Merge pull request #400 from MihailRis/syntax-hightlighting

Text Formatting

doc/en/main-page.md

@@ -14,9 +14,10 @@ Documentation for in-development version 0.26.
 - [Content-packs](content-packs.md)
 - [Engine usage recommendations](engine-use-recommendations.md)
 - [Item properties](item-properties.md)
+- [Particles](particles.md)
 - [Resources (resources.json)](resources.md)
 - [Rigging](rigging.md)
 - [Scripting](scripting.md)
+- [Text styles](text-styles.md)
 - [World generator engine](world-generator.md)
 - [XML UI building](xml-ui-layouts.md)
-- [Particles](particles.md)

doc/en/scripting/builtins/libgui.md

@@ -39,3 +39,25 @@ gui.get_locales_info() -> table of tables {
 ```
 
 Returns information about all loaded locales (res/texts/\*).
+
+```lua
+gui.clear_markup(
+    -- markup language ("md" - Markdown)
+    language: str,
+    -- text with markup
+    text: str
+) -> str
+```
+
+Removes markup from text.
+
+```lua
+gui.escape_markup(
+    -- markup language ("md" - Markdown)
+    language: str,
+    -- text with markup
+    text: str
+) -> str
+```
+
+Escapes markup in text.

doc/en/scripting/ui.md

@@ -32,7 +32,7 @@ document["worlds-panel"]:clear()
 
 Properties that apply to all elements:
 
-| Title         | Type   | Read | Write | Description                                 |
+| Name          | Type   | Read | Write | Description                                 |
 | ------------- | ------ | ---- | ----- | ------------------------------------------- |
 | id            | string | yes  | *no*  | element id                                  |
 | pos           | vec2   | yes  | yes   | element position inside a container         |
@@ -61,7 +61,7 @@ Common element methods:
 Common methods for containers (elements: container, panel, button, pagebox):
 
 | Method                          | Description                                                                                  |
-| ------------------------------- | ------------------------------------------------------------------ |
+| ------------------------------- | -------------------------------------------------------------------------------------------- |
 | clear()                         | clears content                                                                               |
 | add(xml)                        | adds an element, creating it using xml code. Example: `container:add("<image src='test'/>")` |
 | setInterval(interval, callback) | assigns a function to be executed repeatedly at an interval specified in milliseconds        |
@@ -70,7 +70,7 @@ Common methods for containers (elements: container, panel, button, pagebox):
 
 Properties:
 
-| Title       | Type   | Read | Write | Description                                                                          |
+| Name        | Type   | Read | Write | Description                                                                          |
 | ----------- | ------ | ---- | ----- | ------------------------------------------------------------------------------------ |
 | text        | string | yes  | yes   | entered text or placeholder                                                          |
 | placeholder | string | yes  | yes   | placeholder (used if nothing has been entered)                                       |
@@ -82,6 +82,8 @@ Properties:
 | textWrap    | bool   | yes  | yes   | automatic text wrapping (only with multiline: "true")                                |
 | valid       | bool   | yes  | no    | is the entered text correct                                                          |
 | textColor   | vec4   | yes  | yes   | text color                                                                           |
+| syntax      | string | yes  | yes   | syntax highlighting ("lua" - Lua)                                                    |
+| markup      | string | yes  | yes   | text markup language ("md" - Markdown)                                               |
 
 Methods:
 
@@ -95,7 +97,7 @@ Methods:
 
 Properties:
 
-| Title      | Type  | Read | Write | Description           |
+| Name       | Type  | Read | Write | Description           |
 | ---------- | ----- | ---- | ----- | --------------------- |
 | value      | float | yes  | yes   | current value         |
 | min        | float | yes  | yes   | minimum value         |
@@ -108,7 +110,7 @@ Properties:
 
 Properties:
 
-| Title | Type   | Read | Write | Description  |
+| Name  | Type   | Read | Write | Description  |
 | ----- | ------ | ---- | ----- | ------------ |
 | page  | string | yes  | yes   | current page |
 
@@ -123,7 +125,7 @@ Methods:
 
 Properties:
 
-| Title   | Type | Read | Write | Description |
+| Name    | Type | Read | Write | Description |
 | ------- | ---- | ---- | ----- | ----------- |
 | checked | bool | yes  | yes   | mark status |
 
@@ -131,7 +133,7 @@ Properties:
 
 Properties:
 
-| Title | Type   | Read | Write | Description  |
+| Name  | Type   | Read | Write | Description  |
 | ----- | ------ | ---- | ----- | ------------ |
 | text  | string | yes  | yes   | button text  |
 
@@ -139,15 +141,16 @@ Properties:
 
 Properties:
 
-| Title | Type   | Read | Write | Description |
+| Name   | Type   | Read | Write | Description                            |
-| ----- | ------ | ---- | ----- | ----------- |
+| ------ | ------ | ---- | ----- | -------------------------------------- |
 | text   | string | yes  | yes   | label text                             |
+| markup | string | yes  | yes   | text markup language ("md" - Markdown) |
 
 ## Image
 
 Properties:
 
-| Title | Type   | Read | Write | Description  |
+| Name  | Type   | Read | Write | Description  |
 | ----- | ------ | ---- | ----- | ------------ |
 | src   | string | yes  | yes   | texture name |
 
@@ -155,6 +158,6 @@ Properties:
 
 Properties:
 
-| Title     | Type | Read | Write | Description                                       |
+| Name      | Type | Read | Write | Description                                       |
 | --------- | ---- | ---- | ----- | ------------------------------------------------- |
 | inventory | int  | yes  | yes   | id of the inventory to which the element is bound |

doc/en/text-styles.md

@@ -0,0 +1,21 @@
+# Text styles
+
+A proprietary Markdown dialect is used to mark up text styles.
+Formatting works on UI elements: label and textbox, if `markup="md"` is explicitly specified.
+
+## Styles
+
+| Style         | Example                  | Output                     |
+| ------------- | ------------------------ | -------------------------- |
+| Bold          | `**Bold font**`          | **Bold font**              |
+| Italic        | `*Text in italics*`      | *Text in italics*          |
+| Underline     | `__Underlined text__`    | <ins>Underlined text</ins> |
+| Strikethrough | `~~Strikethrough text~~` | ~~Strikethrough text~~     |
+
+Styles can be combined. Example:
+```md
+***__Message__*** using *~~combed~~ combined* styles__~~.~~__
+```
+Output:
+
+***<ins>Message</ins>*** using *~~combed~~ combined* styles<ins>~~.~~</ins>

doc/en/xml-ui-layouts.md

@@ -87,6 +87,7 @@ Inner text is a button text.
 - `autoresize` - automatic change of element size (default - false). Does not affect font size.
 - `multiline` - allows display of multiline text.
 - `text-wrap` - allows automatic text wrapping (works only with multiline: "true").
+- `markup` - text markup language ("md" - Markdown).
 
 ## *image*
 
@@ -112,6 +113,8 @@ Inner text - initially entered text
 - `validator` - lua function that checks text for correctness. Takes a string as input, returns true if the text is correct.
 - `onup` - lua function called when the up arrow is pressed.
 - `ondown` - lua function called when the down arrow is pressed.
+- `syntax` - syntax highlighting ("lua" - Lua).
+- `markup` - text markup language ("md" - Markdown).
 
 ## *trackbar*
 

doc/ru/main-page.md

@@ -19,4 +19,5 @@
 - [Свойства блоков](block-properties.md)
 - [Свойства предметов](item-properties.md)
 - [Скриптинг](scripting.md)
+- [Стили текста](text-styles.md)
 - [Частицы](particles.md)

doc/ru/scripting/builtins/libgui.md

@@ -36,3 +36,25 @@ gui.get_locales_info() -> таблица таблиц где
 ```
 
 Возвращает информацию о всех загруженных локалях (res/texts/\*).
+
+```lua
+gui.clear_markup(
+    -- язык разметки ("md" - Markdown)
+    language: str, 
+    -- текст с разметкой
+    text: str
+) -> str
+```
+
+Удаляет разметку из текста.
+
+```lua
+gui.escape_markup(
+    -- язык разметки ("md" - Markdown)
+    language: str, 
+    -- текст с разметкой
+    text: str
+) -> str
+```
+
+Экранирует разметку в тексте.

doc/ru/scripting/ui.md

@@ -82,6 +82,8 @@ document["worlds-panel"]:clear()
 | textWrap    | bool   | да     | да     | автоматический перенос текста (только при multiline: "true")           |
 | valid       | bool   | да     | нет    | является ли введенный текст корректным                                 |
 | textColor   | vec4   | да     | да     | цвет текста                                                            |
+| syntax      | string | да     | да     | подсветка синтаксиса ("lua" - Lua)                                     |
+| markup      | string | да     | да     | язык разметки текста ("md" - Markdown)                                 |
 
 Методы:
 
@@ -140,8 +142,9 @@ document["worlds-panel"]:clear()
 Свойства:
 
 | Название | Тип    | Чтение | Запись | Описание                               |
-| -------- | ------ | ------ | ------ | ----------- |
+| -------- | ------ | ------ | ------ | -------------------------------------- |
 | text     | string | да     | да     | текст метки                            |
+| markup   | string | да     | да     | язык разметки текста ("md" - Markdown) |
 
 ## Изображение (image)
 

doc/ru/text-styles.md

@@ -0,0 +1,21 @@
+# Стили текста
+
+Для разметки стилей текста используется собственный диалект Markdown.
+Форматирование работает на UI элементах: label и textbox, если явно указано `markup="md"`.
+
+## Стили
+
+| Стиль        | Пример                    | Вывод                         |
+| ------------ | ------------------------- | ----------------------------- |
+| Жирный       | `**Жирный шрифт**`        | **Жирный шрифт**              |
+| Курсив       | `*Текст курсивом*`        | *Текст курсивом*              |
+| Подчеркнутый | `__Подчеркнутый текст__`  | <ins>Подчеркнутый текст</ins> |
+| Зачеркнутый  | `~~Зачеркнутый текст~~`   | ~~Зачеркнутый текст~~         |
+
+Стили могут объединяться. Пример:
+```md
+***__Сообщение__***, демонстрирующее *~~обедненные~~ объединенные* стили__~~.~~__
+```
+Вывод:
+
+***<ins>Сообщение</ins>***, демонстрирующее *~~обедненные~~ объединенные* стили<ins>~~.~~</ins>

doc/ru/xml-ui-layouts.md

@@ -89,6 +89,7 @@
 - `autoresize` - автоматическое изменение размера элемента (по-умолчанию - false). Не влияет на размер шрифта.
 - `multiline` - разрешает отображение многострочного текста.
 - `text-wrap` - разрешает автоматический перенос текста (работает только при multiline: "true")
+- `markup` - язык разметки текста ("md" - Markdown).
 
 ## Изображение - *image*
 
@@ -113,6 +114,8 @@
 - `validator` - lua функция, проверяющая текст на корректность. Принимает на вход строку, возвращает true если текст корректен.
 - `onup` - lua функция вызываемая при нажатии стрелки вверх.
 - `ondown` - lua функция вызываемая при нажатии стрелки вниз.
+- `syntax` - подстветка синтаксиса ("lua" - Lua).
+- `markup` - язык разметки текста ("md" - Markdown).
 
 ## Ползунок - *trackbar*
 

res/layouts/console.xml

@@ -22,6 +22,7 @@
             multiline='true' 
             size-func="gui.get_viewport()[1],40"
             gravity="bottom-left"
+            markup="md"
         ></textbox>
     </container>
     <container id="editorContainer" pos="0,60" color="#00000080"
@@ -32,10 +33,9 @@
             autoresize='true'
             margin='0'
             padding='5'
-            editable='false'
             multiline='true'
             line-numbers='true'
-            text-color="#FFFFFFA0"
+            syntax='lua'
             size-func="gui.get_viewport()[1]-350,40"
             gravity="top-left"
             text-wrap='false'
@@ -55,6 +55,7 @@
     <textbox id='prompt' 
              consumer='submit' 
              margin='0' 
+             markup="md"
              gravity='bottom-left' 
              size-func="gui.get_viewport()[1],40"
              onup="on_history_up()"

src/coders/commons.cpp

@@ -214,6 +214,28 @@ std::string_view BasicParser::readUntil(char c) {
     return source.substr(start, pos - start);
 }
 
+std::string_view BasicParser::readUntil(std::string_view s, bool nothrow) {
+    int start = pos;
+    size_t found = source.find(s, pos);
+    if (found == std::string::npos) {
+        if (nothrow) {
+            pos = source.size();
+            return source.substr(start);
+        }
+        throw error(util::quote(std::string(s))+" expected");
+    }
+    skip(found - pos);
+    return source.substr(start, pos - start);
+}
+
+std::string_view BasicParser::readUntilWhitespace() {
+    int start = pos;
+    while (hasNext() && !is_whitespace(source[pos])) {
+        pos++;
+    }
+    return source.substr(start, pos - start);
+}
+
 std::string_view BasicParser::readUntilEOL() {
     int start = pos;
     while (hasNext() && source[pos] != '\r' && source[pos] != '\n') {

src/coders/commons.hpp

@@ -105,6 +105,8 @@ protected:
     parsing_error error(const std::string& message);
 public:
     std::string_view readUntil(char c);
+    std::string_view readUntil(std::string_view s, bool nothrow);
+    std::string_view readUntilWhitespace();
     std::string_view readUntilEOL();
     std::string parseName();
     std::string parseXmlName();

src/coders/json.cpp

@@ -11,6 +11,7 @@
 
 using namespace json;
 
+namespace {
     class Parser : BasicParser {
         dv::value parseList();
         dv::value parseObject();
@@ -20,6 +21,7 @@ public:
 
         dv::value parse();
     };
+}
 
 inline void newline(
     std::stringstream& ss, bool nice, uint indent, const std::string& indentstr

src/coders/lua_parsing.cpp

@@ -0,0 +1,188 @@
+#include "lua_parsing.hpp"
+
+#include <set>
+
+#include "commons.hpp"
+
+using namespace lua;
+using namespace devtools;
+
+static std::set<std::string_view> keywords {
+    "and", "break", "do", "else", "elseif", "end", "false", "for", "function", 
+    "if", "in", "local", "nil", "not", "or", "repeat", "return", "then", "true",
+    "until", "while"
+};
+
+bool lua::is_lua_keyword(std::string_view view) {
+    return keywords.find(view) != keywords.end();
+}
+
+inline bool is_lua_identifier_start(int c) {
+    return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_';
+}
+
+inline bool is_lua_identifier_part(int c) {
+    return is_lua_identifier_start(c) || is_digit(c);
+}
+
+inline bool is_lua_operator_start(int c) {
+    return c == '=' || c == '~' || c == '+' || c == '-' || c == '/' || c == '*'
+        || c == '%' || c == '^' || c == '#' || c == '<' || c == '>' || c == ':'
+        || c == '.';
+}
+
+class Tokenizer : BasicParser {
+    std::vector<Token> tokens;
+public:
+    Tokenizer(std::string_view file, std::string_view source)
+        : BasicParser(file, source) {
+    }
+
+    std::string parseLuaName() {
+        char c = peek();
+        if (!is_identifier_start(c)) {
+            throw error("identifier expected");
+        }
+        int start = pos;
+        while (hasNext() && is_identifier_part(source[pos])) {
+            pos++;
+        }
+        return std::string(source.substr(start, pos - start));
+    }
+
+    inline Location currentLocation() const {
+        return Location {
+            static_cast<int>(pos),
+            static_cast<int>(linestart),
+            static_cast<int>(line)};
+    }
+
+    void emitToken(
+        TokenTag tag, std::string name, Location start, bool standalone=false
+    ) {
+        tokens.emplace_back(
+            tag,
+            std::move(name),
+            std::move(start),
+            currentLocation()
+        );
+        if (standalone) skip(1);
+    }
+
+    /// @brief Get next operator token without checking operator for existing
+    std::string parseOperator() {
+        int start = pos;
+        char first = peek();
+        switch (first) {
+            case '#': case '+': case '/': case '*': case '^':
+            case '%':
+                skip(1);
+                return std::string({first});
+            case '-':
+                skip(1);
+                if (peekNoJump() == '-') {
+                    skip(1);
+                    return "--";
+                }
+                return std::string({first});
+        }
+        skip(1);
+        char second = peekNoJump();
+        if ((first == '=' && second == '=') || (first == '~' && second == '=') ||
+            (first == '<' && second == '=') || (first == '>' && second == '=')) {
+            skip(1);
+            return std::string(source.substr(start, pos - start));
+        }
+        if (first == '.' && second == '.') {
+            skip(1);
+            if (peekNoJump() == '.') {
+                skip(1);
+            }
+        }
+        return std::string(source.substr(start, pos - start));
+    }
+
+    std::vector<Token> tokenize() {
+        skipWhitespace();
+        while (hasNext()) {
+            skipWhitespace();
+            if (!hasNext()) {
+                continue;
+            }
+            char c = peek();
+            auto start = currentLocation();
+            if (is_lua_identifier_start(c)) {
+                auto name = parseLuaName();
+                emitToken(
+                    is_lua_keyword(name) ? TokenTag::KEYWORD : TokenTag::NAME,
+                    std::move(name),
+                    start
+                );
+                continue;
+            } else if (is_digit(c)) {
+                dv::value value;
+                auto tag = TokenTag::UNEXPECTED;
+                try {
+                    value = parseNumber(1);
+                    tag = value.isInteger() ? TokenTag::INTEGER
+                                            : TokenTag::NUMBER;
+                } catch (const parsing_error& err) {}
+
+                auto literal = source.substr(start.pos, pos - start.pos);
+                emitToken(tag, std::string(literal), start);
+                continue;
+            }
+            switch (c) {
+                case '(': case '[': case '{': 
+                    if (isNext("[==[")) {
+                        auto string = readUntil("]==]", true);
+                        skip(4);
+                        emitToken(TokenTag::COMMENT, std::string(string)+"]==]", start);
+                        continue;
+                    } else if (isNext("[[")) {
+                        skip(2);
+                        auto string = readUntil("]]", true);
+                        skip(2);
+                        emitToken(TokenTag::STRING, std::string(string), start);
+                        continue;
+                    }
+                    emitToken(TokenTag::OPEN_BRACKET, std::string({c}), start, true);
+                    continue;
+                case ')': case ']': case '}': 
+                    emitToken(TokenTag::CLOSE_BRACKET, std::string({c}), start, true);
+                    continue;
+                case ',':
+                    emitToken(TokenTag::COMMA, std::string({c}), start, true);
+                    continue;
+                case ';':
+                    emitToken(TokenTag::SEMICOLON, std::string({c}), start, true);
+                    continue;
+                case '\'': case '"': {
+                    skip(1);
+                    auto string = parseString(c, false);
+                    emitToken(TokenTag::STRING, std::move(string), start);
+                    continue;
+                }
+                default: break;
+            }
+            if (is_lua_operator_start(c)) {
+                auto text = parseOperator();
+                if (text == "--") {
+                    auto string = readUntilEOL();
+                    emitToken(TokenTag::COMMENT, std::string(string), start);
+                    skipLine();
+                    continue;
+                }
+                emitToken(TokenTag::OPERATOR, std::move(text), start);
+                continue;
+            }
+            auto text = readUntilWhitespace();
+            emitToken(TokenTag::UNEXPECTED, std::string(text), start);
+        }
+        return std::move(tokens);
+    }
+};
+
+std::vector<Token> lua::tokenize(std::string_view file, std::string_view source) {
+    return Tokenizer(file, source).tokenize();
+}

src/coders/lua_parsing.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "devtools/syntax.hpp"
+
+namespace lua {
+    bool is_lua_keyword(std::string_view view);
+
+    std::vector<devtools::Token> tokenize(
+        std::string_view file, std::string_view source
+    );
+}

src/coders/xml.cpp

@@ -107,8 +107,8 @@ glm::vec4 Attribute::asColor() const {
 Node::Node(std::string tag) : tag(std::move(tag)) {
 }
 
-void Node::add(const xmlelement& element) {
+void Node::add(std::unique_ptr<Node> element) {
-    elements.push_back(element);
+    elements.push_back(std::move(element));
 }
 
 void Node::set(const std::string& name, const std::string& text) {
@@ -119,7 +119,7 @@ const std::string& Node::getTag() const {
     return tag;
 }
 
-const xmlattribute& Node::attr(const std::string& name) const {
+const Attribute& Node::attr(const std::string& name) const {
     auto found = attrs.find(name);
     if (found == attrs.end()) {
         throw std::runtime_error(
@@ -129,7 +129,7 @@ const xmlattribute& Node::attr(const std::string& name) const {
     return found->second;
 }
 
-xmlattribute Node::attr(const std::string& name, const std::string& def) const {
+Attribute Node::attr(const std::string& name, const std::string& def) const {
     auto found = attrs.find(name);
     if (found == attrs.end()) {
         return Attribute(name, def);
@@ -142,19 +142,23 @@ bool Node::has(const std::string& name) const {
     return found != attrs.end();
 }
 
-xmlelement Node::sub(size_t index) {
+Node& Node::sub(size_t index) {
-    return elements.at(index);
+    return *elements.at(index);
+}
+
+const Node& Node::sub(size_t index) const {
+    return *elements.at(index);
 }
 
 size_t Node::size() const {
     return elements.size();
 }
 
-const std::vector<xmlelement>& Node::getElements() const {
+const std::vector<std::unique_ptr<Node>>& Node::getElements() const {
     return elements;
 }
 
-const xmlelements_map& Node::getAttributes() const {
+const std::unordered_map<std::string, Attribute>& Node::getAttributes() const {
     return attrs;
 }
 
@@ -162,12 +166,12 @@ Document::Document(std::string version, std::string encoding)
     : version(std::move(version)), encoding(std::move(encoding)) {
 }
 
-void Document::setRoot(const xmlelement& element) {
+void Document::setRoot(std::unique_ptr<Node> element) {
-    this->root = element;
+    root = std::move(element);
 }
 
-xmlelement Document::getRoot() const {
+const Node* Document::getRoot() const {
-    return root;
+    return root.get();
 }
 
 const std::string& Document::getVersion() const {
@@ -178,13 +182,21 @@ const std::string& Document::getEncoding() const {
     return encoding;
 }
 
-Parser::Parser(std::string_view filename, std::string_view source)
+inline bool is_xml_identifier_start(char c) {
-    : BasicParser(filename, source) {
+    return is_identifier_start(c) || c == ':';
 }
 
-xmlelement Parser::parseOpenTag() {
+inline bool is_xml_identifier_part(char c) {
+    return is_identifier_part(c) || c == '-' || c == '.' || c == ':';
+}
+
+namespace {
+class Parser : BasicParser {
+    std::unique_ptr<Document> document;
+
+    std::unique_ptr<Node> parseOpenTag() {
         std::string tag = parseXMLName();
-    auto node = std::make_shared<Node>(tag);
+        auto node = std::make_unique<Node>(tag);
 
         char c;
         while (true) {
@@ -210,74 +222,10 @@ xmlelement Parser::parseOpenTag() {
         return node;
     }
 
-void Parser::parseDeclaration() {
+    std::unique_ptr<Node> parseElement() {
-    std::string version = "1.0";
-    std::string encoding = "UTF-8";
-    expect('<');
-    if (peek() == '?') {
-        nextChar();
-        xmlelement node = parseOpenTag();
-        expect("?>");
-        if (node->getTag() != "xml") {
-            throw error("invalid declaration");
-        }
-        version = node->attr("version", version).getText();
-        encoding = node->attr("encoding", encoding).getText();
-        if (encoding != "utf-8" && encoding != "UTF-8") {
-            throw error("UTF-8 encoding is only supported");
-        }
-    } else {
-        goBack();
-    }
-    document = std::make_shared<Document>(version, encoding);
-}
-
-void Parser::parseComment() {
-    expect("!--");
-    if (skipTo("-->")) {
-        skip(3);
-    } else {
-        throw error("comment close missing");
-    }
-}
-
-std::string Parser::parseText() {
-    size_t start = pos;
-    while (hasNext()) {
-        char c = peek();
-        if (c == '<') {
-            break;
-        }
-        nextChar();
-    }
-    return Parser("[string]", std::string(source.substr(start, pos - start)))
-        .parseString('\0', false);
-}
-
-inline bool is_xml_identifier_start(char c) {
-    return is_identifier_start(c) || c == ':';
-}
-
-inline bool is_xml_identifier_part(char c) {
-    return is_identifier_part(c) || c == '-' || c == '.' || c == ':';
-}
-
-std::string Parser::parseXMLName() {
-    char c = peek();
-    if (!is_xml_identifier_start(c)) {
-        throw error("identifier expected");
-    }
-    int start = pos;
-    while (hasNext() && is_xml_identifier_part(source[pos])) {
-        pos++;
-    }
-    return std::string(source.substr(start, pos - start));
-}
-
-xmlelement Parser::parseElement() {
         // text element
         if (peek() != '<') {
-        auto element = std::make_shared<Node>("#");
+            auto element = std::make_unique<Node>("#");
             auto text = parseText();
             util::replaceAll(text, "&quot;", "\"");
             util::replaceAll(text, "&apos;", "'");
@@ -311,7 +259,7 @@ xmlelement Parser::parseElement() {
             while (!isNext("</")) {
                 auto sub = parseElement();
                 if (sub) {
-                element->add(sub);
+                    element->add(std::move(sub));
                 }
                 skipWhitespace();
             }
@@ -326,18 +274,82 @@ xmlelement Parser::parseElement() {
         return element;
     }
 
-xmldocument Parser::parse() {
+    void parseDeclaration() {
+        std::string version = "1.0";
+        std::string encoding = "UTF-8";
+        expect('<');
+        if (peek() == '?') {
+            nextChar();
+            auto node = parseOpenTag();
+            expect("?>");
+            if (node->getTag() != "xml") {
+                throw error("invalid declaration");
+            }
+            version = node->attr("version", version).getText();
+            encoding = node->attr("encoding", encoding).getText();
+            if (encoding != "utf-8" && encoding != "UTF-8") {
+                throw error("UTF-8 encoding is only supported");
+            }
+        } else {
+            goBack();
+        }
+        document = std::make_unique<Document>(version, encoding);
+    }
+
+    void parseComment() {
+        expect("!--");
+        if (skipTo("-->")) {
+            skip(3);
+        } else {
+            throw error("comment close missing");
+        }
+    }
+
+    std::string parseText() {
+        size_t start = pos;
+        while (hasNext()) {
+            char c = peek();
+            if (c == '<') {
+                break;
+            }
+            nextChar();
+        }
+        return Parser("[string]", std::string(source.substr(start, pos - start)))
+            .parseString('\0', false);
+    }
+
+    std::string parseXMLName() {
+        char c = peek();
+        if (!is_xml_identifier_start(c)) {
+            throw error("identifier expected");
+        }
+        int start = pos;
+        while (hasNext() && is_xml_identifier_part(source[pos])) {
+            pos++;
+        }
+        return std::string(source.substr(start, pos - start));
+    }
+public:
+    Parser(std::string_view filename, std::string_view source)
+        : BasicParser(filename, source) {
+    }
+
+    std::unique_ptr<Document> parse() {
         parseDeclaration();
 
-    xmlelement root = nullptr;
+        std::unique_ptr<Node> root;
         while (root == nullptr) {
             root = parseElement();
         }
-    document->setRoot(root);
+        document->setRoot(std::move(root));
-    return document;
+        return std::move(document);
+    }
+};
 }
 
-xmldocument xml::parse(std::string_view filename, std::string_view source) {
+std::unique_ptr<Document> xml::parse(
+    std::string_view filename, std::string_view source
+) {
     Parser parser(filename, source);
     return parser.parse();
 }
@@ -354,13 +366,13 @@ inline void newline(
 
 static void stringifyElement(
     std::stringstream& ss,
-    const xmlelement& element,
+    const Node& element,
     bool nice,
     const std::string& indentStr,
     int indent
 ) {
-    if (element->isText()) {
+    if (element.isText()) {
-        std::string text = element->attr("#").getText();
+        std::string text = element.attr("#").getText();
         util::replaceAll(text, "&", "&amp;");
         util::replaceAll(text, "\"", "&quot;");
         util::replaceAll(text, "'", "&apos;");
@@ -369,10 +381,10 @@ static void stringifyElement(
         ss << text;
         return;
     }
-    const std::string& tag = element->getTag();
+    const std::string& tag = element.getTag();
 
     ss << '<' << tag;
-    auto& attrs = element->getAttributes();
+    auto& attrs = element.getAttributes();
     if (!attrs.empty()) {
         ss << ' ';
         int count = 0;
@@ -388,10 +400,10 @@ static void stringifyElement(
             count++;
         }
     }
-    auto& elements = element->getElements();
+    auto& elements = element.getElements();
     if (elements.size() == 1 && elements[0]->isText()) {
         ss << ">";
-        stringifyElement(ss, elements[0], nice, indentStr, indent + 1);
+        stringifyElement(ss, *elements[0], nice, indentStr, indent + 1);
         ss << "</" << tag << ">";
         return;
     }
@@ -399,7 +411,7 @@ static void stringifyElement(
         ss << '>';
         for (auto& sub : elements) {
             newline(ss, nice, indentStr, indent + 1);
-            stringifyElement(ss, sub, nice, indentStr, indent + 1);
+            stringifyElement(ss, *sub, nice, indentStr, indent + 1);
         }
         newline(ss, nice, indentStr, indent);
         ss << "</" << tag << ">";
@@ -410,16 +422,16 @@ static void stringifyElement(
 }
 
 std::string xml::stringify(
-    const xmldocument& document, bool nice, const std::string& indentStr
+    const Document& document, bool nice, const std::string& indentStr
 ) {
     std::stringstream ss;
 
     // XML declaration
-    ss << "<?xml version=\"" << document->getVersion();
+    ss << "<?xml version=\"" << document.getVersion();
     ss << "\" encoding=\"UTF-8\" ?>";
     newline(ss, nice, indentStr, 0);
 
-    stringifyElement(ss, document->getRoot(), nice, indentStr, 0);
+    stringifyElement(ss, *document.getRoot(), nice, indentStr, 0);
 
     return ss.str();
 }

src/coders/xml.hpp

@@ -13,11 +13,6 @@ namespace xml {
     class Attribute;
     class Document;
 
-    using xmlattribute = Attribute;
-    using xmlelement = std::shared_ptr<Node>;
-    using xmldocument = std::shared_ptr<Document>;
-    using xmlelements_map = std::unordered_map<std::string, xmlattribute>;
-
     class Attribute {
         std::string name;
         std::string text;
@@ -40,13 +35,15 @@ namespace xml {
     /// 'text'
     class Node {
         std::string tag;
-        std::unordered_map<std::string, xmlattribute> attrs;
+        std::unordered_map<std::string, Attribute> attrs;
-        std::vector<xmlelement> elements;
+        std::vector<std::unique_ptr<Node>> elements;
     public:
         Node(std::string tag);
 
+        Node(const Node&) = delete;
+
         /// @brief Add sub-element
-        void add(const xmlelement& element);
+        void add(std::unique_ptr<Node> element);
 
         /// @brief Set attribute value. Creates attribute if does not exists
         /// @param name attribute name
@@ -68,14 +65,14 @@ namespace xml {
         /// @param name attribute name
         /// @throws std::runtime_error if element has no attribute
         /// @return xml attribute - {name, value}
-        const xmlattribute& attr(const std::string& name) const;
+        const Attribute& attr(const std::string& name) const;
 
         /// @brief Get attribute by name
         /// @param name attribute name
         /// @param def default value will be returned wrapped in xmlattribute
         /// if element has no attribute
-        /// @return xmlattribute - {name, value} or {name, def} if not found*/
+        /// @return xml attribute - {name, value} or {name, def} if not found
-        xmlattribute attr(const std::string& name, const std::string& def)
+        Attribute attr(const std::string& name, const std::string& def)
             const;
 
         /// @brief Check if element has attribute
@@ -86,51 +83,37 @@ namespace xml {
         /// @param index sub-element index
         /// @throws std::out_of_range if an invalid index given
         /// @return sub-element
-        xmlelement sub(size_t index);
+        Node& sub(size_t index);
+        const Node& sub(size_t index) const;
 
         /// @brief Get number of sub-elements
         size_t size() const;
 
-        const std::vector<xmlelement>& getElements() const;
+        const std::vector<std::unique_ptr<Node>>& getElements() const;
-        const xmlelements_map& getAttributes() const;
+        const std::unordered_map<std::string, Attribute>& getAttributes() const;
     };
 
     class Document {
-        xmlelement root = nullptr;
+        std::unique_ptr<Node> root = nullptr;
         std::string version;
         std::string encoding;
     public:
         Document(std::string version, std::string encoding);
 
-        void setRoot(const xmlelement& element);
+        void setRoot(std::unique_ptr<Node> element);
-        xmlelement getRoot() const;
+        const Node* getRoot() const;
 
         const std::string& getVersion() const;
         const std::string& getEncoding() const;
     };
 
-    class Parser : BasicParser {
-        xmldocument document;
-
-        xmlelement parseOpenTag();
-        xmlelement parseElement();
-        void parseDeclaration();
-        void parseComment();
-        std::string parseText();
-        std::string parseXMLName();
-    public:
-        Parser(std::string_view filename, std::string_view source);
-
-        xmldocument parse();
-    };
-
     /// @brief Serialize XML Document to string
     /// @param document serializing document
     /// @param nice use human readable format (with indents and line-separators)
     /// @param indentStr indentation characters sequence (default - 4 spaces)
     /// @return XML string
-    extern std::string stringify(
+    std::string stringify(
-        const xmldocument& document,
+        const Document& document,
         bool nice = true,
         const std::string& indentStr = "    "
     );
@@ -139,7 +122,9 @@ namespace xml {
     /// @param filename file name will be shown in error messages
     /// @param source xml source code string
     /// @return xml document
-    extern xmldocument parse(
+    std::unique_ptr<Document> parse(
         std::string_view filename, std::string_view source
     );
+
+    using xmlelement = Node;
 }

src/devtools/syntax.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <string>
+
+namespace devtools {
+    struct Location {
+        int pos;
+        int lineStart;
+        int line;
+    };
+
+    enum class TokenTag {
+        KEYWORD, NAME, INTEGER, NUMBER, OPEN_BRACKET, CLOSE_BRACKET, STRING,
+        OPERATOR, COMMA, SEMICOLON, UNEXPECTED, COMMENT
+    };
+
+    struct Token {
+        TokenTag tag;
+        std::string text;
+        Location start;
+        Location end;
+
+        Token(TokenTag tag, std::string text, Location start, Location end)
+            : tag(tag),
+              text(std::move(text)),
+              start(std::move(start)),
+              end(std::move(end)) {
+        }
+    };
+}

src/devtools/syntax_highlighting.cpp

@@ -0,0 +1,72 @@
+#include "syntax_highlighting.hpp"
+
+#include "coders/commons.hpp"
+#include "coders/lua_parsing.hpp"
+#include "graphics/core/Font.hpp"
+
+using namespace devtools;
+
+static std::unique_ptr<FontStylesScheme> build_styles(
+    const std::vector<devtools::Token>& tokens
+) {
+    using devtools::TokenTag;
+    FontStylesScheme styles {
+        {
+            {false, false, false, false, glm::vec4(0.8f, 0.8f, 0.8f, 1)}, // default
+            {true, false, false, false, glm::vec4(0.9, 0.6f, 0.4f, 1)},   // keyword
+            {false, false, false, false, glm::vec4(0.4, 0.8f, 0.5f, 1)},  // string
+            {false, false, false, false, glm::vec4(0.3, 0.3f, 0.3f, 1)},  // comment
+            {true, false, false, false, glm::vec4(1.0f, 0.2f, 0.1f, 1)},  // unexpected
+        }, 
+        {}
+    };
+    size_t offset = 0;
+    for (int i = 0; i < tokens.size(); i++) {
+        const auto& token = tokens.at(i);
+        if (token.tag != TokenTag::KEYWORD &&
+            token.tag != TokenTag::STRING &&
+            token.tag != TokenTag::INTEGER &&
+            token.tag != TokenTag::NUMBER &&
+            token.tag != TokenTag::COMMENT &&
+            token.tag != TokenTag::UNEXPECTED) {
+            continue;
+        }
+        if (token.start.pos > offset) {
+            int n = token.start.pos - offset;
+            styles.map.insert(styles.map.end(), token.start.pos - offset, 0);
+        }
+        offset = token.end.pos;
+        int styleIndex;
+        switch (token.tag) {
+            case TokenTag::KEYWORD: styleIndex = SyntaxStyles::KEYWORD; break;
+            case TokenTag::STRING:
+            case TokenTag::INTEGER:
+            case TokenTag::NUMBER: styleIndex = SyntaxStyles::LITERAL; break;
+            case TokenTag::COMMENT: styleIndex = SyntaxStyles::COMMENT; break;
+            case TokenTag::UNEXPECTED: styleIndex = SyntaxStyles::ERROR; break;
+            default:
+                styleIndex = 0;
+                break;
+        }
+        styles.map.insert(
+            styles.map.end(), token.end.pos - token.start.pos, styleIndex
+        );
+    }
+    styles.map.push_back(0);
+    return std::make_unique<FontStylesScheme>(std::move(styles));
+}
+
+std::unique_ptr<FontStylesScheme> devtools::syntax_highlight(
+    const std::string& lang, std::string_view source
+) {
+    try {
+        if (lang == "lua") {
+            auto tokens = lua::tokenize("<string>", source);
+            return build_styles(tokens);
+        } else {
+            return nullptr;
+        }
+    } catch (const parsing_error& err) {
+        return nullptr;
+    }
+}

src/devtools/syntax_highlighting.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <string>
+#include <memory>
+
+struct FontStylesScheme;
+
+namespace devtools {
+    enum SyntaxStyles {
+        DEFAULT, KEYWORD, LITERAL, COMMENT, ERROR
+    };
+
+    std::unique_ptr<FontStylesScheme> syntax_highlight(
+        const std::string& lang, std::string_view source
+    );
+}

src/engine.cpp

@@ -206,7 +206,7 @@ void Engine::renderFrame(Batch2D& batch) {
 
     Viewport viewport(Window::width, Window::height);
     DrawContext ctx(nullptr, viewport, &batch);
-    gui->draw(&ctx, assets.get());
+    gui->draw(ctx, *assets);
 }
 
 void Engine::processPostRunnables() {

src/frontend/UiDocument.cpp

@@ -67,9 +67,7 @@ std::unique_ptr<UiDocument> UiDocument::read(
         : scripting::create_doc_environment(penv, name);
 
     gui::UiXmlReader reader(env);
-    auto view = reader.readXML(
+    auto view = reader.readXML(file.u8string(), *xmldoc->getRoot());
-        file.u8string(), xmldoc->getRoot()
-    );
     view->setId("root");
     uidocscript script {};
     auto scriptFile = fs::path(file.u8string()+".lua");

src/frontend/hud.cpp

@@ -124,7 +124,7 @@ std::shared_ptr<InventoryView> Hud::createContentAccess() {
     });
 
     InventoryBuilder builder;
-    builder.addGrid(8, itemsCount-1, glm::vec2(), 8, true, slotLayout);
+    builder.addGrid(8, itemsCount-1, glm::vec2(), glm::vec4(8, 8, 12, 8), true, slotLayout);
     auto view = builder.build();
     view->bind(accessInventory, content);
     view->setMargin(glm::vec4());
@@ -137,7 +137,7 @@ std::shared_ptr<InventoryView> Hud::createHotbar() {
 
     SlotLayout slotLayout(-1, glm::vec2(), false, false, nullptr, nullptr, nullptr);
     InventoryBuilder builder;
-    builder.addGrid(10, 10, glm::vec2(), 4, true, slotLayout);
+    builder.addGrid(10, 10, glm::vec2(), glm::vec4(4), true, slotLayout);
     auto view = builder.build();
     view->setId("hud.hotbar");
     view->setOrigin(glm::vec2(view->getSize().x/2, 0));
@@ -346,9 +346,9 @@ void Hud::update(bool visible) {
         element.getNode()->setVisible(visible);
     }
 
-    glm::vec2 invSize = contentAccessPanel->getSize();
+    glm::vec2 caSize = contentAccessPanel->getSize();
     contentAccessPanel->setVisible(inventoryView != nullptr && showContentPanel);
-    contentAccessPanel->setSize(glm::vec2(invSize.x, Window::height));
+    contentAccessPanel->setSize(glm::vec2(caSize.x, Window::height));
     contentAccess->setMinSize(glm::vec2(1, Window::height));
     hotbarView->setVisible(visible && !(secondUI && !inventoryView));
 

src/frontend/hud.hpp

@@ -95,16 +95,16 @@ class Hud : public util::ObjectsKeeper {
     /// @brief Inventories interaction agent (grabbed item)
     std::shared_ptr<gui::SlotView> exchangeSlot;
     /// @brief Exchange slot inventory (1 slot only)
-    std::shared_ptr<Inventory> exchangeSlotInv = nullptr;
+    std::shared_ptr<Inventory> exchangeSlotInv;
     /// @brief List of all controlled hud elements
     std::vector<HudElement> elements;
 
     /// @brief Player inventory view
-    std::shared_ptr<gui::InventoryView> inventoryView = nullptr;
+    std::shared_ptr<gui::InventoryView> inventoryView;
     /// @brief Block inventory view
-    std::shared_ptr<gui::InventoryView> blockUI = nullptr;
+    std::shared_ptr<gui::InventoryView> blockUI;
     /// @brief Secondary inventory view
-    std::shared_ptr<gui::InventoryView> secondInvView = nullptr;
+    std::shared_ptr<gui::InventoryView> secondInvView;
     /// @brief Position of the block open
     glm::ivec3 blockPos {};
     /// @brief Id of the block open (used to detect block destruction or replacement)
@@ -114,9 +114,9 @@ class Hud : public util::ObjectsKeeper {
     /// @brief Provide cheat controllers to the debug panel
     bool allowDebugCheats = true;
     /// @brief UI element will be dynamicly positioned near to inventory or in screen center
-    std::shared_ptr<gui::UINode> secondUI = nullptr;
+    std::shared_ptr<gui::UINode> secondUI;
 
-    std::shared_ptr<gui::UINode> debugMinimap = nullptr;
+    std::shared_ptr<gui::UINode> debugMinimap;
 
     std::unique_ptr<ImageData> debugImgWorldGen;
     

src/graphics/core/Batch2D.cpp

@@ -261,6 +261,24 @@ void Batch2D::rect(
     vertex(x+w, y+h, u+tx, v, r,g,b,a);
 }
 
+void Batch2D::parallelogram(
+    float x, float y, float w, float h, float skew,
+    float u, float v, float tx, float ty,
+    float r, float g, float b, float a
+){
+    if (index + 6*B2D_VERTEX_SIZE >= capacity) {
+        flush();
+    }
+    setPrimitive(DrawPrimitive::triangle);
+    vertex(x-skew*w, y, u, v+ty, r,g,b,a);
+    vertex(x+(1+skew)*w, y+h, u+tx, v, r,g,b,a);
+    vertex(x+skew*w, y+h, u, v, r,g,b,a);
+
+    vertex(x-skew*w, y, u, v+ty, r,g,b,a);
+    vertex(x+w-skew*w, y, u+tx, v+ty, r,g,b,a);
+    vertex(x+(1+skew)*w, y+h, u+tx, v, r,g,b,a);
+}
+
 void Batch2D::rect(
     float x, float y, float w, float h,
     float r0, float g0, float b0,
@@ -336,6 +354,22 @@ void Batch2D::sprite(float x, float y, float w, float h, int atlasRes, int index
     rect(x, y, w, h, u, v, scale, scale, tint.r, tint.g, tint.b, tint.a);
 }
 
+void Batch2D::sprite(
+    float x,
+    float y,
+    float w,
+    float h,
+    float skew,
+    int atlasRes,
+    int index,
+    glm::vec4 tint
+) {
+    float scale = 1.0f / (float)atlasRes;
+    float u = (index % atlasRes) * scale;
+    float v = 1.0f - ((index / atlasRes) * scale) - scale;
+    parallelogram(x, y, w, h, skew, u, v, scale, scale, tint.r, tint.g, tint.b, tint.a);
+}
+
 void Batch2D::flush() {
     if (index == 0)
         return;

src/graphics/core/Batch2D.hpp

@@ -45,6 +45,7 @@ public:
     void setRegion(UVRegion region);
     void sprite(float x, float y, float w, float h, const UVRegion& region, glm::vec4 tint);
     void sprite(float x, float y, float w, float h, int atlasRes, int index, glm::vec4 tint);
+    void sprite(float x, float y, float w, float h, float skew, int atlasRes, int index, glm::vec4 tint);
     void point(float x, float y, float r, float g, float b, float a);
     
     inline void setColor(glm::vec4 color) {
@@ -79,6 +80,12 @@ public:
         float r, float g, float b, float a
     );
 
+    void parallelogram(
+        float x, float y, float w, float h, float skew,
+        float u, float v, float tx, float ty,
+        float r, float g, float b, float a
+    );
+
     void rect(
         float x, float y, float w, float h,
         float r0, float g0, float b0,

src/graphics/core/Font.cpp

@@ -1,5 +1,6 @@
 #include "Font.hpp"
 
+#include <limits>
 #include <utility>
 #include "Texture.hpp"
 #include "Batch2D.hpp"
@@ -52,18 +53,22 @@ static inline void draw_glyph(
     uint c, 
     const glm::vec3& right,
     const glm::vec3& up,
-    float glyphInterval
+    float glyphInterval,
+    const FontStyle& style
 ) {
+    for (int i = 0; i <= style.bold; i++) {
         batch.sprite(
-        pos.x + offset.x * right.x,
+            pos.x + (offset.x + i / (right.x/glyphInterval/2.0f)) * right.x,
             pos.y + offset.y * right.y,
             right.x / glyphInterval,
             up.y,
+            -0.15f * style.italic,
             16,
             c,
-        batch.getColor()
+            batch.getColor() * style.color
         );
     }
+}
 
 static inline void draw_glyph(
     Batch3D& batch, 
@@ -72,18 +77,21 @@ static inline void draw_glyph(
     uint c, 
     const glm::vec3& right,
     const glm::vec3& up,
-    float glyphInterval
+    float glyphInterval,
+    const FontStyle& style
 ) {
+    for (int i = 0; i <= style.bold; i++) {
         batch.sprite(
-        pos + right * offset.x + up * offset.y,
+            pos + right * (offset.x + i) + up * offset.y,
             up, right / glyphInterval,
             0.5f,
             0.5f,
             16,
             c,
-        batch.getColor()
+            batch.getColor() * style.color
         );
     }
+}
 
 template <class Batch>
 static inline void draw_text(
@@ -93,14 +101,32 @@ static inline void draw_text(
     const glm::vec3& pos,
     const glm::vec3& right,
     const glm::vec3& up,
-    float glyphInterval
+    float interval,
+    const FontStylesScheme* styles,
+    size_t styleMapOffset
 ) {
+    static FontStylesScheme defStyles {{{}}, {0}};
+
+    if (styles == nullptr) {
+        styles = &defStyles;
+    }
+    
     uint page = 0;
     uint next = MAX_CODEPAGES;
     int x = 0;
     int y = 0;
+    bool hasLines = false;
+
     do {
-        for (uint c : text){
+        for (size_t i = 0; i < text.length(); i++) {
+            uint c = text[i];
+            size_t styleIndex = styles->map.at(
+                std::min(styles->map.size() - 1, i + styleMapOffset)
+            );
+            const FontStyle& style = styles->palette.at(styleIndex);
+            hasLines |= style.strikethrough;
+            hasLines |= style.underline;
+
             if (!font.isPrintableChar(c)) {
                 x++;
                 continue;
@@ -109,7 +135,7 @@ static inline void draw_text(
             if (charpage == page){
                 batch.texture(font.getPage(charpage));
                 draw_glyph(
-                    batch, pos, glm::vec2(x, y), c, right, up, glyphInterval
+                    batch, pos, glm::vec2(x, y), c, right, up, interval, style
                 );
             }
             else if (charpage > page && charpage < next){
@@ -121,6 +147,31 @@ static inline void draw_text(
         next = MAX_CODEPAGES;
         x = 0;
     } while (page < MAX_CODEPAGES);
+
+    if (!hasLines) {
+        return;
+    }
+    batch.texture(font.getPage(0));
+    for (size_t i = 0; i < text.length(); i++) {
+        uint c = text[i];
+        size_t styleIndex = styles->map.at(
+            std::min(styles->map.size() - 1, i + styleMapOffset)
+        );
+        const FontStyle& style = styles->palette.at(styleIndex);
+        FontStyle lineStyle = style;
+        lineStyle.bold = true;
+        if (style.strikethrough) {
+            draw_glyph(
+                batch, pos, glm::vec2(x, y), '-', right, up, interval, lineStyle
+            );
+        }
+        if (style.underline) {
+            draw_glyph(
+                batch, pos, glm::vec2(x, y), '_', right, up, interval, lineStyle
+            );
+        }
+        x++;
+    }
 }
 
 const Texture* Font::getPage(int charpage) const {
@@ -135,20 +186,30 @@ const Texture* Font::getPage(int charpage) const {
 }
 
 void Font::draw(
-    Batch2D& batch, std::wstring_view text, int x, int y, float scale
+    Batch2D& batch,
+    std::wstring_view text,
+    int x,
+    int y,
+    const FontStylesScheme* styles,
+    size_t styleMapOffset,
+    float scale
 ) const {
     draw_text(
         *this, batch, text,
         glm::vec3(x, y, 0),
         glm::vec3(glyphInterval*scale, 0, 0),
         glm::vec3(0, lineHeight*scale, 0),
-        glyphInterval/static_cast<float>(lineHeight)
+        glyphInterval/static_cast<float>(lineHeight),
+        styles,
+        styleMapOffset
     );
 }
 
 void Font::draw(
     Batch3D& batch,
     std::wstring_view text,
+    const FontStylesScheme* styles,
+    size_t styleMapOffset,
     const glm::vec3& pos,
     const glm::vec3& right,
     const glm::vec3& up
@@ -157,6 +218,8 @@ void Font::draw(
         *this, batch, text, pos,
         right * static_cast<float>(glyphInterval),
         up * static_cast<float>(lineHeight),
-        glyphInterval/static_cast<float>(lineHeight)
+        glyphInterval/static_cast<float>(lineHeight),
+        styles,
+        styleMapOffset
     );
 }

src/graphics/core/Font.hpp

@@ -11,10 +11,33 @@ class Batch2D;
 class Batch3D;
 class Camera;
 
-enum class FontStyle {
+struct FontStyle {
-    none,
+    bool bold = false;
-    shadow,
+    bool italic = false;
-    outline
+    bool strikethrough = false;
+    bool underline = false;
+    glm::vec4 color {1, 1, 1, 1};
+
+    FontStyle() = default;
+
+    FontStyle(
+        bool bold,
+        bool italic,
+        bool strikethrough,
+        bool underline,
+        glm::vec4 color
+    )
+        : bold(bold),
+          italic(italic),
+          strikethrough(strikethrough),
+          underline(underline),
+          color(std::move(color)) {
+    }
+};
+
+struct FontStylesScheme {
+    std::vector<FontStyle> palette;
+    std::vector<ubyte> map;
 };
 
 class Font {
@@ -46,11 +69,21 @@ public:
     /// @param codepoint character unicode codepoint
     bool isPrintableChar(uint codepoint) const;
 
-    void draw(Batch2D& batch, std::wstring_view text, int x, int y, float scale=1) const;
+    void draw(
+        Batch2D& batch,
+        std::wstring_view text,
+        int x,
+        int y,
+        const FontStylesScheme* styles,
+        size_t styleMapOffset,
+        float scale = 1
+    ) const;
 
     void draw(
         Batch3D& batch,
         std::wstring_view text,
+        const FontStylesScheme* styles,
+        size_t styleMapOffset,
         const glm::vec3& pos,
         const glm::vec3& right={1, 0, 0},
         const glm::vec3& up={0, 1, 0}

src/graphics/render/TextsRenderer.cpp

@@ -103,6 +103,8 @@ void TextsRenderer::renderNote(
     font.draw(
         batch,
         text,
+        nullptr,
+        0,
         pos - xvec * (width * 0.5f) * preset.scale,
         xvec * preset.scale,
         yvec * preset.scale

src/graphics/ui/GUI.cpp

@@ -197,18 +197,18 @@ void GUI::act(float delta, const Viewport& vp) {
     }
 }
 
-void GUI::draw(const DrawContext* pctx, Assets* assets) {
+void GUI::draw(const DrawContext& pctx, const Assets& assets) {
-    auto& viewport = pctx->getViewport();
+    auto& viewport = pctx.getViewport();
     glm::vec2 wsize = viewport.size();
 
     menu->setPos((wsize - menu->getSize()) / 2.0f);
     uicamera->setFov(wsize.y);
 
-    auto uishader = assets->get<Shader>("ui");
+    auto uishader = assets.get<Shader>("ui");
     uishader->use();
     uishader->uniformMatrix("u_projview", uicamera->getProjView());
 
-    pctx->getBatch2D()->begin();
+    pctx.getBatch2D()->begin();
     container->draw(pctx, assets);
 }
 

src/graphics/ui/GUI.hpp

@@ -94,7 +94,7 @@ namespace gui {
         /// @brief Draw all visible elements on main container 
         /// @param pctx parent graphics context
         /// @param assets active assets storage
-        void draw(const DrawContext* pctx, Assets* assets);
+        void draw(const DrawContext& pctx, const Assets& assets);
 
         /// @brief Add element to the main container
         /// @param node UI element

src/graphics/ui/elements/Button.cpp

@@ -52,7 +52,7 @@ Button::Button(
 
 void Button::setText(std::wstring text) {
     if (label) {
-        label->setText(text);
+        label->setText(std::move(text));
     }
 }
 
@@ -77,9 +77,9 @@ void Button::refresh() {
     }
 }
 
-void Button::drawBackground(const DrawContext* pctx, Assets*) {
+void Button::drawBackground(const DrawContext& pctx, const Assets&) {
     glm::vec2 pos = calcPos();
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
     batch->setColor(calcColor());
     batch->rect(pos.x, pos.y, size.x, size.y);

src/graphics/ui/elements/Button.hpp

@@ -7,7 +7,7 @@ namespace gui {
 
     class Button : public Panel {
     protected:
-        std::shared_ptr<Label> label = nullptr;
+        std::shared_ptr<Label> label;
     public:
         Button(const std::shared_ptr<UINode>& content,
                glm::vec4 padding=glm::vec4(2.0f));
@@ -17,7 +17,9 @@ namespace gui {
                const onaction& action,
                glm::vec2 size=glm::vec2(-1));
 
-        virtual void drawBackground(const DrawContext* pctx, Assets* assets) override;
+        virtual void drawBackground(
+            const DrawContext& pctx, const Assets& assets
+        ) override;
 
         virtual Align getTextAlign() const;
         virtual void setTextAlign(Align align);

src/graphics/ui/elements/CheckBox.cpp

@@ -13,12 +13,12 @@ CheckBox::CheckBox(bool checked) : UINode(glm::vec2(32.0f)), checked(checked) {
     setHoverColor({0.05f, 0.1f, 0.2f, 0.75f});
 }
 
-void CheckBox::draw(const DrawContext* pctx, Assets*) {
+void CheckBox::draw(const DrawContext& pctx, const Assets&) {
     if (supplier) {
         checked = supplier();
     }
     glm::vec2 pos = calcPos();
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
     batch->setColor(checked ? checkColor : calcColor());
     batch->rect(pos.x, pos.y, size.x, size.y);

src/graphics/ui/elements/CheckBox.hpp

@@ -15,7 +15,7 @@ namespace gui {
     public:
         CheckBox(bool checked=false);
 
-        virtual void draw(const DrawContext* pctx, Assets* assets) override;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) override;
 
         virtual void mouseRelease(GUI*, int x, int y) override;
 

src/graphics/ui/elements/Container.cpp

@@ -17,11 +17,19 @@ Container::~Container() {
     Container::clear();
 }
 
-std::shared_ptr<UINode> Container::getAt(glm::vec2 pos, std::shared_ptr<UINode> self) {
+std::shared_ptr<UINode> Container::getAt(
+    const glm::vec2& pos, const std::shared_ptr<UINode>& self
+) {
     if (!isInteractive() || !isEnabled()) {
         return nullptr;
     }
-    if (!isInside(pos)) return nullptr;
+    if (!isInside(pos)) {
+        return nullptr;
+    }
+    int diff = (actualLength-size.y);
+    if (scrollable && diff > 0 && pos.x > calcPos().x + getSize().x - scrollBarWidth) {
+        return UINode::getAt(pos, self);
+    }
 
     for (int i = nodes.size()-1; i >= 0; i--) {
         auto& node = nodes[i];
@@ -35,6 +43,35 @@ std::shared_ptr<UINode> Container::getAt(glm::vec2 pos, std::shared_ptr<UINode>
     return UINode::getAt(pos, self);
 }
 
+void Container::mouseMove(GUI* gui, int x, int y) {
+    UINode::mouseMove(gui, x, y);
+    if (!scrollable) {
+        return;
+    }
+    auto pos = calcPos();
+    x -= pos.x;
+    y -= pos.y;
+    if (prevScrollY == -1) {
+        if (x >= size.x - scrollBarWidth) {
+            prevScrollY = y;
+        }
+        return;
+    }
+    int diff = (actualLength-size.y);
+    if (diff > 0) {
+        scroll -= (y - prevScrollY) / static_cast<float>(size.y) * actualLength;
+        scroll = -glm::min(
+            glm::max(static_cast<float>(-scroll), 0.0f), actualLength - size.y
+        );
+    }
+    prevScrollY = y;
+}
+
+void Container::mouseRelease(GUI* gui, int x, int y) {
+    UINode::mouseRelease(gui, x, y);
+    prevScrollY = -1;
+}
+
 void Container::act(float delta) {
     for (const auto& node : nodes) {
         if (node->isVisible()) {
@@ -80,32 +117,44 @@ void Container::setScrollable(bool flag) {
     scrollable = flag;
 }
 
-void Container::draw(const DrawContext* pctx, Assets* assets) {
+void Container::draw(const DrawContext& pctx, const Assets& assets) {
     glm::vec2 pos = calcPos();
     glm::vec2 size = getSize();
     drawBackground(pctx, assets);
 
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
     if (!nodes.empty()) {
         batch->flush();
-        DrawContext ctx = pctx->sub();
+        DrawContext ctx = pctx.sub();
         ctx.setScissors(glm::vec4(pos.x, pos.y, glm::ceil(size.x), glm::ceil(size.y)));
         for (const auto& node : nodes) {
             if (node->isVisible())
                 node->draw(pctx, assets);
         }
+
+        int diff = (actualLength-size.y);
+        if (scrollable && diff > 0) {
+            int h = glm::max(size.y / actualLength * size.y, scrollBarWidth / 2.0f);
+            batch->untexture();
+            batch->setColor(glm::vec4(1, 1, 1, 0.3f));
+            batch->rect(
+                pos.x + size.x - scrollBarWidth,
+                pos.y - scroll / static_cast<float>(diff) * (size.y - h),
+                scrollBarWidth, h
+            );
+        }
         batch->flush();
     }
 }
 
-void Container::drawBackground(const DrawContext* pctx, Assets*) {
+void Container::drawBackground(const DrawContext& pctx, const Assets&) {
     glm::vec4 color = calcColor();
     if (color.a <= 0.001f)
         return;
     glm::vec2 pos = calcPos();
 
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
     batch->setColor(color);
     batch->rect(pos.x, pos.y, glm::ceil(size.x), glm::ceil(size.y));

src/graphics/ui/elements/Container.hpp

@@ -7,21 +7,27 @@
 
 namespace gui {
     class Container : public UINode {
+        int prevScrollY = -1;
     protected:
         std::vector<std::shared_ptr<UINode>> nodes;
         std::vector<IntervalEvent> intervalEvents;
         int scroll = 0;
         int scrollStep = 40;
+        int scrollBarWidth = 10;
         int actualLength = 0;
         bool scrollable = true;
+
+        bool isScrolling() {
+            return prevScrollY != -1;
+        }
     public:
         Container(glm::vec2 size);
         virtual ~Container();
 
         virtual void act(float delta) override;
-        virtual void drawBackground(const DrawContext* pctx, Assets* assets);
+        virtual void drawBackground(const DrawContext& pctx, const Assets& assets);
-        virtual void draw(const DrawContext* pctx, Assets* assets) override;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) override;
-        virtual std::shared_ptr<UINode> getAt(glm::vec2 pos, std::shared_ptr<UINode> self) override;
+        virtual std::shared_ptr<UINode> getAt(const glm::vec2& pos, const std::shared_ptr<UINode>& self) override;
         virtual void add(const std::shared_ptr<UINode>& node);
         virtual void add(const std::shared_ptr<UINode>& node, glm::vec2 pos);
         virtual void clear();
@@ -36,6 +42,9 @@ namespace gui {
         virtual void setScrollStep(int step);
         virtual void refresh() override;
 
+        virtual void mouseMove(GUI*, int x, int y) override;
+        virtual void mouseRelease(GUI*, int x, int y) override;
+
         const std::vector<std::shared_ptr<UINode>>& getNodes() const;
     };
 }

src/graphics/ui/elements/Image.cpp

@@ -15,21 +15,21 @@ Image::Image(std::string texture, glm::vec2 size) : UINode(size), texture(std::m
     setInteractive(false);
 }
 
-void Image::draw(const DrawContext* pctx, Assets* assets) {
+void Image::draw(const DrawContext& pctx, const Assets& assets) {
     glm::vec2 pos = calcPos();
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     
     Texture* texture = nullptr;
     auto separator = this->texture.find(':');
     if (separator == std::string::npos) {
-        texture = assets->get<Texture>(this->texture);
+        texture = assets.get<Texture>(this->texture);
         batch->texture(texture);
         if (texture && autoresize) {
             setSize(glm::vec2(texture->getWidth(), texture->getHeight()));
         }
     } else {
         auto atlasName = this->texture.substr(0, separator);
-        if (auto atlas = assets->get<Atlas>(atlasName)) {
+        if (auto atlas = assets.get<Atlas>(atlasName)) {
             if (auto region = atlas->getIf(this->texture.substr(separator+1))) {
                 texture = atlas->getTexture();
                 batch->texture(atlas->getTexture());

src/graphics/ui/elements/Image.hpp

@@ -10,7 +10,7 @@ namespace gui {
     public:
         Image(std::string texture, glm::vec2 size=glm::vec2(32,32));
 
-        virtual void draw(const DrawContext* pctx, Assets* assets) override;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) override;
 
         virtual void setAutoResize(bool flag);
         virtual bool isAutoResize() const;

src/graphics/ui/elements/InputBindBox.cpp

@@ -9,15 +9,15 @@ using namespace gui;
 
 InputBindBox::InputBindBox(Binding& binding, glm::vec4 padding) 
     : Panel(glm::vec2(100,32), padding, 0),
-      binding(binding) {
+      binding(binding),
-    label = std::make_shared<Label>(L"");
+      label(std::make_shared<Label>(L"")) {
     add(label);
     setScrollable(false);
 }
 
-void InputBindBox::drawBackground(const DrawContext* pctx, Assets*) {
+void InputBindBox::drawBackground(const DrawContext& pctx, const Assets&) {
     glm::vec2 pos = calcPos();
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
     batch->setColor(isFocused() ? focusedColor : calcColor());
     batch->rect(pos.x, pos.y, size.x, size.y);

src/graphics/ui/elements/InputBindBox.hpp

@@ -13,7 +13,10 @@ namespace gui {
         Binding& binding;
     public:
         InputBindBox(Binding& binding, glm::vec4 padding=glm::vec4(6.0f));
-        virtual void drawBackground(const DrawContext* pctx, Assets* assets) override;
+        
+        virtual void drawBackground(
+            const DrawContext& pctx, const Assets& assets
+        ) override;
 
         virtual void clicked(GUI*, mousecode button) override;
         virtual void keyPressed(keycode key) override;

src/graphics/ui/elements/InventoryView.cpp

@@ -54,7 +54,7 @@ InventoryBuilder::InventoryBuilder() {
 void InventoryBuilder::addGrid(
     int cols, int count, 
     glm::vec2 pos, 
-    int padding,
+    glm::vec4 padding,
     bool addpanel,
     const SlotLayout& slotLayout
 ) {
@@ -63,8 +63,8 @@ void InventoryBuilder::addGrid(
 
     int rows = ceildiv(count, cols);
 
-    uint width =  cols * (slotSize + interval) - interval + padding*2;
+    uint width =  cols * (slotSize + interval) - interval + padding.x + padding.z;
-    uint height = rows * (slotSize + interval) - interval + padding*2;
+    uint height = rows * (slotSize + interval) - interval + padding.y + padding.w;
     
     glm::vec2 vsize = view->getSize();
     if (pos.x + width > vsize.x) {
@@ -87,8 +87,8 @@ void InventoryBuilder::addGrid(
                 break;
             }
             glm::vec2 position (
-                col * (slotSize + interval) + padding,
+                col * (slotSize + interval) + padding.x,
-                row * (slotSize + interval) + padding
+                row * (slotSize + interval) + padding.y
             );
             auto builtSlot = slotLayout;
             builtSlot.index = row * cols + col;
@@ -115,7 +115,7 @@ SlotView::SlotView(
     setTooltipDelay(0.0f);
 }
 
-void SlotView::draw(const DrawContext* pctx, Assets* assets) {
+void SlotView::draw(const DrawContext& pctx, const Assets& assets) {
     if (bound == nullptr) {
         return;
     }
@@ -144,7 +144,7 @@ void SlotView::draw(const DrawContext* pctx, Assets* assets) {
         color = glm::vec4(1, 1, 1, 0.2f);
     }
 
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->setColor(color);
     if (color.a > 0.0) {
         batch->texture(nullptr);
@@ -157,7 +157,7 @@ void SlotView::draw(const DrawContext* pctx, Assets* assets) {
     
     batch->setColor(glm::vec4(1.0f));
 
-    auto previews = assets->get<Atlas>("block-previews");
+    auto previews = assets.get<Atlas>("block-previews");
     auto indices = content->getIndices();
 
     auto& item = indices->items.require(stack.getItemId());
@@ -176,7 +176,7 @@ void SlotView::draw(const DrawContext* pctx, Assets* assets) {
         }
         case ItemIconType::SPRITE: {
             auto textureRegion =
-                util::get_texture_region(*assets, item.icon, "blocks:notfound");
+                util::get_texture_region(assets, item.icon, "blocks:notfound");
             
             batch->texture(textureRegion.texture);
             batch->rect(
@@ -187,16 +187,16 @@ void SlotView::draw(const DrawContext* pctx, Assets* assets) {
     }
 
     if (stack.getCount() > 1) {
-        auto font = assets->get<Font>("normal");
+        auto font = assets.get<Font>("normal");
         std::wstring text = std::to_wstring(stack.getCount());
 
         int x = pos.x+slotSize-text.length()*8;
         int y = pos.y+slotSize-16;
 
         batch->setColor({0, 0, 0, 1.0f});
-        font->draw(*batch, text, x+1, y+1);
+        font->draw(*batch, text, x+1, y+1, nullptr, 0);
         batch->setColor(glm::vec4(1.0f));
-        font->draw(*batch, text, x, y);
+        font->draw(*batch, text, x, y, nullptr, 0);
     }
 }
 

src/graphics/ui/elements/InventoryView.hpp

@@ -64,7 +64,7 @@ namespace gui {
     public:
         SlotView(SlotLayout layout);
 
-        virtual void draw(const DrawContext* pctx, Assets* assets) override;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) override;
 
         void setHighlighted(bool flag);
         bool isHighlighted() const;
@@ -136,7 +136,7 @@ namespace gui {
         void addGrid(
             int cols, int count, 
             glm::vec2 pos, 
-            int padding,
+            glm::vec4 padding,
             bool addpanel,
             const SlotLayout& slotLayout
         );

src/graphics/ui/elements/Label.cpp

@@ -6,6 +6,7 @@
 #include "graphics/core/Font.hpp"
 #include "assets/Assets.hpp"
 #include "util/stringutil.hpp"
+#include "../markdown.hpp"
 
 using namespace gui;
 
@@ -66,6 +67,8 @@ Label::Label(const std::wstring& text, std::string fontName)
     cache.update(this->text, multiline, textWrap);
 }
 
+Label::~Label() = default;
+
 glm::vec2 Label::calcSize() {
     auto font = cache.font;
     uint lineHeight = font->getLineHeight();
@@ -78,11 +81,16 @@ glm::vec2 Label::calcSize() {
     );
 }
 
-void Label::setText(const std::wstring& text) {
+void Label::setText(std::wstring text) {
+    if (markup == "md") {
+        auto [processedText, styles] = markdown::process(text, true);
+        text = std::move(processedText);
+        setStyles(std::move(styles));
+    }
     if (text == this->text && !cache.resetFlag) {
         return;
     }
-    this->text = text;
+    this->text = std::move(text);
     cache.update(this->text, multiline, textWrap);
 
     if (cache.font && autoresize) {
@@ -156,9 +164,9 @@ uint Label::getLinesNumber() const {
     return cache.lines.size();
 }
 
-void Label::draw(const DrawContext* pctx, Assets* assets) {
+void Label::draw(const DrawContext& pctx, const Assets& assets) {
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
-    auto font = assets->get<Font>(fontName);
+    auto font = assets.get<Font>(fontName);
     cache.prepare(font, static_cast<size_t>(glm::abs(getSize().x)));
 
     if (supplier) {
@@ -201,10 +209,10 @@ void Label::draw(const DrawContext* pctx, Assets* assets) {
             if (i < cache.lines.size()-1) {
                 view = std::wstring_view(text.c_str()+offset, cache.lines.at(i+1).offset-offset);
             }
-            font->draw(*batch, view, pos.x, pos.y + i * totalLineHeight);
+            font->draw(*batch, view, pos.x, pos.y + i * totalLineHeight, styles.get(), offset);
         }
     } else {
-        font->draw(*batch, text, pos.x, pos.y);
+        font->draw(*batch, text, pos.x, pos.y, styles.get(), 0);
     }
 }
 
@@ -239,3 +247,16 @@ void Label::setTextWrapping(bool flag) {
 bool Label::isTextWrapping() const {
     return textWrap;
 }
+
+void Label::setMarkup(std::string_view lang) {
+    markup = lang;
+    setText(text);
+}
+
+const std::string& Label::getMarkup() const {
+    return markup;
+}
+
+void Label::setStyles(std::unique_ptr<FontStylesScheme> styles) {
+    this->styles = std::move(styles);
+}

src/graphics/ui/elements/Label.hpp

@@ -3,6 +3,7 @@
 #include "UINode.hpp"
 
 class Font;
+struct FontStylesScheme;
 
 namespace gui {
     struct LineScheme {
@@ -51,11 +52,18 @@ namespace gui {
 
         /// @brief Auto resize label to fit text
         bool autoresize = false;
+
+        /// @brief Text markup language
+        std::string markup;
+
+        std::unique_ptr<FontStylesScheme> styles;
     public:
         Label(const std::string& text, std::string fontName="normal");
         Label(const std::wstring& text, std::string fontName="normal");
 
-        virtual void setText(const std::wstring& text);
+        virtual ~Label();
+
+        virtual void setText(std::wstring text);
         const std::wstring& getText() const;
 
         virtual void setFontName(std::string name);
@@ -95,7 +103,7 @@ namespace gui {
         virtual uint getLinesNumber() const;
         virtual bool isFakeLine(size_t line) const;
 
-        virtual void draw(const DrawContext* pctx, Assets* assets) override;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) override;
 
         virtual void textSupplier(wstringsupplier supplier);
 
@@ -107,5 +115,10 @@ namespace gui {
 
         virtual void setTextWrapping(bool flag);
         virtual bool isTextWrapping() const;
+
+        virtual void setMarkup(std::string_view lang);
+        virtual const std::string& getMarkup() const;
+
+        virtual void setStyles(std::unique_ptr<FontStylesScheme> styles);
     };
 }

src/graphics/ui/elements/Menu.hpp

@@ -7,7 +7,7 @@
 namespace gui {
     struct Page {
         std::string name;
-        std::shared_ptr<UINode> panel = nullptr;
+        std::shared_ptr<UINode> panel;
     };
 
     using page_loader_func = std::function<std::shared_ptr<UINode>(const std::string& name)>;

src/graphics/ui/elements/Plotter.cpp

@@ -14,9 +14,9 @@ void Plotter::act(float delta) {
     points[index % dmwidth] = std::min(value, dmheight);
 }
 
-void Plotter::draw(const DrawContext* pctx, Assets* assets) {
+void Plotter::draw(const DrawContext& pctx, const Assets& assets) {
     glm::vec2 pos = calcPos();
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
     batch->lineWidth(1);
     for (int i = index+1; i < index+dmwidth; i++) {
@@ -37,7 +37,7 @@ void Plotter::draw(const DrawContext* pctx, Assets* assets) {
     }
 
     int current_point = static_cast<int>(points[index % dmwidth]);
-    auto font = assets->get<Font>("normal");
+    auto font = assets.get<Font>("normal");
     for (int y = 0; y < dmheight; y += labelsInterval) {
         std::wstring string;
         if (current_point/16 == y/labelsInterval) {
@@ -47,6 +47,13 @@ void Plotter::draw(const DrawContext* pctx, Assets* assets) {
             batch->setColor({1,1,1,0.2f});
             string = util::to_wstring(y / multiplier, 3);
         }
-        font->draw(*batch, string, pos.x+dmwidth+2, pos.y+dmheight-y-labelsInterval);
+        font->draw(
+            *batch,
+            string,
+            pos.x + dmwidth + 2,
+            pos.y + dmheight - y - labelsInterval,
+            nullptr,
+            0
+        );
     }
 }

src/graphics/ui/elements/Plotter.hpp

@@ -29,6 +29,6 @@ namespace gui {
         }
 
         void act(float delta) override;
-        void draw(const DrawContext* pctx, Assets* assets) override;
+        void draw(const DrawContext& pctx, const Assets& assets) override;
     };
 }

src/graphics/ui/elements/TextBox.cpp

@@ -5,6 +5,7 @@
 #include <algorithm>
 
 #include "Label.hpp"
+#include "devtools/syntax_highlighting.hpp"
 #include "graphics/core/DrawContext.hpp"
 #include "graphics/core/Batch2D.hpp"
 #include "graphics/core/Font.hpp"
@@ -12,6 +13,7 @@
 #include "util/stringutil.hpp"
 #include "window/Events.hpp"
 #include "window/Window.hpp"
+#include "../markdown.hpp"
 
 using namespace gui;
 
@@ -46,10 +48,10 @@ TextBox::TextBox(std::wstring placeholder, glm::vec4 padding)
     scrollStep = 0;
 }
 
-void TextBox::draw(const DrawContext* pctx, Assets* assets) {
+void TextBox::draw(const DrawContext& pctx, const Assets& assets) {
     Container::draw(pctx, assets);
 
-    font = assets->get<Font>(label->getFontName());
+    font = assets.get<Font>(label->getFontName());
 
     if (!isFocused()) {
         return;
@@ -57,39 +59,67 @@ void TextBox::draw(const DrawContext* pctx, Assets* assets) {
     glm::vec2 pos = calcPos();
     glm::vec2 size = getSize();
 
-    auto subctx = pctx->sub();
+    auto subctx = pctx.sub();
     subctx.setScissors(glm::vec4(pos.x, pos.y, size.x, size.y));
 
     const int lineHeight = font->getLineHeight() * label->getLineInterval();
     glm::vec2 lcoord = label->calcPos();
     lcoord.y -= 2;
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
+    batch->setColor(glm::vec4(1.0f));
     if (editable && int((Window::time() - caretLastMove) * 2) % 2 == 0) {
         uint line = label->getLineByTextIndex(caret);
         uint lcaret = caret - label->getTextLineOffset(line);
-        batch->setColor(glm::vec4(1.0f));
-
         int width = font->calcWidth(input, lcaret);
-        batch->rect(lcoord.x + width, lcoord.y+label->getLineYOffset(line), 2, lineHeight);
+        batch->rect(
+            lcoord.x + width,
+            lcoord.y + label->getLineYOffset(line),
+            2,
+            lineHeight
+        );
     }
     if (selectionStart != selectionEnd) {
+        auto selectionCtx = subctx.sub(batch);
+        selectionCtx.setBlendMode(BlendMode::addition);
+
         uint startLine = label->getLineByTextIndex(selectionStart);
         uint endLine = label->getLineByTextIndex(selectionEnd);
 
         batch->setColor(glm::vec4(0.8f, 0.9f, 1.0f, 0.25f));
-        int start = font->calcWidth(input, selectionStart-label->getTextLineOffset(startLine));
+        int start = font->calcWidth(
-        int end = font->calcWidth(input, selectionEnd-label->getTextLineOffset(endLine));
+            input, selectionStart - label->getTextLineOffset(startLine)
+        );
+        int end = font->calcWidth(
+            input, selectionEnd - label->getTextLineOffset(endLine)
+        );
         int lineY = label->getLineYOffset(startLine);
 
         if (startLine == endLine) {
-            batch->rect(lcoord.x + start, lcoord.y+lineY, end-start, lineHeight);
+            batch->rect(
+                lcoord.x + start, lcoord.y + lineY, end - start, lineHeight
+            );
         } else {
-            batch->rect(lcoord.x + start, lcoord.y+lineY, label->getSize().x-start-padding.z-padding.x-2, lineHeight);
+            batch->rect(
+                lcoord.x + start,
+                lcoord.y + lineY,
+                label->getSize().x - start - padding.z - padding.x - 2,
+                lineHeight
+            );
             for (uint i = startLine + 1; i < endLine; i++) {
-                batch->rect(lcoord.x, lcoord.y+label->getLineYOffset(i), label->getSize().x-padding.z-padding.x-2, lineHeight);
+                batch->rect(
+                    lcoord.x,
+                    lcoord.y + label->getLineYOffset(i),
+                    label->getSize().x - padding.z - padding.x - 2,
+                    lineHeight
+                );
             }
-            batch->rect(lcoord.x, lcoord.y+label->getLineYOffset(endLine), end, lineHeight);
+            batch->rect(
+                lcoord.x,
+                lcoord.y + label->getLineYOffset(endLine),
+                end,
+                lineHeight
+            );
         }
     }
 
@@ -132,13 +162,13 @@ void TextBox::draw(const DrawContext* pctx, Assets* assets) {
     }
 }
 
-void TextBox::drawBackground(const DrawContext* pctx, Assets*) {
+void TextBox::drawBackground(const DrawContext& pctx, const Assets&) {
     glm::vec2 pos = calcPos();
 
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
 
-    auto subctx = pctx->sub();
+    auto subctx = pctx.sub();
     subctx.setScissors(glm::vec4(pos.x, pos.y-0.5, size.x, size.y+1));
 
     if (valid) {
@@ -162,7 +192,18 @@ void TextBox::drawBackground(const DrawContext* pctx, Assets*) {
 
 void TextBox::refreshLabel() {
     label->setColor(textColor * glm::vec4(input.empty() ? 0.5f : 1.0f));
-    label->setText(input.empty() && !hint.empty() ? hint : getText());
+
+    const auto& displayText = input.empty() && !hint.empty() ? hint : getText();
+    if (markup == "md") {
+        auto [processedText, styles] = markdown::process(displayText, !focused);
+        label->setText(std::move(processedText));
+        label->setStyles(std::move(styles));
+    } else {
+        label->setText(displayText);
+        if (syntax.empty()) {
+            label->setStyles(nullptr);
+        }
+    }
     
     if (showLineNumbers) {
         if (lineNumbersLabel->getLinesNumber() != label->getLinesNumber()) {
@@ -202,7 +243,8 @@ void TextBox::refreshLabel() {
 
     if (multiline && font) {
         setScrollable(true);
-        uint height = label->getLinesNumber() * font->getLineHeight() * label->getLineInterval();
+        uint height = label->getLinesNumber() * font->getLineHeight() *
+                      label->getLineInterval();
         label->setSize(glm::vec2(label->getSize().x, height));
         actualLength = height;
     } else {
@@ -388,7 +430,7 @@ int TextBox::calcIndexAt(int x, int y) const {
     return std::min(offset+label->getTextLineOffset(line), input.length());
 }
 
-inline std::wstring get_alphabet(wchar_t c) {
+static inline std::wstring get_alphabet(wchar_t c) {
     std::wstring alphabet {c};
     if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_') {
         return L"abcdefghijklmnopqrstuvwxyz_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
@@ -433,7 +475,11 @@ void TextBox::click(GUI*, int x, int y) {
     selectionOrigin = index;
 }
 
-void TextBox::mouseMove(GUI*, int x, int y) {
+void TextBox::mouseMove(GUI* gui, int x, int y) {
+    Container::mouseMove(gui, x, y);
+    if (isScrolling()) {
+        return;
+    }
     ptrdiff_t index = calcIndexAt(x, y);
     setCaret(index);
     extendSelection(index);
@@ -529,10 +575,21 @@ void TextBox::stepDefaultUp(bool shiftPressed, bool breakSelection) {
     }
 }
 
+void TextBox::refreshSyntax() {
+    if (!syntax.empty()) {
+        if (auto styles = devtools::syntax_highlight(
+                syntax, util::wstr2str_utf8(input)
+            )) {
+            label->setStyles(std::move(styles));
+        }
+    }
+}
+
 void TextBox::onInput() {
     if (subconsumer) {
         subconsumer(input);
     }
+    refreshSyntax();
 }
 
 void TextBox::performEditingKeyboardEvents(keycode key) {
@@ -632,7 +689,9 @@ size_t TextBox::getLinePos(uint line) const {
     return label->getTextLineOffset(line);
 }
 
-std::shared_ptr<UINode> TextBox::getAt(glm::vec2 pos, std::shared_ptr<UINode> self) {
+std::shared_ptr<UINode> TextBox::getAt(
+    const glm::vec2& pos, const std::shared_ptr<UINode>& self
+) {
     return UINode::getAt(pos, self);
 }
 
@@ -710,6 +769,7 @@ const std::wstring& TextBox::getText() const {
 void TextBox::setText(const std::wstring& value) {
     this->input = value;
     input.erase(std::remove(input.begin(), input.end(), '\r'), input.end());
+    refreshSyntax();
 }
 
 const std::wstring& TextBox::getPlaceholder() const {
@@ -789,3 +849,24 @@ void TextBox::setShowLineNumbers(bool flag) {
 bool TextBox::isShowLineNumbers() const {
     return showLineNumbers;
 }
+
+void TextBox::setSyntax(std::string_view lang) {
+    syntax = lang;
+    if (syntax.empty()) {
+        label->setStyles(nullptr);
+    } else {
+        refreshSyntax();
+    }
+}
+
+const std::string& TextBox::getSyntax() const {
+    return syntax;
+}
+
+void TextBox::setMarkup(std::string_view lang) {
+    markup = lang;
+}
+
+const std::string& TextBox::getMarkup() const {
+    return markup;
+}

src/graphics/ui/elements/TextBox.hpp

@@ -56,6 +56,8 @@ namespace gui {
         bool editable = true;
         bool autoresize = false;
         bool showLineNumbers = false;
+        std::string markup;
+        std::string syntax;
 
         void stepLeft(bool shiftPressed, bool breakSelection);
         void stepRight(bool shiftPressed, bool breakSelection);
@@ -84,6 +86,8 @@ namespace gui {
         void refreshLabel();
 
         void onInput();
+
+        void refreshSyntax();
     public:
         TextBox(
             std::wstring placeholder, 
@@ -212,12 +216,20 @@ namespace gui {
         virtual void click(GUI*, int, int) override;
         virtual void mouseMove(GUI*, int x, int y) override;
         virtual bool isFocuskeeper() const override {return true;}
-        virtual void draw(const DrawContext* pctx, Assets* assets) override;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) override;
-        virtual void drawBackground(const DrawContext* pctx, Assets* assets) override;
+        virtual void drawBackground(const DrawContext& pctx, const Assets& assets) override;
         virtual void typed(unsigned int codepoint) override; 
         virtual void keyPressed(keycode key) override;
-        virtual std::shared_ptr<UINode> getAt(glm::vec2 pos, std::shared_ptr<UINode> self) override;
+        virtual std::shared_ptr<UINode> getAt(
+            const glm::vec2& pos, const std::shared_ptr<UINode>& self
+        ) override;
         virtual void setOnUpPressed(const runnable &callback);
         virtual void setOnDownPressed(const runnable &callback);
+
+        virtual void setSyntax(std::string_view lang);
+        virtual const std::string& getSyntax() const;
+
+        virtual void setMarkup(std::string_view lang);
+        virtual const std::string& getMarkup() const;
     };
 }

src/graphics/ui/elements/TrackBar.cpp

@@ -25,12 +25,12 @@ TrackBar::TrackBar(
     setHoverColor(glm::vec4(0.01f, 0.02f, 0.03f, 0.5f));
 }
 
-void TrackBar::draw(const DrawContext* pctx, Assets*) {
+void TrackBar::draw(const DrawContext& pctx, const Assets&) {
     if (supplier) {
         value = supplier();
     }
     glm::vec2 pos = calcPos();
-    auto batch = pctx->getBatch2D();
+    auto batch = pctx.getBatch2D();
     batch->texture(nullptr);
     batch->setColor(hover ? hoverColor : color);
     batch->rect(pos.x, pos.y, size.x, size.y);

src/graphics/ui/elements/TrackBar.hpp

@@ -21,7 +21,7 @@ namespace gui {
                  double value, 
                  double step=1.0, 
                  int trackWidth=12);
-        virtual void draw(const DrawContext* pctx, Assets* assets) override;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) override;
 
         virtual void setSupplier(doublesupplier);
         virtual void setConsumer(doubleconsumer);

src/graphics/ui/elements/UINode.cpp

@@ -111,11 +111,11 @@ bool UINode::isInside(glm::vec2 point) {
             point.x < pos.x + size.x && point.y < pos.y + size.y);
 }
 
-std::shared_ptr<UINode> UINode::getAt(glm::vec2 point, std::shared_ptr<UINode> self) {
+std::shared_ptr<UINode> UINode::getAt(const glm::vec2& point, const std::shared_ptr<UINode>& self) {
     if (!isInteractive() || !enabled) {
         return nullptr;
     }
-    return isInside(point) ? std::move(self) : nullptr;
+    return isInside(point) ? self : nullptr;
 }
 
 bool UINode::isInteractive() const {

src/graphics/ui/elements/UINode.hpp

@@ -120,7 +120,7 @@ namespace gui {
         /// @brief Called every frame for all visible elements 
         /// @param delta delta timУ
         virtual void act(float delta) {};
-        virtual void draw(const DrawContext* pctx, Assets* assets) = 0;
+        virtual void draw(const DrawContext& pctx, const Assets& assets) = 0;
 
         virtual void setVisible(bool flag);
         bool isVisible() const;
@@ -190,7 +190,7 @@ namespace gui {
         /// @param pos cursor screen position
         /// @param self shared pointer to element
         /// @return self, sub-element or nullptr if element is not interractive
-        virtual std::shared_ptr<UINode> getAt(glm::vec2 pos, std::shared_ptr<UINode> self);
+        virtual std::shared_ptr<UINode> getAt(const glm::vec2& pos, const std::shared_ptr<UINode>& self);
 
         /// @brief Check if element is opaque for cursor
         virtual bool isInteractive() const;

src/graphics/ui/gui_xml.cpp

@@ -56,8 +56,8 @@ static runnable create_runnable(
     const xml::xmlelement& element,
     const std::string& name
 ) {
-    if (element->has(name)) {
+    if (element.has(name)) {
-        std::string text = element->attr(name).getText();
+        std::string text = element.attr(name).getText();
         if (!text.empty()) {
             return scripting::create_runnable(
                 reader.getEnvironment(), text, reader.getFilename()
@@ -83,78 +83,78 @@ static onaction create_action(
 static void _readUINode(
     const UiXmlReader& reader, const xml::xmlelement& element, UINode& node
 ) {
-    if (element->has("id")) {
+    if (element.has("id")) {
-        node.setId(element->attr("id").getText());
+        node.setId(element.attr("id").getText());
     }
-    if (element->has("pos")) {
+    if (element.has("pos")) {
-        node.setPos(element->attr("pos").asVec2());
+        node.setPos(element.attr("pos").asVec2());
     }
-    if (element->has("size")) {
+    if (element.has("size")) {
-        node.setSize(element->attr("size").asVec2());
+        node.setSize(element.attr("size").asVec2());
     }
-    if (element->has("color")) {
+    if (element.has("color")) {
-        glm::vec4 color = element->attr("color").asColor();
+        glm::vec4 color = element.attr("color").asColor();
         glm::vec4 hoverColor = color;
         glm::vec4 pressedColor = color;
-        if (element->has("hover-color")) {
+        if (element.has("hover-color")) {
             hoverColor = node.getHoverColor();
         }
-        if (element->has("pressed-color")) {
+        if (element.has("pressed-color")) {
             pressedColor = node.getPressedColor();
         }
         node.setColor(color);
         node.setHoverColor(hoverColor);
         node.setPressedColor(pressedColor);
     }
-    if (element->has("margin")) {
+    if (element.has("margin")) {
-        node.setMargin(element->attr("margin").asVec4());
+        node.setMargin(element.attr("margin").asVec4());
     }
-    if (element->has("z-index")) {
+    if (element.has("z-index")) {
-        node.setZIndex(element->attr("z-index").asInt());
+        node.setZIndex(element.attr("z-index").asInt());
     }
-    if (element->has("interactive")) {
+    if (element.has("interactive")) {
-        node.setInteractive(element->attr("interactive").asBool());
+        node.setInteractive(element.attr("interactive").asBool());
     }
-    if (element->has("visible")) {
+    if (element.has("visible")) {
-        node.setVisible(element->attr("visible").asBool());
+        node.setVisible(element.attr("visible").asBool());
     }
-    if (element->has("enabled")) {
+    if (element.has("enabled")) {
-        node.setEnabled(element->attr("enabled").asBool());
+        node.setEnabled(element.attr("enabled").asBool());
     }
-    if (element->has("position-func")) {
+    if (element.has("position-func")) {
         node.setPositionFunc(scripting::create_vec2_supplier(
             reader.getEnvironment(),
-            element->attr("position-func").getText(),
+            element.attr("position-func").getText(),
             reader.getFilename()
         ));
     }
-    if (element->has("size-func")) {
+    if (element.has("size-func")) {
         node.setSizeFunc(scripting::create_vec2_supplier(
             reader.getEnvironment(),
-            element->attr("size-func").getText(),
+            element.attr("size-func").getText(),
             reader.getFilename()
         ));
     }
-    if (element->has("hover-color")) {
+    if (element.has("hover-color")) {
-        node.setHoverColor(element->attr("hover-color").asColor());
+        node.setHoverColor(element.attr("hover-color").asColor());
     }
-    if (element->has("pressed-color")) {
+    if (element.has("pressed-color")) {
-        node.setPressedColor(element->attr("pressed-color").asColor());
+        node.setPressedColor(element.attr("pressed-color").asColor());
     }
-    std::string alignName = element->attr("align", "").getText();
+    std::string alignName = element.attr("align", "").getText();
     node.setAlign(align_from_string(alignName, node.getAlign()));
 
-    if (element->has("gravity")) {
+    if (element.has("gravity")) {
         node.setGravity(gravity_from_string(
-            element->attr("gravity").getText()
+            element.attr("gravity").getText()
         ));
     }
 
-    if (element->has("tooltip")) {
+    if (element.has("tooltip")) {
-        node.setTooltip(util::str2wstr_utf8(element->attr("tooltip").getText()));
+        node.setTooltip(util::str2wstr_utf8(element.attr("tooltip").getText()));
     }
-    if (element->has("tooltip-delay")) {
+    if (element.has("tooltip-delay")) {
-        node.setTooltipDelay(element->attr("tooltip-delay").asFloat());
+        node.setTooltipDelay(element.attr("tooltip-delay").asFloat());
     }
 
     if (auto onclick = create_action(reader, element, "onclick")) {
@@ -169,16 +169,16 @@ static void _readUINode(
 static void _readContainer(UiXmlReader& reader, const xml::xmlelement& element, Container& container) {
     _readUINode(reader, element, container);
 
-    if (element->has("scrollable")) {
+    if (element.has("scrollable")) {
-        container.setScrollable(element->attr("scrollable").asBool());
+        container.setScrollable(element.attr("scrollable").asBool());
     }
-    if (element->has("scroll-step")) {
+    if (element.has("scroll-step")) {
-        container.setScrollStep(element->attr("scroll-step").asInt());
+        container.setScrollStep(element.attr("scroll-step").asInt());
     }
-    for (auto& sub : element->getElements()) {
+    for (auto& sub : element.getElements()) {
         if (sub->isText())
             continue;
-        auto subnode = reader.readUINode(sub);
+        auto subnode = reader.readUINode(*sub);
         if (subnode) {
             container.add(subnode);
         }
@@ -189,15 +189,17 @@ void UiXmlReader::readUINode(UiXmlReader& reader, const xml::xmlelement& element
     _readContainer(reader, element, container);
 }
 
-void UiXmlReader::readUINode(UiXmlReader& reader, const xml::xmlelement& element, UINode& node) {
+void UiXmlReader::readUINode(
+    const UiXmlReader& reader, const xml::xmlelement& element, UINode& node
+) {
     _readUINode(reader, element, node);
 }
 
 static void _readPanel(UiXmlReader& reader, const xml::xmlelement& element, Panel& panel, bool subnodes=true) {
     _readUINode(reader, element, panel);
 
-    if (element->has("padding")) {
+    if (element.has("padding")) {
-        glm::vec4 padding = element->attr("padding").asVec4();
+        glm::vec4 padding = element.attr("padding").asVec4();
         panel.setPadding(padding);
         glm::vec2 size = panel.getSize();
         panel.setSize(glm::vec2(
@@ -205,23 +207,23 @@ static void _readPanel(UiXmlReader& reader, const xml::xmlelement& element, Pane
             size.y + padding.y + padding.w
         ));
     }
-    if (element->has("size")) {
+    if (element.has("size")) {
         panel.setResizing(false);
     }
-    if (element->has("max-length")) {
+    if (element.has("max-length")) {
-        panel.setMaxLength(element->attr("max-length").asInt());
+        panel.setMaxLength(element.attr("max-length").asInt());
     }
-    if (element->has("orientation")) {
+    if (element.has("orientation")) {
-        auto &oname = element->attr("orientation").getText();
+        auto &oname = element.attr("orientation").getText();
         if (oname == "horizontal") {
             panel.setOrientation(Orientation::horizontal);
         }
     }
     if (subnodes) {
-        for (auto& sub : element->getElements()) {
+        for (auto& sub : element.getElements()) {
             if (sub->isText())
                 continue;
-            auto subnode = reader.readUINode(sub);
+            auto subnode = reader.readUINode(*sub);
             if (subnode) {
                 panel.add(subnode);
             }
@@ -231,8 +233,8 @@ static void _readPanel(UiXmlReader& reader, const xml::xmlelement& element, Pane
 
 static std::wstring readAndProcessInnerText(const xml::xmlelement& element, const std::string& context) {
     std::wstring text = L"";
-    if (element->size() == 1) {
+    if (element.size() == 1) {
-        std::string source = element->sub(0)->attr("#").getText();
+        std::string source = element.sub(0).attr("#").getText();
         util::trim(source);
         text = util::str2wstr_utf8(source); 
         if (text[0] == '@') {
@@ -246,33 +248,38 @@ static std::wstring readAndProcessInnerText(const xml::xmlelement& element, cons
     return text;
 }
 
-static std::shared_ptr<UINode> readLabel(UiXmlReader& reader, const xml::xmlelement& element) {
+static std::shared_ptr<UINode> readLabel(
+    const UiXmlReader& reader, const xml::xmlelement& element
+) {
     std::wstring text = readAndProcessInnerText(element, reader.getContext());
     auto label = std::make_shared<Label>(text);
     _readUINode(reader, element, *label);
-    if (element->has("valign")) {
+    if (element.has("valign")) {
         label->setVerticalAlign(
-            align_from_string(element->attr("valign").getText(), label->getVerticalAlign())
+            align_from_string(element.attr("valign").getText(), label->getVerticalAlign())
         );
     }
-    if (element->has("supplier")) {
+    if (element.has("supplier")) {
         label->textSupplier(scripting::create_wstring_supplier(
             reader.getEnvironment(),
-            element->attr("supplier").getText(),
+            element.attr("supplier").getText(),
             reader.getFilename()
         ));
     }
-    if (element->has("autoresize")) {
+    if (element.has("autoresize")) {
-        label->setAutoResize(element->attr("autoresize").asBool());
+        label->setAutoResize(element.attr("autoresize").asBool());
     }
-    if (element->has("multiline")) {
+    if (element.has("multiline")) {
-        label->setMultiline(element->attr("multiline").asBool());
+        label->setMultiline(element.attr("multiline").asBool());
-        if (!element->has("valign")) {
+        if (!element.has("valign")) {
             label->setVerticalAlign(Align::top);
         }
     }
-    if (element->has("text-wrap")) {
+    if (element.has("text-wrap")) {
-        label->setTextWrapping(element->attr("text-wrap").asBool());
+        label->setTextWrapping(element.attr("text-wrap").asBool());
+    }
+    if (element.has("markup")) {
+        label->setMarkup(element.attr("markup").getText());
     }
     return label;
 }
@@ -284,19 +291,19 @@ static std::shared_ptr<UINode> readContainer(UiXmlReader& reader, const xml::xml
 }
 
 static std::shared_ptr<UINode> readPanel(UiXmlReader& reader, const xml::xmlelement& element) {
-    float interval = element->attr("interval", "2").asFloat();
+    float interval = element.attr("interval", "2").asFloat();
     auto panel = std::make_shared<Panel>(glm::vec2(), glm::vec4(), interval);
     _readPanel(reader, element, *panel);
     return panel;
 }
 
 static std::shared_ptr<UINode> readButton(UiXmlReader& reader, const xml::xmlelement& element) {
-    glm::vec4 padding = element->attr("padding", "10").asVec4();
+    glm::vec4 padding = element.attr("padding", "10").asVec4();
 
     std::shared_ptr<Button> button;
-    auto& elements = element->getElements();
+    auto& elements = element.getElements();
     if (!elements.empty() && elements[0]->getTag() != "#") {
-        auto inner = reader.readUINode(element->getElements().at(0));
+        auto inner = reader.readUINode(*elements.at(0));
         if (inner != nullptr) {
             button = std::make_shared<Button>(inner, padding);
         } else {
@@ -308,30 +315,32 @@ static std::shared_ptr<UINode> readButton(UiXmlReader& reader, const xml::xmlele
         button = std::make_shared<Button>(text, padding, nullptr);
         _readPanel(reader, element, *button, true);
     }
-    if (element->has("text-align")) {
+    if (element.has("text-align")) {
-        button->setTextAlign(align_from_string(element->attr("text-align").getText(), button->getTextAlign()));
+        button->setTextAlign(align_from_string(
+            element.attr("text-align").getText(), button->getTextAlign()
+        ));
     }
     return button;
 }
 
 static std::shared_ptr<UINode> readCheckBox(UiXmlReader& reader, const xml::xmlelement& element) {
     auto text = readAndProcessInnerText(element, reader.getContext());
-    bool checked = element->attr("checked", "false").asBool();
+    bool checked = element.attr("checked", "false").asBool();
     auto checkbox = std::make_shared<FullCheckBox>(text, glm::vec2(32), checked);
     _readPanel(reader, element, *checkbox);
 
-    if (element->has("consumer")) {
+    if (element.has("consumer")) {
         checkbox->setConsumer(scripting::create_bool_consumer(
             reader.getEnvironment(),
-            element->attr("consumer").getText(),
+            element.attr("consumer").getText(),
             reader.getFilename()
         ));
     }
 
-    if (element->has("supplier")) {
+    if (element.has("supplier")) {
         checkbox->setSupplier(scripting::create_bool_supplier(
             reader.getEnvironment(),
-            element->attr("supplier").getText(),
+            element.attr("supplier").getText(),
             reader.getFilename()
         ));
     }
@@ -339,15 +348,15 @@ static std::shared_ptr<UINode> readCheckBox(UiXmlReader& reader, const xml::xmle
 }
 
 static std::shared_ptr<UINode> readTextBox(UiXmlReader& reader, const xml::xmlelement& element) {
-    auto placeholder = util::str2wstr_utf8(element->attr("placeholder", "").getText());
+    auto placeholder = util::str2wstr_utf8(element.attr("placeholder", "").getText());
-    auto hint = util::str2wstr_utf8(element->attr("hint", "").getText());
+    auto hint = util::str2wstr_utf8(element.attr("hint", "").getText());
     auto text = readAndProcessInnerText(element, reader.getContext());
     auto textbox = std::make_shared<TextBox>(placeholder, glm::vec4(0.0f));
     textbox->setHint(hint);
     
     _readContainer(reader, element, *textbox);
-    if (element->has("padding")) {
+    if (element.has("padding")) {
-        glm::vec4 padding = element->attr("padding").asVec4();
+        glm::vec4 padding = element.attr("padding").asVec4();
         textbox->setPadding(padding);
         glm::vec2 size = textbox->getSize();
         textbox->setSize(glm::vec2(
@@ -357,55 +366,61 @@ static std::shared_ptr<UINode> readTextBox(UiXmlReader& reader, const xml::xmlel
     }
     textbox->setText(text);
 
-    if (element->has("multiline")) {
+    if (element.has("syntax")) {
-        textbox->setMultiline(element->attr("multiline").asBool());
+        textbox->setSyntax(element.attr("syntax").getText());
     }
-    if (element->has("text-wrap")) {
+    if (element.has("multiline")) {
-        textbox->setTextWrapping(element->attr("text-wrap").asBool());
+        textbox->setMultiline(element.attr("multiline").asBool());
     }
-    if (element->has("editable")) {
+    if (element.has("text-wrap")) {
-        textbox->setEditable(element->attr("editable").asBool());
+        textbox->setTextWrapping(element.attr("text-wrap").asBool());
     }
-    if (element->has("autoresize")) {
+    if (element.has("editable")) {
-        textbox->setAutoResize(element->attr("autoresize").asBool());
+        textbox->setEditable(element.attr("editable").asBool());
     }
-    if (element->has("line-numbers")) {
+    if (element.has("autoresize")) {
-        textbox->setShowLineNumbers(element->attr("line-numbers").asBool());
+        textbox->setAutoResize(element.attr("autoresize").asBool());
     }
-    if (element->has("consumer")) {
+    if (element.has("line-numbers")) {
+        textbox->setShowLineNumbers(element.attr("line-numbers").asBool());
+    }
+    if (element.has("markup")) {
+        textbox->setMarkup(element.attr("markup").getText());
+    }
+    if (element.has("consumer")) {
         textbox->setTextConsumer(scripting::create_wstring_consumer(
             reader.getEnvironment(),
-            element->attr("consumer").getText(),
+            element.attr("consumer").getText(),
             reader.getFilename()
         ));
     }
-    if (element->has("sub-consumer")) {
+    if (element.has("sub-consumer")) {
         textbox->setTextSubConsumer(scripting::create_wstring_consumer(
             reader.getEnvironment(),
-            element->attr("sub-consumer").getText(),
+            element.attr("sub-consumer").getText(),
             reader.getFilename()
         ));
     }
-    if (element->has("supplier")) {
+    if (element.has("supplier")) {
         textbox->setTextSupplier(scripting::create_wstring_supplier(
             reader.getEnvironment(),
-            element->attr("supplier").getText(),
+            element.attr("supplier").getText(),
             reader.getFilename()
         ));
     }
-    if (element->has("focused-color")) {
+    if (element.has("focused-color")) {
-        textbox->setFocusedColor(element->attr("focused-color").asColor());
+        textbox->setFocusedColor(element.attr("focused-color").asColor());
     }
-    if (element->has("error-color")) {
+    if (element.has("error-color")) {
-        textbox->setErrorColor(element->attr("error-color").asColor());
+        textbox->setErrorColor(element.attr("error-color").asColor());
     }
-    if (element->has("text-color")) {
+    if (element.has("text-color")) {
-        textbox->setTextColor(element->attr("text-color").asColor());
+        textbox->setTextColor(element.attr("text-color").asColor());
     }
-    if (element->has("validator")) {
+    if (element.has("validator")) {
         textbox->setTextValidator(scripting::create_wstring_validator(
             reader.getEnvironment(),
-            element->attr("validator").getText(),
+            element.attr("validator").getText(),
             reader.getFilename()
         ));
     }
@@ -418,61 +433,70 @@ static std::shared_ptr<UINode> readTextBox(UiXmlReader& reader, const xml::xmlel
     return textbox;
 }
 
-static std::shared_ptr<UINode> readImage(UiXmlReader& reader, const xml::xmlelement& element) {
+static std::shared_ptr<UINode> readImage(
-    std::string src = element->attr("src", "").getText();
+    const UiXmlReader& reader, const xml::xmlelement& element
+) {
+    std::string src = element.attr("src", "").getText();
     auto image = std::make_shared<Image>(src);
     _readUINode(reader, element, *image);
     return image;
 }
 
-static std::shared_ptr<UINode> readTrackBar(UiXmlReader& reader, const xml::xmlelement& element) {
+static std::shared_ptr<UINode> readTrackBar(
+    const UiXmlReader& reader, const xml::xmlelement& element
+) {
     const auto& env = reader.getEnvironment();
     const auto& file = reader.getFilename();
-    float minv = element->attr("min", "0.0").asFloat();
+    float minv = element.attr("min", "0.0").asFloat();
-    float maxv = element->attr("max", "1.0").asFloat();
+    float maxv = element.attr("max", "1.0").asFloat();
-    float def = element->attr("value", "0.0").asFloat();
+    float def = element.attr("value", "0.0").asFloat();
-    float step = element->attr("step", "1.0").asFloat();
+    float step = element.attr("step", "1.0").asFloat();
-    int trackWidth = element->attr("track-width", "12").asInt();
+    int trackWidth = element.attr("track-width", "12").asInt();
     auto bar = std::make_shared<TrackBar>(minv, maxv, def, step, trackWidth);
     _readUINode(reader, element, *bar);
-    if (element->has("consumer")) {
+    if (element.has("consumer")) {
         bar->setConsumer(scripting::create_number_consumer(
-            env, element->attr("consumer").getText(), file));
+            env, element.attr("consumer").getText(), file));
     }
-    if (element->has("sub-consumer")) {
+    if (element.has("sub-consumer")) {
         bar->setSubConsumer(scripting::create_number_consumer(
-            env, element->attr("sub-consumer").getText(), file));
+            env, element.attr("sub-consumer").getText(), file));
     }
-    if (element->has("supplier")) {
+    if (element.has("supplier")) {
         bar->setSupplier(scripting::create_number_supplier(
-            env, element->attr("supplier").getText(), file));
+            env, element.attr("supplier").getText(), file));
     }
-    if (element->has("track-color")) {
+    if (element.has("track-color")) {
-        bar->setTrackColor(element->attr("track-color").asColor());
+        bar->setTrackColor(element.attr("track-color").asColor());
     }
-    if (element->has("change-on-release")) {
+    if (element.has("change-on-release")) {
-        bar->setChangeOnRelease(element->attr("change-on-release").asBool());
+        bar->setChangeOnRelease(element.attr("change-on-release").asBool());
     }
     return bar;
 }
 
 static std::shared_ptr<UINode> readInputBindBox(UiXmlReader& reader, const xml::xmlelement& element) {
-    auto bindname = element->attr("binding").getText();
+    auto bindname = element.attr("binding").getText();
     auto found = Events::bindings.find(bindname);
     if (found == Events::bindings.end()) {
         throw std::runtime_error("binding does not exists "+util::quote(bindname));
     }
-    glm::vec4 padding = element->attr("padding", "6").asVec4();
+    glm::vec4 padding = element.attr("padding", "6").asVec4();
     auto bindbox = std::make_shared<InputBindBox>(found->second, padding);
     _readPanel(reader, element, *bindbox);
 
     return bindbox;
 }
 
-static slotcallback readSlotFunc(InventoryView* view, UiXmlReader& reader, xml::xmlelement& element, const std::string& attr) {
+static slotcallback readSlotFunc(
+    InventoryView* view,
+    const UiXmlReader& reader,
+    const xml::xmlelement& element,
+    const std::string& attr
+) {
     auto consumer = scripting::create_int_array_consumer(
         reader.getEnvironment(), 
-        element->attr(attr).getText()
+        element.attr(attr).getText()
     );
     return [=](uint slot, ItemStack&) {
         int args[] {int(view->getInventory()->getId()), int(slot)};
@@ -480,22 +504,24 @@ static slotcallback readSlotFunc(InventoryView* view, UiXmlReader& reader, xml::
     };
 }
 
-static void readSlot(InventoryView* view, UiXmlReader& reader, xml::xmlelement element) {
+static void readSlot(
-    int index = element->attr("index", "0").asInt();
+    InventoryView* view, UiXmlReader& reader, const xml::xmlelement& element
-    bool itemSource = element->attr("item-source", "false").asBool();
+) {
-    bool taking = element->attr("taking", "true").asBool();
+    int index = element.attr("index", "0").asInt();
-    bool placing = element->attr("placing", "true").asBool();
+    bool itemSource = element.attr("item-source", "false").asBool();
+    bool taking = element.attr("taking", "true").asBool();
+    bool placing = element.attr("placing", "true").asBool();
     SlotLayout layout(index, glm::vec2(), true, itemSource, nullptr, nullptr, nullptr);
-    if (element->has("pos")) {
+    if (element.has("pos")) {
-        layout.position = element->attr("pos").asVec2();
+        layout.position = element.attr("pos").asVec2();
     }
-    if (element->has("updatefunc")) {
+    if (element.has("updatefunc")) {
         layout.updateFunc = readSlotFunc(view, reader, element, "updatefunc");
     }
-    if (element->has("sharefunc")) {
+    if (element.has("sharefunc")) {
         layout.shareFunc = readSlotFunc(view, reader, element, "sharefunc");
     }
-    if (element->has("onrightclick")) {
+    if (element.has("onrightclick")) {
         layout.rightClick = readSlotFunc(view, reader, element, "onrightclick");
     }
     layout.taking = taking;
@@ -505,19 +531,21 @@ static void readSlot(InventoryView* view, UiXmlReader& reader, xml::xmlelement e
     view->add(slot);
 }
 
-static void readSlotsGrid(InventoryView* view, UiXmlReader& reader, xml::xmlelement element) {
+static void readSlotsGrid(
-    int startIndex = element->attr("start-index", "0").asInt();
+    InventoryView* view, const UiXmlReader& reader, const xml::xmlelement& element
-    int rows = element->attr("rows", "0").asInt();
+) {
-    int cols = element->attr("cols", "0").asInt();
+    int startIndex = element.attr("start-index", "0").asInt();
-    int count = element->attr("count", "0").asInt();
+    int rows = element.attr("rows", "0").asInt();
+    int cols = element.attr("cols", "0").asInt();
+    int count = element.attr("count", "0").asInt();
     const int slotSize = InventoryView::SLOT_SIZE;
-    bool taking = element->attr("taking", "true").asBool();
+    bool taking = element.attr("taking", "true").asBool();
-    bool placing = element->attr("placing", "true").asBool();
+    bool placing = element.attr("placing", "true").asBool();
-    int interval = element->attr("interval", "-1").asInt();
+    int interval = element.attr("interval", "-1").asInt();
     if (interval < 0) {
         interval = InventoryView::SLOT_INTERVAL;
     }
-    int padding = element->attr("padding", "-1").asInt();
+    int padding = element.attr("padding", "-1").asInt();
     if (padding < 0) {
         padding = interval;
     }
@@ -528,18 +556,18 @@ static void readSlotsGrid(InventoryView* view, UiXmlReader& reader, xml::xmlelem
     } else if (count == 0) {
         count = rows * cols;
     }
-    bool itemSource = element->attr("item-source", "false").asBool();
+    bool itemSource = element.attr("item-source", "false").asBool();
     SlotLayout layout(-1, glm::vec2(), true, itemSource, nullptr, nullptr, nullptr);
-    if (element->has("pos")) {
+    if (element.has("pos")) {
-        layout.position = element->attr("pos").asVec2();
+        layout.position = element.attr("pos").asVec2();
     }
-    if (element->has("updatefunc")) {
+    if (element.has("updatefunc")) {
         layout.updateFunc = readSlotFunc(view, reader, element, "updatefunc");
     }
-    if (element->has("sharefunc")) {
+    if (element.has("sharefunc")) {
         layout.shareFunc = readSlotFunc(view, reader, element, "sharefunc");
     }
-    if (element->has("onrightclick")) {
+    if (element.has("onrightclick")) {
         layout.rightClick = readSlotFunc(view, reader, element, "onrightclick");
     }
     layout.padding = padding;
@@ -571,11 +599,11 @@ static std::shared_ptr<UINode> readInventory(UiXmlReader& reader, const xml::xml
     reader.addIgnore("slots-grid");
     reader.readUINode(reader, element, *view);
 
-    for (auto& sub : element->getElements()) {
+    for (auto& sub : element.getElements()) {
         if (sub->getTag() == "slot") {
-            readSlot(view.get(), reader, sub);
+            readSlot(view.get(), reader, *sub);
         } else if (sub->getTag() == "slots-grid") {
-            readSlotsGrid(view.get(), reader, sub);
+            readSlotsGrid(view.get(), reader, *sub);
         }
     }
     return view;
@@ -618,18 +646,18 @@ void UiXmlReader::addIgnore(const std::string& tag) {
 }
 
 std::shared_ptr<UINode> UiXmlReader::readUINode(const xml::xmlelement& element) {
-    if (element->has("if")) {
+    if (element.has("if")) {
-        const auto& cond = element->attr("if").getText();
+        const auto& cond = element.attr("if").getText();
         if (cond.empty() || cond == "false" || cond == "nil")
             return nullptr;
     }
-    if (element->has("ifnot")) {
+    if (element.has("ifnot")) {
-        const auto& cond = element->attr("ifnot").getText();
+        const auto& cond = element.attr("ifnot").getText();
         if (!(cond.empty() || cond == "false" || cond == "nil"))
             return nullptr;
     }
 
-    const std::string& tag = element->getTag();
+    const std::string& tag = element.getTag();
     auto found = readers.find(tag);
     if (found == readers.end()) {
         if (ignored.find(tag) != ignored.end()) {
@@ -638,9 +666,9 @@ std::shared_ptr<UINode> UiXmlReader::readUINode(const xml::xmlelement& element)
         throw std::runtime_error("unsupported element '"+tag+"'");
     }
 
-    bool hascontext = element->has("context");
+    bool hascontext = element.has("context");
     if (hascontext) {
-        contextStack.push(element->attr("context").getText());
+        contextStack.push(element.attr("context").getText());
     }
     auto node = found->second(*this, element);
     if (hascontext) {
@@ -655,8 +683,7 @@ std::shared_ptr<UINode> UiXmlReader::readXML(
 ) {
     this->filename = filename;
     auto document = xml::parse(filename, source);
-    auto root = document->getRoot();
+    return readUINode(*document->getRoot());
-    return readUINode(root);
 }
 
 std::shared_ptr<UINode> UiXmlReader::readXML(

src/graphics/ui/gui_xml.hpp

@@ -11,7 +11,8 @@
 namespace gui {
     class UiXmlReader;
 
-    using uinode_reader = std::function<std::shared_ptr<UINode>(UiXmlReader&, xml::xmlelement)>;
+    using uinode_reader = std::function<
+        std::shared_ptr<UINode>(UiXmlReader&, const xml::xmlelement&)>;
 
     class UiXmlReader {
         std::unordered_map<std::string, uinode_reader> readers;
@@ -29,7 +30,7 @@ namespace gui {
         std::shared_ptr<UINode> readUINode(const xml::xmlelement& element);
         
         void readUINode(
-            UiXmlReader& reader, 
+            const UiXmlReader& reader, 
             const xml::xmlelement& element,
             UINode& node
         );

src/graphics/ui/markdown.cpp

@@ -0,0 +1,111 @@
+#include "markdown.hpp"
+
+#include "graphics/core/Font.hpp"
+
+using namespace markdown;
+
+template <typename CharT>
+static inline void emit(
+    CharT c, FontStylesScheme& styles, std::basic_stringstream<CharT>& ss
+) {
+    ss << c;
+    styles.map.emplace_back(styles.palette.size()-1);
+}
+
+template <typename CharT>
+static inline void emit_md(
+    CharT c, FontStylesScheme& styles, std::basic_stringstream<CharT>& ss
+) {
+    ss << c;
+    styles.map.emplace_back(0);
+}
+
+template <typename CharT>
+static inline void restyle(
+    CharT c,
+    FontStyle& style,
+    FontStylesScheme& styles,
+    std::basic_stringstream<CharT>& ss,
+    int& pos,
+    bool eraseMarkdown
+) {
+    styles.palette.push_back(style);
+    if (!eraseMarkdown) {
+        emit_md(c, styles, ss);
+    }
+    pos++;
+}
+
+template <typename CharT>
+Result<CharT> process_markdown(
+    std::basic_string_view<CharT> source, bool eraseMarkdown
+) {
+    std::basic_stringstream<CharT> ss;
+    FontStylesScheme styles {
+        // markdown                                           default
+        {{false, false, false, false, glm::vec4(1,1,1,0.5f)}, {}},
+        {}
+    };
+    FontStyle style;
+    int pos = 0;
+    while (pos < source.size()) {
+        CharT first = source[pos];
+        if (first == '\\') {
+            if (pos + 1 < source.size()) {
+                CharT second = source[++pos];
+                switch (second) {
+                    case '*':
+                    case '_':
+                    case '~':
+                        if (!eraseMarkdown) {
+                            emit_md(first, styles, ss);
+                        }
+                        emit(second, styles, ss);
+                        pos++;
+                        continue;
+                }
+                pos--;
+            }
+        } else if (first == '*') {
+            if (pos + 1 < source.size() && source[pos+1] == '*') {
+                pos++;
+                if (!eraseMarkdown)
+                    emit_md(first, styles, ss);
+                style.bold = !style.bold;
+                restyle(first, style, styles, ss, pos, eraseMarkdown);
+                continue;
+            }
+            style.italic = !style.italic;
+            restyle(first, style, styles, ss, pos, eraseMarkdown);
+            continue;
+        } else if (first == '_' && pos + 1 < source.size() && source[pos+1] == '_') {
+            pos++;
+            if (!eraseMarkdown)
+                emit_md(first, styles, ss);
+            style.underline = !style.underline;
+            restyle(first, style, styles, ss, pos, eraseMarkdown);
+            continue;
+        } else if (first == '~' && pos + 1 < source.size() && source[pos+1] == '~') {
+            pos++;
+            if (!eraseMarkdown)
+                emit_md(first, styles, ss);
+            style.strikethrough = !style.strikethrough;
+            restyle(first, style, styles, ss, pos, eraseMarkdown);
+            continue;
+        }
+        if (first == '\n') {
+            styles.palette.push_back(styles.palette.at(1));
+        }
+        emit(first, styles, ss);
+        pos++;
+    }
+    return {ss.str(), std::make_unique<FontStylesScheme>(std::move(styles))};
+}
+
+Result<char> markdown::process(std::string_view source, bool eraseMarkdown) {
+    return process_markdown(source, eraseMarkdown);
+}
+
+Result<wchar_t> markdown::process(std::wstring_view source, bool eraseMarkdown) {
+    return process_markdown(source, eraseMarkdown);
+}

src/graphics/ui/markdown.hpp

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <string>
+#include <memory>
+#include <sstream>
+
+struct FontStylesScheme;
+
+// VoxelCore Markdown dialect
+
+namespace markdown {
+
+    template <typename CharT>
+    struct Result {
+        /// @brief Text with erased markdown
+        std::basic_string<CharT> text;
+        /// @brief Text styles scheme
+        std::unique_ptr<FontStylesScheme> styles;
+    };
+
+    Result<char> process(std::string_view source, bool eraseMarkdown);
+    Result<wchar_t> process(std::wstring_view source, bool eraseMarkdown);
+
+    template <typename CharT>
+    inline std::basic_string<CharT> escape(std::string_view source) {
+        std::basic_stringstream<CharT> ss;
+        int pos = 0;
+        while (pos < source.size()) {
+            CharT first = source[pos];
+            if (first == '\\' && pos + 1 < source.size()) {
+                CharT second = source[++pos];
+                ss << first << second;
+                pos++;
+                continue;
+            } else if (first == '*' || first == '~' || first == '_') {
+                ss << '\\';
+            }
+            ss << first;
+            pos++;
+        }
+        return ss.str();
+    }
+}

src/items/Inventory.cpp

@@ -5,7 +5,7 @@
 Inventory::Inventory(int64_t id, size_t size) : id(id), slots(size) {
 }
 
-Inventory::Inventory(const Inventory& orig) {
+Inventory::Inventory(const Inventory& orig) : id(0) {
     this->slots = orig.slots;
 }
 

src/logic/scripting/lua/libs/libconsole.cpp

@@ -31,9 +31,16 @@ static int l_add_command(lua::State* L) {
 
 static int l_execute(lua::State* L) {
     auto prompt = lua::require_string(L, 1);
+    try {
         auto result = engine->getCommandsInterpreter()->execute(prompt);
         lua::pushvalue(L, result);
         return 1;
+    } catch (const parsing_error& err) {
+        if (std::string(err.what()).find("unknown command ") == 0) {
+            throw;
+        }
+        throw std::runtime_error(err.errorLog());
+    }
 }
 
 static int l_set(lua::State* L) {

src/logic/scripting/lua/libs/libgui.cpp

@@ -12,6 +12,8 @@
 #include "graphics/ui/elements/TrackBar.hpp"
 #include "graphics/ui/elements/UINode.hpp"
 #include "graphics/ui/gui_util.hpp"
+#include "graphics/ui/markdown.hpp"
+#include "graphics/core/Font.hpp"
 #include "items/Inventories.hpp"
 #include "util/stringutil.hpp"
 #include "world/Level.hpp"
@@ -299,6 +301,22 @@ static int p_get_line_numbers(UINode* node, lua::State* L) {
     return 0;
 }
 
+static int p_get_syntax(UINode* node, lua::State* L) {
+    if (auto box = dynamic_cast<TextBox*>(node)) {
+        return lua::pushstring(L, box->getSyntax());
+    }
+    return 0;
+}
+
+static int p_get_markup(UINode* node, lua::State* L) {
+    if (auto box = dynamic_cast<TextBox*>(node)) {
+        return lua::pushstring(L, box->getMarkup());
+    } else if (auto label = dynamic_cast<Label*>(node)) {
+        return lua::pushstring(L, label->getMarkup());
+    }
+    return 0;
+}
+
 static int p_get_src(UINode* node, lua::State* L) {
     if (auto image = dynamic_cast<Image*>(node)) {
         return lua::pushstring(L, image->getTexture());
@@ -420,6 +438,8 @@ static int l_gui_getattr(lua::State* L) {
             {"lineNumbers", p_get_line_numbers},
             {"lineAt", p_get_line_at},
             {"linePos", p_get_line_pos},
+            {"syntax", p_get_syntax},
+            {"markup", p_get_markup},
             {"src", p_get_src},
             {"value", p_get_value},
             {"min", p_get_min},
@@ -512,6 +532,18 @@ static void p_set_line_numbers(UINode* node, lua::State* L, int idx) {
         box->setShowLineNumbers(lua::toboolean(L, idx));
     }
 }
+static void p_set_syntax(UINode* node, lua::State* L, int idx) {
+    if (auto box = dynamic_cast<TextBox*>(node)) {
+        box->setSyntax(lua::require_string(L, idx));
+    }
+}
+static void p_set_markup(UINode* node, lua::State* L, int idx) {
+    if (auto box = dynamic_cast<TextBox*>(node)) {
+        box->setMarkup(lua::require_string(L, idx));
+    } else if (auto label = dynamic_cast<Label*>(node)) {
+        label->setMarkup(lua::require_string(L, idx));
+    }
+}
 static void p_set_src(UINode* node, lua::State* L, int idx) {
     if (auto image = dynamic_cast<Image*>(node)) {
         image->setTexture(lua::require_string(L, idx));
@@ -612,6 +644,8 @@ static int l_gui_setattr(lua::State* L) {
             {"text", p_set_text},
             {"editable", p_set_editable},
             {"lineNumbers", p_set_line_numbers},
+            {"syntax", p_set_syntax},
+            {"markup", p_set_markup},
             {"src", p_set_src},
             {"caret", p_set_caret},
             {"value", p_set_value},
@@ -694,6 +728,25 @@ static int l_gui_getviewport(lua::State* L) {
     return lua::pushvec2(L, engine->getGUI()->getContainer()->getSize());
 }
 
+static int l_gui_clear_markup(lua::State* L) {
+    auto lang = lua::require_string(L, 1);
+    std::string text = lua::require_string(L, 2);
+    if (std::strcmp(lang, "md") == 0) {
+        auto [processed, _] = markdown::process(text, true);
+        text = std::move(processed);
+    }
+    return lua::pushstring(L, text);
+}
+
+static int l_gui_escape_markup(lua::State* L) {
+    auto lang = lua::require_string(L, 1);
+    std::string text = lua::require_string(L, 2);
+    if (std::strcmp(lang, "md") == 0) {
+        text = std::move(markdown::escape<char>(text));
+    }
+    return lua::pushstring(L, text);
+}
+
 const luaL_Reg guilib[] = {
     {"get_viewport", lua::wrap<l_gui_getviewport>},
     {"getattr", lua::wrap<l_gui_getattr>},
@@ -701,5 +754,8 @@ const luaL_Reg guilib[] = {
     {"get_env", lua::wrap<l_gui_get_env>},
     {"str", lua::wrap<l_gui_str>},
     {"get_locales_info", lua::wrap<l_gui_get_locales_info>},
+    {"clear_markup", lua::wrap<l_gui_clear_markup>},
+    {"escape_markup", lua::wrap<l_gui_escape_markup>},
     {"__reindex", lua::wrap<l_gui_reindex>},
-    {NULL, NULL}};
+    {NULL, NULL}
+};

src/presets/ParticlesPreset.hpp

@@ -53,7 +53,7 @@ struct ParticlesPreset : public Serializable {
     /// @brief Size of random sub-uv region
     float randomSubUV = 1.0f;
     /// @brief Animation frames
-    std::vector<std::string> frames {};
+    std::vector<std::string> frames;
 
     dv::value serialize() const override;
     void deserialize(const dv::value& src) override;

test/coders/lua_parsing.cpp

@@ -0,0 +1,20 @@
+#include <gtest/gtest.h>
+
+#include "coders/commons.hpp"
+#include "coders/lua_parsing.hpp"
+#include "files/files.hpp"
+#include "util/stringutil.hpp"
+
+TEST(lua_parsing, Tokenizer) {
+    auto filename = "../../res/scripts/stdlib.lua";
+    auto source = files::read_string(std::filesystem::u8path(filename));
+    try {
+        auto tokens = lua::tokenize(filename, source);
+        for (const auto& token : tokens) {
+            std::cout << (int)token.tag << " " << util::quote(token.text) << std::endl;
+        }
+    } catch (const parsing_error& err) {
+        std::cerr << err.errorLog() << std::endl;
+        throw err;
+    }
+}