button.scale(sx, sy);
-    button.setPosition(x - w*sx/2, y - h*sy/2);
+    _button.setTexture(*ResourceManager::loadTexture(_texture));
+    _button.setTextureRect(sf::IntRect(_usualState.tx, _usualState.ty, _w, _h));
+    _button.scale(_sx, _sy);
+    _button.setPosition(_x - _w * _sx / 2, _y - _h * _sy / 2);
 
-    text.setFont(*ResourceManager::loadFont(s_font));
-    text.setString(s_text);
-    text.setCharacterSize(h*sy/2);
-    text.setFillColor(textColor);
-    text.setPosition(x - text.getLocalBounds().width/2, y - h*sy/2 + text.getLocalBounds().height/4);
+    _text.setFont(*ResourceManager::loadFont(_font));
+    _text.setString(_textString);
+    _text.setCharacterSize(_h * _sy / 2);
+    _text.setFillColor(_textColor);
+    _text.setPosition(_x - _text.getLocalBounds().width / 2, _y - _h * _sy / 2 + _text.getLocalBounds().height / 4);
+
+    _clickSound.setBuffer(*ResourceManager::loadSoundBuffer(_clickSoundName));
+    _clickSound.setVolume(15);
+}
+
+Button::Button(int x, int y, int width, int height, std::function<void()> click, std::string text, double sx,
+               double sy, std::string texture, tPos usualState, tPos selectedState, tPos pressedState,
+               std::string font, sf::Color textColor, std::string clickSound) : _x(x), _y(y), _w(width), _h(height), _click(std::move(click)),
+               _textString(std::move(text)), _sx(sx), _sy(sy), _texture(std::move(texture)), _usualState(usualState), _selectedState(selectedState), _pressedState(pressedState),
+               _font(std::move(font)), _textColor(textColor), _clickSoundName(std::move(clickSound)){
 
-    clickSound.setBuffer(*ResourceManager::loadSoundBuffer(s_clickSound));
-    clickSound.setVolume(15);
 }
diff --git a/engine/gui/Button.h b/engine/gui/Button.h
index 1422ed1..bd04b51 100755
--- a/engine/gui/Button.h
+++ b/engine/gui/Button.h
@@ -14,44 +14,57 @@ struct tPos {
     int ty;
 };
 
-struct Button
-{
-    int x;
-    int y;
+class Button {
+private:
+    int _x{};
+    int _y{};
 
-    int w;
-    int h;
+    int _w{};
+    int _h{};
 
-    std::function<void()> click;
+    std::function<void()> _click;
 
-    std::string s_text;
+    std::string _textString;
 
-    double sx;
-    double sy;
+    double _sx{};
+    double _sy{};
 
-    std::string s_texture;
-    tPos usualState;
-    tPos selectedState;
-    tPos pressedState;
+    std::string _texture;
+    tPos _usualState{};
+    tPos _selectedState{};
+    tPos _pressedState{};
 
-    std::string s_font;
-    sf::Color textColor;
+    std::string _font;
+    sf::Color _textColor;
 
-    std::string s_clickSound;
+    std::string _clickSoundName;
 
-    sf::Sprite button;
-    sf::Text text;
-    sf::Sound clickSound;
+    sf::Sprite _button;
+    sf::Text _text;
+    sf::Sound _clickSound;
 
-    bool selected = false;
-    bool pressed = false;
-    bool checkBox = false;
+    bool _selected = false;
+    bool _pressed = false;
+    bool _checkBox = false;
+
+public:
+    Button() = default;
+    Button(int x, int y, int width, int height, std::function<void()> click, std::string  text, double sx, double sy, std::string  texture, tPos usualState, tPos selectedState, tPos pressedState, std::string  font, sf::Color textColor, std::string  clickSound);
 
     void select();
     void unSelect();
     void press();
 
     void init();
+
+    [[nodiscard]] int x() const { return _x; }
+    [[nodiscard]] int y() const { return _y; }
+    [[nodiscard]] int w() const { return _w; }
+    [[nodiscard]] int h() const { return _h; }
+    [[nodiscard]] double sx() const { return _sx; }
+    [[nodiscard]] double sy() const { return _sy; }
+    [[nodiscard]] sf::Sprite const& sprite() const { return _button; }
+    [[nodiscard]] sf::Text const& text() const { return _text; }
 };
 
 
diff --git a/engine/gui/Window.cpp b/engine/gui/Window.cpp
index d20168b..1fcb978 100755
--- a/engine/gui/Window.cpp
+++ b/engine/gui/Window.cpp
@@ -10,23 +10,23 @@
 void Window::addButton(int x, int y, int w, int h, std::function<void()> click, const std::string &text, double sx, double sy,
                        const std::string &texture, tPos usualState, tPos selectedState, tPos pressedState,
                        const std::string& font, sf::Color textColor, const std::string& clickSound) {
-    buttons.push_back(Button{x, y, w, h, std::move(click), text, sx, sy, texture, usualState, selectedState, pressedState, font, textColor, clickSound});
-    buttons.back().init();
+    _buttons.push_back(Button{x, y, w, h, std::move(click), text, sx, sy, texture, usualState, selectedState, pressedState, font, textColor, clickSound});
+    _buttons.back().init();
 }
 
 void Window::update() {
 
-    _screen->setTitle(s_name);
-    _screen->drawSprite(back);
+    _screen->setTitle(_name);
+    _screen->drawSprite(_back);
 
     Point4D mousePos = _mouse->getMousePosition();
-    Point4D dMousePos = mousePos - prevMousePosition;
-    back.setPosition(back.getPosition() - sf::Vector2f(dMousePos.x()/30, dMousePos.y()/30));
+    Point4D dMousePos = mousePos - _prevMousePosition;
+    _back.setPosition(_back.getPosition() - sf::Vector2f(dMousePos.x() / 30, dMousePos.y() / 30));
     bool isPressed = _mouse->isButtonTapped(sf::Mouse::Left);
 
-    for(auto& button : buttons) {
-        if( mousePos.x() > button.x - button.w*button.sx/2 && mousePos.y() > button.y - button.h*button.sy/2 &&
-            mousePos.x() < button.x + button.w*button.sx/2 && mousePos.y() < button.y + button.h*button.sy/2) {
+    for(auto& button : _buttons) {
+        if( mousePos.x() > button.x() - button.w() * button.sx() / 2 && mousePos.y() > button.y() - button.h() * button.sy() / 2 &&
+            mousePos.x() < button.x() + button.w() * button.sx() / 2 && mousePos.y() < button.y() + button.h() * button.sy() / 2) {
             button.select();
             if(isPressed)
                 button.press();
@@ -35,19 +35,19 @@ void Window::update() {
         }
 
         if(_screen->isOpen()) {
-            _screen->drawSprite(button.button);
-            _screen->drawText(button.text);
+            _screen->drawSprite(button.sprite());
+            _screen->drawText(button.text());
         }
     }
 
-    prevMousePosition = mousePos;
+    _prevMousePosition = mousePos;
 }
 
 void Window::setBackgroundTexture(const std::string &texture, double sx, double sy, int w, int h) {
-    s_backTexture = texture;
-    std::shared_ptr<sf::Texture> t = ResourceManager::loadTexture(s_backTexture);
+    _backTexture = texture;
+    std::shared_ptr<sf::Texture> t = ResourceManager::loadTexture(_backTexture);
     t->setRepeated(true);
-    back = sf::Sprite(*t, sf::IntRect(0, 0, w + w/30.0, h + h/30.0));
-    back.scale(sx, sy);
-    back.setPosition(sf::Vector2f(-w/30.0, -h/30.0));
+    _back = sf::Sprite(*t, sf::IntRect(0, 0, w + w / 30.0, h + h / 30.0));
+    _back.scale(sx, sy);
+    _back.setPosition(sf::Vector2f(-w / 30.0, -h / 30.0));
 }
diff --git a/engine/gui/Window.h b/engine/gui/Window.h
index 316a149..7b55af4 100755
--- a/engine/gui/Window.h
+++ b/engine/gui/Window.h
@@ -14,27 +14,27 @@
 
 class Window {
 private:
-    std::string s_name;
-    std::string s_backTexture;
-    std::vector<Button> buttons;
+    std::string _name;
+    std::string _backTexture;
+    std::vector<Button> _buttons;
 
-    sf::Sprite back;
+    sf::Sprite _back;
 
-    Point4D prevMousePosition;
+    Point4D _prevMousePosition;
 
     std::shared_ptr<Screen> _screen;
     std::shared_ptr<Mouse> _mouse;
 public:
-    explicit Window(std::shared_ptr<Screen> screen, std::shared_ptr<Mouse> mouse, std::string name = "Menu", std::string backTexture = "") : _screen(screen), _mouse(mouse), s_name(std::move(name)), s_backTexture(std::move(backTexture)){}
+    explicit Window(std::shared_ptr<Screen> screen, std::shared_ptr<Mouse> mouse, std::string name = "Menu", std::string backTexture = "") : _screen(screen), _mouse(mouse), _name(std::move(name)), _backTexture(std::move(backTexture)){}
 
     void addButton(int x, int y, int w, int h,
                    std::function<void()> click,
-                   const std::string& text = "button", double sx = 1, double sy = 1,
+                   const std::string& text = "_button", double sx = 1, double sy = 1,
                    const std::string& texture = "", tPos usualState = {}, tPos selectedState = {}, tPos pressedState = {},
                    const std::string& font = "../engine/fonts/Roboto-Medium.ttf", sf::Color textColor = {255, 255, 255}, const std::string& clickSound = "");
 
-    [[nodiscard]] std::string title() const { return s_name; }
-    void title(const std::string& title) { s_name = title; }
+    [[nodiscard]] std::string title() const { return _name; }
+    void title(const std::string& title) { _name = title; }
 
     void setBackgroundTexture(const std::string& texture, double sx = 1, double sy = 1, int w = 1920, int h = 1080);
 
diff --git a/engine/network/ServerUDP.h b/engine/network/ServerUDP.h
index 704a6f6..67639b3 100755
--- a/engine/network/ServerUDP.h
+++ b/engine/network/ServerUDP.h
@@ -36,7 +36,7 @@ public:
     // virtual functions
     virtual void broadcast(){};
 
-    // here you have to send Init message back to 'targetId' and send NewClient message to all '_clients'
+    // here you have to send Init message _back to 'targetId' and send NewClient message to all '_clients'
     virtual void processConnect(sf::Uint16 senderId){};
     virtual void processClientUpdate(sf::Uint16 senderId, sf::Packet& packet){};
     virtual void processDisconnect(sf::Uint16 senderId){};
diff --git a/engine/physics/RigidBody.cpp b/engine/physics/RigidBody.cpp
index 33677b1..2312b85 100755
--- a/engine/physics/RigidBody.cpp
+++ b/engine/physics/RigidBody.cpp
@@ -178,7 +178,7 @@ CollisionPoint RigidBody::EPA(const Simplex& simplex, std::shared_ptr<RigidBody>
     };
 
     // list: vector4(normal, distance), index: min distance
-    auto [normals, minFace] = GetFaceNormals(polytope, faces);
+    auto [normals, minFace] = _getFaceNormals(polytope, faces);
 
     Point4D minNormal;
     double minDistance = INFINITY;
@@ -200,9 +200,9 @@ CollisionPoint RigidBody::EPA(const Simplex& simplex, std::shared_ptr<RigidBody>
                 if (normals[i].dot(support) > 0) {
                     size_t f = i * 3;
 
-                    AddIfUniqueEdge(uniqueEdges, faces, f,     f + 1);
-                    AddIfUniqueEdge(uniqueEdges, faces, f + 1, f + 2);
-                    AddIfUniqueEdge(uniqueEdges, faces, f + 2, f    );
+                    _addIfUniqueEdge(uniqueEdges, faces, f, f + 1);
+                    _addIfUniqueEdge(uniqueEdges, faces, f + 1, f + 2);
+                    _addIfUniqueEdge(uniqueEdges, faces, f + 2, f);
 
                     faces[f + 2] = faces.back(); faces.pop_back();
                     faces[f + 1] = faces.back(); faces.pop_back();
@@ -222,7 +222,7 @@ CollisionPoint RigidBody::EPA(const Simplex& simplex, std::shared_ptr<RigidBody>
 
             polytope.push_back(support);
 
-            auto [newNormals, newMinFace] = GetFaceNormals(polytope, newFaces);
+            auto [newNormals, newMinFace] = _getFaceNormals(polytope, newFaces);
 
             if(newNormals.empty())
                 break;
@@ -255,7 +255,7 @@ CollisionPoint RigidBody::EPA(const Simplex& simplex, std::shared_ptr<RigidBody>
     return point;
 }
 
-std::pair<std::vector<Point4D>, size_t> RigidBody::GetFaceNormals(const std::vector<Point4D>& polytope, const std::vector<size_t>&  faces) {
+std::pair<std::vector<Point4D>, size_t> RigidBody::_getFaceNormals(const std::vector<Point4D>& polytope, const std::vector<size_t>&  faces) {
     std::vector<Point4D> normals;
     size_t minTriangle = 0;
     double minDistance = INFINITY;
@@ -285,7 +285,7 @@ std::pair<std::vector<Point4D>, size_t> RigidBody::GetFaceNormals(const std::vec
     return { normals, minTriangle };
 }
 
-void RigidBody::AddIfUniqueEdge(std::vector<std::pair<size_t, size_t>>& edges, const std::vector<size_t>& faces, size_t a, size_t b) {
+void RigidBody::_addIfUniqueEdge(std::vector<std::pair<size_t, size_t>>& edges, const std::vector<size_t>& faces, size_t a, size_t b) {
 
     auto reverse = std::find(                   //      0--<--3
             edges.begin(),                      //     / \ B /   A: 2-0
diff --git a/engine/physics/RigidBody.h b/engine/physics/RigidBody.h
index 2fd5692..fa851c9 100755
--- a/engine/physics/RigidBody.h
+++ b/engine/physics/RigidBody.h
@@ -32,8 +32,8 @@ private:
     static bool _triangle(Simplex& points, Point4D& direction);
     static bool _tetrahedron(Simplex& points, Point4D& direction);
 
-    static std::pair<std::vector<Point4D>, size_t> GetFaceNormals(const std::vector<Point4D>& polytope, const std::vector<size_t>&  faces);
-    static void AddIfUniqueEdge(std::vector<std::pair<size_t, size_t>>& edges, const std::vector<size_t>& faces, size_t a, size_t b);
+    static std::pair<std::vector<Point4D>, size_t> _getFaceNormals(const std::vector<Point4D>& polytope, const std::vector<size_t>&  faces);
+    static void _addIfUniqueEdge(std::vector<std::pair<size_t, size_t>>& edges, const std::vector<size_t>& faces, size_t a, size_t b);
 
 protected:
     Point4D _velocity;
@@ -58,7 +58,6 @@ public:
     [[nodiscard]] bool inCollision() const {return _inCollision; }
     [[nodiscard]] bool isCollider() const {return _isCollider; }
     void setInCollision(bool c) { _inCollision = c; }
-    void setCollisionNormal(const Point4D& c) { _collisionNormal = c; }
     void setCollision(bool c) { _collision= c; }
     void setCollider(bool c) { _isCollider = c; }
 
diff --git a/engine/utils/Matrix4x4.cpp b/engine/utils/Matrix4x4.cpp
index 143bfd4..fe54ef7 100755
--- a/engine/utils/Matrix4x4.cpp
+++ b/engine/utils/Matrix4x4.cpp
@@ -65,8 +65,8 @@ Matrix4x4 Matrix4x4::Scale(const Point4D& factor) {
 Matrix4x4 Matrix4x4::Translation(const Point4D& v) {
     Matrix4x4 t{};
 /*
- * ( 1 0 0 dx )(x)   (x + dx)
- * ( 0 1 0 dy )(y) = (y + dy)
+ * ( 1 0 0 dx )(_x)   (_x + dx)
+ * ( 0 1 0 dy )(_y) = (_y + dy)
  * ( 0 0 1 dz )(z)   (z + dz)
  * ( 0 0 0 1  )(1)   (  1   )
  */