# Dark Iron ECS
## Features
- **Entity Creation**: Easily create entities and attach components to them.
- **Event Handling**: Implement event-driven architecture with custom events and event handlers.
- **Coroutines**: Create a coroutine to be executed at specific intervals or delays.
- **Queries**: Efficiently query entities based on their components.
- **Systems**: Implement game logic and behaviors through systems that process entities based on queries.
- **Extensions**: Extend the functionality of the ECS with custom extensions.
- **Chained Building**: World could be create by a chain of methods.
## Example
Demonstrates how to use the `dark_iron_ecs` library to create an Entity Component System (ECS) in Rust. The example includes creating components, querying entities, and setting up systems to interact with those components.
## Setup
First, add the `dark_iron_ecs` dependency to your `Cargo.toml`:
```toml
[dependencies]
dark_iron_ecs = "*" # Replace with the actual version
```
### Imports
For this example the necessary imports:
```rust
use dark_iron_ecs::core::{
coroutine::{Coroutine, CoroutineState, WaitAmountOfSeconds},
entity_manager::EntityManager,
extension::Extension,
query::{Query, Without},
resources::Resource,
system::SystemSchedule,
world::World,
};
```
### Components
Define your components. Components are data associated with entities.
```rust
struct Position {
x: f32,
y: f32,
}
struct Name(String);
struct Health(i32);
```
### Systems
Define systems to operate on entities that have specific components. Systems are functions that process entities.
```rust
fn test_system(q: Query<(&Health,)>, entity_manager: &mut EntityManager) {
entity_manager.create_entity((Health(500),));
for health in q.fetch() {
println!("{:?}", health.0);
}
}
fn test_system_1(
q: Query<(&Health,)>,
q2: Query<(&Health,), Without<(&Name,)>>,
mut camera: Resource,
) {
for health in q.fetch() {
println!("q {:?}", health.0);
}
for health in q2.fetch() {
println!("q2 {:?}", health.0);
}
println!("Hello from test_system_1");
camera.x += 1.0;
println!("{:?} {:?} {:?}", camera.x, camera.y, camera.z);
}
```
### Events
Define events that can be published and subscribed to within the world.
```rust
struct CollisionEvent;
```
### Resources
Define resources that are globally accessible by systems.
```rust
struct Camera {
x: f32,
y: f32,
z: f32,
}
```
### Extension
Define easy extensions to your world.
```rust
pub struct ExtensionExample;
impl Extension for ExtensionExample {
fn build(&self, world: &mut World) {
world.create_entity((Health(100),));
}
}
```
### Main Function
Set up the world, create entities, add systems, and run the ECS.
```rust
use dark_iron_ecs::core::{
coroutine::{Coroutine, CoroutineState, WaitAmountOfSeconds},
entity_manager::EntityManager,
query::{Query, Without},
resources::Resource,
system::SystemSchedule,
world::World,
};
fn main() {
let mut world = World::new();
let entity1 = world.create_entity_with_id((Health(100),));
let entity2 = world.create_entity_with_id((Name("Enemy 2".to_string()), Health(200)));
let entity3 = world.create_entity_with_id((
Position { x: 0.0, y: 0.0 },
Name("Enemy 3".to_string()),
Health(300),
));
if let Some(health) = entity1.get_component::(&world){
println!("Component {:?}", health.0);
}
let mut counter = 10;
world
.create_entity((Velocity(0.0, 0.0),))
.subscribe_event(|_world: &World, _t: CollisionEvent| {
println!("Collision Event Hit");
})
.remove_component::(entity3)
.add_component_to_entity(entity3, Health(400))
.add_coroutine(Coroutine::new("Test Coroutine", move |world| {
if counter == 10 {
println!("Coroutine Started");
}
counter -= 1;
if counter == 0 {
println!("Coroutine Finished");
world.remove_entity(entity3);
world.create_entity((Health(900),));
world.add_component_to_entity(entity1, Name("Player".to_string()));
world.remove_component::(entity2);
world.publish_event(CollisionEvent);
return CoroutineState::Finished;
}
println!("Coroutine Running");
CoroutineState::Yielded(WaitAmountOfSeconds {
amount_in_seconds: 1.0,
})
}))
.add_resource(Camera {
x: 1000.0,
y: 0.0,
z: 0.0,
})
.add_system(SystemSchedule::Startup, test_system)
.add_systems(SystemSchedule::Update, (test_system_1,))
.run_startup()
.add_extension(ExtensionExample)
.build();
let q = world.create_query::<&Health>();
let q1 = world.create_query_with_constraint::<&Health, Without<&Name>>();
for health in q.fetch() {
println!("{:?}", health.0);
}
for health in q1.fetch() {
println!("{:?}", health.0);
}
loop {
world.run_update();
world.update_coroutines(1.0);
std::thread::sleep(std::time::Duration::from_secs(1));
}
}
```
### Running the Project
To run the project, use Cargo:
```bash
cargo run
```
This will compile and run your ECS example, demonstrating how to create and manage entities, components, systems, events, and resources using the dark_iron_ecs library.
## License
This project is licensed under the MIT License. See the [LICENSE](LICENSE) file for details.
MIT License
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