From 895cddc73909c821416a7517898ed0c6da654eac Mon Sep 17 00:00:00 2001
From: tovjemam <tovjemam@deadfish.cz>
Date: Wed, 3 Dec 2025 20:45:32 +0100
Subject: [PATCH] Add comments, change renderers to have Save instead of saving
 on destruction

---
 .clang-format              |  5 +-
 CMakeLists.txt             |  2 +-
 input_file.cpp             | 93 ++++++++++++++++++++++++++++----------
 input_file.hpp             | 14 +++---
 main.cpp                   | 35 ++++++++++++--
 math/constants.hpp         | 15 +++++-
 math/transforms.cpp        |  2 +-
 math/transforms.hpp        | 26 ++++++++++-
 math/vector.hpp            | 43 ++++++------------
 renderers/bitmap.hpp       | 45 ++++++------------
 renderers/pgm_renderer.cpp | 44 ++++++++----------
 renderers/pgm_renderer.hpp | 23 ++++++----
 renderers/renderer.hpp     |  7 ++-
 renderers/svg_renderer.cpp | 40 ++++++++++------
 renderers/svg_renderer.hpp | 22 ++++++---
 shapes/circle.hpp          | 26 +++++------
 shapes/group.hpp           | 75 +++++++++++-------------------
 shapes/line.hpp            | 15 +++---
 shapes/rectangle.hpp       | 32 +++++--------
 shapes/shape.hpp           |  5 ++
 20 files changed, 322 insertions(+), 247 deletions(-)

diff --git a/.clang-format b/.clang-format
index 0836977..869dfe7 100644
--- a/.clang-format
+++ b/.clang-format
@@ -3,4 +3,7 @@ DerivePointerAlignment: false
 PointerAlignment: Left
 IndentWidth: 4        # spaces per indent level
 TabWidth: 4           # width of a tab character
-UseTab: Never         # options: Never, ForIndentation, Alwayss
\ No newline at end of file
+UseTab: Never         # options: Never, ForIndentation, Alwayss
+AccessModifierOffset: -4
+AllowShortFunctionsOnASingleLine: Inline
+BreakTemplateDeclarations: Yes
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ba37e21..c910385 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.10)
 
 project(CppDrawing)
 
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 23)
 
 add_executable(drawing
     "math/transforms.cpp"
diff --git a/input_file.cpp b/input_file.cpp
index 8ccfcd8..fd65db1 100644
--- a/input_file.cpp
+++ b/input_file.cpp
@@ -4,6 +4,7 @@
 #include <iostream>
 #include <map>
 #include <string>
+#include <format>
 
 #include "shapes/circle.hpp"
 #include "shapes/line.hpp"
@@ -19,58 +20,84 @@ InputFile::InputFile(const std::filesystem::path& path) : m_file(path), m_cmdsPr
     }
 }
 
+// istream >> operator for math::Vector
 static std::istream& operator>>(std::istream& is, math::Vector& vec)
 {
     return is >> vec.x >> vec.y;
 }
 
+// command name -> command handler map
 using CommandMap = std::map<std::string, std::function<void(std::istream&)>>;
 
-template <class T> static const char* GetTypeName()
+/**
+ * @brief Get the type name as a string
+ *
+ * @tparam T Type
+ * @return Type name
+ */
+template <class T>
+static const char* GetTypeName()
 {
     return typeid(T).name();
 }
 
-template <> const char* GetTypeName<int>()
+template <>
+const char* GetTypeName<int>()
 {
     return "integer";
 }
 
-template <> const char* GetTypeName<float>()
+template <>
+const char* GetTypeName<float>()
 {
     return "float";
 }
 
-template <> const char* GetTypeName<math::Vector>()
+template <>
+const char* GetTypeName<math::Vector>()
 {
     return "vector";
 }
 
-template <> const char* GetTypeName<std::string>()
+template <>
+const char* GetTypeName<std::string>()
 {
     return "string";
 }
 
-template <class T> static T ReadVal(std::istream& is)
+/**
+ * @brief Read a value from an `istream` and check for errors
+ *
+ * @tparam T Type of the value to read
+ * @param is Input stream
+ * @return Read value
+ */
+template <class T>
+static T ReadVal(std::istream& is)
 {
     T v;
     is >> v;
 
-    // std::cout << "Reading " << GetTypeName<T>() << ' ' << v << std::endl;
-
     if (is.bad())
-    {
-        throw std::runtime_error("Could not parse " + std::string(GetTypeName<T>()) + " from stream");
-    }
+        throw std::runtime_error(std::format("Could not parse {} from stream", GetTypeName<T>()));
 
     return v;
 }
 
+/**
+ * @brief Register a command in a command map
+ *
+ * @tparam TArgs Argument types
+ * @tparam THandler Handler type
+ * @param cmdMap Command map
+ * @param cmd Command name
+ * @param handler Command handler
+ */
 template <class... TArgs, class THandler>
 static void RegisterCommand(CommandMap& cmdMap, const std::string& cmd, THandler&& handler)
 {
     cmdMap[cmd] = [handler = std::forward<THandler>(handler)](std::istream& is) {
-        std::apply(handler, std::tuple<TArgs...>{ReadVal<TArgs>(is)...}); // pres tuple kvuli poradi evaluace...
+        std::apply(handler, std::tuple<TArgs...>{ReadVal<TArgs>(is)...}); // tuple because of order of evaluation...
     };
 }
 
@@ -104,8 +131,9 @@ shapes::Group InputFile::Parse()
 
     RegisterCommand<int, int>(cmds, "translate", [&shapes](int ox, int oy) { shapes.Translate(math::Vector{ox, oy}); });
 
-    RegisterCommand<int, int, float>(
-        cmds, "rotate", [&shapes](int cx, int cy, float deg) { shapes.Rotate(math::Vector{cx, cy}, deg * math::DEG_TO_RAD); });
+    RegisterCommand<int, int, float>(cmds, "rotate", [&shapes](int cx, int cy, float deg) {
+        shapes.Rotate(math::Vector{cx, cy}, deg * math::DEG_TO_RAD);
+    });
 
     RegisterCommand<int, int, float>(cmds, "scale", [&shapes](int cx, int cy, float factor) {
         if (factor < std::numeric_limits<decltype(factor)>().epsilon())
@@ -114,24 +142,39 @@ shapes::Group InputFile::Parse()
         shapes.Scale(math::Vector{cx, cy}, factor);
     });
 
+    /* ---------------------------- */
+
     std::string line;
+    size_t lineNum = 0;
 
-    while (std::getline(m_file, line))
+    try
     {
-        // TODO: find # mid line
-        if (line.empty() || line[0] == '#')
-            continue;
+        while (std::getline(m_file, line))
+        {
+            ++lineNum;
 
-        std::istringstream iss(line);
-        std::string cmdName = ReadVal<std::string>(iss);
+            if (line.empty() || line[0] == '#')
+                continue;
 
-        auto cmd = cmds.find(cmdName);
+            auto commentPos = line.find('#');
+            if (commentPos != std::string::npos)
+                line = line.substr(0, commentPos);
 
-        if (cmd == cmds.end())
-            throw std::runtime_error("Unknown command: " + cmdName);
+            std::istringstream iss(line);
+            std::string cmdName = ReadVal<std::string>(iss);
 
-        cmd->second(iss);
-        ++m_cmdsProcessed;
+            auto cmd = cmds.find(cmdName);
+
+            if (cmd == cmds.end())
+                throw std::runtime_error("Unknown command: " + cmdName);
+
+            cmd->second(iss);
+            ++m_cmdsProcessed;
+        }
+    }
+    catch (const std::exception& e)
+    {
+        throw std::runtime_error(std::format("Line {}: {}", lineNum, e.what()));
     }
 
     return shapes;
diff --git a/input_file.hpp b/input_file.hpp
index 56b2362..6629f28 100644
--- a/input_file.hpp
+++ b/input_file.hpp
@@ -5,19 +5,21 @@
 
 #include "shapes/group.hpp"
 
+/**
+ * @brief Input file parser
+ * 
+ * Parses an input file containing drawing commands and constructs a `Group` of shapes.
+ */
 class InputFile
 {
-  public:
+public:
     InputFile(const std::filesystem::path& path);
 
     shapes::Group Parse();
 
-    size_t GetNumProcessedCmds() const
-    {
-        return m_cmdsProcessed;
-    }
+    size_t GetNumProcessedCmds() const { return m_cmdsProcessed; }
 
-  private:
+private:
     std::ifstream m_file;
     size_t m_cmdsProcessed;
 };
diff --git a/main.cpp b/main.cpp
index ec9cf36..7143ef5 100644
--- a/main.cpp
+++ b/main.cpp
@@ -8,13 +8,30 @@
 #include "renderers/svg_renderer.hpp"
 #include <charconv>
 
+/**
+ * @brief Render shapes using a specific renderer and save to a file
+ *
+ * @tparam T Renderer type
+ * @param shapes Shapes to render
+ * @param path Output file path
+ * @param width Width
+ * @param height Height
+ */
 template <class T>
 void Render(const shapes::Group& shapes, const std::filesystem::path& path, size_t width, size_t height)
 {
-    T renderer(path, width, height);
+    T renderer(width, height);
     shapes.Draw(renderer);
+    renderer.Save(path);
 }
 
+/**
+ * @brief Parse a single dimension from a string
+ *
+ * @param start Pointer to the start of the dimension string
+ * @param end Pointer to the end of the dimension string
+ * @return Parsed dimension
+ */
 static size_t ParseDim(const char* start, const char* end)
 {
     size_t val;
@@ -28,14 +45,18 @@ static size_t ParseDim(const char* start, const char* end)
     return val;
 }
 
+/**
+ * Parse a size string
+ *
+ * @param sizeStr Size string in the format of `<width>x<height>`
+ * @return Tuple of width and height
+ */
 static std::tuple<size_t, size_t> ParseSize(const std::string& sizeStr)
 {
     auto xPos = sizeStr.find('x');
 
     if (xPos == std::string::npos)
-    {
         throw std::runtime_error("Size must be in format of <width>x<height>");
-    }
 
     size_t width = ParseDim(sizeStr.data(), sizeStr.data() + xPos);
     size_t height = ParseDim(sizeStr.data() + xPos + 1, sizeStr.data() + sizeStr.size());
@@ -43,6 +64,9 @@ static std::tuple<size_t, size_t> ParseSize(const std::string& sizeStr)
     return std::make_tuple(width, height);
 }
 
+/**
+ * @brief Run the drawing process
+ */
 static void Run(const std::string& inputFile, const std::string& outputFile, const std::string& sizeStr)
 {
     try
@@ -56,7 +80,7 @@ static void Run(const std::string& inputFile, const std::string& outputFile, con
             Render<SvgRenderer>(shapes, outputFile, width, height);
         else
             Render<PgmRenderer>(shapes, outputFile, width, height);
-        
+
         std::cout << "OK" << std::endl;
         std::cout << file.GetNumProcessedCmds() << std::endl;
     }
@@ -66,6 +90,9 @@ static void Run(const std::string& inputFile, const std::string& outputFile, con
     }
 }
 
+/**
+ * @brief Main entry point
+ */
 int main(int argc, char** argv)
 {
     if (argc < 4)
diff --git a/math/constants.hpp b/math/constants.hpp
index 75d4265..08334ff 100644
--- a/math/constants.hpp
+++ b/math/constants.hpp
@@ -1,10 +1,23 @@
 #pragma once
 
+#include <numbers>
+
 namespace math
 {
 
-constexpr float PI = 3.14159265358979323846f;
+/**
+ * pi
+ */
+constexpr float PI = std::numbers::pi_v<float>;
+
+/**
+ * Degrees to radians conversion factor
+ */
 constexpr float DEG_TO_RAD = PI / 180.0f;
+
+/**
+ * Radians to degrees conversion factor
+ */
 constexpr float RAD_TO_DEG = 1.0f / DEG_TO_RAD;
 
 } // namespace math
diff --git a/math/transforms.cpp b/math/transforms.cpp
index a24b4f3..3e3610c 100644
--- a/math/transforms.cpp
+++ b/math/transforms.cpp
@@ -1,6 +1,6 @@
 #include "transforms.hpp"
-#include <cmath>
 #include "constants.hpp"
+#include <cmath>
 
 math::Vector math::RotatePoint(const Vector& center, float angle, const Vector& p)
 {
diff --git a/math/transforms.hpp b/math/transforms.hpp
index 27f48ac..4ace094 100644
--- a/math/transforms.hpp
+++ b/math/transforms.hpp
@@ -5,9 +5,33 @@
 namespace math
 {
 
+/**
+ * Rotate a point `p` around a center point `center` by `angle` radians.
+ *
+ * @param center The center point to rotate around
+ * @param angle The angle in radians to rotate
+ * @param p The point to be rotated
+ * @return The rotated point
+ */
 Vector RotatePoint(const Vector& center, float angle, const Vector& p);
+
+/**
+ * Scale a point `p` relative to a center point `center` by a `factor`.
+ *
+ * @param center The center point to scale relative to
+ * @param factor The scaling factor
+ * @param p The point to be scaled
+ * @return The scaled point
+ */
 Vector ScalePoint(const Vector& center, float factor, const Vector& p);
+
+/**
+ * Rotate an angle by another angle
+ *
+ * @param originalAngle The original angle in radians
+ * @param rotationAngle The angle in radians to rotate by
+ * @return The new angle in radians in range [0, 2*PI)
+ */
 float RotateAngle(float originalAngle, float rotationAngle);
 
-
 } // namespace math
\ No newline at end of file
diff --git a/math/vector.hpp b/math/vector.hpp
index 02d8012..250b7ac 100644
--- a/math/vector.hpp
+++ b/math/vector.hpp
@@ -1,32 +1,21 @@
 #pragma once
 
-#include <cstddef>
-
 namespace math
 {
 
+/**
+ * @brief 2D Vector
+ *
+ * Represents a point or a vector in 2D. Provides basic vector operations.
+ */
 class Vector
 {
-  public:
-    Vector() : x{0.0f}, y{0.0f}
-    {
-    }
+public:
+    Vector() : x{0.0f}, y{0.0f} {}
+    Vector(float x, float y) : x{x}, y{y} {}
+    Vector(int x, int y) : x{static_cast<float>(x)}, y{static_cast<float>(y)} {}
 
-    Vector(float x, float y) : x{x}, y{y}
-    {
-    }
-
-    Vector(int x, int y) : x{static_cast<float>(x)}, y{static_cast<float>(y)}
-    {
-    }
-
-    // float& operator[](size_t idx) { return m_v[idx]; }
-    // const float& operator[](size_t idx) const { return m_v[idx]; }
-
-    Vector operator+(const Vector& other) const
-    {
-        return Vector(x + other.x, y + other.y);
-    }
+    Vector operator+(const Vector& other) const { return Vector(x + other.x, y + other.y); }
 
     Vector& operator+=(const Vector& other)
     {
@@ -35,10 +24,7 @@ class Vector
         return *this;
     }
 
-    Vector operator-(const Vector& other) const
-    {
-        return Vector(x - other.x, y - other.y);
-    }
+    Vector operator-(const Vector& other) const { return Vector(x - other.x, y - other.y); }
 
     Vector& operator-=(const Vector& other)
     {
@@ -47,10 +33,7 @@ class Vector
         return *this;
     }
 
-    Vector operator*(float factor) const
-    {
-        return Vector(x * factor, y * factor);
-    }
+    Vector operator*(float factor) const { return Vector(x * factor, y * factor); }
 
     Vector& operator*=(float factor)
     {
@@ -59,7 +42,7 @@ class Vector
         return *this;
     }
 
-  public:
+public:
     float x, y;
 };
 
diff --git a/renderers/bitmap.hpp b/renderers/bitmap.hpp
index b1f83b0..ccd2ff7 100644
--- a/renderers/bitmap.hpp
+++ b/renderers/bitmap.hpp
@@ -6,14 +6,10 @@
 
 class Color
 {
-  public:
-    Color() : l{0}
-    {
-    }
+public:
+    Color() : l{0} {}
 
-    Color(uint8_t l) : l{l}
-    {
-    }
+    Color(uint8_t l) : l{l} {}
 
     uint8_t l{}; // luminence
 
@@ -23,18 +19,18 @@ class Color
         // l = alpha;
     }
 
-  private:
+private:
     static uint8_t BlendChannel(uint8_t a, uint8_t b, uint8_t alpha)
     {
-        return static_cast<uint8_t>((static_cast<int>(a) * (255 - static_cast<int>(alpha)) +
-                               static_cast<int>(b) * static_cast<int>(alpha)) /
-                              255);
+        return static_cast<uint8_t>(
+            (static_cast<int>(a) * (255 - static_cast<int>(alpha)) + static_cast<int>(b) * static_cast<int>(alpha)) /
+            255);
     }
 };
 
 class Bitmap
 {
-  public:
+public:
     Bitmap(size_t width, size_t height, const Color& clearColor)
         : m_width(width), m_height(height), m_data(width * height, clearColor)
     {
@@ -50,36 +46,23 @@ class Bitmap
     //     return {&m_data[row * m_width], m_width};
     // };
 
-    Color* operator[](size_t row)
-    {
-        return &m_data[row * m_width];
-    };
+    Color* operator[](size_t row) { return &m_data[row * m_width]; };
 
-    const Color* operator[](size_t row) const
-    {
-        return &m_data[row * m_width];
-    };
+    const Color* operator[](size_t row) const { return &m_data[row * m_width]; };
 
-    size_t GetWidth() const
-    {
-        return m_width;
-    }
+    size_t GetWidth() const { return m_width; }
 
-    size_t GetHeight() const
-    {
-        return m_height;
-    }
+    size_t GetHeight() const { return m_height; }
 
     void Put(int x, int y, const Color& color, uint8_t alpha)
     {
         if (x < 0 || y < 0 || x >= m_width || y >= m_height)
             return; // out of bounds
 
-        (*this)[y][x].Blend(color, alpha); 
-        
+        (*this)[y][x].Blend(color, alpha);
     }
 
-  private:
+private:
     size_t m_width, m_height;
     std::vector<Color> m_data;
 };
\ No newline at end of file
diff --git a/renderers/pgm_renderer.cpp b/renderers/pgm_renderer.cpp
index ed91c6a..85a1be7 100644
--- a/renderers/pgm_renderer.cpp
+++ b/renderers/pgm_renderer.cpp
@@ -1,15 +1,9 @@
 #include "pgm_renderer.hpp"
 #include <cmath>
+#include <fstream>
 #include <stdexcept>
 
-PgmRenderer::PgmRenderer(const std::filesystem::path& path, size_t width, size_t height)
-    : m_file(path), m_bitmap(width, height, Color{0xFF})
-{
-    if (m_file.bad())
-    {
-        throw std::runtime_error("Could not open file for writing: " + path.string());
-    }
-}
+PgmRenderer::PgmRenderer(size_t width, size_t height) : m_bitmap(width, height, Color{0xFF}) {}
 
 void PgmRenderer::DrawLine(const math::Vector& p0, const math::Vector& p1)
 {
@@ -29,10 +23,10 @@ void PgmRenderer::DrawRectangle(const math::Vector& pos, const math::Vector& siz
     const auto pB = pA + bX * size.x;
     const auto pC = pD + bX * size.x;
 
-    PgmRenderer::DrawLine(pA, pB);
-    PgmRenderer::DrawLine(pB, pC);
-    PgmRenderer::DrawLine(pC, pD);
-    PgmRenderer::DrawLine(pD, pA);
+    DrawLine(pA, pB);
+    DrawLine(pB, pC);
+    DrawLine(pC, pD);
+    DrawLine(pD, pA);
 }
 
 void PgmRenderer::DrawCircle(const math::Vector& center, float radius)
@@ -41,26 +35,28 @@ void PgmRenderer::DrawCircle(const math::Vector& center, float radius)
     RasterizeCircle(center.x, center.y, radius);
 }
 
-PgmRenderer::~PgmRenderer()
+void PgmRenderer::Save(const std::filesystem::path& path)
 {
-    Flush();
-}
+    std::ofstream file{path};
 
-void PgmRenderer::Flush()
-{
-    m_file << "P2" << std::endl;
-    m_file << "# KIV/CPP" << std::endl;
-    m_file << m_bitmap.GetWidth() << ' ' << m_bitmap.GetHeight() << std::endl;
-    m_file << 255 << std::endl;
+    if (!file.is_open())
+    {
+        throw std::runtime_error{"Cannot open file for writing: " + path.string()};
+    }
+
+    file << "P2" << std::endl;
+    file << "# KIV/CPP" << std::endl;
+    file << m_bitmap.GetWidth() << ' ' << m_bitmap.GetHeight() << std::endl;
+    file << 255 << std::endl;
 
     for (size_t y = 0; y < m_bitmap.GetHeight(); ++y)
     {
         for (size_t x = 0; x < m_bitmap.GetWidth(); ++x)
         {
-            m_file << static_cast<int>(m_bitmap[y][x].l) << ' ';
+            file << static_cast<int>(m_bitmap[y][x].l) << ' ';
         }
 
-        m_file << std::endl;
+        file << std::endl;
     }
 }
 
@@ -87,7 +83,7 @@ void PgmRenderer::RasterizeLine(int x0, int y0, int x1, int y1)
         ox = 1;
     }
 
-    while (1)
+    while (true)
     {
         // draw a square of pixels for thickness
         for (int i = -w / 2; i <= w / 2; i++)
diff --git a/renderers/pgm_renderer.hpp b/renderers/pgm_renderer.hpp
index 9b80188..3361237 100644
--- a/renderers/pgm_renderer.hpp
+++ b/renderers/pgm_renderer.hpp
@@ -2,28 +2,31 @@
 
 #include <cstddef>
 #include <filesystem>
-#include <fstream>
 
-#include "renderer.hpp"
 #include "bitmap.hpp"
+#include "renderer.hpp"
 
-class PgmRenderer : public Renderer
+/**
+ * @brief PGM Renderer
+ * 
+ * Draws shapes to a PGM format.
+ */
+class PgmRenderer final : public Renderer
 {
-  public:
-    PgmRenderer(const std::filesystem::path& path, size_t width, size_t height);
+public:
+    PgmRenderer(size_t width, size_t height);
 
     void DrawLine(const math::Vector& p0, const math::Vector& p1) override;
     void DrawRectangle(const math::Vector& pos, const math::Vector& size, float angle) override;
     void DrawCircle(const math::Vector& center, float radius) override;
 
-    ~PgmRenderer() override;
+    void Save(const std::filesystem::path& path);
 
-  private:
-    std::ofstream m_file;
+    ~PgmRenderer() override = default;
+
+private:
     Bitmap m_bitmap;
 
     void RasterizeLine(int x0, int y0, int x1, int y1);
     void RasterizeCircle(int xm, int ym, int r);
-  
-    void Flush();
 };
diff --git a/renderers/renderer.hpp b/renderers/renderer.hpp
index 12f3ed4..64479cb 100644
--- a/renderers/renderer.hpp
+++ b/renderers/renderer.hpp
@@ -1,9 +1,14 @@
 #pragma once
 #include "math/vector.hpp"
 
+/**
+ * @brief Renderer interface
+ * 
+ * Represents an inteface for different renderers that can draw basic shapes.
+ */
 class Renderer
 {
-  public:
+public:
     virtual void DrawLine(const math::Vector& p0, const math::Vector& p1) = 0;
     virtual void DrawRectangle(const math::Vector& pos, const math::Vector& size, float angle) = 0;
     virtual void DrawCircle(const math::Vector& center, float radius) = 0;
diff --git a/renderers/svg_renderer.cpp b/renderers/svg_renderer.cpp
index e2c33d1..138a3fb 100644
--- a/renderers/svg_renderer.cpp
+++ b/renderers/svg_renderer.cpp
@@ -1,38 +1,48 @@
 #include "svg_renderer.hpp"
 
 #include "math/constants.hpp"
+#include <fstream>
 
-SvgRenderer::SvgRenderer(const std::filesystem::path& path, size_t width, size_t height) : m_file(path)
+SvgRenderer::SvgRenderer(size_t width, size_t height) : m_width{width}, m_height{height}
 {
-    if (m_file.bad())
-        throw std::runtime_error("Cannot open " + path.string() + " for writing");
-
-    m_file << "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"" << width << "\" height=\"" << height
-           << "\" viewBox=\"0 0 " << width << " " << height << "\" role=\"img\" aria-label=\"KIV/CPP\">" << std::endl;
+    // white bg
+    m_out << "  <rect width=\"100%\" height=\"100%\" fill=\"#FFFFFF\" />" << std::endl;
 }
 
 void SvgRenderer::DrawLine(const math::Vector& p0, const math::Vector& p1)
 {
-    m_file << "  <line x1=\"" << p0.x << "\" y1=\"" << p0.y << "\" x2=\"" << p1.x << "\" y2=\"" << p1.y << "\" "
-           << "stroke=\"#000000\" stroke-width=\"2\" stroke-linecap=\"round\" />" << std::endl;
+    m_out << "  <line x1=\"" << p0.x << "\" y1=\"" << p0.y << "\" x2=\"" << p1.x << "\" y2=\"" << p1.y << "\" "
+          << "stroke=\"#000000\" stroke-width=\"2\" stroke-linecap=\"round\" />" << std::endl;
 }
 
 void SvgRenderer::DrawRectangle(const math::Vector& pos, const math::Vector& size, float angle)
 {
     float angleDeg = angle * math::RAD_TO_DEG;
 
-    m_file << "  <rect x=\"" << pos.x << "\" y=\"" << pos.y << "\" width=\"" << size.x << "\" height=\"" << size.y
-           << "\" fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" stroke-linejoin=\"round\" transform=\"rotate("
-           << angleDeg << ", " << pos.x << ", " << pos.y << ")\" />" << std::endl;
+    m_out << "  <rect x=\"" << pos.x << "\" y=\"" << pos.y << "\" width=\"" << size.x << "\" height=\"" << size.y
+          << "\" fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" stroke-linejoin=\"round\" transform=\"rotate("
+          << angleDeg << ", " << pos.x << ", " << pos.y << ")\" />" << std::endl;
 }
 
 void SvgRenderer::DrawCircle(const math::Vector& center, float radius)
 {
-    m_file << "  <circle cx=\"" << center.x << "\" cy=\"" << center.y << "\" r=\"" << radius
-           << "\" fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" />" << std::endl;
+    m_out << "  <circle cx=\"" << center.x << "\" cy=\"" << center.y << "\" r=\"" << radius
+          << "\" fill=\"none\" stroke=\"#000000\" stroke-width=\"2\" />" << std::endl;
 }
 
-SvgRenderer::~SvgRenderer()
+void SvgRenderer::Save(const std::filesystem::path& path)
 {
-    m_file << "</svg>" << std::endl;
+    std::ofstream file{path};
+
+    if (!file.is_open())
+    {
+        throw std::runtime_error{"Cannot open file for writing: " + path.string()};
+    }
+
+    file << "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"" << m_width << "\" height=\"" << m_height
+         << "\" viewBox=\"0 0 " << m_width << " " << m_height << "\" role=\"img\" aria-label=\"KIV/CPP\">" << std::endl;
+
+    file << m_out.str();
+
+    file << "</svg>" << std::endl;
 }
diff --git a/renderers/svg_renderer.hpp b/renderers/svg_renderer.hpp
index a2bfd99..479e659 100644
--- a/renderers/svg_renderer.hpp
+++ b/renderers/svg_renderer.hpp
@@ -3,19 +3,27 @@
 #include "renderer.hpp"
 
 #include <filesystem>
-#include <fstream>
+#include <sstream>
 
-class SvgRenderer : public Renderer
+/**
+ * @brief SVG Renderer
+ * 
+ * Draws shapes to an SVG format.
+ */
+class SvgRenderer final : public Renderer
 {
-  public:
-    SvgRenderer(const std::filesystem::path& path, size_t width, size_t height);
+public:
+    SvgRenderer(size_t width, size_t height);
 
     void DrawLine(const math::Vector& p0, const math::Vector& p1) override;
     void DrawRectangle(const math::Vector& pos, const math::Vector& size, float angle) override;
     void DrawCircle(const math::Vector& center, float radius) override;
 
-    ~SvgRenderer() override;
+    void Save(const std::filesystem::path& path);
 
-  private:
-    std::ofstream m_file;
+    ~SvgRenderer() override = default;
+
+private:
+    size_t m_width, m_height;
+    std::ostringstream m_out;
 };
\ No newline at end of file
diff --git a/shapes/circle.hpp b/shapes/circle.hpp
index da6b3ca..cd4b044 100644
--- a/shapes/circle.hpp
+++ b/shapes/circle.hpp
@@ -5,22 +5,18 @@
 namespace shapes
 {
 
-class Circle : public Shape
+/**
+ * @brief Circle shape
+ *
+ * Represents a circle defined by a center point and a radius.
+ */
+class Circle final : public Shape
 {
-  public:
-    Circle(const math::Vector& center, float radius) : m_center(center), m_radius(radius)
-    {
-    }
+public:
+    Circle(const math::Vector& center, float radius) : m_center(center), m_radius(radius) {}
 
-    const math::Vector& GetCenter() const
-    {
-        return m_center;
-    }
-
-    float GetRadius() const
-    {
-        return m_radius;
-    }
+    const math::Vector& GetCenter() const { return m_center; }
+    float GetRadius() const { return m_radius; }
 
     void Translate(const math::Vector& offset) override;
     void Rotate(const math::Vector& center, float angle) override;
@@ -30,7 +26,7 @@ class Circle : public Shape
 
     ~Circle() override = default;
 
-  private:
+private:
     math::Vector m_center;
     float m_radius;
 };
diff --git a/shapes/group.hpp b/shapes/group.hpp
index 432e064..035d263 100644
--- a/shapes/group.hpp
+++ b/shapes/group.hpp
@@ -8,67 +8,46 @@
 namespace shapes
 {
 
+/**
+ * @brief Group shape
+ *
+ * Represents a group of shapes that can be used as a canvas
+ */
 class Group : public Shape
 {
-  public:
+public:
     Group() = default;
 
-    Group(Group&& other) : m_shapes{std::move(other.m_shapes)}
-    {
-    }
+    Group(const Group&) = delete;
+    Group& operator=(const Group&) = delete;
+    Group(Group&&) = default;
+    Group& operator=(Group&&) = default;
 
-    Group& operator=(Group&& other)
-    {
-        // TODO: overit
-        m_shapes = std::move(other.m_shapes);
-        return *this;
-    }
-
-    template <class TShape, class... TArgs> void AddShape(TArgs&&... args)
+    template <typename TShape, typename... TArgs>
+        requires std::derived_from<TShape, Shape>
+    void AddShape(TArgs&&... args)
     {
         m_shapes.emplace_back(std::make_unique<TShape>(std::forward<TArgs>(args)...));
     }
 
-    void Translate(const math::Vector& offset) override
-    {
-        ShapesCall<&Shape::Translate>(offset);
-    }
-
-    void Rotate(const math::Vector& center, float angle) override
-    {
-        ShapesCall<&Shape::Rotate>(center, angle);
-    }
-
-    void Scale(const math::Vector& center, float factor) override
-    {
-        ShapesCall<&Shape::Scale>(center, factor);
-    }
-
-    void Draw(Renderer& renderer) const override
-    {
-        ShapesCall<&Shape::Draw>(renderer);
-    }
+    void Translate(const math::Vector& offset) override { ShapesCall<&Shape::Translate>(offset); }
+    void Rotate(const math::Vector& center, float angle) override { ShapesCall<&Shape::Rotate>(center, angle); }
+    void Scale(const math::Vector& center, float factor) override { ShapesCall<&Shape::Scale>(center, factor); }
+    void Draw(Renderer& renderer) const override { ShapesCall<&Shape::Draw>(renderer); }
 
     ~Group() override = default;
 
-  private:
+private:
+    // calls a member function on all shapes in the group
+    template <auto Fun, typename TSelf, typename... TArgs>
+    void ShapesCall(this TSelf&& self, TArgs&&... args)
+    {
+        for (auto& shape : self.m_shapes)
+            (shape.get()->*Fun)(std::forward<TArgs>(args)...);
+    }
+
+private:
     std::vector<std::unique_ptr<Shape>> m_shapes;
-
-    template <auto TFun, class... TArgs> void ShapesCall(TArgs&&... args)
-    {
-        for (auto& shape : m_shapes)
-        {
-            (shape.get()->*TFun)(std::forward<TArgs>(args)...);
-        }
-    }
-
-    template <auto TFun, class... TArgs> void ShapesCall(TArgs&&... args) const
-    {
-        for (const auto& shape : m_shapes)
-        {
-            (shape.get()->*TFun)(std::forward<TArgs>(args)...);
-        }
-    }
 };
 
 } // namespace shapes
\ No newline at end of file
diff --git a/shapes/line.hpp b/shapes/line.hpp
index d1e36ce..cae9a4b 100644
--- a/shapes/line.hpp
+++ b/shapes/line.hpp
@@ -6,12 +6,15 @@
 namespace shapes
 {
 
-class Line : public Shape
+/**
+ * @brief Line shape
+ *
+ * Represents a line defined by two points.
+ */
+class Line final : public Shape
 {
-  public:
-    Line(const math::Vector& p0, const math::Vector& p1) : m_p0(p0), m_p1(p1)
-    {
-    }
+public:
+    Line(const math::Vector& p0, const math::Vector& p1) : m_p0(p0), m_p1(p1) {}
 
     void Translate(const math::Vector& offset) override;
     void Rotate(const math::Vector& center, float angle) override;
@@ -19,7 +22,7 @@ class Line : public Shape
 
     void Draw(Renderer& renderer) const override;
 
-  private:
+private:
     math::Vector m_p0;
     math::Vector m_p1;
 };
diff --git a/shapes/rectangle.hpp b/shapes/rectangle.hpp
index 8f90306..fc247ff 100644
--- a/shapes/rectangle.hpp
+++ b/shapes/rectangle.hpp
@@ -6,27 +6,19 @@
 namespace shapes
 {
 
-class Rectangle : public Shape
+/**
+ * @brief Rectangle shape
+ *
+ * Represents a rectangle defined by a position, size and angle of rotation around it's left-top corner
+ */
+class Rectangle final : public Shape
 {
-  public:
-    Rectangle(const math::Vector& pos, const math::Vector& size) : m_pos(pos), m_size(size), m_angle(0.0f)
-    {
-    }
+public:
+    Rectangle(const math::Vector& pos, const math::Vector& size) : m_pos(pos), m_size(size), m_angle(0.0f) {}
 
-    const math::Vector& GetPosition() const
-    {
-        return m_pos;
-    }
-
-    const math::Vector& GetSize() const
-    {
-        return m_size;
-    }
-
-    const float GetAngle() const
-    {
-        return m_angle;
-    }
+    const math::Vector& GetPosition() const { return m_pos; }
+    const math::Vector& GetSize() const { return m_size; }
+    const float GetAngle() const { return m_angle; }
 
     void Translate(const math::Vector& offset) override;
     void Rotate(const math::Vector& center, float angle) override;
@@ -36,7 +28,7 @@ class Rectangle : public Shape
 
     ~Rectangle() override = default;
 
-  private:
+private:
     math::Vector m_pos;
     math::Vector m_size;
     float m_angle;
diff --git a/shapes/shape.hpp b/shapes/shape.hpp
index 05fe6f0..14311c2 100644
--- a/shapes/shape.hpp
+++ b/shapes/shape.hpp
@@ -7,6 +7,11 @@ class Renderer;
 namespace shapes
 {
 
+/**
+ * @brief Shape interface
+ * 
+ * Interface for 2d shapes that can be transformed and drawn using a Renderer.
+ */
 class Shape
 {
   public: