kon_ecs

kon_ecs is the ECS implementation for Kon Engine, built around SparseSet storage for fast iteration.

Scope

• Bitmask Tagging: O(1) entity filtering with bit operations.
• Zero-Allocation Iteration: Queries don't allocate - they iterate directly over contiguous memory.
• SparseSet Storage: Cache-friendly component storage.
• Standalone Core: Can be used without the rest of Kon Engine.

# Use it as part of the engine
cargo add kon-engine

# Or use the ECS core directly
cargo add kon_ecs

Quick Start (Standalone)

You can use the ECS core independently from the engine.

use kon_ecs::World;

// Define your components
#[derive(Debug, Clone, PartialEq)]
struct Position { x: f32, y: f32 }

#[derive(Debug, Clone, PartialEq)]
struct Velocity { x: f32, y: f32 }

fn main() {
    let mut world = World::new();

    // Spawn entities with components
    world.spawn()
        .insert(Position { x: 0.0, y: 0.0 })
        .insert(Velocity { x: 1.0, y: 1.0 })
        .id();

    // Query and iterate
    world.select_mut::<(Position, Velocity)>().each(|_, (pos, vel)| {
        pos.x += vel.x;
        pos.y += vel.y;
    });
}

Component Definition

You can define components in two ways:

1. Manual (No macro required): Simply use your structs as components.
2. With Macros (Optional): Use the kon_macros crate for a cleaner syntax.

#[component] // Optional with kon_macros
struct Position { x: f32, y: f32 }

License

MIT OR Apache-2.0