A WIP, experimental header-only ECS framework. Written in C++20/17.
Goal of this project is to create a simple ECS (Entity Component System) framework in C++20/17 to increase
my knowledge of modern C++/C++ toolchains, DoD patterns, parallelization and general game dev.
This is an archetype-based ECS taking inspiration from
Unity DOTS and smaller frameworks like
legion,
hecs,
decs &
entt.
The main focus is a clean & minimal API with acceptable performance, perfect aligned contiguous memory of components & easy parallelization of systems.
TODO
Components are just simple structs of data. The only requirement is that they have to be default, move & copy constructible.
struct pos
{
float x{0};
float y{0};
}Systems are defined by their update function where each argument is a component + access (const or not) they want to fetch.
struct example_system
{
// Per entity
void update(pos& p, const vel& v) const {
// do system logic
}
}
struct example_system_perchunk
{
// You can use a single realm::view as an argument
// to access components on a per-chunk basis
void update(realm::view<pos, vel> view) const {
for(auto [p, v] : view) {
// do system logic
}
}
}
// Insert systems to a world
world.insert<example_system>();
world.insert<example_per_chunk>();struct pos
{
float x{0};
float y{0};
}
struct time
{
float dt{1/60};
}
struct move_system
{
void update(pos& p, const vel& v, const time& t) const {
p.x += v.x * t.dt;
p.y += v.y * t.dt;
}
}
// Create a world with capacity of 1000 entities.
auto world = realm::world(1000);
// Create a singleton component
world.singleton<time>();
// Create entities of components pos & vel.
for(auto i{0}; i < 1000; i++) {
auto entt = world.create<pos, vel>();
world.set<vel>(entt, {10, 10});
}
// Insert move_system to the world
world.insert<move_system>();
// Update systems in parallel
world.update();
TODO
- See
TODOfile
Thanks to the guides @skypjack on software for helping me understand the various concepts of an ECS implementation.
Videos & talks:
pyrbin |