LOW Engine

A C++20 2D game engine built for Lords of War — a turn-based strategy game inspired by Warlords 3.

Features

• Entity Component System (ECS) — CRTP-based components with explicit dependency declarations and memory-pooled allocation
• Scene management — scene stack with pause/resume support; each scene owns its own physics world
• 2D physics — Box2D integration with static, dynamic, and kinematic bodies; fixed-timestep FixedUpdate loop
• Sprite rendering — static sprites, frame-based animation, and tile map rendering via SFML
• Tile maps — LDtk format support with multiple layers, navigation grid, and A* pathfinding
• Action-based input — named actions bound to keys or mouse buttons with optional modifier keys (Shift, Ctrl, Alt)
• Audio — sound effects, music playback with queue and crossfade support
• JSON serialization — full project/scene/entity/asset save & load (.lowproj / .lowscene)
• ImGui editor — in-engine editor with world outliner, per-component property panels, asset browser, and file dialogs

Building

Prerequisites: CMake 3.26+, C++20 compiler, OpenGL

Windows (Visual Studio): Run one of the generator scripts to produce a solution, then build inside the IDE:

generate_vs2022-win32-sln.bat
generate_vs2026-win32-slnx.bat

Manual:

cmake -B build -S .
cmake --build build --config Debug

Outputs go to bin/Debug/ or bin/Release/.

CMake options:

Option	Default	Description
BUILD_LOW_EDITOR	ON	Build the LOWEditor executable
BUILD_LOW_ENGINE_SHARED	ON	Build LOWEngine as a shared library

Usage

#include "Game.h"
#include "ecs/ECSHeaders.h"
#include "assets/Assets.h"

using namespace LowEngine;

int main() {
    Game game("My Game");
    game.OpenWindow(1280, 720, 60);

    // Load assets
    Assets::LoadTexture("player", "assets/textures/player.png");

    // Set up a scene
    Scene* scene = game.Scenes.GetCurrentScene();

    Entity* player = scene->AddEntity("Player");
    scene->AddComponent<TransformComponent>(player->Id);

    auto* sprite = scene->AddComponent<SpriteComponent>(player->Id);
    sprite->SetTexture("player");

    // Game loop
    while (game.IsWindowOpen()) {
        game.Draw();
    }
}

Creating a custom component

// Declare dependencies as template parameters
class HealthComponent : public IComponent<HealthComponent, TransformComponent> {
public:
    int HP = 100;

    explicit HealthComponent(Memory::Memory* memory) : IComponent(memory) {}

    void Initialize() override { HP = 100; }
    void Update(float deltaTime) override { /* ... */ }
};

Project structure (at runtime)

my_project/
  my_project.lowproj
  assets/
    textures/
    sounds/
    music/
    fonts/
  scenes/
    main.lowscene

Dependencies

All dependencies are in 3rd_party/ as git submodules.

Library	Purpose
SFML	Graphics, window, input, audio
Box2D	2D physics
TGUI	SFML-based GUI widgets
spdlog	Logging
nlohmann/json	JSON serialization
Dear ImGui (docking)	Editor UI
imgui-sfml	ImGui ↔ SFML backend
ImGuiFileDialog	File browser widget