Remove entities

Feature/positional container

.clang-format

@@ -0,0 +1,297 @@
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+EmptyLineAfterAccessModifier: Never
+EmptyLineBeforeAccessModifier: LogicalBlock
+EnumTrailingComma: Leave
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+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IfMacros:
+  - KJ_IF_MAYBE
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+RequiresExpressionIndentation: OuterScope
+SeparateDefinitionBlocks: Leave
+ShortNamespaceLines: 1
+SkipMacroDefinitionBody: false
+SortIncludes:
+  Enabled:         true
+  IgnoreCase:      false
+SortJavaStaticImport: Before
+SortUsingDeclarations: LexicographicNumeric
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterOperatorKeyword: false
+SpaceAfterTemplateKeyword: true
+SpaceAroundPointerQualifiers: Default
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+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeJsonColon: false
+SpaceBeforeParens: ControlStatements
+SpaceBeforeParensOptions:
+  AfterControlStatements: true
+  AfterForeachMacros: true
+  AfterFunctionDefinitionName: false
+  AfterFunctionDeclarationName: false
+  AfterIfMacros:   true
+  AfterNot:        false
+  AfterOverloadedOperator: false
+  AfterPlacementOperator: true
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+  ExceptDoubleParentheses: false
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+  - QT_REQUIRE_VERSION
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+  - CF_SWIFT_NAME
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+...
+

.clang-uml

@@ -0,0 +1,26 @@
+# When configuring with cmake, use:
+# cmake -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=Debug
+compilation_database_dir: build
+
+# Path to system header needs to be specified,
+# you will probably need to modify this
+add_compile_flags:
+  - '-I/usr/lib/clang/21/include'
+
+output_directory: docs/diagrams
+diagrams:
+  class_diagram:
+    type: class
+    glob:
+      - cpp/src/**/*.cpp
+      - cpp/src/**/*.hpp
+  include_diagram:
+    type: include
+    glob:
+      - cpp/src/**/*.cpp
+    # Include also external system headers
+    #generate_system_headers: true
+    include:
+      # Include only files belonging to these paths
+      paths:
+        - cpp/src

.gitignore

@@ -1,4 +1,8 @@
-tags
-python/.ipynb_checkpoints
-cpp/build
-cpp/pathfinding
+tags
+python/.ipynb_checkpoints
+cpp/build
+cpp/pathfinding
+.aider*
+build
+.vscode
+docs/diagrams/*puml

CMakeLists.txt

@@ -0,0 +1,203 @@
+cmake_minimum_required(VERSION 3.20)
+
+# Vcpkg integration for Windows
+if(WIN32)
+    # Try to find vcpkg automatically
+    if(DEFINED ENV{VCPKG_ROOT})
+        set(CMAKE_TOOLCHAIN_FILE "$ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake"
+            CACHE STRING "Vcpkg toolchain file")
+        message(STATUS "Using vcpkg from: $ENV{VCPKG_ROOT}")
+    elseif(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/vcpkg/scripts/buildsystems/vcpkg.cmake")
+        set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_SOURCE_DIR}/vcpkg/scripts/buildsystems/vcpkg.cmake"
+            CACHE STRING "Vcpkg toolchain file")
+        message(STATUS "Using local vcpkg installation")
+    else()
+        message(WARNING "vcpkg not found. Please set VCPKG_ROOT environment variable or install vcpkg locally.")
+        message(STATUS "To install dependencies with vcpkg:")
+        message(STATUS "  vcpkg install sdl3 sdl3-image glew opengl gtest")
+    endif()
+endif()
+
+project(PathfindingDemo)
+
+set(CMAKE_CXX_STANDARD 23)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+# Platform-specific package finding
+if(WIN32)
+    # Windows: Use vcpkg-compatible find_package with CONFIG
+    find_package(SDL3 CONFIG REQUIRED)
+    find_package(SDL3_image CONFIG REQUIRED)
+    find_package(OpenGL REQUIRED)
+    find_package(GLEW REQUIRED)
+    find_package(GTest CONFIG REQUIRED)
+    
+    # Set vcpkg target names for consistent linking
+    set(SDL3_TARGET SDL3::SDL3)
+    set(SDL3_IMAGE_TARGET $<IF:$<TARGET_EXISTS:SDL3_image::SDL3_image-shared>,SDL3_image::SDL3_image-shared,SDL3_image::SDL3_image-static>)
+    set(GLEW_TARGET GLEW::GLEW)
+else()
+    # Linux/Unix: Use pkg-config
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(SDL3 REQUIRED sdl3)
+    pkg_check_modules(SDL3_image REQUIRED sdl3-image)
+    find_package(OpenGL REQUIRED)
+    find_package(GLEW REQUIRED)
+    find_package(GTest REQUIRED)
+    
+    # Set target names for Unix systems
+    set(SDL3_TARGET ${SDL3_LIBRARIES})
+    set(SDL3_IMAGE_TARGET ${SDL3_image_LIBRARIES})
+    set(GLEW_TARGET GLEW::GLEW)
+
+    # Enable clang-tidy
+    set(CMAKE_CXX_CLANG_TIDY "clang-tidy")
+endif()
+
+# Include directories
+include_directories(cpp/src)
+
+# Source files for the main executable
+set(MAIN_SOURCES
+    cpp/src/main.cpp
+    cpp/src/camera.cpp
+    cpp/src/entities.cpp
+    cpp/src/gameloop.cpp
+    cpp/src/map.cpp
+    cpp/src/pathfinder/base.cpp
+    cpp/src/pathfinder/bfs.cpp
+    cpp/src/pathfinder/dijkstra.cpp
+    cpp/src/pathfinder/gbfs.cpp
+    cpp/src/pathfinder/utils.cpp
+    cpp/src/pathfindingdemo.cpp
+    cpp/src/sprite.cpp
+    cpp/src/tile.cpp
+    cpp/src/user_input.cpp
+    cpp/src/window.cpp
+)
+
+# Header files (for IDE support)
+set(HEADERS
+    cpp/src/array.hpp
+    cpp/src/camera.hpp
+    cpp/src/entities.hpp
+    cpp/src/gameloop.hpp
+    cpp/src/log.hpp
+    cpp/src/map.hpp
+    cpp/src/math.hpp
+    cpp/src/pathfinder/base.hpp
+    cpp/src/pathfinder/bfs.hpp
+    cpp/src/pathfinder/dijkstra.hpp
+    cpp/src/pathfinder/gbfs.hpp
+    cpp/src/pathfinder/utils.hpp
+    cpp/src/pathfindingdemo.hpp
+    cpp/src/sprite.hpp
+    cpp/src/tile.hpp
+    cpp/src/user_input.hpp
+    cpp/src/window.hpp
+)
+
+# Create main executable
+add_executable(pathfinding_demo ${MAIN_SOURCES} ${HEADERS})
+
+# Platform-specific linking
+if(WIN32)
+    # Windows: Use vcpkg targets
+    target_link_libraries(pathfinding_demo 
+        ${SDL3_TARGET}
+        ${SDL3_IMAGE_TARGET}
+        OpenGL::GL
+        ${GLEW_TARGET}
+    )
+
+    # Add compile flags for Windows (vcpkg handles most of this automatically)
+    if(MSVC)
+        if(SDL3_CFLAGS_OTHER)
+            target_compile_options(pathfinding_demo PRIVATE ${SDL3_CFLAGS_OTHER})
+        endif()
+    endif()
+else()
+    # Unix/Linux: Use pkg-config variables
+    target_link_libraries(pathfinding_demo 
+        ${SDL3_TARGET}
+        ${SDL3_IMAGE_TARGET}
+        OpenGL::GL
+        ${GLEW_TARGET}
+    )
+    
+    # Add compile flags for Unix/Linux
+    target_compile_options(pathfinding_demo PRIVATE ${SDL3_CFLAGS_OTHER})
+endif()
+
+
+# Copy resources after build
+add_custom_command(TARGET pathfinding_demo POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy_directory
+    ${CMAKE_SOURCE_DIR}/cpp/resources
+    $<TARGET_FILE_DIR:pathfinding_demo>/resources
+)
+
+# Unit tests executable
+add_executable(unit_tests 
+    cpp/test/test.cpp
+)
+if(WIN32)
+    target_link_libraries(unit_tests GTest::gtest GTest::gtest_main GTest::gmock GTest::gmock_main)
+else()
+    target_link_libraries(unit_tests GTest::gtest GTest::gtest_main)
+endif()
+
+# Performance tests executable
+add_executable(performance_tests 
+    cpp/test/collision_performance.cpp
+)
+if(WIN32)
+    target_link_libraries(performance_tests GTest::gtest GTest::gtest_main GTest::gmock GTest::gmock_main)
+else()
+    target_link_libraries(performance_tests GTest::gtest GTest::gtest_main)
+endif()
+
+# Enable testing
+enable_testing()
+add_test(NAME unit_tests COMMAND unit_tests)
+add_test(NAME performance_tests COMMAND performance_tests)
+
+# Compiler-specific options with MSVC support
+if(MSVC)
+    # MSVC-specific flags: disable permissive mode, enable high warning level
+    target_compile_options(pathfinding_demo PRIVATE /W4 /permissive-)
+    target_compile_options(unit_tests PRIVATE /W4 /permissive-)
+    target_compile_options(performance_tests PRIVATE /W4 /permissive-)
+    
+    # Additional MSVC flags for C++23 and modern standards
+    target_compile_options(pathfinding_demo PRIVATE /Zc:__cplusplus /Zc:preprocessor)
+    target_compile_options(unit_tests PRIVATE /Zc:__cplusplus /Zc:preprocessor)
+    target_compile_options(performance_tests PRIVATE /Zc:__cplusplus /Zc:preprocessor)
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    # GCC/Clang flags
+    target_compile_options(pathfinding_demo PRIVATE -Wall -Wextra -Wpedantic)
+    target_compile_options(unit_tests PRIVATE -Wall -Wextra -Wpedantic)
+    target_compile_options(performance_tests PRIVATE -Wall -Wextra -Wpedantic)
+endif()
+
+# Platform-specific build configurations
+if(MSVC)
+    # MSVC flags
+    set(CMAKE_CXX_FLAGS_DEBUG "/Od /Zi /RTC1")
+    set(CMAKE_CXX_FLAGS_RELEASE "/O2 /DNDEBUG")
+    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "/O2 /Zi /DNDEBUG")
+    set(CMAKE_CXX_FLAGS_MINSIZEREL "/O1 /DNDEBUG")
+else()
+    # GCC/Clang flags with extended debugging symbols
+    set(CMAKE_CXX_FLAGS_DEBUG "-ggdb3 -O0")
+    set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG")
+    # Formatting target (clang only)
+    add_custom_target(format
+    COMMAND clang-format -i ${MAIN_SOURCES} ${HEADERS}
+)
+endif()
+
+
+list(TRANSFORM MAIN_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/")
+list(TRANSFORM HEADERS PREPEND "${CMAKE_SOURCE_DIR}/")
+

CMakePresets.json

@@ -0,0 +1,13 @@
+{
+  "version": 2,
+  "configurePresets": [
+    {
+      "name": "vcpkg",
+      "generator": "Ninja",
+      "binaryDir": "${sourceDir}/build",
+      "cacheVariables": {
+        "CMAKE_TOOLCHAIN_FILE": "$env{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake"
+      }
+    }
+  ]
+}

README.md

@@ -2,13 +2,17 @@
 
 This is a demo of pathfinding on a 2D grid. It consists of 2 main parts:
 
-* python notes and implementation
-    * jupyter notebook file
-    * standalone python script
-* C++ demo - **work in progress**
+* Notes and Python implementation
+    * jupyter notebook file: [`python/pathfinding_demo.ipynb`](./python/pathfinding_demo.ipynb)
+    * standalone python script: [`./python/pathfinding_demo.py`](./python/pathfinding_demo.py)
+* C++ interactive demo: [`cpp`](./cpp/)
 
 ## Python
 
+Plots a path from one end of the map to the other. Black tiles represent low-cost path, white tiles have high-cost.
+
+![Python pathfinding demo](./docs/img/py_screenshot.png)
+
 ### Standalone script
 
 Run `python pathfinding_demo.py`. Requires numpy and matplotlib to be installed.
@@ -17,37 +21,84 @@ Run `python pathfinding_demo.py`. Requires numpy and matplotlib to be installed.
 
 Contains the same demo as the standalone script and some notes. Since Github supports Jupyter Notebooks now, you can go [directly to the file](./python/pathfinding_demo.ipynb).
 
-Alternatively (or if you want to edit the file), you can use the [Jupyeter Lab on the official website](https://jupyter.org/try-jupyter/lab/):
+## C++
 
-* click the icon "Upload files" (on the top of left sidebar)
-* select pathfinding_demo.ipynb
-* file should be now visible in the left sidebar. Double-click it and confirm default kernel selection
-* run all the cells one by one (play button on the top) or run all of at once using menu "Run -> Run All Cells"
+Interactive demo of entities moving on a simple map with terrains of varying cost. Draw left-mouse button over entities to select them, right-mouse button to send them to selected destination. Simple collision checks are implemented.
 
-## TODO
+Uses some C++20 features. Latest generated architecture drawing is available in [`docs/diagrams/class_diagram.svg`](./docs/diagrams/class_diagram.svg)
+
+![C++ pathfinding demo](./docs/img/screenshot_1.png)
+
+### Windows
+
+#### Dependencies
+
+* `vcpkg` needs to be installed and `VCPKG_ROOT` set. See the [installation instructions](https://learn.microsoft.com/en-us/vcpkg/get_started/get-started?pivots=shell-powershell).
+* Visual Studio with Desktop development with C++ workload (or MSVC Build Tools)
+
+#### Build
+
+Run "Developer Command Prompt for VS 20xx":
+
+```cmd
+cmake --preset=vcpkg
+cmake --build build
+```
+
+Run the `pathfinding.exe` binary in the `build` folder.
+
+### Linux
+
+#### Dependencies
+
+* SDL3
+* SDL3-image
+* GLEW
+* gtest
+
+e.g. on Archlinux:
+
+```
+pacman -S glew sdl3 sdl3_image gtest
+```
+
+Optional dependencies for generating class and include diagrams:
+
+* plantuml
+* [clang-uml](https://github.com/bkryza/clang-uml)
+
+clang-uml needs to be either installed from [AUR](https://aur.archlinux.org/packages/clang-uml) or built manually 
+
+#### Build
+
+```bash
+cmake -B build
+cmake --build build -j 16
+```
+
+Optionally you can also use options:
+
+* `-DCMAKE_EXPORT_COMPILE_COMMANDS=ON` to enable compile database export (needed for class diagram generation)
+* `-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++` to use clang
+
+```
+cmake -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=O  -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
+```
+
+Run the `pathfinding` binary in the `build` folder.
+
+#### Generate architecture diagrams
+
+Build with `-DCMAKE_EXPORT_COMPILE_COMMANDS=ON`. Then in the root folder run:
+
+```
+clang-uml
+plantuml -tsvg docs/diagrams/*.puml
+```
+
+The resulting svg files are located in [docs/diagrams/](./docs/diagrams/).
+
+## Acknowledgments
+
+Entity sprite comes from the Bomberman game, taken from [archive.org](https://archive.org/details/bombermansprites/Custom%20Edited%20-%20Bomberman%20Customs%20-%20Bomberman%20Super%20Bomberman%202-Style.png)
 
-- [x] python
-    - [x] get jupyter lab running
-    - [x] drawing utility
-    - [x] interface for pathfinding
-    - [x] research methods
-    - [x] implement methods
-        - [x] DFS
-        - [x] BFS
-        - [x] Dijsktra
-        - [x] GBFS
-        - [x] A*
-    - [x] performance measurement: time/visited nodes
-    - [x] finalize the script and copy back to the jupyter notebook
-    - [x] finish text on the page
-    - [x] create a dedicated python script
-- [ ] C++
-    - [x] re-use 2D game engine
-    - [x] add tiles (with cost) to map
-        - [x] conversion functions from tile coords to world coords
-        - [x] drawing tiles
-        - [x] add "terrain tiles" with different costs
-    - [x] add mouse-click action
-    - [x] add direct movement (through mouse click action, no pathfinding)
-    - [ ] implement pathfinding
-    - [ ] windows build?

cpp/Makefile

@@ -1,34 +0,0 @@
-# ---------------------------------
-# Generated by Kimi K2
-#---------- configurable ----------
-CXX      := g++
-CXXFLAGS := -std=c++23 -Wall -Wextra -Wpedantic -ggdb3
-LDFLAGS  :=
-LDLIBS   := -lSDL3 -lSDL3_image -lGLEW -lGL
-
-SRC_DIR  := src
-BUILD_DIR:= build
-TARGET   := pathfinding
-
-#----------------------------------
-SOURCES := $(wildcard $(SRC_DIR)/*.cpp)
-OBJECTS := $(SOURCES:$(SRC_DIR)/%.cpp=$(BUILD_DIR)/%.o)
-
-#----------------------------------
-.PHONY: all clean
-
-all: $(TARGET)
-
-# link step
-$(TARGET): $(OBJECTS)
-	$(CXX) $(LDFLAGS) -o $@ $^ $(LDLIBS)
-
-# compile step
-$(BUILD_DIR)/%.o: $(SRC_DIR)/%.cpp | $(BUILD_DIR)
-	$(CXX) $(CXXFLAGS) -c -o $@ $<
-
-$(BUILD_DIR):
-	mkdir -p $@
-
-clean:
-	rm -rf $(BUILD_DIR) $(TARGET)

cpp/src/array.hpp

@@ -4,7 +4,7 @@
 #include <stack>
 #include <stdexcept>
 
-namespace array { // TODO rename to container or something
+namespace array {
 
 template <typename U>
 concept Deletable = requires(U u) {
@@ -148,7 +148,6 @@ public:
 
 private:
   pair_t *m_Pool = nullptr;
-  // TODO use unique_ptr
   std::stack<size_t> m_FreeIdx;
 
   size_t m_Capacity = 0;

cpp/src/camera.cpp

@@ -0,0 +1,35 @@
+#include "camera.hpp"
+#include "log.hpp"
+#include "math.hpp"
+
+// for now only pass-through placeholder functions,
+// since we draw the whole map
+
+void Camera::Pan(const WorldPos &delta) { m_Pan += (delta / m_Zoom); }
+
+void Camera::Zoom(float delta) {
+  constexpr float ZOOM_SCALE = 0.1f;
+  m_Zoom += delta * ZOOM_SCALE;
+  LOG_DEBUG("Zoom: ", m_Zoom);
+}
+
+WindowPos Camera::WorldToWindow(WorldPos world) const {
+  const auto &v = world + m_Pan;
+  return WindowPos{v[0], v[1]} * m_Zoom;
+}
+
+WorldPos Camera::WindowToWorld(WindowPos window) const {
+  window /= m_Zoom;
+  return WorldPos{window[0], window[1]} - m_Pan;
+}
+
+WindowSize Camera::WorldToWindowSize(WorldSize world) const {
+  const auto &v = world;
+  // no zoom yet, just pass-through
+  return WindowSize{v[0], v[1]} * m_Zoom;
+}
+
+WorldSize Camera::WindowToWorldSize(WindowSize window) const {
+  window /= m_Zoom;
+  return WorldSize{window[0], window[1]};
+}

cpp/src/camera.hpp

@@ -0,0 +1,33 @@
+#pragma once
+
+#include "math.hpp"
+
+class Camera {
+public:
+  void Pan(const WorldPos &delta);
+  void Zoom(float delta);
+
+  WorldPos GetPan() const { return m_Pan; }
+  float GetZoom() const { return m_Zoom; }
+
+  WindowPos WorldToWindow(WorldPos) const;
+  WorldPos WindowToWorld(WindowPos) const;
+  WindowSize WorldToWindowSize(WorldSize) const;
+  WorldSize WindowToWorldSize(WindowSize) const;
+
+  template <typename T>
+    requires std::floating_point<T>
+  T WindowToWorldSize(T window_size) const {
+    return window_size / static_cast<T>(m_Zoom);
+  }
+
+  template <typename T>
+    requires std::floating_point<T>
+  T WorldToWindowSize(T world_size) const {
+    return world_size * static_cast<T>(m_Zoom);
+  }
+
+private:
+  float m_Zoom = 1.0f;
+  WorldPos m_Pan;
+};

cpp/src/entities.cpp

@@ -25,13 +25,14 @@ void Entity::ZeroActualVelocityInDirection(WorldPos direction) {
   // where e1 is formed by the direction where we want to zero-out
   // the velocity, and e2 is the orthogonal vector.
   // Scalars q1, q2 are coordinates for e1, e2 basis.
-  WorldPos e1 = direction.normalized();
-  WorldPos e2 = e1.orthogonal();
+  WorldPos e1 = direction.GetNormalized();
+  WorldPos e2 = e1.GetOrthogonal();
 
   // q1 * e1 + q2 * e2 = v, from this follows:
   auto &v = GetActualVelocity();
-  float q2 = (v.y * e1.x - v.x * e1.y) / (e2.y * e1.x - e2.x * e1.y);
-  float q1 = (v.x - q2 * e2.x) / e1.x;
+  float q2 =
+      (v.y() * e1.x() - v.x() * e1.y()) / (e2.y() * e1.x() - e2.x() * e1.y());
+  float q1 = (v.x() - q2 * e2.x()) / e1.x();
 
   // We then zero-out the q1, but only if it's positive - meaning
   // it is aiming in the direction of "direction", not out.
@@ -46,6 +47,43 @@ void Entity::Update(float time_delta) {
   m_Position += m_ActualVelocity * time_delta;
 }
 
+std::optional<WorldPos> Entity::GetMoveTarget() {
+  auto &path = GetPath();
+  if (path.empty()) {
+    return {};
+  }
+
+  WorldPos current_pos = GetPosition();
+  WorldPos next_pos = path.front();
+
+  if (current_pos.DistanceTo(next_pos) > 1.0) {
+    // target not reached yet
+    return next_pos;
+  }
+  // target reached, pop it
+  // m_MoveQueue.pop();
+  path.erase(path.begin());
+  // return nothing - if there's next point in the queue,
+  // we'll get it in the next iteration
+  return {};
+}
+
+bool Entity::CollidesWith(const Entity &other) const {
+  const auto &A = *this;
+  const auto &B = other;
+
+  auto position_A = A.GetPosition();
+  auto position_B = B.GetPosition();
+  auto distance_sq = position_A.DistanceSquared(position_B);
+  auto collision_distance_sq =
+      A.GetCollisionRadiusSquared() + B.GetCollisionRadiusSquared() +
+      2 * A.GetCollisionRadius() * B.GetCollisionRadius();
+  if (distance_sq < collision_distance_sq) {
+    return true;
+  }
+  return false;
+}
+
 Player::Player() {
   LOG_DEBUG(".");
   if (m_Sprite == nullptr) {
@@ -60,7 +98,7 @@ Sprite &Player::GetSprite() {
 
 void Player::LoadResources() {
   m_Sprite =
-      std::make_unique<Sprite>("resources/player.png", WorldPos{38.0f, 46.0f});
+      std::make_unique<Sprite>("resources/player.png", WorldPos{19.0f, 23.0f});
 }
 
 std::unique_ptr<Sprite> Player::m_Sprite;

cpp/src/entities.hpp

@@ -4,10 +4,12 @@
 #include <cstdint>
 #include <iostream>
 #include <memory>
+#include <optional>
 #include <string_view>
 
 #include "log.hpp"
 #include "math.hpp"
+#include "pathfinder/base.hpp"
 #include "sprite.hpp"
 
 class Entity {
@@ -56,14 +58,29 @@ public:
 
   void ZeroActualVelocityInDirection(WorldPos direction);
 
+  const pathfinder::Path &GetPath() const { return m_Path; }
+  pathfinder::Path &GetPath() { return m_Path; }
+  void SetPath(pathfinder::Path &path) { m_Path = path; }
+  std::optional<WorldPos> GetMoveTarget();
+
+  bool CollidesWith(const Entity &other) const;
+
+  bool IsCollisionBoxVisible() const { return m_CollisionBoxVisible; }
+
+  void Select() { m_Selected = true; }
+  void Deselect() { m_Selected = false; }
+  bool IsSelected() const { return m_Selected; }
+
 protected:
   WorldPos m_Position;
   WorldPos m_ActualVelocity;
   WorldPos m_RequestedVelocity;
+  pathfinder::Path m_Path;
 
 private:
   bool m_FlagExpired = false;
-  static constexpr float m_CollisionRadiusSq = 1000.0f;
+  bool m_CollisionBoxVisible = true;
+  bool m_Selected = false;
 };
 
 class Player final : public Entity {
@@ -75,7 +92,7 @@ public:
   constexpr Entity::Type GetType() const override {
     return Entity::Type::PLAYER;
   }
-  constexpr float GetCollisionRadius() const override { return 50.0f; }
+  constexpr float GetCollisionRadius() const override { return 25.0f; }
   bool IsMovable() const override { return true; }
   bool IsCollidable() const override { return true; }
 

cpp/src/gameloop.cpp

@@ -1,41 +1,78 @@
-#include <thread>
 #include <memory>
+#include <thread>
 
 #include "gameloop.hpp"
 
-#include "pathfindingdemo.hpp"
-#include "window.hpp"
-#include "user_input.hpp"
 #include "log.hpp"
+#include "math.hpp"
+#include "pathfinder/base.hpp"
+#include "pathfindingdemo.hpp"
+#include "user_input.hpp"
+#include "window.hpp"
+
+void GameLoop::Draw() {
+  // draw the map (terrain tiles)
+  const Map &map = m_Game->GetMap();
+  const auto &tiles = map.GetMapTiles();
+  for (size_t row = 0; row < tiles.size(); row++) {
+    for (size_t col = 0; col < tiles[row].size(); col++) {
+      const auto &camera = m_Game->GetCamera();
+      const auto &position = camera.WorldToWindow(map.TileEdgeToWorld(
+          TilePos{static_cast<int32_t>(row), static_cast<int32_t>(col)}));
+      const auto &size = camera.WorldToWindowSize(map.GetTileSize());
+      // LOG_DEBUG("Drawing rect (", row, ", ", col, ")");
+      m_Window->DrawFilledRect(position, size, tiles[row][col]->R,
+                               tiles[row][col]->G, tiles[row][col]->B,
+                               tiles[row][col]->A);
+    }
+  }
+
+  // draw the path, if it exists
+
+  for (const auto &entity : m_Game->GetEntities()) {
+    WorldPos start_pos = entity->GetPosition();
+    for (const auto &next_pos : entity->GetPath()) {
+      const auto &camera = m_Game->GetCamera();
+      m_Window->DrawLine(camera.WorldToWindow(start_pos),
+                         camera.WorldToWindow(next_pos));
+      start_pos = next_pos;
+    }
+  }
+
+  // draw all the entities (player etc)
+  for (auto &entity : m_Game->GetEntities()) {
+    const auto &camera = m_Game->GetCamera();
+    auto entity_pos = camera.WorldToWindow(entity->GetPosition());
+    m_Window->DrawSprite(entity_pos, entity->GetSprite(), camera.GetZoom());
+    if (entity->IsCollisionBoxVisible()) {
+      float collision_radius =
+          camera.WorldToWindowSize(entity->GetCollisionRadius());
+      m_Window->DrawCircle(entity_pos, collision_radius, 255, 0, 0);
+    }
+    if (entity->IsSelected()) {
+      float collision_radius =
+          camera.WorldToWindowSize(entity->GetCollisionRadius());
+      m_Window->DrawCircle(entity_pos, collision_radius, 0, 255, 0);
+    }
+  }
+
+  // draw the selection box, if present
+  if (m_Game->IsSelectionBoxActive()) {
+    const auto &[corner_pos, size] = m_Game->GetSelectionBoxPosSize();
+    m_Window->DrawRect(corner_pos, size, 200, 20, 20);
+  }
+}
 
 void GameLoop::Run() {
   LOG_INFO("Running the game");
   while (!m_Game->IsExitRequested()) {
     m_Game->HandleActions(m_UserInput->GetActions());
-    m_Game->UpdatePlayerVelocity();
+    m_Game->UpdateWorld();
 
     m_Window->ClearWindow();
-
-    // draw the map (terrain tiles)
-    const Map &map = m_Game->GetMap();
-    const auto &tiles = map.GetMapTiles();
-    for (size_t row = 0; row < tiles.size(); row++) {
-      for (size_t col = 0; col < tiles[row].size(); col++) {
-        // LOG_DEBUG("Drawing rect (", row, ", ", col, ")");
-        m_Window->DrawRect(
-            map.TileToWorld(TilePos{row, col}),
-            map.GetTileSize(), tiles[row][col]->R, tiles[row][col]->G,
-            tiles[row][col]->B, tiles[row][col]->A);
-      }
-    }
-
-    // draw all the entities (player etc)
-    for (auto &entity : m_Game->GetEntities()) {
-      m_Window->DrawSprite(entity->GetPosition(), entity->GetSprite());
-    }
-
+    Draw();
     m_Window->Flush();
-    // TODO measure fps
+
     std::this_thread::sleep_for(std::chrono::milliseconds(30));
   }
 }

cpp/src/gameloop.hpp

@@ -3,30 +3,30 @@
 #include <memory>
 
 #include "pathfindingdemo.hpp"
-#include "window.hpp"
 #include "user_input.hpp"
+#include "window.hpp"
 
 class GameLoop {
 public:
   GameLoop() = default;
   ~GameLoop() = default;
 
-  GameLoop(const GameLoop&) = delete;
-  GameLoop(GameLoop&&) = delete;
-  GameLoop& operator=(const GameLoop&) = delete;
-  GameLoop& operator=(GameLoop&&) = delete;
- 
+  GameLoop(const GameLoop &) = delete;
+  GameLoop(GameLoop &&) = delete;
+  GameLoop &operator=(const GameLoop &) = delete;
+  GameLoop &operator=(GameLoop &&) = delete;
+
   void Run();
 
-  void SetGame(std::unique_ptr<PathFindingDemo> x) {
-    m_Game = std::move(x);
-  }
+  void SetGame(std::unique_ptr<PathFindingDemo> x) { m_Game = std::move(x); }
   void SetWindow(std::unique_ptr<Window> x) { m_Window = std::move(x); }
   void SetUserInput(std::unique_ptr<UserInput> x) {
     m_UserInput = std::move(x);
   }
 
 private:
+  void Draw();
+
   std::unique_ptr<PathFindingDemo> m_Game;
   std::unique_ptr<Window> m_Window;
   std::unique_ptr<UserInput> m_UserInput;

cpp/src/log.hpp

@@ -2,13 +2,21 @@
 
 #include <iostream>
 
-#define LOG_CRITICAL(...) Log::critical(__PRETTY_FUNCTION__, ": ", __VA_ARGS__)
-#define LOG_ERROR(...) Log::error(__PRETTY_FUNCTION__, ": ", __VA_ARGS__)
-#define LOG_WARNING(...) Log::warning(__PRETTY_FUNCTION__, ": ", __VA_ARGS__)
-#define LOG_INFO(...) Log::info(__PRETTY_FUNCTION__, ": ", __VA_ARGS__)
-#define LOG_DEBUG(...) Log::debug(__PRETTY_FUNCTION__, ": ", __VA_ARGS__)
+#if defined(__GNUC__) || defined(__clang__)
+#define PRETTY_FUNC __PRETTY_FUNCTION__
+#elif defined(_MSC_VER)
+#define PRETTY_FUNC __FUNCTION__
+#else
+#define PRETTY_FUNC __func__
+#endif
+
+#define LOG_CRITICAL(...) Log::critical(PRETTY_FUNC, ": ", __VA_ARGS__)
+#define LOG_ERROR(...) Log::error(PRETTY_FUNC, ": ", __VA_ARGS__)
+#define LOG_WARNING(...) Log::warning(PRETTY_FUNC, ": ", __VA_ARGS__)
+#define LOG_INFO(...) Log::info(PRETTY_FUNC, ": ", __VA_ARGS__)
+#define LOG_DEBUG(...) Log::debug(PRETTY_FUNC, ": ", __VA_ARGS__)
 #define LOG_PROFILING_DEBUG(...)                                               \
-  Log::profiling_debug(__PRETTY_FUNCTION__, ": ", __VA_ARGS__)
+  Log::profiling_debug(PRETTY_FUNC, ": ", __VA_ARGS__)
 
 namespace Log {
 enum class LevelTypes {

cpp/src/main.cpp

@@ -5,7 +5,7 @@
 #include "window.hpp"
 #include <memory>
 
-int main(int argc, char **argv) {
+int main() {
   constexpr int error = -1;
 
   /*
@@ -28,7 +28,7 @@ int main(int argc, char **argv) {
    * Initialize the map and run the pathfinding demo
    */
 
-  auto demo = std::make_unique<PathFindingDemo>(10, 10);
+  auto demo = std::make_unique<PathFindingDemo>(100, 100);
   demo->CreateMap();
 
   auto game_loop = GameLoop{};

cpp/src/map.cpp

@@ -6,36 +6,35 @@
 #include "tile.hpp"
 
 Map::Map(int rows, int cols) : m_Cols(cols), m_Rows(rows) {
-  bool sw = true;
   LOG_DEBUG("cols = ", cols, " rows = ", rows);
   m_Tiles = std::vector<std::vector<const Tile *>>{};
   for (size_t row = 0; row < m_Rows; row++) {
     m_Tiles.push_back(std::vector<const Tile *>{});
     for (size_t col = 0; col < m_Cols; col++) {
-      if (sw)
-        m_Tiles[row].push_back(&tile_types.at("Grass"));
-      else
-        m_Tiles[row].push_back(&tile_types.at("Road"));
-      sw = !sw;
+      m_Tiles[row].push_back(&tile_types.at(TileType::GRASS));
     }
-    sw = !sw;
   }
 }
 
 WorldPos Map::TileToWorld(TilePos p) const {
-  return WorldPos{p.x * TILE_SIZE, p.y * TILE_SIZE};
+  return WorldPos{(p.x() + 0.5f) * TILE_SIZE, (p.y() + 0.5f) * TILE_SIZE};
+}
+
+WorldPos Map::TileEdgeToWorld(TilePos p) const {
+  return WorldPos{p.x() * TILE_SIZE, p.y() * TILE_SIZE};
 }
 
 TilePos Map::WorldToTile(WorldPos p) const {
-  return TilePos{p.x / TILE_SIZE, p.y / TILE_SIZE};
+  return TilePos{static_cast<int32_t>(p.x() / TILE_SIZE),
+                 static_cast<int32_t>(p.y() / TILE_SIZE)};
 }
 
-WorldPos Map::GetTileSize() const { return WorldPos{TILE_SIZE, TILE_SIZE}; }
+WorldSize Map::GetTileSize() const { return WorldSize{TILE_SIZE, TILE_SIZE}; }
 
 const Tile *Map::GetTileAt(TilePos p) const {
   assert(IsTilePosValid(p));
-  size_t row = p.x;
-  size_t col = p.y;
+  size_t row = p.x();
+  size_t col = p.y();
 
   return m_Tiles[row][col];
 }
@@ -45,8 +44,93 @@ const Tile *Map::GetTileAt(WorldPos p) const {
 }
 
 bool Map::IsTilePosValid(TilePos p) const {
-  size_t row = p.x;
-  size_t col = p.y;
+  if (p.x() < 0 || p.y() < 0)
+    return false;
+  size_t row = static_cast<size_t>(p.x());
+  size_t col = static_cast<size_t>(p.y());
 
   return row < m_Tiles.size() && col < m_Tiles[0].size();
 }
+
+std::vector<TilePos> Map::GetNeighbors(TilePos center) const {
+  std::vector<TilePos> neighbours;
+  neighbours.reserve(4);
+
+  std::array<TilePos, 4> candidates = {
+      center + TilePos{1, 0},
+      center + TilePos{-1, 0},
+      center + TilePos{0, 1},
+      center + TilePos{0, -1},
+  };
+
+  for (const auto &c : candidates) {
+    if (IsTilePosValid(c))
+      neighbours.push_back(c);
+  }
+  return neighbours;
+}
+
+void Map::PaintCircle(TilePos center, unsigned radius, TileType tile_type) {
+  // get rectangle that wraps the circle
+  TilePos corner1 = TilePos{center.x() - static_cast<int32_t>(radius),
+                            center.y() - static_cast<int32_t>(radius)};
+  TilePos corner2 = TilePos{center.x() + static_cast<int32_t>(radius),
+                            center.y() + static_cast<int32_t>(radius)};
+  // iterate through all valid points, setting the type
+  const unsigned radius_squared = radius * radius;
+  for (int x = corner1.x(); x < corner2.x(); x++) {
+    for (int y = corner1.y(); y < corner2.y(); y++) {
+      TilePos current_tile = {x, y};
+      unsigned distance_squared = static_cast<unsigned>(
+          center.DistanceTo(current_tile) * center.DistanceTo(current_tile));
+      if (IsTilePosValid(current_tile) && distance_squared < radius_squared) {
+        // y is row, x is col
+        m_Tiles[y][x] = &tile_types.at(tile_type);
+      }
+    }
+  }
+}
+
+void Map::PaintLine(TilePos start_tile, TilePos stop_tile, double width,
+                    TileType tile_type) {
+  const vec<double, 2> start{static_cast<double>(start_tile.x()),
+                             static_cast<double>(start_tile.y())};
+  const vec<double, 2> stop{static_cast<double>(stop_tile.x()),
+                            static_cast<double>(stop_tile.y())};
+  const double line_length = start.DistanceTo(stop);
+  const vec<double, 2> step = (stop - start) / line_length;
+  const vec<double, 2> ortho = step.GetOrthogonal();
+  LOG_DEBUG("step = ", step, " ortho = ", ortho);
+
+  // NOLINTNEXTLINE(clang-analyzer-security.FloatLoopCounter)
+  for (double t = 0; t < line_length; t += 1.0) {
+    // NOLINTNEXTLINE(clang-analyzer-security.FloatLoopCounter)
+    for (double ortho_t = 0; ortho_t < width; ortho_t += 0.1) {
+      auto tile_pos = start + step * t + ortho * ortho_t;
+      TilePos tile_pos_int{static_cast<int32_t>(tile_pos.x()),
+                           static_cast<int32_t>(tile_pos.y())};
+      if (IsTilePosValid(tile_pos_int)) {
+        size_t row = static_cast<size_t>(tile_pos.x());
+        size_t col = static_cast<size_t>(tile_pos.y());
+        m_Tiles[row][col] = &tile_types.at(tile_type);
+      }
+    }
+  }
+}
+
+void Map::PaintRectangle(TilePos first_corner, TilePos second_corner,
+                         TileType tile_type) {
+  std::initializer_list<int> xvals = {first_corner.x(), second_corner.x()};
+  std::initializer_list<int> yvals = {first_corner.y(), second_corner.y()};
+  for (int x = std::min(xvals); x < std::max(xvals); x++) {
+    for (int y = std::min(yvals); y < std::max(yvals); y++) {
+      TilePos tile_pos{x, y};
+      LOG_DEBUG("tile_pos = ", tile_pos);
+      if (IsTilePosValid(tile_pos)) {
+        size_t row = static_cast<size_t>(tile_pos.x());
+        size_t col = static_cast<size_t>(tile_pos.y());
+        m_Tiles[row][col] = &tile_types.at(tile_type);
+      }
+    }
+  }
+}

cpp/src/map.hpp

@@ -9,27 +9,38 @@ using TileGrid = std::vector<std::vector<const Tile *>>;
 
 class Map {
 public:
-  static constexpr float TILE_SIZE = 100.0f; // tile size in world
+  static constexpr float TILE_SIZE = 10.0f; // tile size in world
 
   Map(int rows, int cols);
   Map() : Map(0, 0) {}
 
-  Map(const Map&) = delete;
-  Map(Map&&) = delete;
-  Map& operator=(const Map&) = delete;
-  Map& operator=(Map&&) = delete;
+  Map(const Map &) = delete;
+  Map(Map &&) = delete;
+  Map &operator=(const Map &) = delete;
+  Map &operator=(Map &&) = delete;
 
   const TileGrid &GetMapTiles() const { return m_Tiles; }
 
+  // coordinate conversion functions
   WorldPos TileToWorld(TilePos p) const;
+  WorldPos TileEdgeToWorld(TilePos p) const;
   TilePos WorldToTile(WorldPos p) const;
 
-  WorldPos GetTileSize() const;
+  WorldSize GetTileSize() const;
   const Tile *GetTileAt(TilePos p) const;
   const Tile *GetTileAt(WorldPos p) const;
 
   bool IsTilePosValid(TilePos p) const;
 
+  // methods for drawing on the map
+  void PaintCircle(TilePos center, unsigned radius, TileType tile_type);
+  void PaintLine(TilePos start, TilePos stop, double width, TileType tile_type);
+  void PaintRectangle(TilePos first_corner, TilePos second_corner,
+                      TileType tile_type);
+
+  std::vector<TilePos> GetNeighbors(TilePos center) const;
+  float GetCost(TilePos pos) const { return GetTileAt(pos)->cost; }
+
   template <typename T> double GetTileVelocityCoeff(T p) const {
     return 1.0 / GetTileAt(p)->cost;
   }

cpp/src/math.hpp

@@ -1,94 +1,455 @@
 #pragma once
 
+#include <algorithm>
 #include <cassert>
 #include <cmath>
 #include <concepts>
+#include <functional>
 #include <initializer_list>
 #include <iostream>
+#include <numbers>
+#include <numeric>
+#include <ranges>
 #include <utility>
 
-
-template <typename T> struct Vec2D {
-public:
-  Vec2D() = default;
-  ~Vec2D() = default;
-
-  Vec2D &operator+=(const Vec2D &other) {
-    x += other.x;
-    y += other.y;
-    return *this;
-  }
-
-  friend Vec2D operator+(const Vec2D &a, const Vec2D &b) {
-    return Vec2D{a.x + b.x, a.y + b.y};
-  }
-  
-  friend Vec2D operator-(const Vec2D &a, const Vec2D &b) {
-    return Vec2D{a.x - b.x, a.y - b.y};
-  }
-
-  friend Vec2D operator*(float k, const Vec2D &v) {
-    return Vec2D{k * v.x, k * v.y};
-  }
-
-  Vec2D operator*(float b) const { return Vec2D{b * x, b * y}; }
-
-  T distance_squared(const Vec2D &other) const {
-    T dx = x - other.x;
-    T dy = y - other.y;
-    return dx * dx + dy * dy;
-  }
-
-  T distance(const Vec2D &other) const
-    requires std::floating_point<T>
-  {
-    return sqrt(distance_squared(other));
-  }
-
-  void normalize()
-    requires std::floating_point<T>
-  {
-    auto length = sqrt(x * x + y * y);
-    if (length < 1e-6) {
-      x = y = 0;
+template <typename T>
+  requires std::floating_point<T>
+static inline bool equalEpsilon(const T &a, const T &b) {
+  constexpr auto epsilon = []() {
+    if constexpr (std::is_same_v<T, float>) {
+      return T{1e-5};
     } else {
-      x /= length;
-      y /= length;
+      return T{1e-12}; // double, long double
     }
+  }();
+  if (a == b) {
+    // handle special cases: bit equality, Inf...
+    return true;
+  }
+  return std::abs(a - b) < epsilon;
+}
+
+struct Any {};
+
+template <typename T, size_t N, typename Tag = Any> class vec {
+
+  // Friend declaration for move constructor from different tag types
+  template <typename U, size_t M, typename OtherTag> friend class vec;
+
+public:
+  vec() : m_Array{} {}
+
+  template <typename... ArgsT>
+    requires(std::same_as<ArgsT, T> && ...) && (sizeof...(ArgsT) == N)
+  vec(ArgsT... args) : m_Array{args...} {}
+
+  vec(std::array<T, N> array) : m_Array{array} {}
+
+  template <typename OtherTag>
+  vec(vec<T, N, OtherTag> &&other) : m_Array{std::move(other.m_Array)} {}
+
+  //
+  // Access to elements & data
+  //
+
+  const T &operator[](size_t index) const {
+    // we leave run-time checks to the underlying std::array
+    return m_Array[index];
   }
 
-  Vec2D normalized()
-    requires std::floating_point<T>
-  {
-    Vec2D v(*this);
-    v.normalize();
-    return v;
+  T &operator[](size_t index) {
+    // we leave run-time checks to the underlying std::array
+    return m_Array[index];
   }
 
-  Vec2D orthogonal()
-  {
-    Vec2D v(*this);
-    
-    std::swap(v.x, v.y);
-    v.x = -v.x;
-    return v;
-  }
-
-  template <typename U> Vec2D(std::initializer_list<U> list) {
-    assert(list.size() == 2);
-    auto first_element = *list.begin();
-    auto second_element = *(list.begin() + 1);
-    x = static_cast<T>(first_element);
-    y = static_cast<T>(second_element);
-  }
-
-  T x, y;
-
-  friend std::ostream &operator<<(std::ostream &os, const Vec2D &obj) {
-    os << "( " << obj.x << ", " << obj.y << ")";
+  friend std::ostream &operator<<(std::ostream &os, const vec &obj) {
+    os << "( ";
+    for (const auto &element : obj.m_Array) {
+      os << element << " ";
+    }
+    os << ")";
     return os;
   }
+
+  std::array<T, N> &Data() { return m_Array; }
+
+  //
+  // binary operators
+  //
+
+  friend bool operator==(const vec &a, const vec &b)
+    requires(std::is_integral_v<T>)
+  {
+    return std::ranges::equal(a.m_Array, b.m_Array);
+  }
+
+  friend bool operator==(const vec &a, const vec &b)
+    requires(std::is_floating_point_v<T>)
+  {
+    for (const auto &[u, v] : std::views::zip(a.m_Array, b.m_Array)) {
+      if (!equalEpsilon(u, v)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  friend bool operator!=(const vec &a, const vec &b) { return !(a == b); }
+
+  friend vec operator+(const vec &a, const vec &b) {
+    vec<T, N, Tag> c;
+    std::ranges::transform(a.m_Array, b.m_Array, c.m_Array.begin(),
+                           std::plus{});
+    return c;
+  }
+
+  friend vec operator+(const vec &a, T b) {
+    vec<T, N, Tag> c;
+    std::ranges::transform(a.m_Array, std::views::repeat(b), c.m_Array.begin(),
+                           std::plus{});
+    return c;
+  }
+
+  friend vec operator-(const vec &a, const vec &b) {
+    vec<T, N, Tag> c;
+    std::ranges::transform(a.m_Array, b.m_Array, c.m_Array.begin(),
+                           std::minus{});
+    return c;
+  }
+
+  friend vec operator-(const vec &a, T b) {
+    vec<T, N, Tag> c;
+    std::ranges::transform(a.m_Array, std::views::repeat(b), c.m_Array.begin(),
+                           std::minus{});
+    return c;
+  }
+
+  friend vec operator*(const vec &a, const T &scalar) {
+    vec<T, N, Tag> c;
+    std::ranges::transform(a.m_Array, std::views::repeat(scalar),
+                           c.m_Array.begin(), std::multiplies{});
+    return c;
+  }
+
+  friend vec operator*(const T &scalar, const vec &a) { return a * scalar; }
+
+  friend vec operator/(const vec &a, const T &scalar) {
+    vec<T, N, Tag> c;
+    std::ranges::transform(a.m_Array, std::views::repeat(scalar),
+                           c.m_Array.begin(), std::divides{});
+    return c;
+  }
+
+  friend vec operator/(const vec &a, const vec &b) {
+    vec<T, N, Tag> c;
+    std::ranges::transform(a.m_Array, b.m_Array, c.m_Array.begin(),
+                           std::divides{});
+    return c;
+  }
+
+  //
+  // compound-assignment operators
+  //
+
+  vec &operator+=(const vec &b) {
+    vec &a = *this;
+    std::ranges::transform(a.m_Array, b.m_Array, a.m_Array.begin(),
+                           std::plus{});
+    return a;
+  }
+
+  vec &operator-=(const vec &b) {
+    vec &a = *this;
+    std::ranges::transform(a.m_Array, b.m_Array, a.m_Array.begin(),
+                           std::minus{});
+    return a;
+  }
+
+  vec &operator/=(float scalar) {
+    vec &a = *this;
+    auto b = std::views::repeat(scalar);
+    std::ranges::transform(a.m_Array, b, a.m_Array.begin(), std::divides{});
+    return a;
+  }
+
+  //
+  // Utility functions
+  //
+
+  T LengthSquared() const {
+    return std::transform_reduce(m_Array.begin(), m_Array.end(), T{},
+                                 std::plus{}, [](T x) { return x * x; });
+  }
+
+  T Length() const { return std::sqrt(LengthSquared()); }
+
+  T DistanceTo(const vec &b) const {
+    const vec &a = *this;
+    return (a - b).Length();
+  }
+
+  T DistanceSquared(const vec &b) const {
+    const vec &a = *this;
+    return (a - b).LengthSquared();
+  }
+
+  //
+  // In-place vector operations
+  //
+
+  void Normalize() {
+    T length = Length();
+    if (equalEpsilon(length, T{0}))
+      return;
+    std::ranges::transform(m_Array, std::views::repeat(length), m_Array.begin(),
+                           std::divides{});
+  }
+
+  //
+  // Methods returning new object
+  //
+
+  vec GetNormalized() const {
+    vec tmp = *this;
+    tmp.Normalize();
+    return tmp;
+  }
+
+  vec GetOrthogonal() const
+    requires(N == 2)
+  {
+    vec tmp = *this;
+
+    std::swap(tmp.m_Array[0], tmp.m_Array[1]);
+    tmp.m_Array[0] *= -1;
+
+    return tmp;
+  }
+
+  static T DotProduct(const vec &a, const vec &b) {
+    return std::inner_product(a.m_Array.begin(), a.m_Array.end(),
+                              b.m_Array.begin(), T{}, std::plus{},
+                              std::multiplies{});
+  }
+
+  T DotProduct(const vec &b) const {
+    const auto &a = *this;
+    return DotProduct(a, b);
+  }
+
+  //
+  // Helpers
+  //
+
+  const T &x() const
+    requires(N >= 1)
+  {
+    return m_Array[0];
+  }
+
+  T &x()
+    requires(N >= 1)
+  {
+    return m_Array[0];
+  }
+
+  const T &y() const
+    requires(N >= 2)
+  {
+    return m_Array[1];
+  }
+
+  T &y()
+    requires(N >= 2)
+  {
+    return m_Array[1];
+  }
+
+  const T &z() const
+    requires(N >= 3)
+  {
+    return m_Array[2];
+  }
+
+  T &z()
+    requires(N >= 3)
+  {
+    return m_Array[2];
+  }
+
+  template <typename TargetTag> vec<T, N, TargetTag> ChangeTag() const & {
+    return vec<T, N, TargetTag>(m_Array);
+  }
+
+  template <typename TargetTag> vec<T, N, TargetTag> ChangeTag() && {
+    return vec<T, N, TargetTag>(std::move(*this));
+  }
+
+  // Structured binding support for N == 2
+  template <size_t I>
+  const T &get() const
+    requires(N == 2 && I < 2)
+  {
+    return m_Array[I];
+  }
+
+  template <size_t I>
+  T &get()
+    requires(N == 2 && I < 2)
+  {
+    return m_Array[I];
+  }
+
+private:
+  std::array<T, N> m_Array;
+};
+
+//
+// Aliases
+//
+
+using vec2 = vec<float, 2>;
+using vec3 = vec<float, 3>;
+using vec4 = vec<float, 4>;
+using dvec2 = vec<double, 2>;
+using dvec3 = vec<double, 3>;
+using dvec4 = vec<double, 4>;
+using ivec2 = vec<std::int32_t, 2>;
+using ivec3 = vec<std::int32_t, 3>;
+using ivec4 = vec<std::int32_t, 4>;
+using uvec2 = vec<std::uint32_t, 2>;
+using uvec3 = vec<std::uint32_t, 3>;
+using uvec4 = vec<std::uint32_t, 4>;
+
+// tags for differentiating between domains
+struct WorldPosTag {};
+struct WorldSizeTag {};
+struct WindowPosTag {};
+struct WindowSizeTag {};
+struct TilePosTag {};
+struct TileSizeTag {};
+
+// types for each domain
+using WorldPos = vec<float, 2, WorldPosTag>;
+using WindowPos = vec<float, 2, WindowPosTag>;
+using TilePos = vec<int32_t, 2, TilePosTag>;
+// Size
+using WorldSize = vec<float, 2, WorldSizeTag>;
+using WindowSize = vec<float, 2, WindowSizeTag>;
+using TileSize = vec<int32_t, 2, TileSizeTag>;
+
+//
+// Utils
+//
+
+struct TilePosHash {
+  std::size_t operator()(const TilePos &p) const noexcept {
+    std::size_t h1 = std::hash<int>{}(p.x());
+    std::size_t h2 = std::hash<int>{}(p.y());
+    return h1 ^ (h2 + 0x9e3779b9 + (h1 << 6) + (h1 >> 2));
+  }
 };
 
-using TilePos = Vec2D<int>;
-using WorldPos = Vec2D<float>;
+//
+// Matrix
+//
+
+// Collumn major square matrix
+template <typename T, size_t N, typename Tag = Any> class Matrix {
+
+  using vec_type = vec<T, N, Tag>;
+
+public:
+  Matrix() = default;
+
+  // Initialization using flat array of N*N elements
+  template <typename Tarr, size_t M>
+    requires(M == N * N && std::same_as<Tarr, T>)
+  Matrix(std::array<Tarr, M> array) : m_Array{} {
+    std::size_t idx = 0;
+    for (auto col : array | std::views::chunk(N)) {
+      std::ranges::copy(col, m_Array[idx++].Data().begin());
+    }
+  }
+
+  const vec_type &operator[](size_t index) const { return m_Array[index]; }
+  vec_type &operator[](size_t index) { return m_Array[index]; }
+
+  friend std::ostream &operator<<(std::ostream &os, const Matrix &obj) {
+    os << "( ";
+    for (const auto &element : obj.m_Array) {
+      os << element << " ";
+    }
+    os << ")";
+    return os;
+  }
+
+  friend Matrix operator+(const Matrix &A, const Matrix &B) {
+    Matrix C;
+    std::ranges::transform(A.m_Array, B.m_Array, C.m_Array.begin(),
+                           std::plus{});
+    return C;
+  }
+
+  friend Matrix operator-(const Matrix &A, const Matrix &B) {
+    Matrix C;
+    std::ranges::transform(A.m_Array, B.m_Array, C.m_Array.begin(),
+                           std::minus{});
+    return C;
+  }
+
+  friend Matrix operator*(const Matrix &A, const Matrix &B) {
+    Matrix C;
+
+    for (size_t i = 0; i < N; i++) {
+      for (size_t j = 0; j < N; j++) {
+        T sum = 0;
+        for (size_t k = 0; k < N; ++k)
+          sum += A[i][k] * B[k][j];
+        C[i][j] = sum;
+      }
+    }
+    return C;
+  }
+
+  friend vec_type operator*(const Matrix &A, const vec_type &b) {
+    // we assume that b is row vector
+    vec_type c;
+    for (size_t i = 0; i < N; i++) {
+      c[i] = b.DotProduct(A[i]);
+    }
+    return c;
+  }
+
+  static constexpr Matrix Eye() {
+    Matrix E;
+    for (size_t i = 0; i < N; i++) {
+      E[i][i] = T{1};
+    }
+    return E;
+  }
+
+private:
+  std::array<vec_type, N> m_Array;
+};
+
+// Structured binding support for vec<T, 2, Tag>
+namespace std {
+template <typename T, typename Tag>
+struct tuple_size<vec<T, 2, Tag>> : integral_constant<size_t, 2> {};
+
+template <size_t I, typename T, typename Tag>
+struct tuple_element<I, vec<T, 2, Tag>> {
+  using type = T;
+};
+} // namespace std
+
+// ADL-based get for structured bindings
+template <size_t I, typename T, typename Tag>
+const T &get(const vec<T, 2, Tag> &v) {
+  return v.template get<I>();
+}
+
+template <size_t I, typename T, typename Tag> T &get(vec<T, 2, Tag> &v) {
+  return v.template get<I>();
+}

cpp/src/pathfinder.hpp

@@ -1,14 +0,0 @@
-#pragma once
-
-#include <vector>
-
-#include "math.hpp"
-
-namespace pathfinder {
-
-  using Path = std::vector<TilePos>;
-
-  class PathFinderBase {
-
-  };
-}

cpp/src/pathfinder/base.cpp

@@ -0,0 +1,23 @@
+#include <cassert>
+#include <memory>
+#include <queue>
+
+#include "pathfinder/base.hpp"
+
+#include "log.hpp"
+#include "math.hpp"
+
+namespace pathfinder {
+
+PathFinderBase::PathFinderBase(const Map *map) : m_Map(map) {}
+
+// LinearPathFinder also lives here, since it is too small to get it's
+// own implementation file
+Path LinearPathFinder::CalculatePath(
+    WorldPos, WorldPos end) // first argument (start pos) not used
+{
+  auto path = Path{end};
+  return path;
+}
+
+} // namespace pathfinder

cpp/src/pathfinder/base.hpp

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <memory>
+#include <unordered_map>
+#include <vector>
+
+#include "map.hpp"
+#include "math.hpp"
+
+namespace pathfinder {
+
+using Path = std::vector<WorldPos>;
+
+enum class PathFinderType {
+  LINEAR = 1,
+  BFS,
+  DIJKSTRA,
+  GBFS,
+  COUNT,
+};
+
+class PathFinderBase {
+public:
+  PathFinderBase(const Map *m);
+  virtual ~PathFinderBase() = default;
+
+  PathFinderBase(const PathFinderBase &) = delete;
+  PathFinderBase(PathFinderBase &&) = delete;
+  PathFinderBase &operator=(const PathFinderBase &) = delete;
+  PathFinderBase &operator=(PathFinderBase &&) = delete;
+
+  virtual const std::string_view &GetName() const = 0;
+  virtual Path CalculatePath(WorldPos start, WorldPos end) = 0;
+
+protected:
+  const Map *m_Map;
+};
+
+class LinearPathFinder final : public PathFinderBase {
+
+public:
+  LinearPathFinder(const Map *m) : PathFinderBase(m) {}
+  Path CalculatePath(WorldPos start, WorldPos end) override;
+  const std::string_view &GetName() const override { return m_Name; }
+
+private:
+  const std::string_view m_Name = "Linear Path";
+};
+
+} // namespace pathfinder

cpp/src/pathfinder/bfs.cpp

@@ -0,0 +1,67 @@
+#include <queue>
+
+#include "bfs.hpp"
+
+#include "base.hpp"
+#include "map.hpp"
+#include "math.hpp"
+
+namespace pathfinder {
+
+Path BFS::CalculatePath(WorldPos start_world, WorldPos end_world) {
+  if (m_Map == nullptr)
+    return {};
+
+  const TilePos start = m_Map->WorldToTile(start_world);
+  const TilePos end = m_Map->WorldToTile(end_world);
+
+  if (!m_Map->IsTilePosValid(start) || !m_Map->IsTilePosValid(end))
+    return {};
+  if (start == end) {
+    return {};
+  }
+  // clear previous run
+  m_CameFrom.clear();
+  m_Distance.clear();
+
+  std::queue<TilePos> frontier;
+  frontier.push(start);
+  m_CameFrom[start] = start;
+  m_Distance[start] = 0.0f;
+
+  // ---------------- build flow-field ----------------
+  bool early_exit = false;
+  while (!frontier.empty() && !early_exit) {
+    TilePos current = frontier.front();
+    frontier.pop();
+
+    for (TilePos next : m_Map->GetNeighbors(current)) {
+      if (m_CameFrom.find(next) == m_CameFrom.end()) { // not visited
+        frontier.push(next);
+        m_Distance[next] = m_Distance[current] + 1.0f;
+        m_CameFrom[next] = current;
+
+        if (next == end) { // early exit
+          early_exit = true;
+          break;
+        }
+      }
+    }
+  }
+
+  // --------------- reconstruct path -----------------
+  if (m_CameFrom.find(end) == m_CameFrom.end())
+    return {}; // end not reached
+
+  Path path;
+  TilePos cur = end;
+  path.push_back(m_Map->TileToWorld(cur));
+  while (cur != start) {
+    cur = m_CameFrom[cur];
+    path.push_back(m_Map->TileToWorld(cur));
+  }
+  std::reverse(path.begin(), path.end());
+  return path;
+}
+
+} // namespace pathfinder

cpp/src/pathfinder/bfs.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <string_view>
+#include <unordered_map>
+
+#include "base.hpp"
+
+#include "math.hpp"
+
+namespace pathfinder {
+
+class BFS final : public PathFinderBase {
+
+public:
+  BFS(const Map *m) : PathFinderBase(m) {}
+  Path CalculatePath(WorldPos start, WorldPos end) override;
+  const std::string_view &GetName() const override { return m_Name; }
+
+private:
+  const std::string_view m_Name = "Breadth First Search";
+  std::unordered_map<TilePos, double, TilePosHash> m_Distance;
+  std::unordered_map<TilePos, TilePos, TilePosHash> m_CameFrom;
+};
+
+} // namespace pathfinder

cpp/src/pathfinder/dijkstra.cpp

@@ -0,0 +1,71 @@
+#include <queue>
+
+#include "dijkstra.hpp"
+
+#include "base.hpp"
+#include "map.hpp"
+#include "math.hpp"
+#include "utils.hpp"
+
+namespace pathfinder {
+
+Path Dijkstra::CalculatePath(WorldPos start_world, WorldPos end_world) {
+  using QueueEntry = utils::QueueEntry;
+
+  if (!m_Map)
+    return {};
+
+  const TilePos start = m_Map->WorldToTile(start_world);
+  const TilePos end = m_Map->WorldToTile(end_world);
+
+  if (!m_Map->IsTilePosValid(start) || !m_Map->IsTilePosValid(end))
+    return {};
+  if (start == end)
+    return {};
+
+  // clear previous run
+  m_CameFrom.clear();
+  m_Cost.clear();
+
+  std::priority_queue<QueueEntry, std::vector<QueueEntry>, std::greater<>>
+      frontier;
+  frontier.push({0.0f, start});
+  m_CameFrom[start] = start; // sentinel
+  m_Cost[start] = 0.0f;
+
+  while (!frontier.empty()) {
+    const QueueEntry current = frontier.top();
+    frontier.pop();
+
+    if (current.tile == end) // early exit
+      break;
+
+    for (TilePos next : m_Map->GetNeighbors(current.tile)) {
+      // cost of moving to neighbour (uniform 1.0 matches original BFS)
+      const float newCost = m_Cost[current.tile] + m_Map->GetCost(next);
+
+      if (!m_Cost.count(next) || newCost < m_Cost[next]) {
+        m_Cost[next] = newCost;
+        m_CameFrom[next] = current.tile;
+        frontier.push({newCost, next});
+      }
+    }
+  }
+
+  // reconstruct path
+  if (!m_CameFrom.count(end))
+    return {}; // goal never reached
+
+  Path path;
+  TilePos cur = end;
+  path.push_back(m_Map->TileToWorld(cur));
+
+  while (cur != start) {
+    cur = m_CameFrom[cur];
+    path.push_back(m_Map->TileToWorld(cur));
+  }
+  std::reverse(path.begin(), path.end());
+  return path;
+}
+
+} // namespace pathfinder

cpp/src/pathfinder/dijkstra.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <string_view>
+#include <unordered_map>
+
+#include "base.hpp"
+
+#include "map.hpp"
+#include "math.hpp"
+
+namespace pathfinder {
+
+class Dijkstra final : public PathFinderBase {
+
+public:
+  Dijkstra(const Map *m) : PathFinderBase(m) {}
+  Path CalculatePath(WorldPos start, WorldPos end) override;
+  const std::string_view &GetName() const override { return m_Name; }
+
+private:
+  const std::string_view m_Name = "Dijkstra's Algorithm";
+  std::unordered_map<TilePos, double, TilePosHash> m_Cost;
+  std::unordered_map<TilePos, TilePos, TilePosHash> m_CameFrom;
+};
+
+} // namespace pathfinder

cpp/src/pathfinder/gbfs.cpp

@@ -0,0 +1,69 @@
+#include <queue>
+
+#include "gbfs.hpp"
+
+#include "base.hpp"
+#include "map.hpp"
+#include "math.hpp"
+#include "pathfinder/utils.hpp"
+
+namespace pathfinder {
+
+float GBFS::Heuristic(const TilePos &a, const TilePos &b) {
+  return static_cast<float>(std::abs(a.x() - b.x()) + std::abs(a.y() - b.y()));
+}
+
+Path GBFS::CalculatePath(WorldPos start_world, WorldPos end_world) {
+  using QueueEntry = pathfinder::utils::QueueEntry;
+
+  if (!m_Map)
+    return {};
+
+  const TilePos start = m_Map->WorldToTile(start_world);
+  const TilePos end = m_Map->WorldToTile(end_world);
+
+  if (!m_Map->IsTilePosValid(start) || !m_Map->IsTilePosValid(end))
+    return {};
+  if (start == end)
+    return {};
+
+  m_CameFrom.clear();
+
+  std::priority_queue<QueueEntry, std::vector<QueueEntry>, std::greater<>>
+      frontier;
+  frontier.push({Heuristic(start, end), start});
+  m_CameFrom[start] = start; // sentinel
+
+  while (!frontier.empty()) {
+    const QueueEntry current = frontier.top();
+    frontier.pop();
+
+    if (current.tile == end) // early exit
+      break;
+
+    for (TilePos next : m_Map->GetNeighbors(current.tile)) {
+      if (!m_CameFrom.count(next)) // not visited
+      {
+        m_CameFrom[next] = current.tile;
+        frontier.push({Heuristic(end, next), next});
+      }
+    }
+  }
+
+  // reconstruct path
+  if (!m_CameFrom.count(end))
+    return {}; // goal never reached
+
+  Path path;
+  TilePos cur = end;
+  path.push_back(m_Map->TileToWorld(cur));
+
+  while (cur != start) {
+    cur = m_CameFrom[cur];
+    path.push_back(m_Map->TileToWorld(cur));
+  }
+  std::reverse(path.begin(), path.end());
+  return path;
+}
+
+} // namespace pathfinder

cpp/src/pathfinder/gbfs.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <string_view>
+#include <unordered_map>
+
+#include "base.hpp"
+
+#include "map.hpp"
+#include "math.hpp"
+
+namespace pathfinder {
+
+class GBFS final : public PathFinderBase {
+
+public:
+  GBFS(const Map *m) : PathFinderBase(m) {}
+  Path CalculatePath(WorldPos start, WorldPos end) override;
+  const std::string_view &GetName() const override { return m_Name; }
+
+private:
+  static float Heuristic(const TilePos &a, const TilePos &b);
+  const std::string_view m_Name = "Greedy Best First Search";
+  std::unordered_map<TilePos, TilePos, TilePosHash> m_CameFrom;
+};
+
+} // namespace pathfinder

cpp/src/pathfinder/utils.cpp

@@ -0,0 +1,35 @@
+#include <memory>
+
+#include "utils.hpp"
+
+#include "base.hpp"
+#include "log.hpp"
+#include "map.hpp"
+#include "math.hpp"
+#include "pathfinder/bfs.hpp"
+#include "pathfinder/dijkstra.hpp"
+#include "pathfinder/gbfs.hpp"
+
+namespace pathfinder {
+namespace utils {
+
+std::unique_ptr<PathFinderBase> create(PathFinderType type, const Map *map) {
+  using namespace pathfinder;
+  switch (type) {
+  case PathFinderType::LINEAR:
+    return std::make_unique<LinearPathFinder>(map);
+  case PathFinderType::BFS:
+    return std::make_unique<BFS>(map);
+  case PathFinderType::DIJKSTRA:
+    return std::make_unique<Dijkstra>(map);
+  case PathFinderType::GBFS:
+    return std::make_unique<GBFS>(map);
+  case PathFinderType::COUNT:
+    LOG_WARNING("Incorrect pathfinder type");
+    return nullptr;
+  };
+  return nullptr;
+}
+
+} // namespace utils
+} // namespace pathfinder

cpp/src/pathfinder/utils.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <memory>
+
+#include "pathfinder/base.hpp"
+
+#include "map.hpp"
+#include "math.hpp"
+
+namespace pathfinder {
+namespace utils {
+
+struct QueueEntry {
+  float cost;
+  TilePos tile;
+
+  // min-heap -> smallest cost on top
+  bool operator>(const QueueEntry &o) const noexcept { return cost > o.cost; }
+};
+
+std::unique_ptr<pathfinder::PathFinderBase>
+create(pathfinder::PathFinderType type, const Map *map);
+
+} // namespace utils
+} // namespace pathfinder

cpp/src/pathfindingdemo.cpp

@@ -8,64 +8,123 @@
 #include "entities.hpp"
 #include "log.hpp"
 #include "map.hpp"
+#include "pathfinder/base.hpp"
+#include "pathfinder/utils.hpp"
+#include "tile.hpp"
 #include "user_input.hpp"
 
 PathFindingDemo::PathFindingDemo(int width, int height) : m_Map(width, height) {
   LOG_DEBUG(".");
+  // set default pathfinder method
+  m_PathFinder = pathfinder::utils::create(pathfinder::PathFinderType::DIJKSTRA,
+                                           (const Map *)&m_Map);
 }
 
 PathFindingDemo::~PathFindingDemo() { LOG_DEBUG("."); }
 
 void PathFindingDemo::AddEntity(std::shared_ptr<Entity> e) {
-  // TODO emplace_back
   m_Entities.push_back(e);
 }
 
 void PathFindingDemo::CreateMap() {
+  // lake
+  m_Map.PaintCircle(TilePos{50, 50}, 10, TileType::WATER);
+  m_Map.PaintCircle(TilePos{75, 100}, 50, TileType::WATER);
+  // river
+  m_Map.PaintLine(TilePos{0, 0}, TilePos{100, 100}, 3.0, TileType::WATER);
+  // road
+  m_Map.PaintLine(TilePos{17, 6}, TilePos{100, 6}, 5.0, TileType::ROAD);
+  m_Map.PaintLine(TilePos{10, 17}, TilePos{10, 100}, 5.0, TileType::ROAD);
+  m_Map.PaintLine(TilePos{20, 10}, TilePos{10, 20}, 5.0, TileType::ROAD);
+  // bridges
+  m_Map.PaintLine(TilePos{50, 75}, TilePos{70, 75}, 5.0, TileType::WOOD);
+  m_Map.PaintLine(TilePos{95, 26}, TilePos{95, 60}, 5.0, TileType::WOOD);
+  // island
+  m_Map.PaintRectangle(TilePos{70, 60}, TilePos{100, 100}, TileType::GRASS);
+  // walls
+  m_Map.PaintLine(TilePos{71, 60}, TilePos{90, 60}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{77, 67}, TilePos{100, 67}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{71, 60}, TilePos{71, 75}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{72, 73}, TilePos{95, 73}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{95, 73}, TilePos{95, 90}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{71, 81}, TilePos{71, 100}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{72, 81}, TilePos{90, 81}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{89, 87}, TilePos{89, 100}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{84, 81}, TilePos{84, 96}, 1.0, TileType::WALL);
+  m_Map.PaintLine(TilePos{78, 87}, TilePos{78, 100}, 1.0, TileType::WALL);
+
+  // add some controllable entities
   m_Entities.clear();
-  m_Player = std::make_shared<Player>();
-  m_Player->SetPosition(WorldPos{200.0f, 200.0f});
-  m_Entities.push_back(m_Player);
+  auto player = std::make_shared<Player>();
+  player->SetPosition(m_Map.TileToWorld(TilePos{25, 20}));
+  AddEntity(player);
+
+  auto player2 = std::make_shared<Player>();
+  player2->SetPosition(m_Map.TileToWorld(TilePos{50, 20}));
+  AddEntity(player2);
 }
 
 WorldPos PathFindingDemo::GetRandomPosition() const {
-  return WorldPos{0.0, 0.0};
+  return WorldPos{0.0f, 0.0f}; // totally random!
 }
 
-std::optional<WorldPos> PathFindingDemo::GetMoveTarget() {
-  WorldPos current_player_pos = GetPlayer()->GetPosition();
+const std::vector<Collision> &PathFindingDemo::GetEntityCollisions() {
+  static std::vector<Collision> m_Collisions;
+  m_Collisions.clear();
 
-  if (m_MoveQueue.empty()) {
-    return {};
+  for (const auto &entity_A : m_Entities) {
+    for (const auto &entity_B : m_Entities) {
+      if (entity_A == entity_B)
+        continue;
+      if (!entity_A->IsCollidable() || !entity_B->IsCollidable())
+        continue;
+      if (entity_A->CollidesWith(*entity_B)) {
+        // handle collision logic
+        m_Collisions.emplace_back(Collision(entity_A, entity_B));
+      }
+    }
   }
-
-  WorldPos next_player_pos = m_MoveQueue.front();
-
-  if (current_player_pos.distance(next_player_pos) > 10.0) {
-    // target not reached yet
-    return next_player_pos;
-  }
-  // target reached, pop it
-  m_MoveQueue.pop();
-  // return nothing - we'll get the next value in the next iteration
-  return {};
+  return m_Collisions;
 }
 
-void PathFindingDemo::UpdatePlayerVelocity() {
-  auto player = GetPlayer();
-  auto current_pos = player->GetPosition();
-  double tile_velocity_coeff = m_Map.GetTileVelocityCoeff(current_pos);
-  auto next_pos = GetMoveTarget();
-  auto velocity = WorldPos{};
-  if (next_pos) {
-    velocity = next_pos.value() - current_pos;
-    velocity.normalize();
-    LOG_DEBUG("I want to move to: ", next_pos.value(),
-              ", velocity: ", velocity);
-  }
-  player->SetActualVelocity(velocity * tile_velocity_coeff);
+// Update entity positions, handle collisions
+void PathFindingDemo::UpdateWorld() {
+
   float time_delta = 1.0f;
-  player->Update(time_delta);
+
+  for (auto &entity : m_Entities) {
+    // calculate the velocity
+    auto current_pos = entity->GetPosition();
+    double tile_velocity_coeff = m_Map.GetTileVelocityCoeff(current_pos);
+    auto next_pos = entity->GetMoveTarget();
+    WorldPos velocity = WorldPos{};
+    if (next_pos) {
+      velocity = next_pos.value() - current_pos;
+      velocity.Normalize();
+      // LOG_DEBUG("I want to move to: ", next_pos.value(),
+      //           ", velocity: ", velocity);
+    }
+    entity->SetActualVelocity(velocity * tile_velocity_coeff);
+
+    for (const auto &collision : GetEntityCollisions()) {
+      auto weak_A = std::get<0>(collision);
+      auto weak_B = std::get<1>(collision);
+      auto A = weak_A.lock();
+      auto B = weak_B.lock();
+      if (A == nullptr || B == nullptr) {
+        continue;
+      }
+      if (!A->IsMovable())
+        continue;
+      // modify actual speed
+      // LOG_DEBUG("Collision: A is ", A, ", B is ", B);
+      auto AB = B->GetPosition() - A->GetPosition();
+      A->ZeroActualVelocityInDirection(AB);
+    }
+
+    // update the position
+    entity->Update(time_delta);
+  }
 }
 
 void PathFindingDemo::HandleActions(const std::vector<UserAction> &actions) {
@@ -73,19 +132,84 @@ void PathFindingDemo::HandleActions(const std::vector<UserAction> &actions) {
     if (action.type == UserAction::Type::EXIT) {
       LOG_INFO("Exit requested");
       m_ExitRequested = true;
-    } else if (action.type == UserAction::Type::FIRE) {
-      LOG_INFO("Fire");
-      // AddEntity(m_Player->CreateBomb());
-    } else if (action.type == UserAction::Type::MOVE) {
-      LOG_INFO("Move direction ", action.Argument.position);
-      m_Player->SetRequestedVelocity(action.Argument.position * 4.0f);
-    } else if (action.type == UserAction::Type::MOVE_TARGET) {
-      WorldPos wp = action.Argument.position;
-      TilePos p = m_Map.WorldToTile(wp);
-      LOG_INFO("Clearing current move queue and inserting new target: ", wp);
-      std::queue<WorldPos> empty;
-      std::swap(empty, m_MoveQueue);
-      m_MoveQueue.push(wp);
+    } else if (action.type == UserAction::Type::SET_MOVE_TARGET) {
+      WorldPos target_pos =
+          m_Camera.WindowToWorld(std::get<WindowPos>(action.Argument));
+      for (auto &selected_entity : m_SelectedEntities) {
+        LOG_INFO("Calculating path to target: ", target_pos);
+        if (auto sp = selected_entity.lock()) {
+          auto path =
+              m_PathFinder->CalculatePath(sp->GetPosition(), target_pos);
+          sp->SetPath(path);
+          LOG_INFO("Done, path node count: ", path.size());
+        } else {
+          LOG_INFO("Cannot calculate path for destroyed entity "
+                   "(weak_ptr.lock() failed)");
+        }
+      }
+    } else if (action.type == UserAction::Type::SELECT_PATHFINDER) {
+      using namespace pathfinder;
+      PathFinderType type =
+          static_cast<PathFinderType>(std::get<int32_t>(action.Argument));
+      m_PathFinder = pathfinder::utils::create(type, (const Map *)&m_Map);
+      LOG_INFO("Switched to path finding method: ", m_PathFinder->GetName());
+    } else if (action.type == UserAction::Type::CAMERA_PAN) {
+      const auto &window_pan = std::get<WindowPos>(action.Argument);
+      WorldPos world_pan{window_pan.x(), window_pan.y()};
+      m_Camera.Pan(world_pan);
+      LOG_INFO("Camera pan delta: ", world_pan);
+    } else if (action.type == UserAction::Type::CAMERA_ZOOM) {
+      m_Camera.Zoom(std::get<float>(action.Argument));
+      LOG_INFO("Camera zoom: ", std::get<float>(action.Argument));
+    } else if (action.type == UserAction::Type::SELECTION_START) {
+      m_SelectionBox.active = true;
+      m_SelectionBox.start = std::get<WindowPos>(action.Argument);
+      m_SelectionBox.end = std::get<WindowPos>(action.Argument);
+    } else if (action.type == UserAction::Type::SELECTION_END) {
+      m_SelectionBox.end = std::get<WindowPos>(action.Argument);
+      m_SelectionBox.active = false;
+      auto diff = m_SelectionBox.end - m_SelectionBox.start;
+      // here we explicitly change the vector type from WindowPos to WindowSize
+      m_SelectionBox.size = diff.ChangeTag<WindowSizeTag>();
+      WorldPos start = m_Camera.WindowToWorld(m_SelectionBox.start);
+      WorldPos end = m_Camera.WindowToWorld(m_SelectionBox.end);
+      SelectEntitiesInRectangle(start, end);
+    } else if (action.type == UserAction::Type::SELECTION_CHANGE) {
+      m_SelectionBox.end = std::get<WindowPos>(action.Argument);
+      auto diff = m_SelectionBox.end - m_SelectionBox.start;
+      m_SelectionBox.size = diff.ChangeTag<WindowSizeTag>();
     }
   };
 }
+
+void PathFindingDemo::DeselectEntities() {
+  std::for_each(m_SelectedEntities.begin(), m_SelectedEntities.end(),
+                [](auto &x) {
+                  if (auto entity = x.lock())
+                    entity->Deselect();
+                });
+  m_SelectedEntities.clear();
+}
+
+void PathFindingDemo::SelectEntitiesInRectangle(WorldPos A, WorldPos B) {
+  DeselectEntities();
+  auto [x_min, x_max] = std::minmax(A.x(), B.x());
+  auto [y_min, y_max] = std::minmax(A.y(), B.y());
+  for (const auto &entity : m_Entities) {
+    const auto &pos = entity->GetPosition();
+    bool x_in_range = x_min < pos.x() && pos.x() < x_max;
+    bool y_in_range = y_min < pos.y() && pos.y() < y_max;
+    if (x_in_range && y_in_range) {
+      m_SelectedEntities.push_back(std::weak_ptr(entity));
+      entity->Select();
+    }
+  }
+  LOG_INFO("Selected ", m_SelectedEntities.size(), " entities");
+}
+
+std::pair<WindowPos, WindowSize> PathFindingDemo::GetSelectionBoxPosSize() {
+  const auto &pos = m_SelectionBox.start;
+  WindowPos size_pos = m_SelectionBox.end - m_SelectionBox.start;
+  WindowSize size = size_pos.ChangeTag<WindowSizeTag>();
+  return std::pair(pos, size);
+}

cpp/src/pathfindingdemo.hpp

@@ -5,11 +5,21 @@
 #include <queue>
 #include <vector>
 
+#include "camera.hpp"
 #include "entities.hpp"
 #include "log.hpp"
 #include "map.hpp"
+#include "pathfinder/base.hpp"
 #include "user_input.hpp"
 
+using Collision = std::pair<std::weak_ptr<Entity>, std::weak_ptr<Entity>>;
+
+struct SelectionBox {
+  WindowPos start, end;
+  WindowSize size;
+  bool active;
+};
+
 class PathFindingDemo {
 public:
   PathFindingDemo(int width, int height);
@@ -20,22 +30,33 @@ public:
   PathFindingDemo &operator=(const PathFindingDemo &) = delete;
   PathFindingDemo &operator=(PathFindingDemo &&) = delete;
 
-  std::shared_ptr<Player> GetPlayer() { return m_Player; }
   std::vector<std::shared_ptr<Entity>> &GetEntities() { return m_Entities; }
   const Map &GetMap() const { return m_Map; }
+  const Camera &GetCamera() const { return m_Camera; }
   bool IsExitRequested() const { return m_ExitRequested; }
 
   void AddEntity(std::shared_ptr<Entity> e);
   void CreateMap();
-  std::optional<WorldPos> GetMoveTarget();
-  void UpdatePlayerVelocity();
+  void UpdateWorld();
   void HandleActions(const std::vector<UserAction> &actions);
   WorldPos GetRandomPosition() const;
 
+  void SelectEntitiesInRectangle(WorldPos A, WorldPos B);
+  void DeselectEntities();
+  bool IsSelectionBoxActive() const { return m_SelectionBox.active; }
+  std::pair<WindowPos, WindowSize> GetSelectionBoxPosSize();
+  std::vector<std::weak_ptr<Entity>> GetSelectedEntities() {
+    return m_SelectedEntities;
+  }
+
 private:
+  const std::vector<Collision> &GetEntityCollisions();
+
   bool m_ExitRequested = false;
-  std::vector<std::shared_ptr<Entity>> m_Entities;
-  std::shared_ptr<Player> m_Player;
-  std::queue<WorldPos> m_MoveQueue;
   Map m_Map;
+  Camera m_Camera;
+  std::vector<std::shared_ptr<Entity>> m_Entities;
+  std::unique_ptr<pathfinder::PathFinderBase> m_PathFinder;
+  std::vector<std::weak_ptr<Entity>> m_SelectedEntities;
+  SelectionBox m_SelectionBox;
 };

cpp/src/positional_container.hpp

@@ -0,0 +1,203 @@
+#pragma once
+
+#include <algorithm>
+#include <cmath>
+#include <cstdlib>
+#include <iterator>
+#include <memory>
+#include <vector>
+
+#include "log.hpp"
+#include "math.hpp"
+
+template <typename T>
+concept HasPosition = requires(T t, WorldPos pos) {
+  { t.GetPosition() } -> std::convertible_to<WorldPos>;
+  t.SetPosition(pos);
+};
+
+template <typename T>
+  requires HasPosition<T>
+
+class IPositionalContainer {
+public:
+  virtual ~IPositionalContainer() = default;
+  virtual bool Add(std::shared_ptr<T> t) = 0;
+  virtual std::vector<std::weak_ptr<T>> Get(const WorldPos &p,
+                                            float radius) = 0;
+  virtual void UpdateAll() = 0;
+  virtual void Update(std::shared_ptr<T> item) = 0;
+};
+
+template <typename T>
+class IColliderContainer : public IPositionalContainer<T> {
+public:
+  virtual std::vector<std::weak_ptr<T>> GetCollisions() = 0;
+};
+
+template <typename T> class SimpleContainer : IPositionalContainer<T> {
+public:
+  bool Add(std::shared_ptr<T> t) override {
+    m_Items.push_back(t);
+    return true;
+  }
+
+  std::vector<std::weak_ptr<T>> Get(const WorldPos &center,
+                                    float radius) override {
+    std::vector<std::weak_ptr<T>> matched_items;
+    for (const auto &item : m_Items) {
+      if (center.DistanceTo(item->GetPosition()) < radius) {
+        matched_items.push_back(item);
+      }
+    }
+    return matched_items;
+  }
+
+  // no update needed here, as we have no smart lookup scheme
+  void UpdateAll() override {}
+  void Update(std::shared_ptr<T>) override {}
+
+private:
+  std::vector<std::shared_ptr<T>> m_Items;
+};
+
+template <class T> class PositionalContainer : IPositionalContainer<T> {
+public:
+  PositionalContainer(const WorldSize &size, size_t chunks)
+      : m_GridSize{size}, m_GridStep{size / chunks}, m_ChunksPerAxis{chunks} {
+    LOG_INFO("Size: ", m_GridSize, " step: ", m_GridStep);
+    m_Grid.reserve(chunks);
+    for (size_t i = 0; i < chunks; i++) {
+      m_Grid.emplace_back(chunks);
+      for (size_t j = 0; j < chunks; j++) {
+        m_Grid[i][j].reserve(16);
+      }
+    }
+  }
+
+  // calling Add on object that is already in the container is UB
+  bool Add(std::shared_ptr<T> item) override {
+    const auto &world_pos = item->GetPosition();
+    if (!CheckBounds(world_pos)) {
+      return false;
+    }
+    m_Items.push_back(item);
+    auto coords = GetCoords(world_pos);
+    m_Grid[coords.x()][coords.y()].push_back(item);
+    m_ReverseGridLookup[item] = coords;
+    return true;
+  }
+
+  std::vector<std::weak_ptr<T>> Get(const WorldPos &center,
+                                    float radius) override {
+    vector_wptr output_vec{};
+
+    Get(output_vec, center, radius);
+
+    return output_vec;
+  }
+
+  void Get(std::vector<std::weak_ptr<T>> &output_vec, const WorldPos &corner,
+           const WorldSize &size) {
+    const WorldSize half_size = size / 2.0f;
+    const WorldPos center = corner + half_size.ChangeTag<WorldPos>();
+    float radius = half_size.x();
+    Get(output_vec, center, radius);
+  }
+
+  void Get(std::vector<std::weak_ptr<T>> &output_vec, const WorldPos &center,
+           float radius) {
+    output_vec.clear();
+    const WorldPos corner_1 = center + radius;
+    const WorldPos corner_2 = center - radius;
+
+    const auto A = GetCoords(corner_1);
+    const auto B = GetCoords(corner_2);
+
+    auto [x_min_f, x_max_f] = std::minmax(A.x(), B.x());
+    auto [y_min_f, y_max_f] = std::minmax(A.y(), B.y());
+
+    size_t x_min = static_cast<size_t>(std::floor(x_min_f));
+    size_t x_max = static_cast<size_t>(std::ceil(x_max_f));
+    size_t y_min = static_cast<size_t>(std::floor(y_min_f));
+    size_t y_max = static_cast<size_t>(std::ceil(y_max_f));
+
+    for (size_t x = x_min; x <= x_max; x++) {
+      for (size_t y = y_min; y <= y_max; y++) {
+        if (!CheckBounds(x, y)) {
+          continue;
+        }
+        for (auto item_wptr : m_Grid[x][y]) {
+          if (auto shared = item_wptr.lock()) {
+            if (center.DistanceTo(shared->GetPosition()) < radius) {
+              output_vec.push_back(item_wptr);
+            }
+          }
+        }
+      }
+    }
+  }
+
+  void UpdateAll() override {
+    for (auto ptr : m_Items) {
+      Update(ptr);
+    }
+  }
+  void Update(std::shared_ptr<T> item) override {
+    coord_type current_coords = GetCoords(item->GetPosition());
+    coord_type last_known_coords = m_ReverseGridLookup[item];
+    if (current_coords == last_known_coords) {
+      return;
+    }
+    vector_wptr &vec = m_Grid[last_known_coords.x()][last_known_coords.y()];
+    // remove the old weak ptr from the map
+    vec.erase(std::remove_if(vec.begin(), vec.end(),
+                             [&](const std::weak_ptr<T> &w) {
+                               return !w.owner_before(item) &&
+                                      !item.owner_before(w);
+                             }),
+              vec.end());
+    // add new weak ptr to the map
+    m_Grid[current_coords.x()][current_coords.y()].push_back(item);
+  }
+
+private:
+  using coord_type = vec<size_t, 2>;
+  using vector_wptr = std::vector<std::weak_ptr<T>>;
+  using grid_type = std::vector<std::vector<vector_wptr>>;
+
+  coord_type GetCoords(const WorldPos &wp) {
+    auto coord_float = wp / m_GridStep.ChangeTag<WorldPos>();
+    return coord_type{static_cast<size_t>(coord_float.x()),
+                      static_cast<size_t>(coord_float.y())};
+  }
+
+  bool CheckBounds(size_t x, size_t y) const {
+    bool x_in_bounds = x < m_Grid.size();
+    bool y_in_bounds = y < m_Grid.size();
+    return x_in_bounds && y_in_bounds;
+  }
+
+  bool CheckBounds(const WorldPos &pos) const {
+    auto [x, y] = pos;
+    bool x_in_bounds = 0.0f < x && x < m_GridSize.x();
+    bool y_in_bounds = 0.0f < y && y < m_GridSize.y();
+    return x_in_bounds && y_in_bounds;
+  }
+
+  WorldSize m_GridSize;
+  WorldSize m_GridStep;
+  size_t m_ChunksPerAxis;
+  std::vector<std::shared_ptr<T>> m_Items;
+  grid_type m_Grid;
+
+  // normal  lookup: WorldPos -> coord_type -> vector_wptr -> std::shared_ptr<T>
+  // reverse lookup: std::shared_ptr<T> -> vector_wptr -> coord_type
+  // we need the reverse lookup because T.GetPosition() may change and we need
+  // to delete the old weak_ptr from vector_wptr (without iterating through all
+  // of them). Also it might be useful to have T -> location lookup Note: hash
+  // of std::shared_ptr<T> may give us trouble if we free the memory and new one
+  // points to the same location, maybe it would be better to hash the object
+  // itself? NOTE how about using counting bloom filter for this?
+  std::unordered_map<std::shared_ptr<T>, coord_type> m_ReverseGridLookup;
+};

cpp/src/sprite.cpp

@@ -12,13 +12,13 @@
 
 Sprite::Sprite() : m_Texture(nullptr, SDL_DestroyTexture) {}
 
-Sprite::Sprite(std::string path, Vec2D<float> center) : Sprite() {
+Sprite::Sprite(std::string path, WorldPos center) : Sprite() {
   LoadImage(path, center);
 }
 
 Sprite::~Sprite() { LOG_DEBUG("."); }
 
-void Sprite::LoadImage(std::string path, Vec2D<float> image_center) {
+void Sprite::LoadImage(std::string path, WorldPos image_center) {
   LOG_INFO("Loading image ", path);
   assert(m_Renderer != nullptr);
 
@@ -26,7 +26,7 @@ void Sprite::LoadImage(std::string path, Vec2D<float> image_center) {
       IMG_Load(path.c_str()), SDL_DestroySurface);
 
   if (surface == nullptr) {
-    LOG_ERROR("IMG_Load failed to load ", path);
+    LOG_ERROR("IMG_Load failed: ", SDL_GetError());
     throw std::runtime_error("Failed to load resources");
   }
 

cpp/src/sprite.hpp

@@ -14,7 +14,7 @@ class Sprite {
 public:
   Sprite();
   ~Sprite();
-  explicit Sprite(std::string path, WorldPos center = {0, 0});
+  explicit Sprite(std::string path, WorldPos center = WorldPos{});
 
   Sprite(const Sprite &) = delete;
   Sprite &operator=(const Sprite &) = delete;
@@ -25,15 +25,15 @@ public:
 
   // GetTexture cannot return pointer to const, as SDL_RenderTexture modifies it
   SDL_Texture *GetTexture() { return m_Texture.get(); }
-  WorldPos GetSize() const { return m_Size; }
+  WorldSize GetSize() const { return m_Size; }
   WorldPos GetCenter() const { return m_ImageCenter; }
 
-  void LoadImage(std::string path, WorldPos image_center = {0.0, 0.0});
+  void LoadImage(std::string path, WorldPos image_center = WorldPos{});
 
 private:
   static std::shared_ptr<SDL_Renderer> m_Renderer;
   std::unique_ptr<SDL_Texture, decltype(&SDL_DestroyTexture)> m_Texture;
-  WorldPos m_Size;
+  WorldSize m_Size;
   WorldPos m_ImageCenter;
   float m_TextureWidth = 0;
   float m_TextureHeight = 0;

cpp/src/tile.cpp

@@ -1,8 +1,14 @@
+#include <array>
+#include <unordered_map>
+
 #include "tile.hpp"
 
-const std::map<std::string_view, Tile> tile_types = {
-    {"Grass", {1.0, 0, 200, 0, 255}},
-    {"Mud", {2.0, 100, 100, 100, 255}},
-    {"Road", {0.5, 200, 200, 200, 255}},
-    {"Water", {10.0, 0, 50, 200, 255}},
+// we could use array here, but this is more explicit,
+// and we don't access tile_types that often, so it should be ok
+const std::unordered_map<TileType, Tile> tile_types = {
+    {TileType::GRASS, Tile{1.0, 0, 200, 0, 255}},
+    {TileType::WOOD, Tile{1.0, 132, 68, 0, 255}},
+    {TileType::ROAD, Tile{0.5, 20, 20, 20, 255}},
+    {TileType::WATER, Tile{10.0, 0, 50, 200, 255}},
+    {TileType::WALL, Tile{1000.0, 144, 33, 0, 255}},
 };

cpp/src/tile.hpp

@@ -1,12 +1,22 @@
 #pragma once
 
+#include <array>
 #include <cstdint>
 #include <map>
 #include <string_view>
+#include <unordered_map>
 
 struct Tile {
   float cost;
   uint8_t R, G, B, A;
 };
 
-extern const std::map<std::string_view, Tile> tile_types;
+enum class TileType {
+  GRASS,
+  WOOD,
+  ROAD,
+  WATER,
+  WALL,
+};
+
+extern const std::unordered_map<TileType, Tile> tile_types;

cpp/src/user_input.cpp

@@ -2,6 +2,7 @@
 #include <expected>
 #include <map>
 #include <string>
+#include <unordered_set>
 #include <vector>
 
 #include "user_input.hpp"
@@ -19,73 +20,105 @@ UserInput::~UserInput() { LOG_DEBUG("."); };
 
 std::expected<void, std::string> UserInput::Init() { return {}; }
 
+void UserInput::GetActions_mouse(const SDL_Event &event) {
+  static bool mouse_pan = false;
+
+  SDL_MouseButtonEvent mouse_event = event.button;
+  MouseButton button = static_cast<MouseButton>(mouse_event.button);
+
+  if (event.type == SDL_EVENT_MOUSE_BUTTON_DOWN) {
+    if (button == MouseButton::LEFT) {
+      LOG_DEBUG("Selection start at ", mouse_event.x, ", ", mouse_event.y);
+      m_SelectionActive = true;
+      m_Actions.emplace_back(UserAction::Type::SELECTION_START,
+                             WindowPos{mouse_event.x, mouse_event.y});
+    } else if (button == MouseButton::RIGHT) {
+      LOG_DEBUG("Set move target to: ", mouse_event.x, ", ", mouse_event.y);
+      m_Actions.emplace_back(UserAction::Type::SET_MOVE_TARGET,
+                             WindowPos{mouse_event.x, mouse_event.y});
+    } else if (button == MouseButton::MIDDLE) {
+      mouse_pan = true;
+    }
+  } else if (event.type == SDL_EVENT_MOUSE_BUTTON_UP) {
+    if (button == MouseButton::LEFT) {
+      LOG_DEBUG("Selection end at ", mouse_event.x, ", ", mouse_event.y);
+      m_SelectionActive = false;
+      m_Actions.emplace_back(UserAction::Type::SELECTION_END,
+                             WindowPos{mouse_event.x, mouse_event.y});
+    }
+    if (button == MouseButton::MIDDLE) {
+      mouse_pan = false;
+    }
+  } else if (event.type == SDL_EVENT_MOUSE_MOTION) {
+    SDL_MouseMotionEvent motion_event = event.motion;
+    if (mouse_pan) {
+      m_Actions.emplace_back(UserAction::Type::CAMERA_PAN,
+                             WindowPos{motion_event.xrel, motion_event.yrel});
+    }
+    if (m_SelectionActive) {
+      m_Actions.emplace_back(UserAction::Type::SELECTION_CHANGE,
+                             WindowPos{mouse_event.x, mouse_event.y});
+    }
+  } else if (event.type == SDL_EVENT_MOUSE_WHEEL) {
+    SDL_MouseWheelEvent mouse_wheel = event.wheel;
+    m_Actions.emplace_back(UserAction::Type::CAMERA_ZOOM, mouse_wheel.y);
+  }
+}
+
+void UserInput::GetActions_keyboard(const SDL_Event &event) {
+  bool key_down = event.type == SDL_EVENT_KEY_DOWN ? true : false;
+  SDL_KeyboardEvent kbd_event = event.key;
+  if (kbd_event.repeat) {
+    // SDL repeats KEY_DOWN if key is held down, we ignore that
+    return;
+  }
+  LOG_DEBUG("Key '", static_cast<char>(kbd_event.key),
+            key_down ? "' down" : "' up");
+
+  switch (kbd_event.key) {
+  case 'q':
+    m_Actions.emplace_back(UserAction::Type::EXIT);
+    return;
+  case '1':
+  case '2':
+  case '3':
+  case '4':
+    if (key_down) {
+      int selection = kbd_event.key - '0';
+      m_Actions.emplace_back(UserAction::Type::SELECT_PATHFINDER, selection);
+      LOG_INFO("Pathfinder selected: ", selection);
+    }
+    break;
+  default:
+    LOG_INFO("Key '", static_cast<char>(kbd_event.key), "' not mapped");
+    break;
+  }
+}
+
 const std::vector<UserAction> &UserInput::GetActions() {
-  m_Actions.clear();
-  static WorldPos move_direction = {0.0f, 0.0f};
-  static bool send_move_action = false;
+
+  static std::unordered_set<uint32_t> mouse_events = {
+      SDL_EVENT_MOUSE_MOTION,    SDL_EVENT_MOUSE_BUTTON_DOWN,
+      SDL_EVENT_MOUSE_BUTTON_UP, SDL_EVENT_MOUSE_WHEEL,
+      SDL_EVENT_MOUSE_ADDED,     SDL_EVENT_MOUSE_REMOVED,
+  };
+
+  static std::unordered_set<uint32_t> keyboard_events = {
+      SDL_EVENT_KEY_DOWN,
+      SDL_EVENT_KEY_UP,
+  };
+
   SDL_Event event;
+  m_Actions.clear();
 
   while (SDL_PollEvent(&event)) {
-    if (event.type == SDL_EVENT_KEY_DOWN || event.type == SDL_EVENT_KEY_UP) {
-      bool key_down = event.type == SDL_EVENT_KEY_DOWN ? true : false;
-      SDL_KeyboardEvent kbd_event = event.key;
-      if (kbd_event.repeat) {
-        // SDL repeats KEY_DOWN if key is held down, we ignore that
-        continue;
-      }
-      LOG_DEBUG("Key '", static_cast<char>(kbd_event.key),
-                key_down ? "' down" : "' up");
-
-      switch (kbd_event.key) {
-      case 'q':
-        m_Actions.emplace_back(UserAction::Type::EXIT);
-        // further processing of inputs is not needed
-        return m_Actions;
-      case 'w':
-      case 's':
-      case 'a':
-      case 'd':
-      case SDLK_UP:
-      case SDLK_DOWN:
-      case SDLK_LEFT:
-      case SDLK_RIGHT: {
-        static std::map<char, WorldPos> move_base{
-            {'w', {0.0, 1.0}},
-            {'s', {0.0, -1.0}},
-            {'a', {1.0, 0.0}},
-            {'d', {-1.0, 0.0}},
-            {static_cast<char>(SDLK_UP), {0.0, 1.0}},
-            {static_cast<char>(SDLK_DOWN), {0.0, -1.0}},
-            {static_cast<char>(SDLK_LEFT), {1.0, 0.0}},
-            {static_cast<char>(SDLK_RIGHT), {-1.0, 0.0}},
-        };
-
-        float direction = key_down ? -1.0f : 1.0f;
-        send_move_action = true;
-        move_direction += move_base[kbd_event.key] * direction;
-        break;
-      }
-      case SDLK_SPACE:
-        if (key_down)
-          m_Actions.emplace_back(UserAction::Type::FIRE);
-        break;
-      default:
-        LOG_INFO("Key '", static_cast<char>(kbd_event.key), "' not mapped");
-        break;
-      }
-    } else if (event.type == SDL_EVENT_MOUSE_BUTTON_DOWN) {
-      SDL_MouseButtonEvent mouse_event = event.button;
-      LOG_DEBUG("Mouse down: ", mouse_event.x, ", ", mouse_event.y);
-      m_Actions.emplace_back(UserAction::Type::MOVE_TARGET,
-                             WorldPos{mouse_event.x, mouse_event.y});
+    if (keyboard_events.contains(event.type)) {
+      GetActions_keyboard(event);
+    } else if (mouse_events.contains(event.type)) {
+      GetActions_mouse(event);
     } else {
-      // TODO uncomment, for now too much noise
-      // LOG_WARNING("Action not processed");
+      LOG_WARNING("Action not processed");
     }
   }
-  if (send_move_action) {
-    m_Actions.emplace_back(UserAction::Type::MOVE, move_direction.normalized());
-    send_move_action = false;
-  }
   return m_Actions;
 }

cpp/src/user_input.hpp

@@ -7,22 +7,34 @@
 #include "log.hpp"
 #include "math.hpp"
 
+// Seems like SDL doesn't have named constants for mouse button
+enum class MouseButton { LEFT = 1, MIDDLE, RIGHT };
+
 class UserAction {
 public:
-  enum class Type { NONE, EXIT, MOVE, CROUCH, STAND, FIRE, MOVE_TARGET };
+  enum class Type {
+    NONE,
+    EXIT,
+    SET_MOVE_TARGET,
+    SELECT_PATHFINDER,
+    CAMERA_PAN,
+    CAMERA_ZOOM,
+    SELECTION_START,
+    SELECTION_CHANGE,
+    SELECTION_END
+  };
 
-  UserAction() = default;
-  UserAction(Type t) : type(t) {}
-  UserAction(Type t, char key) : type(t), Argument{.key = key} {}
-  UserAction(Type t, WorldPos v) : type(t), Argument{.position = v} {}
+  UserAction() : type(Type::NONE), Argument{0} {}
+  UserAction(Type t) : type(t), Argument{0} {}
+  UserAction(Type t, char key) : type(t), Argument{key} {}
+  UserAction(Type t, WindowPos v) : type(t), Argument{v} {}
+  UserAction(Type t, int32_t arg) : type(t), Argument{arg} {}
+  UserAction(Type t, float arg) : type(t), Argument{arg} {}
   ~UserAction() = default;
 
   Type type;
 
-  union {
-    WorldPos position;
-    char key;
-  } Argument;
+  std::variant<WindowPos, char, int32_t, float> Argument;
 };
 
 class UserInput {
@@ -41,4 +53,8 @@ public:
 
 private:
   std::vector<UserAction> m_Actions;
+  bool m_SelectionActive = false;
+
+  void GetActions_keyboard(const SDL_Event &);
+  void GetActions_mouse(const SDL_Event &);
 };

cpp/src/window.cpp

@@ -62,7 +62,6 @@ std::expected<void, std::string> Window::Init() {
   // Set renderer to the Sprite class
   Sprite::SetRenderer(m_Renderer);
 
-  // TODO this needs to be tied to map size
   SDL_SetRenderScale(m_Renderer.get(), 1.0f, 1.0f);
 
   return {};
@@ -76,21 +75,28 @@ Window::~Window() {
   LOG_DEBUG(".");
 }
 
-void Window::DrawSprite(const WorldPos &position, Sprite &s) {
-  WorldPos size = s.GetSize();
-  WorldPos img_center = s.GetCenter();
-  SDL_FRect rect = {position.x - img_center.x, position.y - img_center.y,
-                    size.x, size.y};
+void Window::DrawSprite(const WindowPos &position, Sprite &s, float scale) {
+  WorldSize size = s.GetSize() * scale;
+  WorldPos img_center = s.GetCenter() * scale;
+  SDL_FRect rect = {position.x() - img_center.x(),
+                    position.y() - img_center.y(), size.x(), size.y()};
   SDL_RenderTexture(m_Renderer.get(), s.GetTexture(), nullptr, &rect);
 }
 
-void Window::DrawRect(const WorldPos &position, const WorldPos size, uint8_t R,
-                      uint8_t G, uint8_t B, uint8_t A) {
-  SDL_FRect rect = {position.x, position.y, size.x, size.y};
+void Window::DrawFilledRect(const WindowPos &position, const WindowSize size,
+                            uint8_t R, uint8_t G, uint8_t B, uint8_t A) {
+  SDL_FRect rect = {position.x(), position.y(), size.x(), size.y()};
   SDL_SetRenderDrawColor(m_Renderer.get(), R, G, B, A);
   SDL_RenderFillRect(m_Renderer.get(), &rect);
 }
 
+void Window::DrawRect(const WindowPos &position, const WindowSize size,
+                      uint8_t R, uint8_t G, uint8_t B) {
+  SDL_FRect rect = {position.x(), position.y(), size.x(), size.y()};
+  SDL_SetRenderDrawColor(m_Renderer.get(), R, G, B, 255);
+  SDL_RenderRect(m_Renderer.get(), &rect);
+}
+
 void Window::ClearWindow() {
   SDL_SetRenderDrawColor(m_Renderer.get(), 50, 50, 50, 255);
   SDL_RenderClear(m_Renderer.get());
@@ -98,14 +104,20 @@ void Window::ClearWindow() {
 
 void Window::Flush() { SDL_RenderPresent(m_Renderer.get()); }
 
-void Window::DrawCircle(const WorldPos &position, float radius) {
-  int cx = static_cast<int>(position.x);
-  int cy = static_cast<int>(position.y);
-  SDL_SetRenderDrawColor(m_Renderer.get(), 255, 0, 0, 255);
+void Window::DrawCircle(const WindowPos &position, float radius, uint8_t R,
+                        uint8_t G, uint8_t B) {
+  int cx = static_cast<int>(position.x());
+  int cy = static_cast<int>(position.y());
+  SDL_SetRenderDrawColor(m_Renderer.get(), R, G, B, 255);
   for (int i = 0; i < 360; ++i) {
-    double a = i * M_PI / 180.0;
+    double a = i * std::numbers::pi / 180.0;
     SDL_RenderPoint(m_Renderer.get(),
                     cx + static_cast<int>(std::round(radius * std::cos(a))),
                     cy + static_cast<int>(std::round(radius * std::sin(a))));
   }
 }
+
+void Window::DrawLine(const WindowPos &A, const WindowPos &B) {
+  SDL_SetRenderDrawColor(m_Renderer.get(), 255, 0, 0, 255);
+  SDL_RenderLine(m_Renderer.get(), A.x(), A.y(), B.x(), B.y());
+}

cpp/src/window.hpp

@@ -22,18 +22,21 @@ public:
   Window &operator=(Window &&) = delete;
 
   std::expected<void, std::string> Init();
-  void DrawSprite(const WorldPos &position, Sprite &s);
-  void DrawRect(const WorldPos &position, const WorldPos size, uint8_t R,
-                uint8_t G, uint8_t B, uint8_t A);
+  void DrawSprite(const WindowPos &position, Sprite &s, float scale = 1.0f);
+  void DrawFilledRect(const WindowPos &position, const WindowSize size,
+                      uint8_t R, uint8_t G, uint8_t B, uint8_t A);
+  void DrawRect(const WindowPos &position, const WindowSize size, uint8_t R,
+                uint8_t G, uint8_t B);
   void ClearWindow();
   void Flush();
-  void DrawCircle(const WorldPos &position, float radius);
-
-  std::shared_ptr<SDL_Renderer> m_Renderer = nullptr;
-  SDL_Window *m_Window;
-  SDL_GLContext m_Context;
+  void DrawCircle(const WindowPos &position, float radius, uint8_t R, uint8_t G,
+                  uint8_t B);
+  void DrawLine(const WindowPos &A, const WindowPos &B);
 
 private:
   uint32_t m_Width;
   uint32_t m_Height;
+  std::shared_ptr<SDL_Renderer> m_Renderer = nullptr;
+  SDL_Window *m_Window;
+  SDL_GLContext m_Context;
 };

cpp/test/collision_performance.cpp

@@ -0,0 +1,251 @@
+#include <gtest/gtest.h>
+#include <chrono>
+#include <iostream>
+#include <iomanip>
+#include <random>
+#include <algorithm>
+#include <set>
+
+#include "positional_container.hpp"
+
+/**
+ * @file collision_performance.cpp
+ * @brief Performance tests for collision detection systems
+ * 
+ * This file contains performance benchmarks and tests for various
+ * collision detection algorithms and optimizations.
+ */
+
+/**
+ * @brief Helper class to measure and print execution time
+ */
+class PerformanceTimer {
+public:
+    using Clock = std::chrono::high_resolution_clock;
+    using TimePoint = std::chrono::time_point<Clock>;
+    using Duration = std::chrono::duration<double, std::milli>;
+    
+    PerformanceTimer(const std::string& name) : name_(name) {
+        start_ = Clock::now();
+    }
+    
+    ~PerformanceTimer() {
+        auto end = Clock::now();
+        Duration duration = end - start_;
+        std::cout << std::fixed << std::setprecision(3)
+                  << "[PERF] " << name_ << ": " 
+                  << duration.count() << " ms" << std::endl;
+    }
+    
+    double elapsed_ms() const {
+        auto end = Clock::now();
+        Duration duration = end - start_;
+        return duration.count();
+    }
+    
+private:
+    std::string name_;
+    TimePoint start_;
+};
+
+/**
+ * @brief Run a function multiple times and measure average execution time
+ * @param name Name of the test for output
+ * @param iterations Number of iterations to run
+ * @param func Function to benchmark
+ */
+template<typename Func>
+void benchmark_function(const std::string& name, int iterations, Func func) {
+    auto start = PerformanceTimer::Clock::now();
+    
+    for (int i = 0; i < iterations; ++i) {
+        func();
+    }
+    
+    auto end = PerformanceTimer::Clock::now();
+    PerformanceTimer::Duration total_duration = end - start;
+    double avg_duration = total_duration.count() / iterations;
+    
+    std::cout << std::fixed << std::setprecision(6)
+              << "[BENCHMARK] " << name << ":\n"
+              << "  Total: " << total_duration.count() << " ms\n"
+              << "  Iterations: " << iterations << "\n"
+              << "  Average: " << avg_duration << " ms\n"
+              << "  Throughput: " << (iterations / (total_duration.count() / 1000.0))
+              << " ops/sec" << std::endl;
+}
+
+/**
+ * @brief Simple dummy class that conforms to HasPosition concept
+ * Used for testing PositionalContainer without heavy dependencies
+ */
+class Dummy {
+public:
+    Dummy() : m_Position{0.0f, 0.0f}, m_Id(next_id++) {}
+    Dummy(float x, float y) : m_Position{x, y}, m_Id(next_id++) {}
+    Dummy(WorldPos pos) : m_Position(pos), m_Id(next_id++) {}
+    
+    WorldPos GetPosition() const { return m_Position; }
+    void SetPosition(WorldPos pos) { m_Position = pos; }
+    int GetId() const { return m_Id; }
+    
+private:
+    WorldPos m_Position;
+    int m_Id;
+    static int next_id;
+};
+
+int Dummy::next_id = 0;
+
+/**
+ * @brief Helper function to generate random float in range [min, max]
+ */
+float random_float(std::mt19937& gen, float min, float max) {
+    std::uniform_real_distribution<float> dist(min, max);
+    return dist(gen);
+}
+
+/**
+ * @brief Compare two sets of weak_ptrs by comparing the IDs of the objects they point to
+ */
+bool compare_results(const std::vector<std::weak_ptr<Dummy>>& a, 
+                    const std::vector<std::weak_ptr<Dummy>>& b) {
+    std::set<int> ids_a, ids_b;
+    
+    for (const auto& weak : a) {
+        if (auto shared = weak.lock()) {
+            ids_a.insert(shared->GetId());
+        }
+    }
+    
+    for (const auto& weak : b) {
+        if (auto shared = weak.lock()) {
+            ids_b.insert(shared->GetId());
+        }
+    }
+    
+    return ids_a == ids_b;
+}
+
+TEST(CollisionPerformance, CompareContainers) {
+    std::cout << "\n=== Collision Performance Comparison ===\n" << std::endl;
+    
+    // Configuration
+    const int NUM_OBJECTS = 1000;
+    const int NUM_LOOKUPS = 100;
+    const float WORLD_SIZE = 1000.0f;
+    const float LOOKUP_RADIUS = 50.0f;
+    const size_t CHUNKS = 20;
+    
+    // Random number generator
+    std::random_device rd;
+    std::mt19937 gen(rd());
+    
+    // Create containers
+    PositionalContainer<Dummy> pos_cont{WorldSize{WORLD_SIZE, WORLD_SIZE}, CHUNKS};
+    SimpleContainer<Dummy> simp_cont;
+    
+    // Create and add dummy objects with random positions
+    std::vector<std::shared_ptr<Dummy>> objects;
+    objects.reserve(NUM_OBJECTS);
+    
+    std::cout << "Creating " << NUM_OBJECTS << " objects with random positions..." << std::endl;
+    for (int i = 0; i < NUM_OBJECTS; ++i) {
+        float x = random_float(gen, 10.0f, WORLD_SIZE - 10.0f);
+        float y = random_float(gen, 10.0f, WORLD_SIZE - 10.0f);
+        auto obj = std::make_shared<Dummy>(x, y);
+        objects.push_back(obj);
+        pos_cont.Add(obj);
+        simp_cont.Add(obj);
+    }
+    std::cout << "Objects created and added to containers." << std::endl;
+    
+    // Generate random lookup positions
+    std::vector<WorldPos> lookup_positions;
+    lookup_positions.reserve(NUM_LOOKUPS);
+    for (int i = 0; i < NUM_LOOKUPS; ++i) {
+        float x = random_float(gen, 0.0f, WORLD_SIZE);
+        float y = random_float(gen, 0.0f, WORLD_SIZE);
+        lookup_positions.push_back(WorldPos{x, y});
+    }
+    
+    // Benchmark SimpleContainer
+    double simple_total_time = 0.0;
+    std::vector<std::vector<std::weak_ptr<Dummy>>> simple_results;
+    simple_results.reserve(NUM_LOOKUPS);
+    
+    std::cout << "\nBenchmarking SimpleContainer with " << NUM_LOOKUPS << " lookups..." << std::endl;
+    for (const auto& pos : lookup_positions) {
+        auto start = PerformanceTimer::Clock::now();
+        auto result = simp_cont.Get(pos, LOOKUP_RADIUS);
+        auto end = PerformanceTimer::Clock::now();
+        
+        PerformanceTimer::Duration duration = end - start;
+        simple_total_time += duration.count();
+        simple_results.push_back(result);
+    }
+    
+    double simple_avg_time = simple_total_time / NUM_LOOKUPS;
+    std::cout << std::fixed << std::setprecision(6)
+              << "[BENCHMARK] SimpleContainer:\n"
+              << "  Total time: " << simple_total_time << " ms\n"
+              << "  Average time per lookup: " << simple_avg_time << " ms\n"
+              << "  Throughput: " << (NUM_LOOKUPS / (simple_total_time / 1000.0)) 
+              << " lookups/sec" << std::endl;
+    
+    // Benchmark PositionalContainer
+    double positional_total_time = 0.0;
+    std::vector<std::vector<std::weak_ptr<Dummy>>> positional_results;
+    positional_results.reserve(NUM_LOOKUPS);
+    
+    std::cout << "\nBenchmarking PositionalContainer with " << NUM_LOOKUPS << " lookups..." << std::endl;
+    for (const auto& pos : lookup_positions) {
+        auto start = PerformanceTimer::Clock::now();
+        auto result = pos_cont.Get(pos, LOOKUP_RADIUS);
+        auto end = PerformanceTimer::Clock::now();
+        
+        PerformanceTimer::Duration duration = end - start;
+        positional_total_time += duration.count();
+        positional_results.push_back(result);
+    }
+    
+    double positional_avg_time = positional_total_time / NUM_LOOKUPS;
+    std::cout << std::fixed << std::setprecision(6)
+              << "[BENCHMARK] PositionalContainer:\n"
+              << "  Total time: " << positional_total_time << " ms\n"
+              << "  Average time per lookup: " << positional_avg_time << " ms\n"
+              << "  Throughput: " << (NUM_LOOKUPS / (positional_total_time / 1000.0)) 
+              << " lookups/sec" << std::endl;
+    
+    // Verify results match
+    std::cout << "\nVerifying results correctness..." << std::endl;
+    int mismatches = 0;
+    for (size_t i = 0; i < NUM_LOOKUPS; ++i) {
+        if (!compare_results(simple_results[i], positional_results[i])) {
+            mismatches++;
+            std::cout << "Mismatch at lookup " << i 
+                     << " (pos: " << lookup_positions[i] << ")" << std::endl;
+        }
+    }
+    
+    if (mismatches == 0) {
+        std::cout << "✓ All " << NUM_LOOKUPS << " lookups produced identical results!" << std::endl;
+    } else {
+        std::cout << "✗ Found " << mismatches << " mismatches out of " 
+                 << NUM_LOOKUPS << " lookups" << std::endl;
+    }
+    
+    // Performance comparison
+    std::cout << "\n=== Performance Summary ===\n";
+    double speedup = simple_avg_time / positional_avg_time;
+    std::cout << std::fixed << std::setprecision(2)
+              << "PositionalContainer is " << speedup << "x "
+              << (speedup > 1.0 ? "faster" : "slower") 
+              << " than SimpleContainer" << std::endl;
+    
+    std::cout << "\n======================================\n" << std::endl;
+    
+    // Assertions
+    EXPECT_EQ(mismatches, 0) << "Results should match between containers";
+    EXPECT_GT(speedup, 1.0) << "PositionalContainer should be faster than SimpleContainer";
+}

python/pathfinding_demo.py

@@ -56,7 +56,8 @@ class Map:
         x_center, y_center = center_point
         for x in range(-1,2):
             for y in range(-1,2):
-                if x == 0 and y == 0:
+                diagonal = x == y # includes center 0,0
+                if diagonal:
                     continue
                 p = Point2D((x + x_center, y + y_center))
                 if self.IsPointValid(p):
@@ -304,10 +305,6 @@ class GBFS(PathFinderBase):
 
     @staticmethod
     def heuristic(a: Point2D, b: Point2D) -> float:
-        # for now we use Manhattan distance, although
-        # it is probably not entirely correct, given that
-        # we can also move diagonally in the grid
-        # TODO a problem for future me
         x_a, y_a = a
         x_b, y_b = b
         return abs(x_a - x_b) + abs(y_a - y_b)
@@ -348,10 +345,6 @@ class A_star(PathFinderBase):
 
     @staticmethod
     def heuristic(a: Point2D, b: Point2D) -> float:
-        # for now we use Manhattan distance, although
-        # it is probably not entirely correct, given that
-        # we can also move diagonally in the grid
-        # TODO a problem for future me
         x_a, y_a = a
         x_b, y_b = b
         return abs(x_a - x_b) + abs(y_a - y_b)

scripts/pre-commit.sample

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+# Copy this file to .git/hooks
+
+# Run clang-format before commiting
+files=$(git diff --cached --name-only --diff-filter=ACM | grep -E '\.(cpp|hpp)$')
+[ -z "$files" ] && exit 0
+clang-format -i $files
+git add $files

vcpkg-configuration.json

@@ -0,0 +1,14 @@
+{
+  "default-registry": {
+    "kind": "git",
+    "baseline": "b2c74683ecfd6a8e7d27ffb0df077f66a9339509",
+    "repository": "https://github.com/microsoft/vcpkg"
+  },
+  "registries": [
+    {
+      "kind": "artifact",
+      "location": "https://github.com/microsoft/vcpkg-ce-catalog/archive/refs/heads/main.zip",
+      "name": "microsoft"
+    }
+  ]
+}

vcpkg.json

@@ -0,0 +1,12 @@
+{
+  "dependencies": [
+    "glew",
+    "opengl",
+    "sdl3",
+    {
+      "name": "sdl3-image",
+      "features": [ "png" ]
+    },
+    "gtest"
+  ]
+}