Gearecs

A lightweight Entity Component System library for C game development, built on top of raylib. Gearecs provides a modern, data-oriented architecture for creating efficient and scalable games.

Gearecs implements the ECS pattern, which separates data from logic:

• Entities: Unique identifiers representing game objects
• Components: Data containers (position, velocity, health, etc.)
• Systems: Functions that process entities with specific components

Enables highly performant, cache-friendly code with excellent modularity and reusability.

Features

• ECS Architecture - Flexible, data-driven design pattern
• Built-in Components - Transform, RigidBody, Collider, Sprite, and more
• Physics Simulation - Complete collision detection, forces, gravity, and rigid body dynamics
• Hierarchy Relationships - Parent-child relationships for complex object structures
• Scripting - Entity-specific logic across multiple execution phases
• Scene Management - Automatic scene setup with camera and generic game loop
• Multi-platform Support - Linux, Windows, Web...
• Raylib Integration - Seamless rendering and input handling

Quick Start

CMake

Fetch Content

cmake_minimum_required(VERSION 3.25)
set(CMAKE_C_STANDARD 11)

include(FetchContent)
set(FETCHCONTENT_QUIET FALSE)
set(GEARECS_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
FetchContent_Declare(
  gearecs
  GIT_REPOSITORY https://github.com/fals3bool/gearecs.git
  GIT_TAG main
)
FetchContent_MakeAvailable(gearecs)

Build

cmake -S . -B build -DCMAKE_BUILD_TYPE=$(BUILD_TYPE)
cmake --build build

emcmake cmake -S . -B build -DCMAKE_BUILD_TYPE=$(BUILD_TYPE)
cmake --build build

Basic Example

#include <gearecs.h>

void MoveScript(ECS *ecs, Entity self) {
  // Get transform component
  Transform *t = GetComponent(ecs, self, Transform);

  // Keyboard
  Vector3 d = {0};
  if (IsKeyDown(KEY_UP))
    d.y += 1;
  if (IsKeyDown(KEY_DOWN))
    d.y -= 1;
  if (IsKeyDown(KEY_LEFT))
    d.x -= 1;
  if (IsKeyDown(KEY_RIGHT))
    d.x += 1;

  // Move
  t->translation =
      Vector3Add(t->translation, Vector3Scale(d, 100 * GetFrameTime()));
}

int main(void) {
  // Raylib window and camera
  InitWindow(800, 450, "GearECS Example");

  // Registry
  ECS *world = EcsWorld();

  // Player entity
  Entity player = EcsEntity(world, "Player");
  AddComponent(world, player, Transform, TransformOrigin);
  AddComponent(world, player, Collider, ColliderCube(10, false));
  AddScript(world, player, MoveScript, EcsOnUpdate);

  // Optional (debug) system
  System(world, DebugColliderSystem, EcsOnRender, Collider);

  // Main game loop
  EcsLoop(world);

  // Cleanup
  EcsFree(world);
  CloseWindow();
  return 0;
}